Xiaoxuan Zhou, Hongjie Hu, Yue Qian, Yuxin Han, Mingzhou Ye, Jianbin Tang, Peipei Pang, Jun Yang

Tumor metastasis accounts for the related mortality, and precise diagnostic imaging of distant metastasis plays a significant role in clinical administration and treatment plan. Enhanced MRI with small-molecule contrast agent (CA) is a favorite imaging modality. However, small-molecule CA has some unsatisfied flaws such as short blood circulation time, low relaxivity and non-specificity. In this study, we synthesized a macromolecular CA with high relaxivity and long blood circulation time, and assessed early liver metastasis with enhanced MRI using this macromolecular CA.

Gabriele Beck, Michael Wyss, Rene Patzwahl, Joachim Hohmann, Christoph Andreas Binkert, Lars van Loon, Hans Peeters

We investigated a motion immune Dixon TFE approach incorporating a 3D radial stack-of-stars acquisition module interleaved with a spiral excitation navigator to gate and track the acquisition. Image quality, sharpness and streaking artifact level and its variability over different patient breathing patterns is efficiently improved to an extent where it is preferred over the state-of-the art breath hold (BH) Dixon scans. Next to that, it allowed scan time reductions of 30% in average. This technique provides motion-free, high resolution hepatic imaging with the benefits of Dixon providing consistent good fat suppression over a large FOV with water, fat, IP and OP diagnostic information all-in-one scan.

Rosalind Gerson, Chris Bowen, Manjari Murthy, Sharon Clarke

Non-invasive quantification of hepatic fat and iron with MRI has generated increasing clinical interest, particularly given the prevalence of chronic liver disease. Elevated R2* is a biomarker of iron deposition in the liver and spleen. The normative distribution of R2* in these organs at 3T is not well described, but is necessary for confident diagnosis of mild to moderate levels of iron deposition.  Based on measurements in 97 adults selected from the general population, we confirm that ~20% have fatty liver and suggest that a hepatic R2* > 89 s^-1 and splenic R2* > 69 s^-1 can be considered abnormal.

Koji Fujimoto, Li Feng, Rocardo Otazo, Kai Block, Henry Rusinek, Nicole Wake, Hersh Chandarana

A method to combine information of respiratory states with a non-rigid motion model is proposed to reconstruct motion-compensated 4D images of dynamic-contrast enhanced MRI with high temporal resolution. Abdominal DCE-GRASP MRI was reconstructed by grouping 4 consecutive spokes as one dynamic frame (0.6sec/frame). Respiratory motion was obtained from central k-space data (as in XD-GRASP). A temporal TV constraint was applied separately for each respiratory state. By using an optical-flow algorithm, four sets of motion vectors were obtained. Motion-compensated GRASP reconstruction was performed by including the motion vectors and showed improved image quality and reduced motion blurring. 

Mounes Aliyari Ghasabeh, Manijeh Zarghampour, Li pan, Pegah Khoshpouri, Farnaz Najmi Varzaneh, Nannan Shao, Ankur Pandy, Pallavi Pandy, Danial Fouladi, Ihab R Kamel

Liver steatosis is the most common parenchymal liver disease in Western Countries and it may progress to steatohepatis, fibrosis and cirrhosis. Also, fat deposition in liver and pancreas can cause diabetes by increasing resistance to insulin. Magnetic Resonance Spectroscopy (MRS) has been shown to strongly correlate with histology in liver fat quantification. However, MRS has some limitations such as breathing artifact and difficulties in avoiding vessels or bile ducts within the voxel. So, it is desirable to utilize a novel and robust imaging technique that can screen for the presence of fat in the liver and pancreas.

Paul Kennedy , Kevin Glaser, Curtis Johnson, Bradley Bolster Jr. , Jalpan Jani, Kashif Khokhar, Richard Ehman, Bachir Taouli

We present initial results of 2D MR elastography (MRE) and 3D MRE acquired in liver and spleen using a dual driver configuration in 13 subjects, 5 healthy and 8 with liver disease. 2D MRE showed a trend to higher stiffness in healthy subjects however in cirrhotic subjects liver stiffness was generally higher with 3D MRE. 3D MRE showed significantly higher liver stiffness in cirrhotic subjects compared to healthy subjects, with spleen stiffness also increased but not reaching significance. Coefficient of variation with single and dual drivers was 5% for liver and spleen in 2D and 3D MRE. 

Takeshi Yoshikawa, Yoshiharu Ohno, Katsusuke Kyotani, Kouya Nishiyama, Shinichiro Seki, Yuji Kishida

We introduced new assessment method of liver hemodynamics using 4D-PCA and new flow analytic technique including wall shear stresses. We found 4D-PCA and MRFD enables detailed hemodynamic assessment and has the potential to be used for liver disease assessments.

Zerwa Farooq, Ashkan Heshmatzadeh Behzadi, Jon Blumenfeld, Martin Prince

ADPKD patients (n=25) undergoing abdominal MRI were analyzed 2 times each by 2 separate reviewers using a) thresholding; b) region growing c) cyst diameter d) semi-manual segmentation to determine liver cyst volume. Using the most reproducible technique, 75 additional ADPKD patients were studied correlating their liver parameters with genotype, gender and age. Semi-manual segmentation was the best technique for measuring cyst volume with intraclass correlation coefficient of 0.99. PKD1 mutation was found to be associated with higher total liver volume and liver cyst volume across different age groups and gender compared to PKD2 mutation, suggesting greater hepatic involvement with PKD1. 

Huimin Lin, Hongjiang Wei, Xu Yan, Caixia Fu, Stephan Kannengiesse, Chunlei Liu, Fuhua Yan

This study aimed to evaluate the performance of Quantitative Susceptibility Mapping (QSM) on estimating and grading the liver iron concentration (LIC), using Ferriscan-R2 values as reference. Thirty-three patients suspected of hepatic iron overload were included in this study. The results showed a significant positive correlation between QSM and Ferriscan-based LIC (r=0.924). ROC analysis revealed that QSM could accurately grade LIC for low and moderate iron overload patients, indicating that high-quality QSM maps may allow to reliably estimate and grade iron deposition in the liver.

Sara Lewis, Steven Peti, Stefanie Hectors, Michael King, Juan Putra, Swan Thung, Bachir Taouli

ADC measurement using DWI have shown promise for characterizing focal liver lesions. In this study, we assessed the ability of advanced ADC histogram parameters to distinguish the histological diagnosis and the grade of primary malignant liver cancers. We found that both ADC mean and ADC percentiles could distinguish between tumor types; ADC percentiles were also predictive of tumor grade for HCC and ICC. Advanced ADC histogram analysis may be useful for accurate tumor diagnosis and prediction of tumor grade.

Zhang Lan

To evaluate the value of DCE-MR for hepatic reserve function assessment and staging in post-hepatitic liver cirrhosis (PHLC). 10 patients with compensatory PHLC, 10 with decompensatory PHLC and 10 healthy volunteers were performed DCE-MRI scanning. All data were calculated by Extended Tofts model fitting with pharmacokinetic curve and the permeability and perfusion parameters were measured in quantification. The new method validated the feasibility of using quantitative parameters of DCE-MRI with pharmacokinetic model to assess liver cirrhosis. In conclusion, DCE-MRI quantitative parameters can be used for diagnosing and staging liver cirrhosis.

Diego Hernando, Changqing Wang, Ryan Mattison, Takeshi Yokoo, Scott Reeder

R2-based techniques for liver iron quantification using Spin-Echo (SE) imaging require long acquisitions. In contrast, single-voxel Stimulated-Echo Acquisition Mode (STEAM)-MR spectroscopy enables liver R2 measurements in a single breath-hold. However, the accuracy and field strength dependence of STEAM-MRS R2 quantification are unknown. This study evaluated the accuracy and field strength dependence of STEAM-MRS for R2 quantification in healthy controls and patients with liver iron overload. At 1.5T, STEAM-MRS R2 was in close agreement with SE-MRI-based R2. Further, STEAM-MRS R2 measurements were highly correlated across field strengths. Finally, STEAM-MRS R2 measurements at 1.5T and 3.0T were calibrated to liver iron concentration. 

Ruo-kun Li, Fu-hua Yan, Jin-wei Qiang, Hui-min Lin, Weibo Chen, Tomoyuki Okuaki, Eunju Kim

There were 16 consecutive patients (12 men, 5 women; mean age, 45.7 years; range, 33–65 years).   Imaging was performed on clinical 3T scanner (Philips Ingenia) using 32ch body/cardiac coil.  A hepatocyte fraction (HF) map and K map were derived. The HF and K values for Gd-EOB-DTPA were correlated with Child-Pugh scores.  Patients with Child-Pugh class B disease showed significantly lower liver FA value and K value. HF value and K value were positively correlated with the Child–Pugh scores  (r=0.752 to 0.855, p<0.05). HF value and K value had the largest AUC of 0.975 and 0.78 for distinguishing the Child–Pugh class A of cirrhosis from class B.  K value had the most area under receiver operating characteristic curve (AUC) of 0.99 for identifying the presence of liver cirrhosis.The study suggested that hepatocyte fraction and hepatic uptake derived from Gd-EOB-DTPA-enhanced MRI can quantify liver function. 

Mengqi He, Yingjie Mei, Jing Zhang, Zeyu Zheng, Hongxiang Li, Tomoyuki Okuaki, Eunju Kim, Yikai Xu

Gadoxetic acid has been shown to evaluate liver function as it is known to be actively taken up by hepatocytes via organic anion transporters (OATPs). The measurement of hepatic parenchymal enhancement during the hepatobiliary phase (HBP) may accurately reflect liver function. This study evaluated the liver function of the subject in the Child-Pugh classification method which is still the most commonly applied method for evaluating liver function in clinical. The hepatocyte fractions were significantly different among groups classified according to Child–Pugh scores between A and C, B and C. The hepatocyte fraction could be considered as a promising method for the quantitative assessment of liver function.

Jia Ning, Tilman Schubert, Huijun Chen, Chun Yuan, Scott Reeder

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) with pharmacokinetic modeling can help to quantify the perfusion and function of liver. The accurate pharmacokinetic modeling relies on the accurately and reliably captured vascular input function (VIF)s. However, due to the fast blood velocity, the blood in the large vessels including abdominal aorta and the main branch of the portal vein experiences only a limited number of excitations and hasn’t reached a steady state. This introduces bias in the VIFs, and consecutively bias in pharmacokinetic parameters. In this study, we sought to correct the inflow effect on VIF acquisition in liver DCE-MRI.

Kristina Ringe, Julian Luetkens, Rolf Fimmers, Renate Hammerstingl, Guenter Layer, Martin Maurer, Claas Naehle, Sabine Michalik, Peter Reimer, Christina Schraml, Andreas Schreyer, Patrick Stumpp, Thomas Vogl, Frank Wacker, Winfried Willinek, Guido Kukuk

In this prospective multicenter study, interrater agreement and reliability for characterization and grading of respiratory motion artifacts related to the injection of gadoxetate disodium were evaluated. Interrater agreement and reliability for scoring of motion artifacts in the arterial phase was excellent among experienced abdominal radiologists from different European tertiary referral centers with an intraclass correlation coefficient of 0.983 and 0.985, respectively. Characterization and grading of respiratory motion artifacts can thus be performed with a high level of confidence, which is a prerequisite for assessing the incidence of this phenomenon in larger multicenter studies. 
 

Xiaohong Ma, Shuang Wang, Yongjian Zhu, Han Ouyang, Chunwu Zhou, Xinming Zhao

Radiation-induced liver injury (RILI) is one of the most dreaded complications of radiation therapy (RT),which prevents radiation dose escalation and limits the effectiveness of the treatment . Therefore, it was important to predict and evaluate the RILI on hepatic malignancy using the RT in the early term. In this study, the ADCmid-RT value was significantly highest, and had negative correlation with the radiation dose. As the ADCmid-RT value was less than 1.29 x10-3mm2/s, the RILI could possibly occur. Therefore, the ADCmid-RT value may serve as a biomarker for predicting RILI in patients with hepatic malignancies treated with RT.

Arthur Wunderlich, Holger Cario, Isabelle Tomczak, Meinrad Beer, Stefan Schmidt

To investigate the relation between signal intensity ratios gained from gradient echo (GRE) MRI and liver iron concentration (LIC), we studied the influence of patient characteristics. 168 patients (71 f, 97 m; 49 with Thalassemia major, 101 without Thalassemia) suspected for liver iron overload were scanned according to Ferriscan® with spin echo MRI to obtain reference LIC values, and GRE protocols suitable for LIC determination. GRE analysis by manually drawn liver and muscle ROIs yielded liver-to-muscle signal intensity ratios (SIR). Correlation analysis of ln (SIR) to reference LIC revealed differences between patient subgroups concerning disease, gender and age.

Jei Hee Lee, Bohyun Kim, Young Bae Kim

For visualization of capsule appearance on HCC, GaMR is comparable with dynamic CT. And pathologic fibrous capsule can be seen as hypointense rim in HBP. Lower visualization of capsule appearance in TP on GaMR seem to be parenchymal enhancement during the transitional phases. Hyperintensity rim in T2 weighted images with hopointense rim on HBP shows disruption of fibrous capsule with extension of tumor cells across the fibrous capsule in pathology. Hypointense rim on the HBP in the 2014 version of LI-RADS should not be considered as capsule appearance, and further study is also needed.

Sahar Semaan, Christopher Song, Sara Lewis, Manjil Chatterji, M. Isabel Fiel, Cecilia Besa, Bachir Taouli

In this study, we present preliminary data comparing the diagnostic performance of multiphasic contrast-enhanced CT with contrast enhanced MRI using a liver specific gadolinium based contrast agent (GBCA), gadoxetic acid (Gd-EOB-DTPA) and extracellular (EC) GBCAs, using explant pathologic data as the reference. We also assessed the added value of delayed hepatobiliary phase (HBP) imaging and DWI in HCC detection. Our data suggests that CT and MRI have similar overall sensitivities for HCC detection and that the addition of DWI and HBP improved HCC detection when using Gd-EOB-DTPA. 

kan liu, qi zhang, hong mei zhang, han ouyang, xinming zhao

To determine the value of MRE in the differential diagnosis of hepatocellular carcinoma and intrahepatic cholangiocarcinoma with 3.0-T MR scanner . The MRE were performed in 36 patients(26 hepatocellular carcinomas and 11 intrahepatic cholangiocarcinomas) by using 60-Hz mechanical waves and Spin echo echo planar sequence.Intrahepatic cholangiocarcinomas had significantly greater mean shear stiffness than hepatocellular carcinoma (9.08 ±2.13kPa vs 6.54 ±1.84kPa). They have statistically significant differences(p<0.01).MRE can help the differentiation of hepatocellular carcinoma and intrahepatic cholangiocarcinoma.

Tomohiro Namimoto, Masataka Nakagawa, Kie Shimizu, Takeshi Nakaura, Kosuke Morita, Yasuyuki Yamashita

To compare automated six-point-Dixon(6-p-Dixon) with dual-echo GRE chemical shift imaging(CSI) for quantification of hepatic fat fraction(FF) with CT. In a phantom study, various FF vials were performed to validate the accuracy. In clinical study, fifty-nine patients were examined both 3.0T MRI and CT. Quantitative measurements were calculated SI-index of CSI and imaging-FF of 3D-6-p-Dixon. In phantom study, linear regression between FF and imaging-FF/SI-index showed good agreement(imaging-FF R²=0.992:0-100%FF;SI-index R²=0.978:0-34.7%FF). In clinical study, linear regression between imaging-FF and SI-index showed good agreement(R²=0.890). CT attenuation value was strongly correlated with imaging-FF(R²=0.852) and SI-index(R²=0.812). Imaging-FF of 6-p-Dixon has potential for automated hepatic fat quantification.

Hyun Jeong Park, Kyung Mi Jang

With recent advances of MRI in abdominal imaging, improved performances on T2-weighted image and diffusion- weighted imaging (DWI) are achieved for pancreatic tumors. We hypothesized that diagnostic performance for detection of primary solid tumors of pancreas on noncontrast MRI with DWI could be sufficiently high and noncontrast MRI with DWI would be useful for pancreas screening. We conducted this study to determine the diagnostic performance of noncontrast MRI with DWI for detection of primary small (≤20mm) pancreatic solid tumors and prediction of ductal adenocarcinoma in comparison with pancreas CT and pancreas MRI with MR cholangiopancreatography.

Camilo Campo, Diego Hernando, Tilman Schubert, Andrew Van Pay, Scott Reeder

This study evaluated the inter- and intra-reviewer agreement of different region-of-interest (ROI) sampling methods for the quantification of liver R2* (1/T2*) in patients with iron overload. 37 MRI datasets from patients suspected of having liver iron overload were retrospectively analyzed using ROI sampling methods that have been previously reported. Our results demonstrate that the inter- and intra-reviewer agreement of liver R2* quantification improve when using ROIs that are large in size and number. We conclude that researchers and clinicians should strive to sample as much area of the liver by using multiple large ROIs.

Yuelang Zhang, Xiang Li, Haitian Liu, Chenxia Li, Jian Yang

To collect and summarize parameters used by gadoxetic acid-enhanced MR imaging (GD-EOB-DTPA-enhanced MRI) for staging of liver fibrosis (LF) and evaluate diagnostic performance. A systematic literature search was performed in PubMed, Web of science, Embase and Medline database. Studies used frequently-used parameter were included. Pooled weighted mean difference (WMD) was applied to determine the clinical significance. Pooled sensitivity, specificity, and summary receiver operating characteristics (SROC) curve were calculated to evaluate diagnostic performance. Finally, 5 studies were included, and contrast enhancement index (CEI) was the most frequently-used parameter, which was considered to be an efficient biomarker in the staging of LF.

In Kyung Park, Jeong-Sik Yu, Eun-Suk Cho, Joo Hee Kim, Jae Joon Chung

Depending on the difference of cellular densities related to the histopathologic grades of HCCs, some investigators have recently suggested apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI) as an effective biomarker for the prediction of the patients’ prognosis before the treatment of HCC. In the present study, ADCs of well- or poorly differentiated HCCs were lower than moderately differentiated HCCs; meanwhile the degree of arterial phase enhancement during the dynamic imaging rather well stratified the ADCs of the lesions. We concluded that ADC could not be independently used to estimate the histopathologic grades of HCCs.

Yuan Tian, Pengfei Liu, Lizhi Xie

This article is to explore the feasibility of liver fat quantification via dynamic liver enhancement scanning after injection of Gd-EOB-DTPA. IDEAL-IQ was used to quantify liver fat in 65 patients who were injected with contrast. IDEAL-IQ was performed four times to determine the fat fraction (FF) and R2*. One-way repeated-measures analysis was conducted to evaluate the difference between the four time points of the FF. The assessment of FF at four time points in liver, spleen and spine showed no significant differences. However, after injection of contrast agent, R2* was increased, and the IDEAL-IQ result was relatively stable.

huang can

Several models have been proposed to explain the anomalous diffusion in biological tissues. Among them, the fractional motion (FM) model was considered more appropriate. In this study, the FM model was applied to assess its feasibility for diagnosing malignant tumors of liver. It was found that the FM model could improve the diagnostic accuracy in differentiation normal liver tissue and tumor lesion, indicating the potential of the FM model to facilitate future studies of pathological changes in clinical populations.

Arthur Wunderlich, Holger Cario, Isabelle Tomczak, Meinrad Beer, Stefan Schmidt

Tissue signal intensity ratio (SIR) has been used for a long time to determine liver iron concentration (LIC) based on gradient echo MRI. We studied the influence of acquisition parameters FA, RF spoiling and saturation regions, as well as image quality score, on the correlation of natural logarithm of SIR values to reference LIC obtained with spin echo. In our cohort of 85 patients, no significant influence on the slope of linear regression line was found, neither of acquisition protocol settings nor image quality, whereas the intercept was dependent on parameters influencing T₁ sensitivity, namely FA and RF spoiling.

Sarah Keller, Jan Sedlacik, Fabian Kording, Gerhard Adam, Christoph Schramm, Jin Yamamura

This study evaluates the feasibility of  dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with Gd-EOB-DTPA for detection of hepatic inflammation/fibrosis in comparison to Ultrasound elastography in primary sclerosing cholangitis (PSC).

Li Yang, Mengsu Zeng, Xuhao Song, Caixia Fu, Xu Yan

Intravoxel incoherent motion (IVIM) model provides both pure water motion and microcirculation by using multiple b values. IVIM imaging has been shown to be useful for assessment of liver diseases, including liver fibrosis and hepatocellular carcinoma. However, the clinical implementation of IVIM imaging is limited by long acquisition time. We compared IVIM imaging with different b-values to determine the combination of b-values in IVIM imaging that allows the relatively short acquisition time to obtain reproducible values of the IVIM parameters in patients with hepatocellular carcinoma. Our results showed at least 10b-values should be used in IVIM imaging for the assessment of hepatocellular carcinoma, and 5b-values IVIM imaging might increase errors in the perfusion-related f and D* values.

Weibo Chen, Xin Chen, Li Yang, Shanshan Wang, Queenie Chan, Guangbin Wang

ROI-based analysis may suffer from sampling errors due to the user-defined placement of the ROI and the choice of slice location. The aim of our study was to find an approach that allow the detection and measurement of the T1rho values of the hepatic segments.

Yoshifumi Noda, Satoshi Goshima, Natsuko Suzui, Tatsuhiko Miyazaki, Kimihiro Kajita, Hiroshi Kawada, Nobuyuki Kawai, Hiromi Koyasu, Masayuki Matsuo

Pancreatic cancer (PC) occurs a histopathologically stronger pancreatic fibrosis compared to other non-PC. The risk factors of postoperative pancreatic fistula (POPF) were reported as soft or normal pancreatic parenchyma, and ampullary or duodenal disease. In this study, in patients with non-PC, frequency of POPF was greater due to lower grade of pancreatic fibrosis, and our results suggest that T1 signal and ADC value of the pancreas may link to the POPF. The T1 signal and ADC value of the pancreas may be a potentially useful imaging biomarker for the assessment of pancreatic fibrosis and POPF.

Tomohiro Sato, Katsuyoshi Ito, Tsutomu Tamada , Akira Yamamoto, Akihiko Kanki

The liver plays a pivotal role in glucose metabolism, so 60-80% of patients with cirrhosis experience impaired glucose tolerance and hyperinsulinemia, and 10-50% develop diabetes. This study was intended to clarify the extent to which pancreatic MRI findings are affected by the presence of diabetes mellitus in patients with liver cirrhosis. On 3-T MRI, size of the pancreas was significantly increased, the grade of pancreatic lobulation was significantly reduced, and pancreatic SIRs on T2WI with fat suppression were significantly increased in cirrhotic patients complicated with diabetes as compared to cirrhotic patients without diabetes.

Yoshisuke Kadoya, Tosiaki Miyati, Naoki Ohno, Satoshi Kobayashi, Toshifumi Gabata

Portal venous flow (PVF) seems to be affected by gravity, ie., it depends on the body posture. We validated the effect of gravity on PVF in supine and upright positions using an original multi-posture MRI. We compared maximum PVF, PVF velocity, PVF volume, and cross-sectional area of portal vein between supine and upright positions. The mean PVF velocity, PVF volume, maximum PVF, and cross-sectional area in the upright position were significantly lower than those in the supine position. Gravity reduces PVF velocity and volume, and these differences between postures potentially provide new diagnostic information.

Nikhar Kinger, Peter Harri, Lauren Alexander, Courtney Moreno, Pardeep Mittal

SPN is a rare epithelial neoplasm of low grade malignant potential for local and metastatic spread, occurring predominantly in young females. Differential diagnosis of SPN includes a wide spectrum of cystic and solid entities in the pancreas including pancreatic neuroendocrine, serous or mucinous cystadenoma or carcinoma, intrapancreatic splenules etc. Contrast enhanced MRI plays a key role in characterization of SPN and its mimics , helps to reach a specific diagnosis and narrows the differential, which is complimentary to EUS and biopsy when findings are equivocal to reach an accurate diagnosis which is of utmost importance for management and treatment planning

Davinia Ryan, Alessandra Borgheresi, Simone Krebs, Sarah Eskreis-Winkler, Lorenzo Mannelli

We correlate pre-operative quantification of hepatic fat on MRI in patients with colorectal cancer metastatic to the liver with the presence of fat on histology of the resected specimen, patient BMI and hospital length of stay. 

Mariska Damen, Quincy van Houtum, Maarten van Leeuwen, Peter Luijten, Andrew Webb, Dennis Klomp, Catalina Arteaga de Castro

Inversion recovery and echo time series were obtained at 7T with a multi-transmit system to determine the T1 and T2 relaxation times of the healthy pancreas. These parameters are crucial when optimizing MR protocols. The T1 and T2 values found were in average 921+/-98 ms and 57+/-12 ms respectively. Excellent T2 contrast is obtained for the pancreas at TE/TR=80ms/17s.

Mehri kaviani , Carolyn Chee, Caroline Hoad, Stephen Bawden, Peter Mansell, Sally Cordon, Aithal Guruprasad, Ian Macdonald, Penny Gowland

With the rise in obesity globally, there is great interest in quantifying body composition and in particular metabolically active visceral adipose tissue (VAT).  Increased accumulation of VAT has been linked with an increase in risk factors for cerebrovascular disease  and Type 2 Diabetes (T2DM) .  We investigated the degree to which weight, subcutaneous fat visceral fat,  liver and lipid markers are affected by 2 weeks of overfeeding at 25% excess energy given as either carbohydrate or fat. 2 weeks of 25% excess energy overfeeding of either carbohydrate of fat does not alter subcutaneous or visceral abdominal fat in line with no changes in weight. MRI measurements of SAT and VAT can be used in longitudinal studies of diet to ascertain any changes in abdominal body fat deposition.

shuangshuang xie, qing li, zhizheng zhuo, yu zhang, yue cheng, wen shen

This study investigated the merit of liver T1rho values for detecting fibrosis in patients with chronic hepatitis B and the potential impact of fatty liver on T1rho measurements. Eighteen healthy control subjects, eighteen patients with clinically diagnosed simple fatty and eighteen with liver fibrosis were underwent T1rho MRI and mDIXON-Quant. Mean T1rho values and fat fraction (FF) were compared among the three groups. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the merit of T1rho values for detecting liver fibrosis. T1rho values were correlated with FF and clinical data. Our results showed significant differences in T1rho values among the three groups and T1rho had moderate diagnostic efficacy to detect fibrosis. T1rho values were not correlated with FF, subject age, or body mass index. We conclude liver T1rho values can be used as a MR biomarker for liver fibrosis and are not influenced by fatty liver severity.

Peng Hu, Jihong Sun, Fangfang Lv, Borui Pi, Fangping Xu, Guocan Han, Xi Hu, Yue Wang, Ning Huang, Xia Wu, Yong Zhang, Jun Yang, Peipei Pang, Xiaoming Yang

Liver fibrosis caused by Hepatitis B virus (HBV) is a worldwide health problem. However, liver biopsy as the gold standard of diagnosing and evaluating therapy of liver fibrosis is an invasive examination with possible errors from sampling and intra- and inter-observer interpretation (1, 2). The non-invasive MRI may be a promising modality to evaluate the liver fibrosis. We used diffusion-weighted imaging (DWI) and variable flip angle (VFA) T1 mapping to explore the progression of liver fibrosis caused by HBV infection in a longitudinal study.

Tiffany Lin, Shirong Zhang, Michael Liu, Sachin Jambawalikar

Literature has suggested mixed results regarding agreement between T2 relaxivity based liver iron concentration (LIC) and T2* relaxivity based LIC The purpose of the following study is to determine whether or not choice of relaxivity fitting models will impact the agreement of the results.

Yesenia Covarrubias, Jonathan Hooker, Ethan Sy, Saya Igarashi, Jennifer Cui, Cheng Hong, Nikolaus Szeverenyi, Jeffrey Schwimmer, Rohit Loomba, Scott Reeder, Kevin Glaser, Meng Ying, Richard Ehman, Claude Sirlin

This analysis of 129 adults compared the wave-image quality of two-dimensional (2D) and three-dimensional (3D) magnetic resonance elastography (MRE) across a range of body mass indices (BMIs). Wave-image quality of each scan was measured quantitatively by region of interest (ROI) areas. We found that 3D MRE provides higher wave-image quality compared to 2D MRE and that wave-image quality was not statistically associated with BMI (p=0.3422). Further research with larger BMI cohorts is needed to confirm our findings. 

Jonathan Hooker, Yesenia Covarrubias, Cheng Hong, Soudabeh Dehkordy, Adrija Mamidipalli, Ethan Sy, Gavin Hamilton, Claude Sirlin

The range of R2* values estimated from MR sequences using low flip angles (FA) is limited by the background signal decay. The administration of contrast allows the use of higher FAs and increases the signal to noise ratio (SNR), allowing the estimation of a greater range of R2* values. We compared pre- and post-contrast R2* values in 158 patients and observed large discrepancies at R2* values greater than 300s^-1. Our findings suggest that in patients with severe iron overload, post-contrast high-FA R2* mapping may be the preferred sequence for iron quantification.

Takeshi Yoshikawa, Katsusuke Kyotani, Yoshimori Kassai, Kouya Nishiyama, Shinichiro Seki, Yuji Kishida, Yoshiharu Ohno

To reduce distortion on abdominal EPI-DWI, we developed Fast Advanced Spin Echo (FASE)-DWI for abdominal 3T imaging. FASE-DWI improved distortion and showed equivalent diagnostic performance and be used as an alternative to EPI-DWI.

Thomas Benkert, Kai Block, Samantha Heller, Melanie Moccaldi, Daniel Sodickson, Sungheon Kim, Linda Moy

Conventional clinical breast MRI consists of several separate T₁-weighted scans, including both pre-contrast fat-suppressed and non-fat-suppressed acquisitions as well as the acquisition of dynamic contrast-enhanced phases.

Here, we show how this entire exam can be replaced by a single comprehensive scan, therefore reducing overall scan time and simplifying the clinical workflow. This is achieved by using radial stack-of-stars sampling in combination with a model-based fat/water separation technique, which takes into account the off-resonant blurring of fat and integrates both compressed sensing and parallel imaging. The approach is validated in 24 patients and results were evaluated by two radiologists.

Kimihiro Kajita, Satoshi Goshima, Yoshifumi Noda, Hiroshi Kawada, Tomoyuki Okuaki, Masatoshi Honda, Nobuyuki Kawai, Hiromi Koyasu, Masayuki Matsuo

We applied five free-breathing scan sequences to gadoxetic acid-enhanced hepatobiliary phase imaging. Breath hold eTHRIVE demonstrated the highest SNR on the liver, although it is also revealed the disadvantage for the patients with unstable breath hold. On the other hand, free-breathing 3D VANE with gate and track demonstrated the highest image quality with equivalent SNR to breath hold eTHRIVE. It is notable that free-breathing 3D VANE produced steady and effective image quality for all patients regardless of breath hold ability.

Bozhu Chen, Jian He, Zhengyang Zhou

Glucose ingestion activates the pancreatic functions and increases the oxygen consumption, we hypothesized that BOLD MRI could detect the alterations during the glucose challenge. BOLD MRI was performed in 12 volunteers before and after glucose ingestion. A transient but significant decrease in pancreatic T2* values was observed after glucose ingestion. BOLD MRI may serve as a non-invasive tool to detect the activation of human pancreas.

Ye Ju, Ailian Liu, Qingwei Song, Meiyu Sun, Lihua Chen, Lizhi Xie

Intravoxel incoherent motion (IVIM) imaging is an extension of diffusion weighted imaging (DWI) that can be used to investigate both diffusion and perfusion changes in tissues. DKI adapts a kurtosis based model to depict the non-Gaussian diffusion process, which could be caused by the presence of different barriers in cellular complex structures (e.g. cell membranes and organelle compartments).Initial application of DKI focused on neuroimaging, Recently, it has also been reported that DKI may help to assess response to treatment in HCC. Comparing the IVIM and DKI parameters between carcinoma (HCC) and hepatic hemangioma(HHA) we found that IVIM and DKI can supply many meritorious parameters, combining with the IVIM and DKI may help in increasing the sensitivity and specificity of antidiastole.

Takeshi Yoshikawa, Katsusuke Kyotani, Yoshimori Kassai, Kouya Nishiyama, Shinichiro Seki, Yuji Kishida, Yoshiharu Ohno

The purpose of this study was to assess capability of computed DWI in evaluation of various abdominal diseases. We found cDWI can improve image quality and malignant lesion contrast, conspicuity, and detection. cDWI is a useful post-processing tool for abdominal MRI.

Alex Weller, Matthew Orton, David Collins, James D'Arcy, Nandita de-Souza

In 5 patients with lung cancer, UTE-MRI was used to derive pulmonary R2* in lung and establish its repeatability. Plausible R2* values were obtained only when using TEs of 0.08 and 0.2 ms: higher TEs produced implausible mean negative R2* within individual patients and a cohort R2* not significantly different from zero, due to lack of signal decay beyond TE=0.2ms. Pulmonary R2* values derived using TEs of 0.08 and 0.2ms were higher than prior reports where longer echo-times were employed. Test-retest limits-of-agreement were +90.5%to -47.5% indicating that a 90% increase in R2*is required post-radiotherapy to reliably demonstrate radiation-induced change.

Yohei Itoh, Yasuo Takehara, Naoki Ooishi, Masataka Sugiyama, Ikumi Igarashi, Maho Hayashi, Satoshi Usami, Takasuke Ushio, Yuki Hirai, Nobuko Yoshizawa, Shuhei Yamashita, Hatsuko Nasu, Tetsuya Wakayama, Atsushi Nozaki, Hiroyuki Kabasawa, Harumi Sakahara

We tried reduced-FOV MR elastography using a local excitation technique called FOCUS for the pancreas. Comparing conventional-MRE with FOCUS-MRE, there was no significant differences of the measurable are of pancreas.  In both methods, the higher the body mass index was, the smaller the measurable area of the pancreas.

Jun Chen, Phillip Rossman, Kevin Glaser, Richard Ehman

All the previous test-retest human liver MRE studies could involve physiological stiffness change . In this study, our goal was to evaluate MRE test-retest repeatability with liver phantoms to avoid the possible influence of physiological changes in humans. We hypothesized that the variations of test-retest MRE stiffness measurements of phantoms were smaller than that of human livers.  

Mamoru Takahashi, Yasuo Takehara, Norihiro Tooyama, Katsutoshi Ichijo, Tomoyasu Amano, Takuya Matsumoto, Tomoyuki Okuaki, Yukiko Fukuma, Harumi Sakahara

First clinical study using 3D dual echo UTE sequence for suspected gall stone patients was performed. All gallstones were able to be detected as positive signal in-vivo. Our study may indicate that UTE has an added value of depicting impacted stones or hepatolithiasis as positive signal.  

Yoshie Omiya, Shintaro Ichikawa, Utaroh Motosugi, Hiroshi Onishi

 We evaluated the feasibility of magnetic resonance elastography (MRE) for uterine fibroids and the effect of imaging sequences (i.e., spin-echo echo-planar imaging [SE-EPI] and gradient-echo [GRE]) on stiffness measurements. All MRE were performed in two cross-sectional planes (i.e., axial and sagittal). SE-EPI-MRE showed lower fibroid stiffness values than GRE-MRE. Each MRE method is a valid and reliable technique for measuring the stiffness of uterine fibroids.

Byung Chul Kang, Hye Ran Hyun

MRS(MR Spectroscopy) as well as T2Wi, and  diffusion weighted images may be used to evaluate the response of LACC to CCRT.

Cho Ja Ryong, Park Jong Bin, Cho Seoung Bong

Evaluation of image analysis according to changing breath hold methods of B1 calibration .

Qiong Zhang, Yuanyuan Kang

A simple 2D pace module was implemented in a Breath-Hold imaging work flow to trigger the normal scan and supervise the  motion.  Our preliminary experiments show that within the newly added module, images are more immune to respiratory motion artifacts and the detail  of small structures are clearer.

Ty Cashen, Naoyuki Takei, Kang Wang, Tao Zhang, Lloyd Estkowski, Ersin Bayram

Acoustic noise generated by MR systems represents one of the major barriers to patient comfort, particularly for the pediatric population. Reducing the slew rate of the gradient field is one way to effectively decrease acoustic noise; however, this comes at the expense of scan time. For breath-hold abdominal imaging, longer scan times mean a more stressful breath-hold for the patient, reduce temporal resolution for multi-phase imaging, and may allow for more motion artifact due to suboptimal breath-holding. This work describes an accelerated 3D multi-phase technique compatible with fat saturation for both quiet and motion-robust abdominal imaging.

Dhaval Shah, Nicola Bertolino, Marilena Preda, Robert Zivadinov, Ferdinand Schweser

Preclinical MR lung imaging has been challenging due to lower tissue density compared to other organs. Current practice has been 2D spin-echo or gradient echo with relatively lower resolution. In this work we present an optimized high resolution 3D Multi Gradient Echo and demonstrate the results by comparing it with state of the art 2D Gradient echo.

Terence Jones, Narendra Reddy, Sarah Wayte, Thomas Barber, Charles Hutchinson

Brown adipose tissue (BAT) has lower fat content than white adipose tissue (WAT), which has been exploited using Dixon-based MRI to identify BAT. We sought to identify the optimal threshold to differentiate between BAT and WAT in rats on the basis of fat fraction.

Fat fraction within BAT was significantly lower than WAT in rodents. Receiver operating characteristic analysis showed that differentiating BAT and WAT on the basis of fat fraction had excellent accuracy in both ex vivo and in situ. The optimal cut-off to separate BAT and WAT was significantly lower in rats exposed to cold, likely secondary to lipolysis.

Yong-Lan He, Ning Ding, Ya-Fei Qi, Tianyi Qian, Yuan Li, Huadan Xue, Zhengyu Jin

This study aimed to demonstrate the cyclic changes of the boundary sharpness of uterine three zonal structures of young and middle-aged women on 3T using a 3D T2-weighted SPACE sequence during the menstrual cycle. Peri-ovulatory phase exhibited the clearest boundary sharpness of corpus zonal structures following by FP, LP and MP, while that of the cervix were almost well-defined during the menstrual cycle.

Ivana Sequeira, Wilson Yip, Louise Lu, Reza Nemati, Dech Dokpuang, Jun Lu, Sally Poppitt

Prediction of risk for dysglycaemia and adverse metabolic health is difficult, with some outwardly lean individuals having greater susceptibility to type 2 diabetes (T2D) than obese resilient individuals. Using 3T MR Imaging and spectroscopy we showed, in 10 Asian Chinese and 6 European Caucasian healthy or prediabetic women (18 – 70 years and BMI 25 – 50 kg/m²), that greater storage of fat within riskier ectopic sites, i.e. pancreas and liver, may in part explain the reported increased risk of T2D in Asian Chinese populations compared to their Caucasian counterparts at the same BMI and younger age. 

Wansha Wu, Ke Ren, Jiannan Shang, Wenge Sun, Yi Liu, Songbai Li, Ke Xu

Our purpose was to investigate the feasibility of NCE-MRA using Time-SLIP technique on healthy volunteers by determining the optimized TI value and its preliminary relationship with age as well. 61 healthy volunteers were recruited and divided into two age groups. The acquired data using six differernt TIs sequences were measured and analyzed to get three parameters including VKR, grade of renal artery branches and grade of imaging quality. In conclusion, the Time-SLIP technique is able to obtain renal MR angiography with optimized TI value 1500ms. Moreover, the age of individual subjects can affect the optimized TI value. 

Toshihiro Furuta, Masayuki Yamaguchi, Manabu Minami, Osamu Abe, Hirofumi Fujii

Visualization of irradiated liver parenchyma may assist safety margin assessment in radiotherapy. We demonstrate that an MR imaging technique has the ability to visualize irradiated liver parenchyma after 30-Gy irradiation in a tumor-bearing rat model. In this technique, superparamagnetic iron oxide (SPIO) is administered to label Kupffer cells (KCs) before, rather than after irradiation. A dose of 30-Gy is a lower, more clinically relevant dose than that used in the previous studies. Our results suggest that 30-Gy irradiation delays the recovery of hepatic T2*-weighted signal after SPIO administration. Presumably, irradiation delays degradation process of SPIO in the KCs.

Martin Buechert, Thomas Lange, Peter Deibert, Paul Urbain

Changes in fat distribution and composition during ketonic diet were investigated in a sub group of twelve volunteers of a larger study. Liver fat concentrations in the examined cohort turned out to be surprisingly low compared to patient cohorts with similar BMI measured in other studies. The hypotheses that intra-hepatic fat may be reduced during a ketogenic diet could not be confirmed. However the composition of the sub group may have biased the outcome. While the MRI protocol and analysis worked well, MRS analysis of data acquired with the given protocol in subjects with low hepatic fat reaches its limitations.

Haris Shuaib, Brandon Whitcher, Kevin Keraudren, David Greer, Geoff Charles-Edwards, Louise Goff

This work explores the role of body composition and its relationship with the development of type 2 diabetes in White European and Black African men. An investigation of differences in body composition between these two groups was performed via automated image segmentation and analysis of Dixon MR images. Our initial results suggest visceral adipose tissue may not be a principal determinant in the development of type 2 diabetes in Black African men as it is with White European men.

Nikita Garnov, Stefanie Lehmann, Ulf Retschlag, Nicolas Linder, Alexander Schaudinn, Arne Dietrich, Andreas Oberbach, Thomas Kahn, Harald Busse

In obesity research and clinical practice, disease progress or response to therapy is typically evaluated by the reduction of body weight, adipose tissue (AT) volume or comorbidity remission rates. However, little is currently known about therapy-induced changes in subcutaneous and visceral AT composition and how to quantify them. Lean control subjects had recently been shown to have significantly higher T1 relaxation times in both SAT (301 ms) and VAT (360 ms) than severely obese patients (275 and 294 ms, respectively). Aims of this study were to characterize AT by quantitative MRI and evaluate the intra-individual changes at two time points.

Limei Guo, Yujiao Zhao, Zhizheng Zhuo, Wen Shen

Vaginal childbirth is an important cause to pelvic floor injuries. In this study, we aim to identify various forms of the injuries and the association with obstetrical risk factors in primiparous women. The results showed that there were significant differences about the proportions of various patterns of the pelvic floor injuries and the severity of LAM injuries between the groups with and without obstetrical risk factors.

Lorenz Pfleger, Peter Wolf, Martin Gajdošík, Sabina Smajiš, Marek Chmelík, Anton Luger, Siegfried Trattnig, Michael Krebs, Martin Krššák

This study employed ultra-high field  (7T)  ¹H and ³¹P MRS for the characterization of subtle hepatic tissue changes in insulin sensitive and insulin resistant group of healthy volunteers. Hepatic lipids, the forward rate of ATP synthesis and profile of metabolites containing ³¹P were assessed. Decreased inorganic phosphate was found in the subgroup of volunteers with increased hepatic fat accumulation and increased phosphocholine was found in the insulin sensitive subgroup. Concentration of ³¹P containing metabolites found here are well within the range of previous publications and subtle differences point towards their role in pathophysiology of metabolic syndrome and/or hepatic steatosis.

Anneloes de Boer, Margreet Sanders, Nico van den Berg, Peter Blankestijn, Tim Leiner

The presence of multiple renal arteries per kidney is associated with hypertension. The smaller vessel diameter is thought to lead to decreased renal perfusion, which activates the renin-angiotensin-aldosterone system (RAAS), resulting in increased systemic blood pressure. We measured renal blood flow (RBF) using dynamic contrast enhanced (DCE) MRI to investigate the relation between number of renal arteries, RAAS activity and RBF. The number of renal arteries was associated with reduced RBF and increased RAAS activity. In all patients, we observed that reduced RBF was associated with increased RAAS activity.

Ethan Leng, Jin Jin, Lin Zhang, Joseph Koopmeiners, Gregory Metzger

A novel lesion-wise metric was developed to evaluate the quality of predictive models of prostate cancer that use quantitative multiparametric MR data to perform prediction on a voxel-wise basis. The metric is based on the Jaccard similarity coefficient and emphasizes overlap and co-localization of ground truth and predicted lesions. Experiments to characterize the metric demonstrated that it qualitatively reflected the goodness of predictions and was more accurate and informative than voxel-wise measures of sensitivity and specificity. We propose that the metric may be customized to select the best predictive models for specific clinical applications such as performing targeted prostate biopsies.

Edward Johnston, Colleen Bailey, Elisenda Bonet-Carne, Hayley Pye, Susan Heavey, Dominic Patel, Ashwin Sridhar, Bernard Siow, Thomy Mertzanidou, William Devine, Jagadish Kalasthry, Joey Clemente, David Hawkes, Hayley Whitaker, Manuel Rodriguez-Justo, Greg Shaw, Daniel Alexander, Alexander Freeman, Roger Bourne, Eleftheria Panagiotaki, Shonit Punwani

The biophysical basis of MRI signal in the normal human prostate is uncertain, whereby the normal peripheral zone has high ADC values and returns high signal on T2-weighted imaging. In this study, we use MRI in combination with quantitative digital histopathology to offer an explanation. Paired scans were performed at 3T on a human prostate, prior to and following prostatectomy and changes in zonal morphology and MRI characteristics were measured. The peripheral zone collapsed and reduced in T2 signal intensity and ADC value ex-vivo. Digital histopathological analysis suggested the peripheral zone stores more ejaculatory fluid than the transition zone.

Fabian Gutjahr, Thomas Kampf, Stephan Günster, Patrick Winter, Volker Herold, Wolfgang Bauer, Peter Jakob

Renal perfusion measurements in coronal view using FAIR-ASL can be problematic in small animals as the selective inversion slice can label a large fraction of the inflowing blood. In this work, an alternative orientation for the selective inversion slice is shown to increase the sensitivity of the measurement.

Nan Yu, Chuangbo Yang, Qi Yang, Shaoyu Wang, Yong Yu, Taiping He

Star VIBE (MRI) sequence in obtaining scan under free breathing can provide high-resolution imaging. Therefore, we assessed the accuracy of magnetic resonance imaging (MRI) for detecting pulmonary nodules by comparing the detection rate of high-resolution Star vibe sequence with the MSCT results.    We concluded that pulmonary nodules with the maximum diameter more than 3mm can be detected by star-vibe (MRI) sequence with a satisfactory accuracy. Although pulmonary nodules with the max diameter less than 3mm had relatively low sensitivity, the accurate treatment decisions may also be made.

Feng Feng, Ganlin Xia, Peng Cao

A histogram analysis approach has been shown to be a premising tool in discriminating malignant and benign SPNs in terms of their heterogeneity. The purpose of our study was thus to primarily assess the diagnostic performance of DCE-MRI for stratifying the malignant and benign using histogram analysis. The results showed that the mean value of K^trans and K_ep, Kurtosis and skewness assessments from V_eof DCE-MRI histograms may be useful for differentiating malignant from benign SPNs.

Peter Harri, Juan Camacho, Lauren Alexander, Pardeep Mittal

Cholangiocarcinoma may demonstrate typical imaging manifestations and common patterns of organ involvement, guiding diagnosis, and facilitating imaging follow up after therapy. Adequate knowledge of tumoral biology in cholangiocarcinoma and current image-guided therapeutic approaches, along with imaging appearance of cholangiocarcinoma before and after image-guided interventions is crucial for adequate diagnosis and surveillance .MR imaging plays a key role for patient management, assessing therapy response and patient surveillance.

Li Ya-Hui, Chen Ran-Chou, Huang Wen-Yen, Chang Wei-Chou, Tang Zun-Cheng

Functional imaging techniques have a potential role in evaluation of treatment response in patients with HCC after SABR. After SABR, the increase of ADC value > 10% had marginally improved local control. A further large-scale study to identify the predictive value of parameters in functional MRI in validated.

Mathilde Wagner, Idoia Corcuera, Sara Lewis, Martin Kang, Stefanie Hectors, Ardeshir Rastinehad, Yasmina Chaibi, Bachir Taouli

We compared image quality, lesion conspicuity and diagnostic performance of calculated and acquired b1600 DW images for prostate cancer (PCa) detection and assessed the added value of calculated b2000 images for PCa detection. We showed that calculated b1600 had equivalent image quality and diagnostic performance for PCa detection compared to acquired b1600 images with improved tumor-to-PZ contrast ratio, which suggests that calculated b1600 could be an alternative to acquired b1600 to decrease acquisition time. We also showed that calculated b2000 had better tumor conspicuity than b1600. 

Josephin Gawlitza, Martin Reiss-Zimmermann, Gregor Thörmer, Alexander Schaudinn, Nikita Garnov, Lars-Christian Horn, Minh Do, Roman Ganzer, Jens-Uwe Stolzenburg, Thomas Kahn, Michael Moche, Harald Busse

Multiparametric MRI has been shown to improve detection, localization and characterization of patients with suspected prostate cancer (PCa). The current PIRADS guideline (v2, 2015) states that the additional use of an endorectal imaging coil (ERC) increases SNR at any magnetic field strength which may be particularly useful for staging and inherently lower SNR sequences (DWI or DCE). On the other hand, phased array coils with 16 or more elements may also provide adequate SNR. This work assesses the potential benefit of an ERC for the detection of prostate cancer– within the same patients.

Michela Antonelli, Edward Johnston, Manuel Cardoso, Sebastien Ourselin*, Shonit Punwani*

Gleason grade is the most important determinant of prognosis and survival in prostate cancer, and is determined using prostate biopsy. Here we investigate whether multi-parametric MRI can be used to classify Gleason grade non-invasively with logistic regression (LR) models, classifying tumours into 3+3 and those containing a 4 component. A selection of clinical and quantitative MRI metrics were used. The LR model was trained in ninety-nine patients and tested following a Leave-One-Out (LOO) analysis on a temporal separated cohort of nineteen patients. LR models were shown to predict the presence of Gleason 4 component in cancer lesions both before and after LOO analysis.

Marina Malikova, Jaroslaw Tkacz, Priscilla Slanetz, Adam Aakil, Chao-Yu Guo, Hernan Jara

The T1/T2 ratios obtained by qMRI  provide measures that strongly correlate with histopathological findings. This quantitative information of tissue properties can provide basis for improving the specificity of diagnostic breast imaging and serve as a tool to assess response to treatment and contralateral breast involvement.

Elizabeth Maddox, Ashley Cahoon, Jessica Robbins, Krupa Patel-Lippmann, David Kushner, Ahmed Al-Niaimi, Elizabeth Sadowski

MRI can exclude myometrial invasion (MI) and cervical invasion (CI) with high accuracy in endometrial carcinoma. Women with small tumors, no MI, no CI and no evidence of extra-uterine spread have a very low risk of lymph node metastasis, and lymphadenectomy can be avoided.  The goal of our study was to demonstrate how using preoperative MRI to prevent unnecessary lymphadenectomy can affect operating room time (OR) and post-operative complications.  We performed an IRB approved retrospective study evaluating MRI results, lymphadenectomy status, operative times, and post-operative complications.  This demonstrated a statistically significant decrease in OR times and post-operative complications.

Shuchang Zhou, Liming Xia

The study aim to compare the intravoxel incoherent motion (IVIM) and DCE-MRI for distinguishing benign pulmonary nodules and lung cancer and  evaluate the diagnostic performance of two methods. We found ADCtotal,D,D*from IVIM and Tmax,SLE from DCE-MRI valuable for differential diagnosis ,with D and Tmax have better sensitivity and accuracy.But parameters between the two methods show poor correlation.Combination of IVIM and DCE-MRI can get excellent diagnostic performance.

Robert Hicks, Andreas Loening, Shreyas Vasanawala, Michael Ohliger, Thomas Hope

Variable refocusing flip angle single-shot fast spin echo (vrfSSFSE) decreases T2-decay related blurring, allows increased K-space coverage while maintaining clinically relevant echo times, and reduces specific absorption rate.  We evaluated clinical image quality and acquisition time of vrfSSFSE for imaging liver lesions in comparison with conventional SSFSE in patients undergoing 68Ga-DOTA-TOC PET on a 3T time-of-flight PET/MRI.  Quantitative analysis of 53 lesions in 27 patients demonstrated higher mean CNR with vrfSSFSE (9.9 vs. 6.7, p<0.001) and 1.7-fold increase in speed compared to SSFSE. vrfSSFSE improves liver lesion contrast with shorter scan times acquired using a single 20 second breath hold.

In Chan Song, Sang Youn Kim, Jeong Yeon Cho, Seung Hyup Kim

In an IVIM technique, atypical signal intensity decay in low b factors or its variation at neighboring pixels at tumor lesion may be caused by tumor heterogeneity or spatial mismatch due to image distortion in EPI sequence, which can make estimated IVIM parameters be unreliable in conventional pixel-by-pixel method. Thus, to obtain more reliable IVIM outputs for prostate IVIM MR imaging, we suggest a new and simple ROI-based analysis method using all data of surrounding pixels in estimation and our study demonstrates a ROI-based analysis method decreased variation in IVIM parameters and can provide more reliable IVIM map images.

Tingting Xu, Guangyu Tang

Purpose: This study aimed to evaluate the difference in dynamic contrast enhanced magnetic resonance imaging characteristics between low-risk and non-low-risk breast cancers and to explore the possible pathological basis.

Materials and methods: Approval from the institutional review board and informed consent were acquired for this study. The MR images of 104 lesions with pathologically proven breast cancer were retrospectively analyzed.

Result: Low-risk tumors showed significantly lower K^trans and K_ep values and higher ADC value than non-low-risk breast cancers.

Conclusion: The prediction parameter using K^trans, K_ep, and ADC obtained on DCE-MRI and diffusion-weighted imaging could facilitate the identification of low-risk breast cancers.

 

Wang Huihui, Wang Xiaoying

To evaluate the value of different preoperative examniations in differenciating high/low Gleason score, prostate volumev(PV), PSA, PSA density (PSAD), DRE, multiparametric MRI (mpMRI) and transrectal ultrasound guided biopsy were analyzed. The area under curve (AUC) of PSAD was 0.911 with the cut-off level of 0.25, which was even better than biopsy(AUC=0.887). MpMRI performed good diagnostic accuracy according to PI-RADS v2 by Reader 1(AUC=0.831) and 2(AUC=0.933).

Shuai Ma, Yi Liu, Ge Gao, Rui Wang, Yahui Shi, Zuofeng Li, Juan Wei, Xiaoying Wang

The decision tree trained on MR descriptions by natural language processing (NLP) method represents a desirable performance in identifying low-risk PI-RADS 2-3 classes with high precision and high-risk PI-RADS 5 class with high recall. From the decision path, several specific features are adopted to make decision and the identification of key indicator contributes to distinguish PI-RADS 2 class from PI-RADS 3 class.

Isabel Dregely, Claudia Prieto, Radhouene Neji, Camila Munoz, Rene Botnar, Andrew Mallia, Gary Cook, Vicky Goh

To avoid overtreatment and repeated use of invasive biopsies, there is a need for improved diagnostic tools for prostate cancer risk stratification. Simultaneous Positron Emission Tomography / Magnetic Resonance Imaging (PET/MRI) systems are promising, however, fundamental differences in PET and MR imaging methodology currently limit full integration and thus the true potential of simultaneous PET/MR: While PET is a rather straightforward, single 3D scan, the MRI exam is complex and current clinical practice consists of several 2D sequences with different image contrast weightings and spatial coverage, performed in a serial fashion. Here, we propose a single, 3D, quantitative T2-MRI sequence that parallels the continuous scan workflow of PET data acquisition. 

Yan Zhong, Lu Ma, Yanguang Shen, Yingwei Wang, Jingjing Pan, Haiyi Wang, Huiyi Ye

To evaluate the value of the (kurtosis, perfusion and diffusion) parameters in the differentiation of TZ cancer from benign GH.30 patients underwent preoperative 3-T magnetic resonance (MR) imaging. Each parameter in TZ carcinomas and GH were compared using Student's t test, receiver operating characteristics (ROC) analysis. All parameters except for D* in TZ carcinoma and GH were significantly different, and showed the same sensitivity for differentiating TZ carcinoma from GH (92.3%), and K and ADCs with equal specificity (96.7%).The monoexponential ultra-high b value ADC calculation is more practical to discriminate TZ carcinoma from GH.

Xijia Deng, Ailian Liu, Jinghong Liu, Meiyu Sun, Bing Wu, Lihua Chen, Anliang Chen, Jiaojiao Zhu

Ovarian cancer is one of the most common malignant tumor of female reproductive organs, which is the first cause of death in gynecological malignancies. A mixed cystic and solid appearance of an ovarian mass is usually difficult to differentiate from degenerated subserous leiomyoma. In this study, DTI MR measurements were performed to investigate the difference of the ADC and FA values in ROIs of the soild component region between ovarian tumors and uterine fibroids.

Wang Huihui, Wang Xiaoying

The diagnostic accuracy of PI-RADS v2 for clinically significant cancer was evaluated by using whole-mount step-section slides as standard of reference. All significant cancers could be identified and the accuracy of PI-RADS 3 to 5 for predicting significant cancer was 91.7%, with high sensitivity (100%) and negative predictive value (100%). 

James O'Callaghan, Edward Johnston, Arash Latifoltojar, Harbir Sidhu, Magdalena Sokolska, Jamshed Bomanji, Alan Bainbridge, Shonit Punwani

The staging of lymph nodes in prostate cancer is important for the planning and monitoring of treatments.  However, there is currently a paucity of techniques that can accurately identify the presence of metastases in small nodes.

In this study, we investigate the usefulness of signal fat fraction from MRI mDixon acquisitions in discriminating between benign and metastatic nodes using ¹⁸F-Choline PET as a reference standard.

We present data suggesting that in comparison to commonly used diameter measurements, mDixon fat fraction may be better at discriminating benign from involved lymph nodes that are <10mm in short axis diameter. 

Ru wen, Junkang Shen, Wenlu Zhao, Peng Cao, Jiangfen Wu

There are different treatments for low-risk and high-risk prostate cancer patients in clinical, NCCN guidelines recommend proactive monitoring management as the preferred treatment for patients with  low risk PCa(GS ≤6 ),and active measures for intermediate/high-risk patients. Our research found that both DCE and IVIM quantitative parameters Histogram analysis results can successfully distinguish  LG from HG PCa ,and their diagnostic performance was not statistically significant. Considering the method we used to acquire quantitative parameters of  DCE-MRI , IVIM may provide  us a new way for those who cannot bear the invasive intravenous injection of contrast agent .

Suresh Anand Sadananthan, Wei Wei Pang, Navin Michael, Mya Thway Tint, Kuan Jin Lee, Lynette Shek, Yap Fabian, Keith Godfrey, Melvin Leow, Yung Seng Lee, Peter Gluckman, Christiani Jeyakumar Henry, Marielle Fortier, Yap Seng Chong, S. Sendhil Velan

The association of the duration of breastfeeding with childhood obesity is equivocal. The first year of life is a period of hypertrophic expansion of adipocytes with little increase in adipocyte number. Hence, over-nutrition during this period could potentially result in persistent changes in adipocyte size that may last until adulthood. In this study, we have investigated the association of breastfeeding duration with abdominal fat distribution and adipose tissue cellularity at 4.5 years. Our results indicate a weak protective effect of longer breastfeeding duration on abdominal subcutaneous adipose tissue volumes and subcutaneous adipose tissue morphology.

Yu Guo, Penghui Wang, Chao Chai, Zhizheng Zhuo, Yu Zhang, Wen Shen

The purpose of the study was to evaluate the clinical usefulness of IVIM technique for the PCa and furtherly investigate the diffusion and perfusion characteristics among PCa, normal peripheral zone (PZ) and central gland (CG) comparing to pharmacokinetic parameters based on quantitative DCE-MRI. The IVIM was performed at 11 b values of 0, 10, 20, 30, 50, 75, 100, 250, 500, 750 and 1000s/mm². The D value in prostate cancer were significantly lower than those in the PZ and CG. The perfusion fractions in PCa were significantly higher than those in the PZ. There were no significant differences in the PCa, PZ and CG for the D*, which had large SDs. D showed significant negative correlations with Ktrans and Kep respectively, while f showed a significantly positive correlations with Ktrans and Kep. IVIM can provide more detailed information on perfusion and diffusion of prostate cancer noninvasively without intravenous contrast agent administration. 

 

Angeline Nemeth, Hélène Ratiney, Benjamin Leporq, Kevin Seyssel, Bérénice Segrestin, Pierre-Jean Valette, Martine Laville, Olivier Beuf

Overweight and obesity are a major worldwide health problem increasing the risk to develop pathologies such as diabetes and cardiovascular disease. The metabolic risk is modulated by the adiposity distribution and the fatty acid composition. Quantitative MRI to assess the fat volumes and composition is still little used. This study shows, using a single 3D multiple gradient echo sequence, that overfeeding has a significant effect on fat storage in the body with an increase of visceral and subcutaneous abdominal adipose tissues volumes, fat storage in the liver and seems to have an effect on stored fat composition.

Devkumar Mustafi, Erin McAuley, Rebecca Valek, Erica Markiewicz, Marta Zamora, Aytekin Oto, Donald VanderGriend, Gregory Karczmar

Lower urinary tract symptoms (LUTS) affect many elderly men and cause urinary obstruction and prostatic enlargement. The aim of this study was to use functional/anatomic MRI for serial imaging of LUTS development in a testosterone/estrogen-supplemented experimental mouse model.  These mice exhibited a greater increase in prostate volume and decrease in urethra volume than control mice, and changes in urethral and prostatic volume were strongly inversely correlated. Results suggest that serial MRI could improve understanding of initiation and development of LUTS as well as the origin of clinical symptoms of benign prostatic hyperplasia, and evaluate effects of therapy in mouse models.

Xiaohuan Cao, Jianhua Yang, Yaozong Gao, Guorong Wu, Dinggang Shen

Registering pelvic CT and MRI can help propagate accurate delineation of pelvic organs (prostate, bladder and rectum) from MRI to CT, since it is difficult to directly obtain accurate organ labels from CT due to its low soft-tissue contrast. We propose to use image synthesis to first eliminate the appearance gap between modalities by performing image synthesis in bi-directions in order to provide more anatomical information for guiding the registration. Then, a hierarchical region-adaptive registration framework is proposed to utilize the significant anatomical information from each modality to guide accurate MRI/CT deformable registration.

Julian Emmerich, Rebecca Schilling, Sina Straub, Asja Pfaffenberger, Frederik Laun

Due to field inhomogeneities, MR-images suffer from image distortions in frequency-encoding direction. Using MRI as a tool for dose planning in MR-guided radiation therapy, image distortions play an important role in defining safety margins and the planning target volume (PTV). To investigate the influence of susceptibility-related field inhomogeneities on the distortion in prostate and cervix, distortions maps based on phase images were calculated for data acquired in a MR-guidance study. It was found that maximum distortions in prostate and rectum can be as large as 0.6 mm or 1.0 mm respectively, which should be considered when defining PTVs.

Wang Huihui, Wang Xiaoying

To determine the value of ADC map in identifying clinically significant prostate cancer, the ADC PI-RADS scores and mean ADC values of index lesion based on PI-RADS v2 were measured. ADC PI-RADS score may be good as overall PI-RADS v2 score in predicting clinically significant PCa. The clinically significant cancers had higher ADC scores and lower ADC values. An ADC value of 619-889×10-6 mm2/s may be useful in the identification of clinically significant cancers.  

Paul Stoddard, Valentina Taviani, Suchandrima Banerjee, Bruce Daniel, Anshul Haldipur, Brian Hargreaves, Shreyas Vasanawala, Andreas Loening

3D T2-weighted imaging (T2WI) of the prostate for prostate cancer (PCa) is often hampered by motion artifacts and signal starvation. However, incorporating reduced phase field of view capability using outer volume suppression (OVS) into 3D fast spin echo (FSE) can overcome these obstacles. In the prostatic transition zone (TZ), superior contrast and diminished blur were found over standard 2D FSE, with preserved SNR and anatomic detail. Diagnostic confidence was greater with 3D, whether used alone or in combination with 2D. Furthermore, less equivocal diagnoses resulted with the combination of 2D and 3D.

Kareem Elfatairy, Christopher Filson, Adeboye Osunkoya, Rachel Geller, Sherif Nour

Consistent results throughout repeated biopsy sessions is an essential requirement for any tool used for active surveillance. TRUS biopsy showed inconsistent results in repeated biopsy sessions. Regarding MRI guided biopsy, the reliability of repeated biopsies needs to be established. 5 patients with 17 lesions which were repeatedly biopsied under direct MRI guidance were included. Kappa statistics showed moderate agreement. Negative predictive value for 2nd biopsy was 93% and for 3rd biopsy was 90%. Consistent biopsy results may obviate the need for the current paradigm of obtaining annual prostate biopsies in patients undergoing active surveillance

Ge Gao, Chengyan Wang, Xiaoying Wang, Jue Zhang, Yajing Zhang, Yajing Zhang

Multiparametric MRI (mpMRI), including T2WI, DWI/ADC and DCE, is becoming a promising noninvasive tool for prostate cancer (PCa) detection, localization and stage. Although PI-RADS has provides recommendations for image reading and reporting, the interpretation of mpMRI is still challenging for clinical work, for poor interobserver agreement and strong experience dependence. We therefore developed a machine learning model that combines features derived from mpMRI for PCa detection and localization. The model predicted the transition zone (TZ) and peripheral zones (PZ) separately and compared with whole-mount step-section slide. The computer-aided diagnosis (CAD) achieved excellent performance both in PZ and TZ.

Jingling Li, Xiaocheng Wei, Shun Qi, Hong Yin, Haitao Zhao

Bone marrow toxicity is very common side effect during radio-chemotherapy treatment of pelvic tumors. In this study, six patients with cervical cancer were included. The Bone marrow fat faction of the subjects were evaluated using quantitative fat fraction MR technique before each week’s treatment and at the end of whole five weeks’ therapy. The results indicated that MRI was sensitive to marrow composition changes and can evaluate the real time bone marrow toxicity during radio-chemotherapy. This could potentially benefit patient with a more optimized treatment plan.

Xianlun Zou, Yaqi Shen, Yao Hu, Zhen Li, Daoyu Hu

Differentiating intrahepatic mass-forming cholangiocarcinoma (IMCC) and poorly differentiated hepatocellular carcinoma(pHCC) is often difficult for radiologists, but it is important for providing appropriate treatments. In our study, we use noncontrast MRI with diffusion-weighted imaging in combination with whole-tumor quantitative apparent diffusion coefficient (ADC) histogram analysis to differentiate IMCC from pHCC. The result reveals that ADC histogram analysis based on the whole-tumor can be considered a useful and noninvasive method to help differentiate IMCC from pHCC. Especially ADC_25% of histogram analysis allows differentiation of IMCC from pHCC with higher accuracy.

Sandra Garza, Tara Sagebiel, Wei Wei, Jingfei Ma, Priya Bhosale

Distinguishing uterine malignant mixed mullerian tumors (MMMTs) from endometrial carcinomas preoperatively by pelvic MRI may help with surgical and treatment planning of this highly aggressive tumor. Our study found that prolapse of tumor through the external cervical os, delayed iso- or hyper-enhancement, high mean tumor: myometrium positive enhancement integral (PEI) ratio and low tumor signal enhancement ratio (SER) are more commonly seen in patients with MMMT and may alert the radiologist to the possibility of this diagnosis. 

Deuk Jae Sung, Ki Choon Sim, Na Yeon Han, Beom Jin Park, Min Ju Kim, Sung Bum Cho

A low T2 signal intensity is a well-known feature of fat-poor angiomyolipoma and papillary renal cell carcinoma. However, many other renal tumors showing low T2 signal intensity are encountered in daily practice. So, a low T2 signal intensity is not a pathognomonic finding for fat-poor angiomyolipoma and papillary RCC. Even though renal mass biopsy might be considered to establish a diagnosis for tumors without typical imaging features of renal cell carcinoma, the decision to biopsy or not sometimes seems to be difficult in small renal tumors. Accurate MR imaging characterization of renal masses is essential for ensuring appropriate management and avoiding unnecessary surgical procedure.

Sung Kyoung Moon, Hyug-Gi Kim, Kyung Mi Lee, Joo Won Lim

The purpose of our study is to assess the usefulness of subtracted images from 4-1 min in DCE MR imaging for the prostate cancer diagnosis. Subtracted images from 4-1 min were assessed for the visual washout scores of prostate cancer and normal PZ, and compared with the time-contrast media curve patterns in each patient. A subtraction image set of DCE MRI 4-1 min mirrored time - concentration curve patterns of DCE MR imaging in prostate cancer and normal PZ. This subtraction image set can be a more simple method to display the DCE characteristics without any additional post-processing.

Xiaoduo Yu, Meng Lin, Lizhi Xie, Han Ouyang, Chunwu Zhou

Tumor blood supply is closely related to the tumor occurrence, development, metastasis and prognosis. MRI is the optimal imaging method for investigating uterine cervical carcinoma, which provides excellent morphological information using conventional series. Additionally, the tumor perfusion information can be quantitatively assessed by dynamic contrast-enhanced MRI (DCE-MRI). DCE derived parameters include MaxSlop, CER, IAUGC, K^trans, K_ep and V_e.  Our results showed mild negative correlation to clinical FIGO stage based on mean and maximum of K^trans and K_ep, increased minimum MaxSlop, and increased max- and mini-mum K^trans in squamous cell carcinoma than those of adenocarcinoma. DCE-MRI is a significant supplement to provide valuable morphological information that contributes to clinical decision-making and prognosis prediction.

Yuan Chen, Jingliang Cheng

Yuan Chen,female,graduated from Zhengzhou University,Master's degree in reading at the First Affiliated Hospital of Zhengzhou University.

Sin-Yuin Yeo, Ulrich Katscher, Young-Sun Kim, Holger Gruell

MR-HIFU is a non-invasive thermal therapy used to treat symptomatic uterine fibroids. During therapies, clinicians utilize information provided by MRI for treatment planning and to ensure ablation of fibroids using non-invasive temperature monitoring via PRFS thermometry. Thereafter, the therapeutic outcome is determined by measuring the non-perfused volume (NPV) following contrast agent administration. We present a case study using Electric Properties Tomography (EPT) for assessment of treatment outcome by correlating the change in conductivity to the NPV. An increase in conductivity of up to 20% was observed. Thus, EPT is a promising approach for assessment of treatment outcome.

Basen Li, Liang Wang

Prostatic arterial embolization (PAE) is a minimally invasive procedure developed in the recent years. Recent studies reported clinical applications of PAE in the treatment of BPH, and its safety and efficacy was confirmed. For the basic theory research, some scholars have made preliminary animal experiments in beagle dogs and pigs.To the best of our knowledge, there is no longitudinal study regarding BPH morphological and functional characteristics of BPH in different periods after PAE with multi-parametric magnetic resonance imaging (mp-MRI).

Leonidas Georgiou, Nisha Sharma, David Broadbent, Daniel Wilson, Barbara Dall, Anmol Gangi, David Buckley

An ideal breast MRI protocol might include high spatial and high temporal resolution images acquired following a single contrast agent injection. Here we present an acquisition strategy to acquire both for clinical reporting and tracer kinetic analysis. The approach was evaluated using simulations and tested through application in patients undergoing neoadjuvant chemotherapy. Radiologists could adapt similar protocol strategies to examine the physiological characteristics of tumors and their associated changes during treatment without significantly compromising the data used for clinical reporting.

Matthew Mouawad, Heather Biernaski, Muriel Brackstone, Michael Lock, Anat Kornecki, Olga Shmuilovich, Ilanit Nachum, Frank Prato, R. Terry Thompson, Stewart Gaede, Neil Gelman

Patient movement during dynamic contrast enhanced breast MRI acquisition can degrade signal enhancement curves. Non-rigid image registration can improve enhancement curves, but computation time can be long, especially if all voxels are sampled for cost function estimation. This work investigates the influence of the percentage of voxels sampled (PS) on goodness-of-fit, kinetic model parameter values and uncertainties. The spatial distribution of parameter values was more strongly influenced by registration and PS compared to global tumor measures. Registration with very low PS values increased parameter uncertainties compared to unregistered. 5 PS provided similar performance to 100 PS with reduced computation time.

MASAKO KATAOKA, Natsuko Onishi, Shotaro Kanao, Hajime Sagawa, Mami Iima, Makiko Kawai, Akane Ohashi, Rena Sakaguchi, Ayami Kishimoto, Marcel Nickel, Masakazu Toi, Kaori Togashi

Using ultrafast DCE MRI (UF-DCE)with compressed sensing reconstruction, detection rate and morphology of breast lesions on very early phase images within 1 minutes post contrast injection were compared to those on full diagnostic protocol (FDP). Almost all (95%) of the lesions reported on FDP were identified on UF-DCE. Size of the lesions were slightly smaller on UF-DCE but within-2mm difference in 96% of masses. Considering that wash-in kinetic information can be obtained by UF-DCE, the current data of equivalent lesion detection, size and morphology evaluation on UF-DCE support its application to abbreviated breast MRI protocol.

Jorge Jimenez, Roberta Strigel, Kevin Johnson, Leah Henze Bancroft, Scott Reeder, Walter Block

In this work, we present a new methodology for an abbreviated dynamic contrast enhanced (DCE) MRI breast screening protocol. The methodology relays on a novel dynamic reconstruction scheme, local low-rank, applied to breast MR imaging for the first time. Our work provides the framework for a high resolution (0.83 mm isotropic), ultra-fast (10 second volumetric frame rate) imaging technology to deliver detailed information of the early enhancement phase of breast lesions, preserving diagnostic accuracy while shortening exam times. We demonstrate the feasibility of the proposed approach.

Jun Chen, Roger Grimm, Anshuman Panda, Bhavika Patel, Judy James, Kevin Glaser, Jennifer Kugel, Yuan Le, Alvin Silva, Richard Ehman

Sternum drivers for breast MRE can produce shear waves in breasts without breast compression effect, which can result in increased breast stiffness due to tissue nonlinearity. A recent 5-slice 2D GREMRE sequence study found sternum driver MRE was a very reproducible method. In our current study, we were able to use 40-slice 3D GREMRE volumetric MRE sequence to compute volumetric breast elastograms in patients.

Xiaoqi Wang, Lan Liu

Utilizing the state of art water-fat separation method with multi-echo acquisition in mDIXON quant to explore the relationship between magnetic resonance transverse relaxation time (T2*) and the pathological type of breast tumors.

Marco Borri, Kristiana Gordon, Julie Hughes, Erica Scurr, Dow-Mu Koh, Martin Leach, Peter Mortimer, Maria Schmidt

Here we present an MRI-based approach to assess breast cancer related lymphoedema tissue composition (fluid, fat, and muscle volumes) and we evaluate a cohort of 13 patients. Our measurements indicate that fat, which cannot be eliminated by first line treatment, was the predominant component of the swelling. Furthermore, changes in tissue composition were not uniform along the arm. Quantification of the volume and spatial distribution of different tissue components could greatly improve treatment delivery and patient selection for optimal treatment. With a 6 minute MRI scan and automated post-processing, this methodology shows potential for implementation in clinical practice.

Artem Mikheev, Laura Heacock, Jean Logan, Henry Rusinek

Breast density, defined as fraction of fibroglandular tissue (FGT), and post-contrast FGT enhancement (background parenchymal enhancement) are considered cancer risk factors. These MRI measures are recommended for radiologic reports and are promising cancer biomarkers. There is a general agreement that isolating the breasts from the chest wall (CW) is the most difficult to automate step in the FGT segmentation pipeline. Various methods for this task have been reported, but all show significant limitations. We have previously developed a semi-automated FGT segmentation tool that required approximately 7 min per case. We are reporting a new algorithm based on six overlapping Experts that significantly improves segmentation speed and accuracy.

Leah Henze Bancroft, Diego Hernando, Xiaoke Wang, Scott Reeder, Roberta Strigel

Increased breast density is a known risk factor for the development of breast cancer.  Quantitative MRI methods have the potential to provide accurate, volumetric measures of breast tissue volume and density.  A novel, confounder-corrected chemical shift encoded (CSE) MRI technique designed to provide accurate fibroglandular tissue volume and density quantification is validated using a fat and water phantom.  The CSE MRI technique provided accurate quantification of water and volumes  and was robust to changes in spatial resolution and complexity of fat/water interfaces, indicating this method is expected to produce accurate and robust quantification of fibroglandular and adipose tissue in-vivo.

Meredith Sadinski, Dana Haddad, Michelle Zhang, Elizabeth Morris, Elizabeth Sutton

Reported T2 values in breast tissue are sparse and often disagree. In this study we estimate the T2 relaxation time of fibroglandular breast tissue including fatty compartments intermixed within the fibroglandular matrix. T2 mapping was performed at high spatial resolution for 15 patients at 3T with 4 TEs from 12 to 160 ms and intra- and inter-patient T2 heterogeneity were evaluated. T2 within the finroglandular environment is on the order of 100 ms with a mean standard deviation per patient of 29.6 ms. We hypothesize that this heterogeneity may reflect differences in the fibroglandular microenvironment related to breast cancer risk.

Yiqi Hu, Tao Ai, Xu Yan, Dominik Nickel, Liming Xia

As the use of neoadjuvant chemotherapy is gradually increased in the treatment of breast cancer, evaluating its therapeutic effect is gaining importance. However, tumors are markedly heterogeneous in cells, micro-environmental factors and vasculature structures, which manifests as radiologic heterogeneity. A few studies have been trying to extract heterogeneity metrics from regions of interest (ROIs) such as by means of histogram analysis. Thus, the aim of our study is to investigate the feasibility of whole-lesion histogram analysis of pharmacokinetic parameters in breast T1-weighted dynamic contrast-enhanced MR imaging (DCE-MRI) for differentiating the malignant from benign breast lesions.

Jessica McKay, Sudhir Ramanna, Steen Moeller, Edward Auerbach, Gregory Metzger, Michael Nelson, Kamil Ugurbil, Essa Yacoub, Patrick Bolan

Diffusion weighted imaging (DWI) has applications in the screening, diagnosis, and treatment monitoring of breast cancer, but its clinical value in is limited by the low resolution and artifacts of standard methods. In this work we compared a standard method with two high-resolution techniques: read-out segmented EPI (RS-EPI) and single-shot simultaneous multi-slice EPI with in-plane slice encoding (SMS-IPSE). Both the SMS-IPSE and RS-EPI methods can produce high-resolution, accurate diffusion-weighted images at the cost of decreased SNR within a clinically practical 5-minute time window, enabling the detection of smaller lesions.

Suzan Vreemann, Alejandro Rodriguez-Ruiz, Dominik Nickel, Marnix Maas, Nico Karssemeijer, Elisabeth Weiland, Berthold Kiefer, Ritse Mann

Previous work showed that ultrafast breast DCE-MRI enables assessment of the contrast inflow curve while providing images at diagnostic spatial resolution. However, the slice thickness (~2.5mm) prevented multiplanar reconstructions and therefore did not yield the same morphological information as obtained with conventional T1-weighted series. We evaluate a compressed sensing VIBE sequence (CS-VIBE) for ultrafast breast MRI that enables high spatio-temporal resolution for both dynamic inflow analysis and morphological evaluation. Two reader-studies were conducted to evaluate image quality and lesion morphology assessment. Our results show that CS-VIBE combines the advantages of both high-spatial and high-temporal resolution of clinically available sequences. 

Ting Liang, Hongwen Du, Gang Niu, Peng Cao, Chenxia Li, Heng Liu, Miaomiao Wang, Jian Yang

DCE quantitative measurement plays an important role in the identification of breast tumors. However, different ROI placement can directly affect the inspection results. However, there is no clear standard protocol for clinical routine use. This study aims to evaluate the effect of 2-dimensional maximum diameter (2DMD) and 3-dimensional whole-tumor (3DWT) on quantitative DCE-MRI in differentiating invasive ductal carcinoma (IDC) and breast fibroadenoma which are confirmed by surgical pathology, and determined the more efficient approach for ROI measurement. Our results suggested that 2DMD mean value has more diagnostic performance than 3DWT assessment in distinguishing IDC from fibroadenoma.

Jessica Gibbs, Ella Jones, Lisa Wilmes, David Newitt, John Kornak, Melanie Regan, Nola Hylton

Diffusion weighted imaging is a promising technique to monitor treatment response in patients undergoing pre-surgical chemotherapy, but manually drawn whole tumor measurements are time-consuming and subject to inter-user variability. In this study of 60 patients with sequential DWI exams during treatment, we measured apparent diffusion coefficient (ADC) from whole tumor ROIs and from a single central slice of the tumor. We found strong agreement in ADC between the two methods, suggesting that a slice from the center of the tumor may accurately represent the ADC of the entire tumor.

Stephanie Lee-Felker, Lindsey Storer, Bo Li, Anne Hoyt, Melissa Joines

            In this retrospective study, an abbreviated protocol consisting of pre-contrast T1 and first post-contrast T1 sequences with fat saturation had near perfect detection of index and secondary cancers, as well as suspicious axillary and internal mammary lymph nodes, in women with newly diagnosed breast cancer.  In conjunction with clinical histories and prior imaging examinations, an abbreviated breast MRI protocol is adequate for ipsilateral extent of disease and contralateral breast screening in newly diagnosed breast cancer. 

Kang Wang, Naoyuki Takei, Courtney Morrison, Leah Henze Bancroft, Ping Ni Wang, James Holmes, Ersin Bayram, Roberta Strigel, Frederick Kelcz , Frank Korosec

In clinical breast MRI, the dynamic contrast-enhanced (DCE) T1-weighted fat-suppressed scan plays an essential role for lesion detection and characterization. In order to improve temporal resolution of the dynamic scan, view-sharing techniques are typically used along with Dixon-based water-fat separation methods. However, there are several limitations and drawbacks of using Dixon-based techniques. In this work, we proposed to use chemical fat suppression with view-sharing to improve the temporal resolution of DCE breast MRI.

Kanae Miyake, Debra Ikeda, Jafi Lipson, Jeong Seon Park, Lloyd Estkowski, Bruce Daniel

3D Fast-Spin-Echo MRI with Short Tau inversion recovery fat suppression and 2-point Dixon decomposition of water and silicone signal (STIR Cube-FLEX or “Si-Cube”) is a recently developed silicone-specific sequence providing isotropic, high-resolution 3D datasets that are easily reformatted into any plane. We performed a reader study to evaluate the image quality of Si-Cube in 39 females, and found Si-Cube is robust to artifacts and has equivalent image quality to conventional 2D silicone-specific sequences (C-2D). The ability to reformat Si-Cube images in any plane potentially obviates the need to obtain C-2D sequences in other planes, streamlining the overall implant imaging protocol.

Ying-ying Wang, Yan Zhang, Jingliang Cheng , Baohong Wen, Dandan Zheng

In order to comparethe diagnosis efficiency of different parameters derived from diffusion kurtosis imaging model in benign and malignant breast lesions, eighty patients were analyzed in this study . DKI data with six b-values and 15 directions were acquired using single-shot SE-EPI sequence. The values of mean kurtosis (MK), axial kurtosis (AK) and radial kurtosis(RK) in malignant lesions group were significantly higher than those in benign lesions groups. The diagnosis efficiency of these parameters were also analyzed. The results showed that DKI-derived parameters can be used to distinguish the malignant lesions and benign lesions, especially AK and MK

Averi Kitsch, Brian Johnston, Savannah Partridge, Habib Rahbar

Ductal carcinoma in situ (DCIS) is a pre-invasive breast cancer that may be overtreated due to lack of reliable clinical and pathological prognostic features. Kinetics parameters on dynamic contrast-enhanced MRI have shown promise as breast cancer risk biomarkers. We compared imaging parameters of lesions and normal breast tissue between patients with DCIS recurrence and matched controls and found that patients with larger lesions with higher signal enhancement ratio (SER) and higher background parenchymal enhancement (BPE) on preoperative MRI were more likely to recur. These MRI biomarkers show promise for decreasing DCIS overtreatment and warrant further study in larger cohorts.

Dania Daye, Dorothy Sippo, Elkan Halpern, Vishala Mishra, Constance Lehman, Aditya Bardia

Emerging studies suggest that imaging features could complement standard pathologic variables in cancer prognostic assessment. Studies on the association of background parenchymal enhancement (BPE) with breast cancer prognosis remain limited. The goal of this study was to investigate the complementary value of breast BPE as a prognostic marker for breast cancer recurrence risk assessment. DCE-MRI images were retrospectively analyzed from 100 women with breast cancer. Oncotype DX score was used as a surrogate for cancer recurrence. Our results suggest that BPE could complement histopathologic factors in predicting breast cancer recurrence risk and could potentially improve breast cancer prognostication.

Vivian Park, Eun-Kyung Kim, Min Jung Kim, Jung Hyun Yoon, Hee Jung Moon

We investigated the association between perfusion parameters in pretreatment MR imaging and survival outcome. This retrospective study included 61 consecutive patients (median age, 50 years; range, 27-77 years) diagnosed with TNBC who underwent pretreatment DCE breast MR imaging and definitive surgery. The median follow-up time was 46.1 months. Among pretreatment variables, a higher ve value and higher peak enhancement at pretreatment MR imaging were significantly associated with worse disease-specific survival in patients with TNBC. With further validation, these perfusion parameters have the potential to aid in the pretreatment risk stratification of patients with TNBC and in evidence-based clinical decision support.

Vignesh Arasu, Paul Kim, Roy Harnish, Cody McHargue, Wen Li, David Newitt, Ella Jones, Laura Esserman, Bonnie Joe, Nola Hylton

The purpose of this study was to investigate how background parenchymal enhancement (BPE) may additively improve an MR tumor model for prediction of non-pathologic complete response (non-PCR) patients in the neoadjuvant setting. BPE identified 24-36% of non-PCR patients independent of tumor factors while maintaining a low misclassification of PCR patients.  In conjunction with a tumor model using tumor and treatment factors, addition of BPE may improve residual cancer prediction of up to 60% of patients, but results were not statistically significant. 

Wenwen Fan, Han Ouyang, Chunwu Zhou, Xinming Zhao, Lizhi Xie

Synopsis In recent years, the incidence rate of breast cancer in China has been rising rapidly, which highlights the importance of early diagnosis. Therefore, how to improve the detection rate and reduce the recall rate become significant for the breast cancer prevention and treatment. Considering the tissue overlapping effect from conventional digital mammary gland photography technology may lead to false positive and negative results. 

Gene Cho, Elizabeth Sutton, Linda Moy, Lucas Gennaro, Artem Mikheev, Henry Rusinek, James Babb, Daniel Sodickson, Elizabeth Morris, Sunitha Thakur, Eric Sigmund

This study compares data collected from different MR vendor systems using different software packages to better understand the robustness and reproducibility of IVIM metrics. Patient data from 2 sites (Site 1 & 2) from 1.5/3T systems (GE/Siemens) were analyzed with 2 software packages to derive IVIM biomarkers and their intersite/software variability. Results show that metrics of IVIM average and histogram analysis are robust quantitative imaging biomarkers for breast cancer.

Yuan Jiang, Yi Liu, Yahui Shi, Zuofeng Li, Juan Wei, Xiaoying Wang

The decision tree trained on MR descriptions by natural language processing (NLP) method shows desirable capability in identifying the high-risk BI-RADS 5-6 class.From the decision path, we identify the key indicators to distinguish BI-RADS 5-6 from the relatively low-risk classes. And the inner heterogeneity of BI-RADS 4 cases makes it difficult to build a general model for this class.

Tae Hee Kim, Doo Kyoung Kang, Sun Young Park, Joo Sun

We quantitatively analyzed the background parenchymal enhancement of whole breast on MRI using in-house software with MATLAB.

The mean values of BPE were well correlated with qualitative grades of BPE. 

The mean and ninety percentile values of BPE were lowest in 2nd week of menstrual cycle and highest in 4th week with statistical significance (p=0.005 for mean values and p=0.003 for nienty percentile, respectively). 

Jacob Johnson, Leah Henze Bancroft, Ryan Zea, Diego Hernando, Scott Reeder, Roberta Strigel

Segmentation of breast MR images remains a challenge and a necessity for a variety of quantitative applications. We present a semi-automatic methodology for segmentation of breast tissue for the special case of low resolution, low flip angle chemical shift encoded MRI (CSE-MRI) with water-fat separation. User interaction is required to set the bounds of the segmentation, while the chest wall and skin are segmented automatically. The results differed with corrections by an experienced radiologist by 4.2% average error per case. The method exhibits comparable accuracy to published methods and high agreement between non-expert reviewers.

Frederick Kelcz, Leah Bancroft, Jorge Jimenez, Walter Block

Although DCE-MRI is the mainstay of breast MRI diagnosis, specificity is limited due to multiple enhancing benign lesions.  Specificity can by improved by viewing T2 information, but conventional T2 imaging is limited by spatial resolution.  We performed a prospective clinical study of a novel T2-like imaging sequence with sub-mm spatial resolution to determine if a breast radiologist could improve his assessment of benignity. Results show that excellent spatial resolution was achieved, but at the cost of increased noise and loss of T2 contrast.  Ultimately, the radiologist felt less confident in more cases than he felt more confident regarding benign lesions.

Min Sun Bae, Luca A. Carbonaro, Elizabeth J. Sutton, Elizabeth A. Morris

Breast conservation surgery (BCS) is a standard treatment for early-stage breast cancer, and includes a complete removal of the tumor with a margin of tumor-free breast tissue. If margins of the resected tissue are involved at final surgical pathology, patients undergo additional surgery. Although MR imaging is the most sensitive modality for breast cancer, the effect of preoperative MR imaging on the improvement of surgical outcomes is controversial. There are only a few studies evaluating association between preoperative MR imaging features and positive resection margins (RMs) in patients with invasive breast cancer.  
 

Barbara Bennani-Baiti, Pascal Baltzer

While breast density is a recognized risk factor for breast cancer, the role of background parenchymal enhancement (BPE) is still controversially discussed. Since BPE reflects hormonally active breast tissue, it may serve as a biomarker for malignancy. Current assessment of BPE, however, is hampered by the subjective nature of its assessment. We therefore tested an automated approach that quantified the percentage of enhancing breast tissue of the entire contralateral breast. This pilot study finds the amount of quantitatively assessed enhanced breast parenchyma as a percentage of the entire breast to inversely correlate with breast cancer risk, while visually estimated BPE did not correlate with breast cancer. 

Oi Lei Wong, Gladys Goh Lo, Jing Yuan, Helen Hei Lun Chan, Ting Ting Wong, Polly Suk Yee Cheung

In this study, we intended to investigate the relationship between ADC heterogeneity of DCIS lesions and DCIS lesioxn morphology, histological grade and BIRADS classification using 3T DW breast MRI. Increasing heterogeneity was observed with increasing DCIS histological grade and increasing BIRADS, but not reaching significance level, was observed based on our results. This study was mainly limited in the small numbers of DCIS lesions, so statistical power has to be further strengthened in future studies with larger sample size.

Anthony Jedd, James Costello, Shannon Urbina, Bobby Kalb, Diego Martin

CT-PA is the gold standard for diagnosis of pulmonary embolism, but requires use of radiation and iodinated contrast.  There is an overall low incidence of positive studies (5%) in the patient population 18-45.  Our study evaluates the negative predictive value of MRI as the primary imaging modality for exclusion of suspected PE in patients <40 y/o and/or relative contraindication to iodinated contrast.  We found a negative predictive value of 99% in our patient population.  These results suggest that MRI is an effective first-line imaging modality to exclude PE, while reducing exposure to ionizing radiation and iodinated contrast.

Lucia Flors, Talissa Altes, John Mugler III, G Miller, Jaime Mata, Sarah Kilbourne, Hannah Mannem, Max Weder, Yun Shim

Purpose: To determine if the changes in lung ventilation using HP 3He-MRI can provide in vivo pulmonary physiology highly relevant in defining CLAD phenotypes among lung transplant patients, phenotypes which otherwise are undetectable by the usual PFT parameters such as FEV1. Methods: Thirteen lung transplant recipients underwent ventilation HP 3He MR lung imaging and spirometry; the latter was compared to baseline spirometry. Time from transplant was 2.5 ±2.5 yrs. Results/ Conclusion: Declined lung function after lung transplant correlated well with decreased ventilated lung volume in the transplanted lung found with HP 3He MRI. 
 

Ho-Fung Chan, Neil Stewart, Juan Parra-Robles, Guilhem Collier, Jim Wild

3D whole lung morphometry maps were acquired with ¹²⁹Xe DW-MRI and compressed sensing. Prospective three-fold undersampled 3D ¹²⁹Xe lung morphometry (Lm_D) maps were derived using the stretched exponential model (SEM) and compared with equivalent ³He datasets. Five healthy volunteers were imaged using a range of ¹²⁹Xe diffusion times and the most agreeable ¹²⁹Xe and ³He Lm_Dresults were obtained with a ¹²⁹Xe diffusion time of 8.5 ms. These results indicate that the Lm_D values derived from the SEM are dependent on diffusion time and that ¹²⁹Xe could present a clinically-viable alternative to ³He for whole lung morphometry mapping. 

Guilhem Collier, Paul Hughes, Felix Horn, Ho-Fung Chan, Graham Norquay, Neil Stewart, Jim Wild

The feasibility and suitability of using compressed sensing to accelerate the acquisition of 3D lung ventilation images with hyperpolarized ¹²⁹Xe and to enable same-breath anatomical ¹H imaging was investigated. Fully sampled and prospective data were acquired from one healthy smoker. Retrospective simulations showed a good agreement between fully sampled and reconstructed images using different error metrics. The method was further validated by comparing quantitative imaging metrics; percentage ventilated volume, distribution of signal intensity and maps of coefficient of variation in prospectively acquired data. The results indicate that the method can be implemented for clinical evaluation in patients with lung diseases.

Graham Norquay, Guilhem Collier, Madhwesha Rao, Adam Maunder, Oliver Rodgers, Neil Stewart, Jim Wild

Rapid production of large volumes of highly polarized ¹²⁹Xe with continuous-flow spin-exchange optical pumping (SEOP) ¹²⁹Xe polarizers is vital for high-throughput hyperpolarized (HP) ¹²⁹Xe lung imaging and emergent clinical applications with dissolved ¹²⁹Xe, e.g. brain perfusion. However, the production rate is limited by cell volume, previously between 300-1500 cm³. Here we present a custom-built ¹²⁹Xe polarizer designed with a SEOP cell volume of 3500 cm³ which can produce ¹²⁹Xe polarized to 35% at a Xe production rate of 1200 mL/hour, enabling high-SNR ¹²⁹Xe lung imaging of naturally abundant Xe and high-SNR ¹²⁹Xe brain imaging with isotopically-enriched Xe.   

Felix Horn , Guilhem Collier, Ho-Fung Chan, Neil Stewart, Laurie Smith, Jim Wild

Single breath washout (SBW) is an emerging pulmonary function test due to its relative simplicity and speed. Most significant outcome parameter, phase III ‘alveolar’ slope (tracer gas decay during mid-exhalation) is sensitive to ventilation heterogeneity. In this work, a method is presented for SBW-imaging with two tracer gases with inherently different physical properties: hyperpolarized ¹²⁹Xe and ³He. Findings in our study are in agreement with trends seen in SBW from pulmonary function lab: the heavier, less diffusive gas (¹²⁹Xe) has a steeper phase III slope. This indicates increased regional ventilation heterogeneity due to a lesser degree of diffusional mixing.

Lin Cheng, Matthew Blackledge, David Collins, Nina Tunariu, Matthew Orton, Martin Leach, Dow-Mu Koh

We demonstrate the repeatability of tumour volume and apparent diffusion coefficient (ADC) estimates; obtained by combining 3D semi-automatic segmentation with a global ADC threshold using DW-MRI in malignant pleural mesothelioma. The results of our classification of solid tumour show excellent repeatability of mean and median ADC estimates and tumour volume. Our methodology provides a clinical tool for radiologists to evaluate tumour burden of MPM in a fast and highly repeatable way.

Jeff Kammerman, Andrew Hahn, Scott Robertson, Bastiaan Driehuys, Sean Fain

Dissolved-phase hyperpolarized Xenon-129 imaging shows promise as a means to evaluate gas transfer from the airspaces of the lungs to parenchymal tissue and the blood stream.  This typically requires selective excitation of dissolved-phase 129Xe, but its short T₂* requires the use of short RF pulses. This reduces the achievable spectral selectivity and often leads to unwanted excitation of gas-phase Xenon. In this work, we present a method to selectively remove gas-phase contamination from dissolved-phase images.  Our method is developed and validated with guidance from simulated data using a digital phantom and shown to be feasible in human subject scans.

Andreas Weng, Tobias Wech, Lenon Mendes Pereira, Simon Veldhoen, Andreas Kunz, Thorsten Bley, Herbert Köstler

SElf-gated Non-Contrast-Enhanced FUnctional Lung imaging (SENCEFUL) allows assessment of lung ventilation and perfusion without the use of contrast agent or ionizing radiation. The original implementation, however, is rather inefficient in terms of data usage when reconstructing perfusion weighted datasets, as it analyzes data from a single breathing state only. In this study we present an approach that uses data from all breathing states, aiming at an improved quality of the resulting perfusion maps. A registration algorithm was applied for this purpose.

Paul Hughes, Laurie Smith, Felix Horn, Alberto Biancardi, Neil Stewart, Graham Norquay, Guilhem Collier, Jim Wild

Repeatability of inflation levels, and the imaging metrics derived from them, is important in hyperpolarized gas MRI, particularly when attempting to measure a response from interventions. This work presents same-session repeatability of 5 different inflation levels and their accuracy in comparison to plethysmography measures. Further the effect of inflation level on percent ventilated lung volume and coefficient of variation was investigated. The most repeatable lung volumes were total lung capacity, functional residual capacity plus 1 liter and residual volume. Percent ventilated lung volume was repeatable to within a maximum of 2% error.

Thomas Ng, Ravi Seethamraju, Ritu Gill

Clinical diagnosis of pleural malignancies and evaluation of their treatment response to novel anti-angiogenic agents would benefit from quantitative clinical DCE-MRI. Implementation of robust DCE-MRI of the thorax is challenging given the presence of significant respiratory motion. We optimized a clinical DCE-MRI protocol based upon the Radial Stack of Stars acquisition scheme to obtain 3-dimensional motion insensitive DCE-MRI of pleural malignancies. When compared to other commonly used DCE-MRI protocols with cartisian acquisitions, our free breathing protocol demonstrated good SNR, minimal motion down  to a spatial resolution of 2mm3.

Neil Stewart, Nicholas Weatherley, Ho-Fung Chan, Laura Saunders, Madhwesha Rao, Guilhem Collier, Laurie Smith, Matthew Austin, Graham Norquay, Stephen Renshaw, Stephen Bianchi, Jim Wild

The reproducibility of quantitative parameters of pulmonary gas-exchange function derived from ¹²⁹Xe chemical shift saturation recovery (CSSR) and high-resolution spectroscopy (HRS) was evaluated in patients with idiopathic pulmonary fibrosis. Of the CSSR-derived parameters, surface-area-to-volume ratio was found to be most reproducible (intraclass correlation κ=0.756). Furthermore, the ratio of ¹²⁹Xe signal in pulmonary red blood cells (RBC) to tissue/plasma (TP) from HRS exhibited good reproducibility (κ=0.760). The clinical interpretation of these results is discussed along with methodological considerations and their bearing on the future clinical potential of these techniques.

Konstantinos Zeimpekis, Klaas Prüssmann, Florian Wiesinger, Patrick Veit-Haibach, Gaspar Delso

The primary objective of this study is to test 3D UTE Cones clinically for MR lung imaging. The purpose of the investigation is twofold. Primary goal is to test whether or not Cones can be used for high resolution lung anatomical imaging that might be useful for imaging vessels or pulmonary nodules.  We test also the possibility for detecting and visualising the lung density that can also be used for imaging parenchyma diseases and more importantly can lead to more accurate extraction of lung attenuation maps for PET/MR attenuation correction.

Neil Stewart, Jim Wild

The effect of B₀ and B₁ transmit inhomogeneity on 3D bSSFP lung imaging with hyperpolarized ¹²⁹Xe was simulated using flip angle and off-resonance frequency maps in combination with the matrix product operator approach to predict ¹²⁹Xe magnetization dynamics and associated bSSFP signal distributions. B₁-related signal drop-off was predicted in posterior and some anterior regions, whilst central regions were generally robust to flip angle variations. Regions of high off-resonance frequency near the diaphragm resulted in low simulated bSSFP signal, corresponding spatially to banding artifact locations. When combined, the two factors led to mean bSSFP image intensity variations ~15-20%.

Wei Zha, Mu He, Bastiaan Driehuys, Sean Fain

There is a need to establish robust quantification pipelines to analyze ¹²⁹Xe ventilation MRI for multi-center studies. Moreover, there is increasing interest in quantifying not only ventilation defect percent, but also regions of low and high ventilation. To this end, we sought to determine inter-method agreement between two different semi-automated quantitative mapping approaches — linear binning and adaptive K-means. The results suggest that once bias field corrections are applied consistently, both ventilation analysis methods agree well when classifying ventilation into 4 bins. Thus, with key steps outlined here, either method can be readily deployed in multi-center studies.

Marta Tibiletti, Armin Nagel, Volker Rasche

Fluorinated gases as hexafluorane (SF6) may be used to visualize ventilations in lungs clinical and preclinical acquisitions. SF6 is characterized by T1 ~ T2* ~ 1 ms, therefore is best visualized with sequences allowing for short TR and TE, such as 3D UTE. SNR is generally limited by low spin density and low thermal polarization. In this work, we applied a density-adapted sampling scheme, previously developed for 23Na imaging, to the visualization of SF6 in phantom and in-vivo lung mice acquisitions. We verified that it increases image SNR and sharpness with respect to regular sampling without significant drawbacks.

Elianna Bier, Scott Robertson, Rohan Virgincar, Mu He, Ziyi Wang, Geoff Schrank, Rose Marie Smigla, Craig Rackley, H. Page McAdams, Bastiaan Driehuys

The spectral parameters of ¹²⁹Xe in airspaces, interstitium and red blood cells (RBCs) are sensitive to disease. We sought to test how these parameters change during inhalation, breath-hold, and exhalation, and identify dynamic signatures that distinguish healthy subjects from patients with idiopathic pulmonary fibrosis (IPF). We find in all subjects that the RBC amplitude oscillates at the cardiac pulsation frequency. However, in IPF patients, this oscillation is also prominent in the chemical shift and phase of the RBC resonance. These dynamic metrics are potentially useful biomarkers for disease progression, as well as discriminating between different pathologies that impact gas exchange.

Wolfgang Kilian, Lorenz Mitschang, Sergey Korchak, Jan Wind

A semipermeable membrane was utilized to separate the process gas helium from a continuous gas stream containing hyperpolarized $$$^{129}$$$Xe. By this the xenon partial pressure was increased by a factor of ten and the gross amount of helium was removed from the gas stream  which was fed from the polarizer to a liquid probe within an NMR spectrometer. Using a sample of dissolved cryptophane-A cage allowed to separate the effects of up-concentration and polarization loss. The increase in xenon partial pressure was still a twofold higher than the polarization loss we have seen and improvements are obvious from the analysis.

Evangelia Kaza, David Collins, Matthew Orton, Martin Leach

Diaphragm motion range during controlled breath-holding at three different inspiratory levels was assessed during dynamic MRI employing an Active Breathing Coordinator (ABC). Colour intensity projections displayed diaphragm position with time. Diaphragm displacements were calculated from difference images between the end and beginning of breath-holds. Overall, diaphragm volume displacements were smaller for the 75% deep inhalational volume (DIV) threshold typically applied in lung and breast radiotherapy, than for the shallower inspiratory levels of 50% and 25% DIV. The clinical standard 75% DIV threshold not only expands the lungs more but also decreases diaphragm motion range.

Jose Ulloa, Alexandra Morgan, Tony Lacey, Geoff Parker

Technical validation of dynamic oxygen–enhanced MRI (OE-MRI) techniques is required for them to become accepted and useful imaging biomarkers. In this work we quantify the impact of using different scanner platforms and protocols on the parameterisation of dynamic single-slice OE-MRI of the lung. Results show that blood in-flow effects consistently provided lower estimates of baseline T₁ and higher estimates of maximum change in partial pressure of oxygen, but it does not influence the wash in time estimation. This suggests that sensitivity to variation in ventilation is approximately equivalent using both protocols.

Jascha Zapp, Sebastian Domsch, Sebastian Weingärtner, Lothar Schad

The reversible transverse relaxation time is currently under investigation as a promising biomarker for diagnosis of lung diseases. We propose an enhanced point-resolved spectroscopy sequence for precise relaxation quantification with self-navigation robust to breathing state variation. The obtained relaxation times show evidence for sensitivity to tissue structure alteration during normal breathing. This approach potentially enables a precise assessment of tissue structure in pulmonary diseases such as fibrosis and COPD.

Ozkan Doganay, Tahreema Matin, Brian Burns, Rolf Schulte, Fergus Gleeson, Daniel Bulte

We implemented a spiral k-space sampling approach for Dynamic hyperpolarized ¹²⁹Xe Ventilation Imaging (DXeVI) of human lungs. The gas-inflow effect, susceptibility artifacts, spatial and temporal resolutions for capturing Gas Flow Patterns (GFPs) were quantified in the gas-flow phantom and compared to corresponding simulated GFPs. DXeVI of GFPs are shown to be sensitive to small gas flow changes between the anterior and posterior lung regions in healthy three subject. This technique can potentially be used to detect and quantify ventilation defects associated with early stage COPD or asthma to assess disease severity, response to treatments and to identify disease progression.

He Deng, Junshuai Xie, Huiting Zhang, Xianping Sun, Xin Zhou

The magnetization of hyperpolarized media (such as Xenon-129, Helium-3 and Carbon-13) is nonrenewable, which makes it difficult to achieve both high signal-to-noise ratio and good spatial resolution in reconstructed MR images. Consequently, a k-space based restoration method is proposed to improve the quality of hyperpolarized MR images in this study, aiming to improve the visual quality of such images. Moreover, a new descriptor is proposed to measure the visual quality of hyperpolarized MR images. Experimental results demonstrated the proposed method is beneficial in visualizing detailed structures in pulmonary images, such as ventilation fine defects. 

Huiting Zhang, Junshuai Xie, Sa Xiao, Xian Chen, Xiuchao Zhao, Ke Wang, Guangyao Wu, Chaohui Ye, Xin Zhou

This work is to investigate the feasibility of compressed sensing (CS) on the morphologic measurement of lung microstructure using hyperpolarized ¹²⁹Xe diffusion magnetic resonance imaging (MRI). The fully sampled (FS) and prospective CS multi-b diffusion MRI data were obtained from five healthy subjects and one COPD patient, respectively. The maps and global average values of mean linear intercept length (L_m) were calculated using cylinder model. The results were compared between FS and CS method for all subjects. The difference between FS and CS ranged from -2.3% to 7.2%. A highly Person’s correlation (R=0.988) between FS and CS was presented.

Liya Wang, Zhou Liu, Tianran Li, Sulan Wei, Xien Bai, Yuzhong Zhang, Hui Mao

This work demonstrated that lung MRI can be applied to imaging and characterize the abnormalities and lesions in patients with history of pulmonary tuberculosis (TB) with the validation of clinical CT.  Results and examples show that MRI not only offers a non-radiation imaging alternative to CT for the lung examination, but also can provide additional information on lung soft tissue properties.

Mary Neal, Prosenjit Dutta, John Simpson, Andrew Blamire, Pete Thelwall

¹⁹F-MRI of inhaled perfluoropropane gas allows assessment of lung ventilation properties with a thermally polarised tracer gas. Due to the scarcity of signal from the non-hyperpolarised gas-phase imaging agent, optimal scan protocol design plays a critical role in image quality. Acquisition variables and coil power performance were modelled to determine the optimal image acquisition parameters for a spoiled gradient echo pulse sequence for human ¹⁹F birdcage and chest surface coils. Application of optimised scan protocols to human studies shows acceptable image quality for assessment of lung function.

Ashlyn Kopanski, Francis Hane, Tao Li, Mitchell Albert

We used 80% propane/20% oxygen mixture as an imaging agent and conventional 1H MRI to image the lungs of a living rat. We believe that this is the first time propane gas has been used in vivo for imaging of the lungs. We obtained an SNR approaching 50 from the propane in the lungs. Our results demonstrate that propane has a possibility of being used as a lung imaging modality for detection of various pulmonary diseases.

Rohan Virgincar, Jerry Dahlke, Scott Robertson, Bastiaan Driehuys, John Nouls

Hyperpolarized ¹²⁹Xe MRI is a powerful probe of lung ventilation, perfusion and gas-exchange. It can be used in both clinical and preclinical settings, where the latter enables rapid discovery of new applications and early testing of therapies in animal models. However, preclinical hyperpolarized gas MRI has been limited to a few expert sites, owing to the challenge of reliably delivering hyperpolarized gas to small animals. Here, we present a constant-volume ventilator that allows for high-resolution hyperpolarized gas imaging and spectroscopy during precisely controlled multi-breath acquisitions. The ventilator is compact, portable, and easy to duplicate and disseminate.

Ryotaro Kamei, Yuji Watanabe, Sungtak Hong, Koji Sagiyama, Ryo Murayama, Satoshi Kawanami, Hiroshi Honda

Breath-hold black-blood magnetic resonance imaging of the lung provides promising results in focal lesion detection. Using peripheral pulse gating, we intended to monitor the degree of vascular suppression and the changes in tissue contrast more closely than in the previously reported methods. Black-blood fat-saturated T2-weighted images were acquired for healthy volunteers with incremental delay time points throughout the pulse cycle. The relative ratios of the specific tissue to the muscle were quantified. The systolic phase provided superior black-blood effects and was considered optimal for signal acquisition.