Patricia O'Gorman, Monique Tourell, Tonima Ali , Honor Hugo , Thomas Lloyd , Erik Thompson , Konstantin Momot

Single-sided NMR was used to investigate the ability of spin-relaxation time constants to distinguish between regions of low and high mammographic density in human breast tissue. Measurements were performed on breast slices obtained from women undergoing breast reduction surgery or prophylactic mastectomy. T₁ values in regions of high mammographic density were found to be significantly different to those measured in regions of low mammographic density. The findings suggest that portable NMR may be suitable for quantification of mammographic density in the breast tissue, presenting a promising and low-cost means of MD assessment in vivo without the use of ionising radiation.  

Ananya Panda, Yong Chen, Satyam Ghodasara, Katherine Wright, Nicole Seiberlich, Mark Griswold, Vikas Gulani

3D Breast Magnetic Resonance Fingerprinting (MRF) allows simultaneous breast tissue T₁ and T₂ mapping. In this study, same session repeatability of 3D MRF technique in normal breast tissue was evaluated (test/retest 10 minutes apart) and in two consecutive visits. The within subject coefficient of variance (wCV) for two visit scans was < 6% for T₁ and < 5% for T₂. The wCV for test-retest scan for T₁ was <5% and for T₂ was 6.5%. One-week repeatability of 3D MRF was good for both T₁ and T₂ (ICC T₁: 0.81 T₂: 0.88 at second visit). These variations are smaller than observed inter-subject variability. Thus breast MRF may be useful for longitudinal patient follow-up. 

Neil Jerome, Igor Vidic, Liv Egnell, Torill Sjøbakk, Agnes Østlie, Hans Fjøsne, Pål Erik Goa, Tone Bathen

Diffusion-weighted MR imaging (DWI) is an essential tool in oncology. Diffusion models beyond monoexponential fitting attempt to capture non-Gaussian decay using additional data acquisition. Model repeatability and suitability is critical, but often neglected. We report findings from fitting multiple diffusion models in a benign breast cancer repeatability cohort, and show no clear dominance of diffusion models across voxels, patients, or scans. Repeatability of ADC, IVIM, and stretched exponential parameters are reported, and highlight the complexity of making inferences from DWI parameters.The potential of DWI in oncology is tempered by a need for critical appraisal of the model and parameter applicability. 

Keith S Cover, Katya M Duvivier, Pim de Graaf, Rianne Wittenberg, Ruth Smit, Joost PA Kuijer, Mark MB Hofman, Ben J Slotman, Ruud M Verdaasdonk

Ultrafast dynamic contrast enhancement (DCE) is a MRI sequence that, when used standalone, can serially screen for breast cancer in 2 minutes. However, each acquisition generates thousands of 2D images in a 4D stack. Color intensity projections (CIP) images are 2 parameter color images that encode the time of arrival (ToA) of contrast agent in the hue (red, orange, yellow, green, cyan, blue) and the amount of contrast enhancement in the brightness. A CIP image of each ultrafast slice provides an informative summary to radiologists with the same sensitivity and specificity to malignancies as the ultrafast 4D stack.

Ken Yamaguchi, Takahiko Nakazono, Ryoko Egashira, Hiroyuki Irie

•  The purpose of our study is to determine the correlation between the parameters obtained from ultrafast dynamic contrast-enhanced (ultrafast DCE) MRI and prognostic factors of breast cancer. 
•  Fifty five breast cancers were included in this study. Ultrafast DCE sequence was performed using higher than usual parallel imaging factor and obtained with 8.3 second temporal resolution. Kinetic parameters obtained from ultrafast DCE were compared with prognostic factors.
•  Mean maximum slope of invasive cancer (10.2) was significantly higher than that of DCIS (8.2).
•  Ultrafast DCE MRI is useful for differentiating DCIS and invasive breast cancer. 

Jeon-Hor Chen, Siwa Chan, Yang Zhang, Dah-Cherng Yeh, Min-Ying Su

We applied an MR-based quadrant percent density (QPD) method to investigate the association between the occurrence of cancer and the amount of dense tissue. Computer-aided method was applied to segment the breast and dense tissue, and then a breast was divided into four quadrants using nipple, centroid, and chestwall as the anatomic landmarks. In a total of 206 women, 88 (42.7%) had cancer growing in the upper-outer quadrant. Only 42 (20.4%) women had cancer growing in the quadrant with the highest QPD, suggesting that the amount of dense tissue cannot explain the disproportional occurrence of breast cancer in different quadrants.

Jeon-Hor Chen, Siwa Chan, Yang Zhang, Dah-Cherng Yeh, Min-Ying Su

We correlated breast tissue stiffness measured by US elastography with the MR-measured density from the whole breast and the tissue in the US stiffness measurement window. Twenty women were studied, and only the normal breast was analyzed. A finite element model was applied to deform the prone MRI to match with supine US images by using the inversed gravity loaded transformation to locate the corresponding tissue region. There were no correlation between breast stiffness and the whole breast percent density (r=-0.09) and the local percent density (r=-0.12), suggesting that breast density and stiffness may be independent cancer risk factors.

Jing Luo, Daniel Hippe, Habib Rahbar, Sana Parsian, Savannah Partridge

Diffusion tensor imaging (DTI) may provide additional information on tissue characteristics over dynamic contrast enhanced (DCE) MRI, however there are conflicting results regarding its utility. Our study evaluated DCE and DTI features of histologically proven breast lesions on 3T MRI. Using a machine learning-based LASSO approach for multivariate regression and bootstrap-based internal validation, the model incorporating DCE and DTI parameters demonstrated significantly better performance in differentiating malignant and benign lesions compared to models using DCE or DTI parameters alone. These findings suggest that the addition of DTI sequences to DCE MRI may improve diagnostic performance.

Andrea Liu, Artem Mikheev, Eric Kim, David Rigie, Sylvia Adams, Deborah Axelrod, Henry Rusinek, Alto Stemmer, Kimberly Jackson, Jean Logan, Linda Moy, Amy Melsaether, Sungheon Kim, Eric Sigmund

Aggressive breast tumors possess heterogeneity that impacts successful diagnosis and treatment.  Mapping this complexity with imaging biomarkers of different biologic specificity supports patient-specific management.  We compare biomarkers from diffusion-weighted MRI (intravoxel incoherent motion (IVIM)) and ¹⁸F-fluorodeoxyglucose (FDG) PET (dynamic pharmacokinetic modeling) in 10 breast cancer patients in a simultaneous PET/MR system.  Voxelwise correlations were performed to study intralesion relationships between biomarkers.  Intralesion correlations were observed, such as between PET plasma transfer rate K₁ and tissue diffusivity D_t, that also showed potential diagnostic value in tumor classification.  This feasibility study establishes a workflow that enables more detailed investigation in larger cohorts.

Jacob Johnson, Roberta Strigel, Leah Henze Bancroft, Amy Fowler, Alan McMillan

While Positron Emission Tomography (PET) used jointly with Magnetic Resonance (MR) Imaging shows promise in breast imaging, unique constraints require novel solutions to achieve attenuation-corrected images. We propose an algorithm for producing a linear attenuation coefficient map and truncation completion created from MR images using deep learning.

Mami Iima, Masako Kataoka, Kanae Kawai Miyake, Maya Honda, Rena Sakaguchi, Ayami Ohno Kishimoto, Mizue Suzuki, Katsutoshi Murata, Thorsten Feiweier, Masakazu Toi, Kaori Togashi

The diffusion time dependence of ADC measurements has been investigated using OGSE and PGSE sequences in human breast tumors. Relative changes in ADC values corresponding to two diffusion times, in addition to ADC values for each diffusion time were calculated in malignant and benign breast lesions as well as in normal breast tissues. Significant differences of ADC changes, in addition to ADC values for each diffusion time, have been found among malignant and benign lesions and normal breast tissue. No ADC changes have been identified in a dedicated breast phantom. ADC maps corresponding to different diffusion times indicate that ADC changes might provide insight in revealing new tissue features like, for instance, intracellular structure of breast tumors.

Mami Iima, Masako Kataoka, Maya Honda, Yuta Urushibata, Ryosuke Okumura, Takashi Koyama, Kenji Uwakubo, Katsutoshi Murata, Mitsuyo Matsumoto, Yu Ueda, Kaori Togashi

The novel method for quality control applicable for commonly used breast MR images (T1WI, T2WI and DWI) in terms of semi-quantitative and quantitative analysis was proposed. The scan was performed across multiple sites on both a breast phantom and a volunteer. The provided scores and apparent spatial resolution were comparable between a phantom and a volunteer. Quality of breast MR images across sites were variable, and standardization using a dedicated breast phantom is considered necessary to assure good diagnostic performance of breast MRI.

Anabel Scaranelo, Hadassa Degani, Dov Grobgeld, Nancy Talbot, Karen Bodolai, Edna Furman-Haran

We have investigated whether the values of the diffusion tensor imaging (DTI) parameters of breast normal tissue, as well as of benign and cancer lesions are affected by gadolinium-based contrast administration.  Changes in the DTI parameters and consequently in DTI-based lesion size were evaluated pre and post dynamic contrast enhanced (DCE) MRI. Results indicated that scanning with DTI post DCE did not impact the diffusion parameters in breast normal tissue and benign lesions and the lesions’ size but revealed a significant reduction of the diffusion coefficients in breast cancers, suggesting potential improvement of DTI diagnostic specificity post-contrast.

Sai Man Cheung, Ehab Husain, Yazan Masannat, Klaus Wahle, Steven Heys, Jiabao He

High level of aerobic glycolysis and an elevated lactate accumulation have been linked to tumour aggressiveness. However, current evidence, mainly based on small animal models or biopsy sections, remains controversial. Since lactate and lipid share the same spectral frequency, conventional MRS is inadequate in measuring lactate under overwhelming lipid signal. Multiple quantum coherence (MQC) MRS allows excellent suppression of lipid even in breast tissues. We applied MQC MRS to measure lactate concentration in grade II and III freshly excised whole human breast tumours to assess if there was a difference between the two groups.

Myra Shapiro-Feinberg, Edna Furma-Haran, Dov Grobgeld, Hadassa Degani

Ellipsoid mapping of the breast with a specific colorization mode has been developed as a visualization means for evaluating the entire information embedded in breast Diffusion Tensor Imaging (DTI) and improve breast cancer detection.  The 3D ellipsoid maps were displayed at voxel resolution with their shape and orientation determined by a respective eigenvalue-eigenvector pair of the associated diffusion tensor, followed by colorizing the ellipsoids according to the values of each diffusion tensor parameter. The results show that the enhanced ellipsoid mapping with λ1 colorization accentuating breast malignancy, may allow efficient differentiation of breast malignancy from normal breast tissue. 

Craig Detheridge, Philip Saponara, Jaspreet Bhangu, Boris Bloch, Kevin Thomas

Contrast-Enhanced Breast MRI is a common method for diagnosis of Breast Cancer. An Artificial Intelligence Machine Learning Algorithm was developed to analyze Non-Contrast Breast MRI scans and predict diagnoses. The algorithm was trained using MRI data that had pathological specimens to validate diagnoses, obtained from The Cancer Imaging Archive. The AI was found to be 95% accurate in classifying tissue as cancerous or benign. This algorithm could be used to assist diagnoses in clinical practice. Future work will assess the generalizability of the algorithm on data from other scan sites, and the potential for classifying specific subtypes of Breast Cancer.

Kang Wang, Dawei Gui, James Holmes, Alan McMillan, Leah Henze Bancroft, Roberta Strigel, Frank Korosec, Ersin Bayram

Breast MR exams can be challenging for inexperienced MR technologists. For example, breast MRI typically requires the prescription of two carefully positioned and sized shim volumes, one for each breast, to improve the local B0 homogeneity and fat suppression. Normally, this procedure is performed manually, which requires an experienced MR technologist and can be challenging for new technologists. The goal of this project is to use deep learning to automate breast MR prescription, including placing the two shim volumes and imaging volumes automatically, to improve breast MR prescription consistency, quality, and to shorten the exam time.

Paul Jaeger, Sebastian Bickelhaupt, Frederik Laun, Wolfgang Lederer, Heidi Daniel, Tristan Kuder, Stefan Delorme, Heinz-Peter Schlemmer, Franziska Steudle, Klaus Maier-Hein

Two fundamentally different approaches have been proposed recently for the classification of breast lesions on diffusion-weighted MRI Images: “Radiomics” extracts quantitative parameters by fitting a biophysical model to the q-space signal and subsequently computes handcrafted features to feed a classifier. Convolutional neural networks on the other hand autonomously learn all processing components in an end-to-end training. To date it is unclear how the two methods compare with respect to overall performance, complementary value of features and combinability. We address these open research questions and propose a combined model that significantly outperforms the two standalone approaches.  

Tianwen Xie, Qiufeng Zhao, Robert Grimm, Caixia Fu, Yajia Gu, Weijun Peng

Recently, several studies have shown the value of Magnetic Resonance Imaging (MRI) radiomics in non-invasive lesion subtype classification. In this study, we proposed the use of histogram texture features of multiparametric maps to differentiate subtypes of breast cancer. 34 different whole-tumor histogram features were analyzed. Classification was performed between ER-positive and Triple-negative groups resulted in AUROC of 0.94, while classification between ER-positive and HER2-positive groups, and classification between HER2-positive and Triple-negative yielded AUROC of 0.79, and 0.86, respectively.

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

In this work, we show the value of a digital phantom to evaluate a dynamic reconstruction. We evaluated the fidelity of the reconstruction using SSIM measurements from simulations and three patients to support conclusions derived from the digital phantom. The highly configurative characteristics of the in-silico platform provide a tool for other researchers to test, evaluate and compare their own acquisition and reconstruction techniques.  

Raphael Tomi-Tricot, Vincent Gras, Thu Ha Dao, Antoine Perrot, Franck Mauconduit, Nicolas Boulant, Pierre Zerbib, Alain Rahmouni, Alexandre Vignaud, Alain Luciani, Alexis Amadon

Breast MRI can benefit from the improved signal-to-noise ratio brought by high-field systems to achieve finer spatial or temporal resolutions. However, dielectric resonance associated with the shorter RF wavelength provokes inhomogeneous excitation in the tissues. In this work, it was shown that such artefacts can induce hyperintensity in T2-weighted images, thus potentially misleading clinicians into excluding malignancy in a lesion. A solution is proposed to reduce the RF artefact on 3D T2w acquisitions using single-transmit-channel k_T-points, which could be used on any 3T scanner. 

Mei Xue, Jing Li, Shunan Che, Liyun Zhao, Yuan Tian, Lizhi Xie, Bing Wu, Xiangfei Chai, Panli Zuo, Chencui Huang

Axillary lymph node (ALN) status is an important prognostic factor for overall breast cancer survival. The number of axillary lymph node metastases is closely related to the risk of distant metastasis1. Accurate identi?cation of axillary lymph node involvement in patients with breast cancer is crucial for prognosis and treatment strategy decisions. Axillary lymph node dissection (ALND) is currently the standard procedure for determining ALN status. Sentinel lymph node biopsy was used to determine whether axillary lymph node dissection was needed, which is invasive2. Image based non-invasive predictors of axillary lymph nodes are highly desirable, and currently face challenges. The aim of this study was to develop and validate a radiomics nomogram that incorporates both the radiomics signature and clinicopathologic risk factors for individual preoperative prediction of axillary lymph node metastasis in patients with breast cancer.

Sunitha Thakur, Joao Horvat, Dilip Giri, Aditi Iyer, Manuela Durando, Elizabeth Morris, Katja Pinker

Heterogeneity in breast cancer is related to aggressiveness and poor prognosis. In this study, we evaluated if qualitative visual evaluation and quantitative assessment with histogram analysis of tumor heterogeneity on diffusion weighted imaging (DWI) could be used to predict molecular subtype in invasive breast cancer. We retrospectively evaluated 91 patients with invasive ductal carcinoma. Two radiologists classified the imaging appearance of tumors on DWI according to heterogeneity. The lesions were also evaluated with histogram analysis on apparent diffusion coefficient maps. There was no statistically significant difference on heterogeneity among molecular subtypes on visual evaluation or histogram analysis.

Linxi Shi , Steffi Perkins, Catherine Moran, Brian Hargreaves, Bruce Daniel

The quantitative application of breast MRI is hindered by image non-uniformity artifact due to B0 and B1 variations. In this work, we developed an effective intensity non-uniformity correction algorithm for breast MRI with high computational efficiency. Compare to existing methods, the proposed method is readily implementable clinically as a software plug-in without modification of existing imaging protocols or hardware, and can potentially be applied to MR images of other anatomical sites.

Yanping Sun, Jia Guo, Pallavi Balte, Stephen Dashnaw, Martin Prince, Elizabeth Oelsner, Christian Lo Cascio, Mitchell Albert, Jim Wild, Emlyn Hughes, R. Graham Barr

Chronic obstructive pulmonary disease (COPD) is defined as persistent airflow limitation by spirometry. However, some smokers with normal spriometry have significant respiratory symptoms. We used 3He apparent diffusion coefficient (ADC) to examine the lungs in older smokers with and without COPD (n=50). This study showed high ADC in both smokers with and without COPD. The difference in ADC between COPD and non-COPD was significant. ADC was correlated positively with percent emphysema and %FVC, and negatively with FEV1 to FVC ratio and, non-significantly with FEV1. 3He ADC may provide different information of lung microarchitecture from spirometry in smoking related pulmonary diseases.

Michael Meier-Schroers, Rami Homsi, Hans Schild, Daniel Thomas

Due to increased interest in pulmonary MRI as a radiation free alternative to CT for lung cancer screening, we analyzed MRI characteristics of pulmonary nodules with different non-enhanced sequences.

Chien-Yuan Lin, Hsiao-Ling Lin, Charng-Chyi Shieh, Chia-Wei Li, Wing P. Chan

A high resolution, rapid scanning in one breath-hold and three-dimensional zero-echo time protocol for lung imaging was established in this study. It successfully captured rapid-decaying lung signal and eliminated the motion artifact and consequently exhibit high quality of pulmonary anatomy, including the tortuous vessels architecture and bronchial wall in exceptional clarity and detail. Additionally, it provides the volume estimation of pulmonary tissue and shows somewhat comparable with the calculation result from computed tomography.

Grzegorz Bauman, Orso Pusterla, Oliver Bieri

In this work we propose an alternative acquisition framework for functional lung imaging using matrix pencil (MP) decomposition (a derivative of Fourier decomposition method) based on partially spoiled ultra-fast steady-state free-precession (ps-ufSSFP) imaging. We showed that MP decomposition is feasible in healthy volunteers using ps-ufSSFP at 1.5T and 3T. Hence, ps-ufSSFP can be a viable solution for the application of MP MRI at 3T where imaging with balanced ufSSFP can be problematic due to the occurrence of off-resonance artifacts.

Luis Torres, Wei Zha, Mu He, Bastiaan Driehuys, Sean Fain

IPF is a pulmonary disease with no validated biomarkers in current clinical use. Here, we compared pulmonary perfusion in an IPF subject versus healthy subject using Dynamic Contrast-Enhanced MRI (DCE-MRI). A decrease in PBF, PBV and an increase in MTT was seen in IPF compared to the healthy control. High spatial correlation of perfusion defects and fibrosis is seen when compared to the morphological images, suggesting DCE-MRI may prove to be a useful technique for evaluating IPF.

Shuchang Zhou, Liming Xia, Xu Yan

Theoretically, DKI and quantitative DCE-MRI can provide more precise microstructure and perfusion information of tissues. However, the two methods had rarely been reported in solitary pulmonary nodules (SPNs) to date, so we collected 37 patients with SPNs underwent both DKI and DCE-MRI and measured relative parameters. The Kapp, Ktrans, Ve and iAUC values were significantly higher in lung cancer than in benignity. Kapp had best sensitivity and accuracy, and iAUC had best specificity. The combination of both methods can provide a robust way to discriminate SPNs before clinical management.

Bradley Allen, Mark Schiebler, Hans-Ulrich Kauczor, Jürgen Biederer, Timothy Kruser, Nisha Mohindra, David Odell, James Carr, Gorden Hazen

Lung cancer screening with low dose CT (LDCT) has been shown to result in a 20% mortality reduction, but has relatively low specificity for lung cancer diagnosis, as well as concerns related to radiation dose and overdiagnosis. Lung MRI has similar sensitivity and improved specificity for lung cancer detection. In this study, we developed a Markov model of lung cancer screening to compare performance of LDCT and MRI. Based on our analysis, lung cancer screening with MRI could provide an equivalent number of lung cancer diagnoses, while dramatically reducing the number of false positive findings relative to LDCT.

Naoharu Kobayashi, Abbie Begnaud, Tadashi Allen, Gregory Metzger, Robert Kratzke, Michael Garwood

Retrospective respiratory gating using a 3D time series lung image reconstructed with sub-second temporal resolution is introduced to achieve accurate small pulmonary nodule detection with ultrashort echo time (UTE) MRI. Changes of the diaphragmatic level during free breathing were tracked using the 3D time series lung image. With the extracted respiratory motion, the data in exhalation were reconstructed to a high resolution image. The feasibility and robustness of the proposed retrospective gating method were tested by surveilling incident lung nodules in two UTE MRI examinations: a baseline scan and a follow-up scan in 10 weeks.

Can HUANG, Yang FAN, Tao JIANG

Radiation may has great impact on teenagers who are the high risk population for pneumothorax. Compared to X-ray and CT, MRI is a imaging modality without radiation. The purpose of this study is to examine the feasibility of using UTE MRI to diagnose the pneumothorax. 

Nicholas Weatherley, Helen Marshall, Paul Hughes, Jody Bray, David Capener, Matthew Austin, Laurie Smith, Stephen Renshaw, Stephen Bianchi, Jim Wild

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) produces metrics of lung perfusion at the capillary level. To date, little assessment of patients with idiopathic pulmonary fibrosis (IPF) has been reported with DCE-MRI. In fourteen patients with IPF, we found that regions of low flow and high transit times were associated with anatomical disease. Whole lung metrics of transit time and heterogeneity of blood volume demonstrated a relationship with pulmonary function tests. Such functional imaging strategies may be useful in quantifying functional changes in the pulmonary vasculature in IPF.

Ho-Fung Chan, Nicholas Weatherley, Neil Stewart, Guilhem Collier, Stephen Bianchi, Jim Wild

Apparent diffusion coefficient (ADC) calculated from hyperpolarized gas diffusion-weighted (DW)-MRI has been shown to be elevated in lungs afflicted with idiopathic pulmonary fibrosis (IPF). This work assesses the sensitivity of ³He DW-MRI metrics to longitudinal changes in IPF patients by evaluating ³He ADC and mean diffusive length scale (Lm_D) from the stretched exponential model at baseline, 6 and 12 months. ADC was not significantly different between visits, but a statistically significant increase of 13 µm in Lm_­D was observed after 12 months suggesting multiple b-value DW-MRI is sensitive to progressive microstructural changes in the lungs in IPF. 

Hooman Hamedani, Kai Ruppert, Yi Xin, Stephen Kadlecek, Faraz Amzajerdian, Ryan Baron, Ian Duncan, Luis Loza, Mehrdad Pourfathi, Sarmad Siddiqui, Harrilla Profka, Mary Spencer, Tahmina Achekzai, Maurizio Cereda, Rahim Rizi

In response to the global shortage of ³He, we studied the feasibility and safety of performing a multi-breath wash-in MR imaging technique to measure fractional ventilation using hyperpolarized (HP) ¹²⁹Xe in the same manner as with ³He. 

Orso Pusterla, Simon Andermatt, Grzegorz Bauman, Sylvia Nyilas, Philipp Madörin, Tanja Haas, Simon Pezold, Francesco Santini, Philipp Latzin, Philippe Cattin, Oliver Bieri

Automatic lung segmentation of MR images is challenging; especially in the presence of pathologies. In this work, we tackle lung segmentation of 2D and 3D ultra-fast steady-state free precession MRI in cystic fibrosis patients by using deep learning based on a neural network of multi-dimensional gated recurrent units.

Simon Triphan, Mark Wielpütz, Hans-Ulrich Kauczor, Bertram Jobst

T1 in the lungs has been found to be interesting both for oxygen enhanced imaging and as a biomarker in COPD. In this work, T1 mapping in human lungs was implemented using a cylindrically encoded 3D measurement using asymmetric radial encoding in an inversion recovery experiment. Breathing was compensated by employing DC-gating with the MR signal, using a correction to cancel the influence of the inversion recovery. It is shown that using a segmented scheme for 3D phase encoding steps that spreads steps over k-space while minimizing leaps in T1-weighting improves gating performance and thus the resulting T1 maps. 

Xue Feng, Nicholas Tustison, Renkun Ni, Zixuan Lin, John Mugler, III, Craig Meyer, Talissa Altes, Joanne Cassani, Y. Michael Shim, Kun Qing

With rapid development of pulmonary MRI techniques, increasingly useful morphological and functional information can be obtained, such as pulmonary perfusion, ventilation and gas uptake through hyperpolarized-gas MRI.  Identification of lung anatomy is usually the first step for quantitative analysis. In the work, we proposed and validated a new approach for automatic segmentation of lung anatomy from proton MRI based on 3D U-Net structure. The new method had a relatively consistent performance in all subjects (dice overlap 0.90-0.97). Its future application for anatomical based analysis of structural and/or functional pulmonary MRI data needs further validation in larger number of data.

Filip Klimeš, Andreas Voskrebenzev, Marcel Gutberlet, Agilo Kern, Lea Behrendt, Till Kaireit, Alexander Rotärmel, Julius Renne, Christian Schönfeld, Frank Wacker, Jens Vogel-Claussen

Ventilation-perfusion (V/Q) scan plays an important role in the assessment of lung function. Currently, Fourier Decomposition (FD), a method for simultaneous ventilation and perfusion measurement, uses fractional ventilation (FV) as a semi-quantitative measurement of lung ventilation. Just recently, a multi-echo spoiled gradient echo sequence method for regional alveolar ventilation (AV) measurement with FD was presented. This study demonstrates that both methods suffer from an artificial proton amount change during registration, which affects quantification. Correction factors are derived for both methods and used to compare AV and FV measurement. Additionally, the regional influence of T₂* correction is assessed.

Yoshiharu Ohno, Masao Yui, Shigeharu Ohyu, Yuji Kishida, Shinichiro Seki, Katsusuke Kyotani, Takeshi Yoshikawa

To the best of our knowledge, no studies have been reported of a direct comparison of dynamic CE-perfusion MRI with PET/CT for therapeutic effect prediction for NSCLC patients treated with chemoradiotherapy.  We hypothesized that multiparametric approach of quantitatively assessed dynamic CE-perfusion MRI with PET/CT have potential for better therapeutic effect prediction than single parametric methods by both modalities in NSCLC patients treated with chemoradiotherapy.  The purpose of this study was therefore to directly compare the capability for therapeutic response prediction by among quantitatively assessed dynamic CE-perfusion MRI, FDG-PET/CT and multiparametric approach by both modalities in NSCLC patients treated with chemoradiotherapy.

Yoshiharu Ohno, Masao Yui, Mitsue Miyazaki, Yuji Kishida, Shinichiro Seki, Katsusuke Kyotani, Takeshi Yoshikawa

No major reports have been reported the capability for differentiating malignant and benign pulmonary lesions among multi- and single parametric approaches by CEST imaging, DWI and PET/CT.  We hypothesized that multi parametric approach by all three techniques had better potential for diagnosis of pulmonary nodule than single parametric approach, when applied with CEST imaging, DWI and FDG-PET/CT.  The purpose of this study was to directly and prospectively compare the capability for differentiating of malignant from benign pulmonary nodules between multi- and single-parametric approaches by CEST, DWI, and FDG-PET/CT.  

Andrew Westcott, Rachel Eddy, Dante Capaldi, Heather Young, David McCormack, Grace Parraga

Ventilation heterogeneity measured using hyperpolarized noble-gas magnetic-resonance imaging (MRI), presents a significant challenge in terms of the need for imaging processing tools to generate rapid, reproducible, intuitive and clinically relevant biomarkers. In particular, new tools are needed to differentiate ventilation defects and patchy ventilation that likely represent different functional phenotypes. Therefore, here we developed a new way to quantify MRI ventilation heterogeneity using the surface area between ventilation clusters – the ratio of surface area to ventilation volume (SAVV) measured in units of mm^-1.  MRI SAVV was significantly greater in severe asthmatics (n=24), as compared to mild-to-moderate asthmatics (n=16).  

Leo Cheng, Isabella Dittmann, Li Su, Johannes Kurth, Andreas Schuler, Yannick Berker, Lindsey Vandergrift, Sarah Dinges, Piet Habbel, Eugene Mark, David Christiani

A widespread, minimally-invasive method for early detection of lung cancer is urgently needed in the lung cancer clinic. Using high resolution magic angle spinning magnetic resonance spectroscopy, we measured paired tissue and serum samples from the same patients. We correlated serum and tissue results to discover and verify serum markers for lung cancer types and stages and predicted overall survival for early Stage I lung cancer. Measured from serum, prolonged survival is associated with relative overexpression of glutamine, valine, glycine, and relative suppression of glucose and lipids.

Wei Zha, Robert Cadman, Scott Nagle, Sean Fain

Recent technical advances in oxygen-enhanced (OE) MRI using 3D radial UTE sequence support quantitative differentiation of diseased vs healthy lungs using ventilation defect percent (VDP). A cohort of cystic fibrosis (CF) subjects with different disease severities underwent spirometry, hyperpolarized (HP) 3He and OE-MRI and a subset of those returned for a repeat visit 1-2 weeks later. The results suggest global VDP measures from HP- and OE-MRI were correlated (ρ=0.80, p<0.0001) with comparable test-retest repeatability, showed similar correlation with spirometry. Moreover, UTE OE-MRI with isotropic spatial resolution provides both structural and functional evaluations of obstructed lungs. 

Yu-Sen Huang, Emi Niisato, Mao-Yuan Su, Alto Stemmer, Jin-Shing Chen, Yeun-Chung Chang

UTE with 3D variable-TE stack-of-spirals sampling has been developed recently and allows shorter scan times by using undersampling in combination with an iterative, self-consistent parallel imaging reconstruction (SPIRiT). The goal of this study was to investigate the feasibility of this new technique in patients for detecting pulmonary nodules. The sequence was optimized for both free-breathing and breath-holding. Compared with CT images, the detection rate for pulmonary nodules in the UTE images was 92% for free-breathing and 75% for breath-holding. Our results suggest that the proposed UTE sequence has the capacity to detect pulmonary nodules under both free-breathing and breath-holding conditions.

Min Jae Cha, Hyun Jeong Park, Eun Sun Lee, Sung Bin Park, Yang Soo Kim, Byung In Choi

We have demonstrated the feasibility of respiratory-gated ultrashort echo time sequence with spiral acquisition technique (spiral UTE; 1.5-mm isotropic resolution; echo time, 0.05 msec) of the lung for pulmonary nodule detection in oncology patients. Overall nodule detection rate was 86% (43 of 50 nodules) and the detection rate for nodules of ≥5 mm was 100 % (20 of 20 nodules). Mean acquisition time for spiral UTE was 327 seconds (range, 300 – 465 seconds). We think that spiral UTE could be a potential alternative to chest CT in oncology patients, who are in the risk of inevitable radiation exposure.

Samuel Frankel, Ananya Panda, Debra McGivney, Gregory O'Connor, Alice Yu, Mark Griswold, Chaitra Badve, Vikas Gulani

Prostate cancer and prostatitis can have considerable overlap on conventional MR imaging.  Texture analysis on multiparametric MRI shows promise in characterization of prostate, but has not been used on quantitative prostate maps.  Here we utilize texture analysis on magnetic resonance fingerprinting (MRF) maps of prostate for characterization of prostate lesions.  Results show that texture features can differentiate cancer and non-cancerous transition zone and between grades of cancer in peripheral zone. This could add value to MRF-based relaxometry and conventional MRI to improve lesion characterization.  

Min Xu, Xiangming Fang, Mengjie Fang, Di Dong, Jie Tian, Zhongshuai Zhang

Quantitative Radiomic features based on multiparametric Magnetic Resonance Imaging have great clinical value in discriminating prostate cancer and benign lesions with same imaging findings. We extracted Radiomic features and compared the discrimination efficiency of the combined three types of images with each single type of images, then incorporated independent clinical risk factors and further developed an individual prediction model. The experimental results show that the individual prediction model achieved more accurate diagnosis results than only using Radiomic signatures or clinical factors

Huan Zhang, Wenhua Li, Feixiang Hu, Yiqun Sun, Tingdan Hu, Tong Tong

The aim of this study was to determine if pre-treated MR texture features of colorectal liver metastases (CRLMs) are predictive of chemotherapy response after the first-line chemotherapy. The results indicate that MR texture features on pre-treated T2 images seem to be a promising tool for predicting the chemotherapy response of patients with colorectal liver metastases.

Lina Zhu, Ge Gao, Xiaoying Wang, Jing Liu, Rui Wang, Kai Zhao, Yuan Jiang

Computer-aided diagnosis (CAD) for prostate cancer (PCa) detection based on multiparametric MRI (mpMRI) has become an active field of research, which has shown good stand-alone performance. Before its widely use in daily clinical work, further study still should be done for CAD reading paradigm and the interaction between CAD and human reader. In this article, we implemented CAD in the real world practice, aiming to evaluate the feasibility of integrating CAD as a second reader into the clinical diagnostic process. The results showed this reading paradigm was feasible and CAD might help readers detect more patients with PCa.

Albert Roh, Andreas Loening, Richard Fan, Geoffrey Sonn, Shreyas Vasanawala

The value of the Dynamic Contrast Enhanced (DCE) sequence in scoring a prostate lesion using PI-RADS version 2 is unknown.  Our retrospective review of 213 patients who underwent prostate MRI and subsequent biopsy determined that the rate at which DCE was needed for obtaining the final PI-RADS score was 9%.  This low rate raises the possibility of limiting the initial screening prostate MRI to an abbreviated non-contrast protocol, calling back the patient for the DCE sequence only if the initial exam is equivocal.

Aritrick Chatterjee, Sevil Tokdemir, Alexander Gallan, Shiyang Wang, Ambereen Yousuf, Tatjana Antic, Gregory Karczmar, Aytekin Oto

This study investigated the multi-parametric MRI features and pathologic outcome of wedge shaped lesions on T2-weighted images in 76 patients. A greater percentage of wedge shaped features were found to be malignant than shown previously. Malignant wedge shaped regions were primarily highly hypointense on ADC maps and showed early enhancement on DCE-MRI. Benign wedge shaped lesions were predominantly mildly hypointense on ADC maps and showed no early enhancement and pathologically outcome showed prostatitis, hemosiderin-laden macrophages, prominent blood vessels, intraluminal blood and atrophy. Malignant wedge shaped lesions were found to have significantly lower ADC compared to benign wedge shaped regions.

Aritrick Chatterjee, Alexander Gallan, Dianning He, Xiaobing Fan, Devkumar Mustafi, Ambereen Yousuf, Tatjana Antic, Gregory Karczmar, Aytekin Oto

This study investigates multiparametric MRI (mpMRI) appearance of different types of BPH and whether quantitative mpMRI is effective in differentiating between PCa and BPH in 60 patients. mpMRI and specifically quantitative ADC values can be used for differentiating PCa and BPH, improving PCa diagnosis in the transition zone. However, DCE-MRI metrics are not effective in distinguishing PCa and BPH. In contrast to previous understanding, glandular BPH has short T2 values (hypointense on T2-weighted images), demonstrates restricted diffusion, and may have similar quantitative mpMRI measurements to stromal BPH. Additionally, glandular and cystic BPH appear differently on mpMRI and are histologically different. 

Aritrick Chatterjee, Dianning He, Xiaobing Fan, Tatjana Antic, Ajit Devaraj, Yulei Jiang , Gregory Karczmar, Aytekin Oto

This study develops a new tool that estimates the risk map for prostate cancer using quantitative mpMRI metrics and investigates the feasibility of this tool in screening for PCa. Quantitative mpMRI parameters: ADC, T2 and DCE signal enchantment values were calculated and subsequently cancer presence was predicted based on estimated risk scores. The sensitivity, specificity, positive predictive value and negative predictive value for PCa detection using a sector based analysis were 75.0%, 88.6%, 84.7% and 80.8% respectively. The area under the curve in ROC analysis was 0.818. Importantly, all the index lesions were identified by the risk map tool.

Francesco Giganti, Giulio Gambarota, Caroline Moore, Neil McCartan, Mark Emberton, Clare Allen, Alex Kirkham

We investigated MRI changes in quantitative T2 parameters in lesions and healthy tissue in men on active surveillance (AS) for prostate cancer (PCa) taking dutasteride or placebo for six months. The protocol included a multi-echo sequence for quantification of the T2 relaxation times. A synthetic signal contrast (T2Q) between lesion and healthy tissue was assessed using quantitative T2 values. Signal contrast was calculated using T2-weighted sequence (T2W contrast). No differences for T2W contrast were observed. A significant correlation between T2Q and T2W contrast was shown. Dutasteride does not influence T2 contrast and relaxation in men on AS for PCa.

Tobias Franiel, Julia Mai, Mohamed Abubrig, Thomas Lehmann, Felix Güttler, Elisabeth Weiland, Tom Hilbert, René Aschenbach, Friedrich-Carl von Rundstedt, Marc-Oliver Grimm, Ulf Teichgräber

Purpose: Determination of quantitative T2 values in prostate tissue and their evaluation for detection and grading of prostate cancer.

Methods: 3T T2 maps and ADC maps of 75 patients with 857 prostate areas (378x normal, 177x cancer, 150x BPH, 119x prostatitis and 33x precancer) were determined.

Results: T2 values differed significantly between cancer and normal (AUC=0.871), between cancer and BPH (AUC=0.827) and between cancer with GleasonScore 6 and ≥ 7 (AUC=0.742). T2 relaxivities decreased with increasing GleasonScore and correlated significantly with ADC-values (r=0.772).

 Conclusion: T2 values seem to be adequate for the differentiation between prostate cancer and normal tissue or BPH.

Steve Patterson, Peter Lee, Chris Bowen, Jennifer Merrimen, Cheng Wang, Steven Beyea, Sharon Clarke

We show that a simple machine learning algorithm validated most, but not all, aspects of the Prostate Imaging Reporting and Data System (PI-RADS) version 2 formalism derived exclusively from clinical perspectives. Specifically, the value of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) sequences in the peripheral zone was confirmed. In contradistinction to PI-RADS, DWI was found to be more valuable in the transition zone than T2 weighted imaging; however, a T2 texture feature afforded a small but significant increase in classifier accuracy in this zone.  

Liang Wang

Deep learning has great potential in medical imaging.  168 patients underwent 3T mpMRI of prostate before mpMR-targeted biopsies plus systematic sampling. Two radiologists from two separate institutions, by using the Prostate Imaging Reporting and Data System (PI-RADS) V2 and a multimodal convolutional neural networks (CNN)-based deep learning, independently assessed prostate MRI examinations. Histopathologic findings were used as the reference standard. In detecting csPCa, both reviewers had significantly higher AUCs using CNN-based deep learning. Reviewer 2 benefited much more from CNN-based deep learning than did reviewer 1. Combined PI-RADS with CNN-based deep learning contribute significant incremental value in the detection of csPCa.

Bart Philips, Rutger Stijns, Sören Johst, Stephan Orzada, Ansje Fortuin, Jelle Barentsz, Marnix Maas, Tom Scheenen

Ultrahigh field MRI offers opportunities for USPIO enhanced MRI for diagnosing lymph node metastases in prostate cancer, by improving resolution and  increasing the sensitivity to USPIO particles. The assessment of lymph nodes based on size, shape and USPIO uptake can improve the differentiation between non-cancer and metastatic lymph nodes and may also lower the detection size limit for metastatic nodes. In this work we show the first results of USPIO enhanced MRI and computed echo time imaging of patients with high risk prostate cancer at 7 Tesla.

Susanna Kallioinen, Terence Jones, James Harding, Manpreet Dhillon, Sachin Modi, Nigel Hacking, Drew Maclean, Charles Hutchinson

Pre-prostate artery embolization (PAE) magnetic resonance images (MRI) from patients with benign prostatic hypertrophy (BPH) were segmented and analysed using two different texture analysis software, qMaZda and TexRad. Percentage reduction in prostate volume and percentage reduction in the International Prostate Symptom Score (IPSS) were used as MRI based outcome measures to build models to be able to predict outcomes from PAE. MRI texture analysis using qMaZda with a linear regression model is able to somewhat predict the percentage prostate volume reduction three months after PAE but not the percentage reduction in IPSS.

Ely Felker, Leonard Marks, Fuad Elkhoury, David Lu, Daniel Margolis, Shyam Natarajan, James Sayre, Steven Raman

We evaluated the utility of multiparametric prostate MRI, including T2-weighted imaging, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging, in predicting treatment response following focal laser ablation of prostate cancer in a multi-reader study.  DWI appears to be the most useful sequence in response assessment, but inter-reader agreement was moderate at best.

Jin Wang, TianHui Zhang, Ying Deng, Sichi Kuang, Bingjun He, Qungang Shan, Jun Chen, Phillip Rossman, Arvin Arani, Xin Gao, Ziying Yin, Meng Yin, Kevin Glaser, Richard Ehman

Prostate cancer(PCa) is one of the leading causes of cancer-related deaths in North American men. Nodal metastases occur in 3-42% of men with clinically localized prostate cancer and the presence of nodal metastases has a strong negative impact on survival. Lymph node staging plays an important role in planning initial management in nonmetastatic PCa. Early detection and resection are important for staging and for the prognosis. We evaluated the diagnostic performance of MR elastography (MRE) in patients with PCa. Results from 33 patients with PCa show that MRE at both of 60Hz and 90Hz has the potential to be a useful technique for predicting PCa lymph node metastases and to establish prognosis and treatment planning.

Martina Pecoraro, Riccardo Campa, Giovanni Barchetti, Isabella Ceravolo, Vincenzo Salvo, Elena Indino, Maurizio Del Monte, Carlo Catalano, Valeria Panebianco

To validate the role of mpMRI combined to CAD system, to increase prostate cancer detection rate using TRUS-MRI guided biopsy. 167 individuals, with elevated PSA level and no previous positive biopsy were enrolled and 63 underwent targeted biopsy. Two radiologists evaluated the exams adopting PIRADSv2 and CAD system. Radiologists’ evaluation proved better diagnostic performance compared to CAD. The highest detection rate for clinically significant cancer was obtained biopsying “target into target” lesions. CAD system proved to be useful in pinpointing the neoplastic area within MRI lesions, representing a valuable tool in identifying biopsy targets to improve CDR.  

Lei Qin, Daniel Glazer, Pelin Ciris, Andriy Fedorov, Thiele Kobus, Fiona Fennessy, Stephan Maier, Robert Mulkern

Intravoxel Incoherent Motion (IVIM) DWI was acquired with 13 b-values, ranging from 0 to 250 s/mm². With such low b-values, a short TE results in a better signal-to-noise ratio. Monoexponential fitting was performed to obtain ADC, and biexponential fitting was performed to obtain diffusion D, perfusion fraction f, and perfusion related pseudo-diffusion coefficient D*. In a prostate cancer (PCa) patient cohort, we only found a significant difference between normal and tumor tissue for D, which was absent in ADC, f, and  D*. This suggests that IVIM biexponential analysis can help remove perfusion component from diffusion, leading to a more accurate measurement in diffusion coefficient.

Amirhossein Mohammadian Bajgiran, Sohrab Afshari Mirak, Ely Felker, Preeti Ahuja, Cleo Maehara, William Hsu, David Lu, Robert Reiter, Anthony Sisk, Steve Raman

We evaluated the performance of the 3 Tesla multiparametric MRI (mp-MRI) for detection of prostate cancer (PCa) based on Prostate Imaging Reporting and Data System (PI-RADS) Version 2 in 429 patients with 874 lesions. The overall and index tumor detection rate of 3T mp-MRI was 49.3% and 77.9% respectively. The tumor detection rate based on PIRADS v2 increased by size, grade, stage, solitariness and smaller prostate volume.  Most missed lesions were small and low grade although a small proportion of large and high grade lesions were not detected. 

Ethan Leng, Benjamin Spilseth, Gregory Metzger

A single-observer, experiential study was conducted to understand how predictive models of prostate cancer on multiparametric MRI can be used clinically, and to determine whether such models have the potential to improve observer performance.  A radiologist experienced in prostate MRI was asked to interpret mpMRIs for 34 patients before and after viewing model-generated predictive maps. Results show that the radiologist generally had low confidence in the accuracy of the predictive maps. However, his performance was significantly improved in the cases where he judged the predictive maps to be helpful. A multi-reader iteration of the study is planned.

Ethan Leng, Jonathan Hendriksen, Jin Jin, Stephen Schmechel, Gregory Metzger

For the development of CAD systems of prostate cancer, manual annotation of cancer by experienced pathologists is the gold standard for establishing the ground truth. However, the process is tedious and has finite precision. Here, we describe a framework that uses quantitative analysis of IHC-stained slides to derive parameters, which in turn are used by a trained predictive model to estimate the spatial distribution of malignant epithelium. Thresholding of the results provides a reasonable map of cancer that is comparable to manual annotation.

Sean McGarry, Sarah Hurrell, Kenneth Jacobsohn, Kenneth Iczkowski, Michael Griffin, Petar Duvnjak, Andrew Nencka, Mark Hohenwalter, Peter LaViolette

Prostate cancer is clinically defined by the Gleason Score (GS), based on the pattern of cells and glands. While imaging is useful for localizing prostate cancer, clinical diagnosis is based only on pathology; as such, tools which combine clinical imaging and pathology are highly useful as training tools. This study combines expert annotated histology aligned with clinical imaging to provide a visualization tool, allowing the user to select a region on the MRI and view the underlying pathology and Gleason annotation. 

Sohrab Afshari Mirak, Kyung Sung, Amirhossein Mohammadian Bajgiran, Nazanin Asvadi, Ely Felker, Preeti Ahuja, Anthony Sisk, Robert Reiter, Steven Raman

We investigated the diagnostic performance of qualitative and quantitative parameters of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) of prostate cancer (PCa) in 238 patients with 303 lesions located in transition (TZ) and peripheral zone (PZ) stratified by pathology Gleason score (GS) and PI-RADSv2 score with whole mount histopathology validation. There was a significant difference in qualitative and quantitative values between low and high-grade tumors and PI-RADSv2 scores in PZ PCa lesions. However, for tumors located in TZ, only DCE curve type was significantly different between low and high-grade PCa.

Natalie Korn, Olga Starobinets, Jeffry Simko, John Kurhanewicz, Susan Noworolski

Inflammation can complicate the ability to distinguish normal tissue from cancer in the peripheral zone of the prostate. In this work, we show that a multiparametric MRI including dynamic contrast-enhanced imaging (DCE) and diffusion-weighted imaging can distinguish inflammation in the peripheral zone of the prostate from both low-grade prostate cancer and normal tissue. A depth-restricted decision tree built on the apparent diffusion coefficient (ADC) and maximal wash-in slope on DCE correctly classified 79.6% of regions of normal tissue, inflammation, and low-grade cancer in the peripheral zone of the prostate based on pathologist-detailed regions on whole-mount resected glands.

Katja Pinker-Domenig, Michelle Zhang, Joao Horvat, Blanca Bernard-Davila, Rosa Elena Ochoa-Albiztegui, Elisabeth Morris, Sunitha Thakur, Pascal Baltzer, Thomas Helbich

To develop a multiparametric MRI model incorporating the ACR BI-RADS recommended descriptors for DCE-MRI, T2-weighted and DW imaging biomarkers for accurate breast cancer diagnosis. A multivariate logistic regression analysis of multiparametric MRI data from 210 breast tumors was performed to determine parameters that jointly predicted malignancy. A multiparametric MRI model incorporating quantitative and qualitative for DCE-MRI [mass margins (p=0.0012), initial EH (p=0.422) and delayed enhancement (0.0065)] and DW imaging biomarkers [ADCmean (p=0.0031)] enables an accurate breast cancer diagnosis. Results indicate that to maximize diagnostic accuracy a multiparametric MRI approach with DWI and DCE sequences must be considered.

Federico Pineda, Ty Easley, Hiroyuki Abe, David Schacht, Gregory Karczmar

59 patients with dense breasts and suspicious findings on mammography underwent pre-biopsy DCE-MRI including high-temporal-resolution (‘ultrafast’) imaging during the first minute post-contrast. Parameters descriptive of early enhancement (initial slope and initial area under the gadolinium curve) were significantly different between benign and malignant lesions. Ultrafast imaging allowed for measurement of kinetic parameters with respect to the bolus time-of-arrival in the breast; removing dependence on variables such as cardiac output. High-temporal resolution DCE allows accurate measurements of very early enhancement kinetics, when differences between benign and malignant lesions may be largest; this could aid in the evaluation of suspicious breast lesions.  

Silu Han, Renee Cattell, James Kang, Thomas Ren, Pauline Huang, Haifang Li, Jules Cohen, Paul Fisher, Roxanne Palermo, Tim Duong

MRI primary breast lesion volume has been shown to be a strong predictor in the response to chemotherapy for invasive breast cancer. However, the prediction accuracy remains low. In this study, we investigated the feasibility of using lymph node volume and signal enhancement ratio as predictors of the chemotherapy response. The result shows that the lymph nodes signal-enhancement ratio is a stronger predictor than lymph node volume and primary in-breast lesion volume.  

Meredith Sadinski, Natsuko Onishi, Katherine Gallagher, Theodore Hunt, Amita Shukla-Dave, Danny Martinez, Brittany Dashevsky, Elizabeth Morris, Elizabeth Sutton

132 patients with invasive breast cancer were imaged with our DCE-MRI protocol incorporating ultrafast, DISCO imaging of early wash-in phase with standard, steady state DCE-MRI. Heuristic and pharmacokinetic metrics were calculated from the DISCO and steady state images and compared between invasive lobular and invasive ductal carcinomas. Bolus Arrival Time was significantly higher in ILC than in IDC. Association of parameters with pathological complete response to neoadjuvant chemotherapy administered after the imaging exam was investigated for a subset of 25 patients. Heterogeneity-related parameters were significantly higher in the pCR group encouraging further investigation into imaging biomarkers predictive of treatment response.

Zezhong Ye, Na Zhao, Joshua Lin, Qingsong Yang, Jeff Viox, Peng Sun, Jianping Lu, Song-Kwei Song

Recent consensus suggested breast MRI lacks necessary sensitivity or specificity to detect breast cancer. MRI may over-diagnose breast cancer and result in over-treatment. The novel diffusion MRI histology (D-Histo) method demonstrated its ability to accurately locate lesion and quantify cancer cellularity and afforded greater sensitivity and specificity than ADC did in distinguishing between tumor and benign tissues. D-Histo’s improved diagnostic accuracy thus better guides treatment planning, and more accurately measures treatment efficacy. 

Mami Iima, Masako Kataoka, Rena Sakaguchi, Shotaro Kanao, Natsuko Onishi, Makiko Kawai, Katsutoshi Murata, Kaori Togashi

The effect of breastfeeding on IVIM and non-Gaussian diffusion MRI was investigated. ADC₀ and sADC values significantly decreased (P < 0.001 and P < 0.001) while K values significantly increased (P < 0.05)  post-breastfeeding. fIVIM values significantly increased after breastfeeding (P < 0.01). No significant difference was found in D* values. There was significant heterogeneity in ADC₀ maps post-breastfeeding, both in retroareolar and segmental scores (P < 0.0001 and = 0.0001). IVIM and non-Gaussian diffusion parameters significantly changed between pre- and post-breastfeeding status, and care needs to be taken in interpreting DWI data in lactating breasts. 

Maya Honda, Masako Kataoka, Natsuko Onishi, Shotaro Kanao, Hajime Sagawa, Mami Iima, Kanae Miyake, Dominik Nickel, Masakazu Toi, Kaori Togashi

We evaluated new parameters of breast ultrafast dynamic contrast-enhanced (UF-DCE) MRI using compressed sensing technique: the maximum slope (MS), time to enhancement (TTE) and the time interval between arterial and venous visualization (AVI). MS was higher, and TTE and AVI were shorter in malignant lesions compared to benign lesions, although there were discrepancies among these parameters and BI-RADS based delayed phase patterns. There seemed to be some relevance between these parameters and histopathologic findings.

Lawrence Dougherty, Elizabeth McDonald, Gamaliel Isaac, Thuy-My Le, Mark Rosen

A retrospective reader study was performed to assess breast MRI diagnostic performance as a function of contrast dose. There was an increase in sensitivity for malignancy with increasing contrast dose with no significant decrease in specificity. Greater confidence in the lesion assessment was also shown by the inter-observer agreement, which increased at the higher doses. Diagnostic performance of DCE-MR breast imaging was greater when subjects received a higher gadolinium dose than the current standard of 0.10 mmol/kg.

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

We investigated the potential of diffusional kurtosis imaging (DKI) and conventional diffusion weighted imaging (DWI) for differentiation of additional suspicious lesions on preoperative breast MRI patients with known breast cancer. This study included 53 pathologically confirmed lesions larger than 10mm in 45 women with known breast cancer. DKI and DWI parameters were compared between lesions. Multiple DKI parameters showed a significant difference between benign vs. invasive breast lesions and a few differed between DCIS vs. invasive breast lesions, with high specificity. However, DKI and DWI could not distinguish DCIS from benign lesions and may have lower potential in this subgroup

Keith S Cover, Joost PA Kuijer, Mark MB Hofman, Jeroen Veltman, Monique D Dorrius, Ritse M Mann, Katya M Duvivier

Currently, MRI screening for breast cancer in women with a BRCA mutation is annually. However, studies on tumour doubling times indicate that some tumours grow faster. To assess the value of more frequent screening we numerically simulated annual and 6 monthly screening based on reported tumour doubling times in women with the BRCA mutation. For annual screening, the simulation predicted 14% of cancers with poor prognosis (diameter > 2 cm), in line with clinical studies. For 6 monthly screening the simulation predicted 3% with poor prognosis. Therefore, 6 monthly screening should yield a substantial reduction in tumours with a poor prognoses .

Chenglu Ke, Shunan Che, Jing Li, Lizhi Xie

The current study aimed to evaluate the application of diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) in the differential diagnosis  of breast lesions. The association of DKI and IVIM derived parameters were compared with pathological types, histologic grade, and Ki-67 expression of primary breast cancers. The results indicated that MD, MK, D and f are capable of distinguishing benign from malignant breast lesions. Furthermore, significant correlations were observed between MD and different histologic grade and Ki-67 expression, repsectivley.

Xiuhua Lv, Feihan Jiao, Junqing Xu, Hong Yin

This study aimed to investigate the clinical value of reduced field-of-view (rFOV) sagittal delayed enhanced MRI in diagnosing of breast tumor. we assessed two groups with and without rFOV sagittal delayed enhanced scanning with a time interval of at least six months.In our study, the detection rate,  specificity and positive predictive value of the test group with rFOV were significantly higher than that of the control group without rFOV. rFOV sagittal delayed enhanced scanning indicated clinical value in detecting and differential diagnosis of benign and malignant breast tumors.

Qiuju Fan, Hui Tan, Nan Yu, Yuxin Lei, Shaoyu Wang, Yong YU

Severe breast pain may significantly affect activities related to life quality, while its aetiology is still poorly understand. DTI and IVIM can provide valuable information on tissue microstructure, microcirculation and pathophysiology that has been extensively used on the breast cancer ^[1].

Paola Clauser, Thomas Helbich, Panagiotis Kapetas, Maria Bernathova, Katja Pinker, Pascal Baltzer

The aim of our study was to compare a 0.075 mmol/kg dose of gadobenate dimeglumine, with a 0.15 mmol/kg dose of gadoterate meglumine for breast lesion detection and characterization at 3T-MRI. Patients included underwent two examinations, 24-72h apart, one with gadobenate and one with gadoterate administered in randomized order. Three readers evaluated the examinations and diagnostic performance was calculated and compared. 104 women with 142 histologically verified breast lesions (109 malignant, 33 benign) were included. Detection with gadobenate was comparable to gadoterate (p>0.165). Gadobenate demonstrated significantly higher specificity and accuracy (p<0.007). Multivariate analysis demonstrated reader-independent superior diagnostic accuracy with gadobenate. 

Hyung Won Choi, Melissa Joines, Anne Hoyt, Laura Doepke, Jane Dascalos, Cheryce Fischer, Nanette DeBruhl, Nazanin Yaghmai, Kara Lee Pool, Bo Li, James Sayre, Stephanie Lee-Felker

In this IRB-approved, HIPAA-compliant retrospective study, 63 consecutive women with newly diagnosed breast cancer undergoing neoadjuvant chemotherapy with pre- and post- chemotherapy breast MRI on a 3.0 Tesla scanner prior to surgery at our institution between January 2013 and December 2015 were included for analysis.  Decrease in tumor size, decrease in peak enhancement, increase in time to peak, decrease in wash in, and decrease in wash out on post-chemotherapy breast MRIs were predictive of pathologic complete response on surgical pathology, a surrogate for prognosis.

Jack Virostko, Anna Sorace, Chengyue Wu, Stephanie Barnes, Angela Jarrett, Debra Patt, Boone Goodgame, Sarah Avery, Thomas Yankeelov

Magnetization transfer MRI (MT-MRI) may be sensitive to changes in the macromolecular content of tumors and the extracellular matrix that occur during neoadjuvant therapy for breast cancer. We demonstrate in a pilot population of breast cancer patients that the magnetization transfer ratio declines after the first cycle of chemotherapy in women who achieve response to therapy, while the magnetization transfer ratio increases in tumors that do not respond to therapy. 

Sarah Eskreis-Winkler, Katherine Simon, Youngwook Kee, Junghun Cho, Thanh Nguyen, Pascal Spincemaille, Michele Drotman, Yi Wang

During MR-guided breast biopsy, a titanium biopsy marker is deployed in the biopsy cavity to mark the spot. Conventional MR cannot distinguish between these markers and the pockets of air that are often introduced during the biopsy, necessitating a subsequent mammogram to confirm biopsy marker location. Our goal is to replace post-biopsy mammogram with a short MR protocol leveraging the difference in magnetic susceptibility between titanium and air in order to distinguish them as sources of MR signal voids. To this end, we generate quantitative susceptibility maps (QSM) using 3D fast spin echo acquired at four frequency offsets.

Pingni Wang, Roberta Strigel, Makiko Kawai, Ty Cashen, Julia Velikina, Kang Wang, Frank Korosec, Urvi Tailor, Jillian Karow, Kevin Johnson, Andre Fischer, James Holmes

Dynamic contrast-enhanced (DCE) MRI using conventional Cartesian sampling is used in routine clinical practice due to its high sensitivity for breast cancer. However, ghosting artifacts caused by cardiac motion can obscure the axilla, making interpretation of this area more difficult and potentially obscuring findings. Radial acquisitions are less motion sensitive due to more frequent sampling of the center of k-space and prior work has suggested these methods for breast MRI. In this study, we report results from a reader study to assess image quality of a 3D stack-of-stars radial acquisition compared with Cartesian imaging for breast MRI.

Maya DELBANY, Julie POUJOL, Aurélien BUSTIN, Isabelle THOMASSIN-NAGGARA, Jacques FELBLINGER, Pierre-André VUISSOZ, Freddy ODILLE

High-resolution diffusion-weighted imaging (DWI) has the potential to improve the specificity of breast MRI. In this work a method is proposed for 3D isotropic DWI of the whole breasts. Three breast DWI datasets were acquired using a readout-segmented DW-EPI sequence (rs-EPI) with thick slices (3 mm) and 1mm-shifts in the slice direction. A high isotropic resolution (1x1x1 mm³) DWI dataset was reconstructed using a super-resolution reconstruction (SRR) on the low-resolution anisotropic acquisiitons, with different regularization schemes (Tikhonov and Beltrami, an edge-preserving constraint). This study shows the benefit of this strategy compared to native acquisitions with 1 mm slice thickness. A quantitative SNR evaluation is presented.

Naranamangalam Jagannathan, Khusbhu Agarwal, Uma Sharma, Smriti Hari, Vurthaluru Seenu, Sandeep Mathur, Siddhartha Gupta, Rajinder Parshad

Potential of addition of in-vivo proton (¹H) MRS to DCEMRI data especially in indeterminate DCE findings was evaluated. MRS and DCEMRI data of 56 breast cancer patients were included in the analysis. 47/56 cases showed type III curve indicating cancer with a sensitivity of 83.9%. MRS showed true positive findings of cancer in 44/47 cases. Among 9 indeterminate DCE cases, MRS was positive for cancer in 6 cases, implying that 50/56 cases were true positive for cancer with 89.3% sensitivity. Addition of MRS to DCEMRI data increases the sensitivity of cancer detection especially in indeterminate DCE findings.  

Chengyue Wu, Federico Pineda, Gregory Karczmar, Thomas Yankeelov

Identifying and characterizing vascular inputs and outputs in tumors would be useful in both the diagnostic and prognostic settings. In this contribution, we propose a novel methodology that combines vessel detection with analysis of ultra-fast DCE-MRI data to integrate both morphological and functional information of tumor associated vessels to identify those that serve as inputs and outputs to breast tumors.

Hajime Sagawa, Masako Kataoka, Shotaro Kanao, Natsuko Onishi, Maya Honda, Dominik Nickel, Masakazu Toi, Katsuhiko Ueda, Kaori Togashi

The contrast effects of 1.0M gadobutrol were compared to that of 0.5M gadoteridol in breast cancer at 3T using hybrid MRI protocol which combined conventional DCE (C-DCE) with ultrafast DCE (UF-DCE). The significant differences were observed only in UF-DCE, maximum enhancement ratio (MER) and maximum slope (MS). The slightly higher peak relative enhancement produced by gadobutrol compared with gadoteridol might help in the detection and evaluation of breast lesions in the earlier phases.

Jeon-Hor Chen, Yang Zhang, Siwa Chan, Dah-Cherng Yeh, Min-Ying Su

A 3D morphological analysis method was developed to analyze the fat content on tumor boundary interface and in different peri-tumoral shells away from the tumor. A total of 114 mass type breast cancers were analyzed, including 87 HR(+), 13 HR(-)HER2(+), and 14 TN. The volumetric fat percentage in three shells surrounding the tumor: 150%-100%, 200%-150%, 250%-200% of the tumor convex hall were measured, also the mean contrast enhancement in fibroglandular tissue contained within three shells were measured. The peri-tumor fat content and contrast enhancement is the highest in the most aggressive TN tumors compared to other subtypes.

Ting Li, Siying Wang, Yun Xiong, Kangan Li

The aim of this study is to evaluate the diagnostic efficacy of 3.0T MRI diffusion kurtosis imaging and quantitative dynamic contrast enhancement in benign and malignant breast lesions, and to explore the differential diagnosis ability of different pathological types and molecular subtype lesions. The results showed that 3.0T MRI diffusion kurtosis imaging and dynamic contrast-enhanced quantitative hemodynamic parameters are of great value in the differential diagnosis of benign and malignant breast lesions. The combination of both can significantly improve the diagnostic efficiency.

William Garrison, Kun Qing, Sina Tafti, John Mugler, Y Shim, Jaime Mata, Gordon Cates, Eduard de Lange, Craig Meyer, Jing Cai, G Miller

Radiotherapy in the context of lung cancer can become less effective if lung biomechanics are not well-characterized. MRI of grid-tagged, inhaled hyperpolarized He-3 gas provides images with strong signal at the tag locations, allowing time-resolved tracking of regional lung motion that can be used to inform strategies for precision radiotherapy. The present work demonstrates rapid acquisition of high-quality 3D grid-tagged images obtained with 8-fold under-sampling and reconstructed using compressed sensing. The dramatic imaging acceleration inherent in this technique allows multiple 3D image sets to be acquired during a single breath-hold, effectively permitting 4D-MRI of lung motion during exhalation.

David Mummy, Wei Zha, Shannon Kehoe, Guy Olson, Ronald Sorkness, Nizar Jarjour, Mark Schiebler, Loren Denlinger, Michael Evans, Sean Fain

We assessed the high ventilation percent (HVP) as well as the ventilation defect percent (VDP) on hyperpolarized (HP) ³He MRI and found that both measures were associated with exacerbation in the year following imaging, with the HVP exhibiting the stronger association. Both measures were strong predictors relative to other measures of lung function. These findings suggest that HVP is sensitive to one-year risk of asthma exacerbation and is a potential biomarker of asthma instability.

Dmitriy Yablonskiy, Alexander Sukstanskii, James Quirk, Chase Hall, Mario Castro, David Gierada, Vanessa Curtis, Miranda Kirby, Eric Hoffman, Roger Yusen

    Air trapping (retention of inspired air during expiration) is usually associated with small conducting airways disease. However, limited information exists on integrity of acinar airways (i.e., alveolar ducts and sacs) in lung regions affected by air trapping. In this study we combine novel CT and MRI metrics to understand the sub-lobar level relationships between MR-derived acinar anatomy and CT-based air trapping metrics. We studied healthy non-smokers, smokers and COPD subjects and found significant associations between air trapping and acinar airways shallowing in upper and middle lungs in all groups but very little association in lower lung, except for COPD patients.

Bilal Tahir, Helen Marshall, Paul Hughes, Guilhem Collier, Rob Ireland, Jim Wild

Image registration of lung CT images acquired at different inflation levels has been proposed as a surrogate method to map lung ‘ventilation’. However, this technique requires validation against established ventilation imaging modalities such as hyperpolarized gas MRI. Variations in lung inflation may affect regional lung function as imaged with the two modalities. Here, we evaluate the impact of the lung inflation level during MRI when comparing gas MRI and CT ventilation for a cohort of 7 patients with asthma.

Andras Lindenmaier, Brandon Zanette, Elaine Stirrat, Brian Kavanagh, Giles Santyr

Performing 129Xe morphometry at multiple pressures allows for direct mapping of microstructural changes and micromechanical properties of the lung (eg. pseudo-compliance) in both health and disease. In the present study, the effects of posture and gravity on the linear portion of lung pseudo-compliance are investigated using this approach in healthy mechanically-ventilated rats. Spatial gradients in lung pseudo-compliance due to gravity and posture are shown to vary, consistent with the expectations that the lungs are denser dorsally due to the weight above. Scaled regional pseudo-compliance is shown to be in agreement with whole lung compliance measured using 1H MRI.

Sa Xiao, He Deng, Caohui Duan, Junshuai Xie, Xianping Sun, Chaohui Ye, Xin Zhou

Dynamic hyperpolarized gas MRI of lung is able to visualize the dynamic changes of pulmonary morphology during the ventilation process, which provides the important information about lung physiology and pathophysiology. However, there is a lack of an effective method to depict the gas flow patterns in the whole lung. In this work, we propose a motion field calculation method based on the pulmonary gas flow properties, which can acquire the velocity and direction of gas flow. The performance of the proposed method is investigated experimentally.

Brandon Zanette, Giles Santyr

Pulmonary disease involving lung injury (e.g. ventilator-induced lung injury, radiation-induced lung injury, interstitial lung disease) can lead to pulmonary dysfunction which may not be detectable using proton pulmonary magnetic resonance imaging or ventilation imaging with hyperpolarized noble gases. The solubility of ¹²⁹Xe in biological tissues and resultant chemical shifts allow for the quantification of physiological gas exchange which hold promise for the clinical evaluation of early pulmonary dysfunction. In this work we demonstrate an approach for dissolved-phase ¹²⁹Xe gas exchange imaging within a single breath-hold in healthy human volunteers.

Brandon Zanette, Giles Santyr

Spiral-IDEAL is a fast and efficient technique for imaging dissolved-phase hyperpolarized ¹²⁹Xe in tissue/blood plasma (T/P) and red blood cell (RBC) compartments of the lung. Previously, spiral-IDEAL has been limited to pre-clinical rodent models using multi-breath techniques not suitable for human subjects. In this work we optimize and demonstrate clinical translation of spiral-IDEAL for single breath-hold ¹²⁹Xe imaging of human subjects. We compare and contrast several interleaved imaging strategies. Furthermore, we also demonstrate 3D spiral-IDEAL for simultaneous volumetric imaging of gas, T/P, and RBC compartments.

Jorge Chacon-Caldera, Adam Maunder, Madhwesha Rao, Graham Norquay, Oliver Rodgers, Matthew Clemence, Claudio Puddu, Lothar Schad, Jim Wild

Dissolved hyperpolarized ¹²⁹Xe MRI is an emerging technique. Inhaled xenon dissolves in the blood in the lungs and with a long T₁ (8s) has the potential for imaging other organs that are well perfused such as the kidneys. An RF coil array was designed with an anatomically focused transmit field to avoid RF depolarization of dissolved xenon in its transit from the lungs whilst providing local sensitivity over the kidney. Dynamic imaging of dissolved ¹²⁹Xe in kidneys was performed in 2 healthy volunteers. The signal evolution in the cortex was obtained which might provide novel physiological insight into kidney physiology.

Ozkan Doganay, Mitchell Chen, Tahreema Matin, Marzia Rigolli, Julie-Ann Phillips, Anthony McIntyre, Fergus Gleeson

This proof of concept study describes implementation and analysis of an IDEAL (Iterative Decomposition of water and fat with Echo Asymmetry and Least-square estimation) based imaging technique for imaging hyperpolarized Xenon-129 (HPX) gas ventilation and dissolved phase compartments in human lungs. The time-series IDEAL imaging approach was tested in a healthy subject corroborating with Bloch equations and a numerical gas-exchange model showing that HPX gas ventilation and dissolved phase compartment images can be obtained, and the gas-transfer dynamics can be measured, in a single breath-hold interval of 8 seconds using 1L of HPX gas with polarization of ~10%. 

Jeff Kammerman, Andrew Hahn, Sean Fain

Dissolved-phase hyperpolarized xenon-129 imaging provides regional information on gas exchange between the lung airspaces, parenchymal tissues, and blood stream.  Current spectroscopic techniques require that the dissolved-phase 129Xe signal be acquired with no gas-phase excitation.  However, the short T₂* of the dissolved-phase requires short RF pulses, limiting the spectral selectivity achievable.  This, combined with the high spin density of the gas-phase relative to the dissolved-phase, leads to unwanted gas-phase excitation.  In this work, we retrospectively remove contaminant gas-phase signal from both simulated and human subject images using a multi-echo acquisition with iterative estimation of the contaminant gas-phase signal.

Mu He, Fei Tan, Wei Zha, Leith Rankine, Sean Fain, Bastiaan Driehuys

¹²⁹Xe ventilation MRI lacks a reference standard. Here, we circumvent this problem in part by comparing and evaluating the robustness of two independent methods for quantifying ventilation – linear-binning and adaptive k-means - by adding MR noise to the source images until the algorithms fail. Results at different noise levels were compared to that quantified using the original high signal-to-noise ratio (SNR) ventilation image. We found that both methods provide robust quantification until SNR is less than 1.7 ± 0.8 for the linear-binning method, and 2.1 ± 1.2 for the uncorrected adaptive k-means method.

Agilo Kern, Marcel Gutberlet, Andreas Voskrebenzev, Filip Klimes, Alexander Rotärmel, Frank Wacker, Jens Hohlfeld, Jens Vogel-Claussen

Chemical shift saturation recovery (CSSR) spectroscopy is a method, which is able to assess lung microstructure using ¹²⁹Xe gas uptake and to discriminate between healthy volunteers and chronic obstructive pulmonary disease (COPD) patients. However, the absent spatial encoding of standard CSSR spectroscopy poses a limitation of the method for detecting early disease. A method for voxel-based mapping of lung microstructural parameters is proposed. Preliminary data from a study in healthy volunteers and COPD patients employing both CSSR mapping and spectroscopy are presented. Whole-lung median wall thickness and surface-to-volume ratio are highly reproducible and correlate significantly with global values from spectroscopy in COPD patients.

Agilo Kern, Marcel Gutberlet, Andreas Voskrebenzev, Filip Klimes, Frank Wacker, Jens Hohlfeld, Jens Vogel-Claussen

The NMR line shape in the lung parenchyma exhibits significant broadening due to numerous jumps in magnetic susceptibility. The purpose of this work was to extract this line shape from the ¹²⁹Xe dissolved-phase spectrum. Free induction decays were acquired in healthy volunteers and COPD patients and a model function including two resonances and a superimposed frequency distribution was fitted to the time-domain data. Both second moment and skewness of the fitted frequency distribution were significantly elevated in COPD patients. The ratio of ¹²⁹Xe in red blood cells and lung tissue was significantly reduced in COPD patients.

Elianna Bier, Scott Robertson, Geoff Schrank, Craig Rackley, Joseph Mammarappallil, Sudarshan Rajagopal, H. Page McAdams, Bastiaan Driehuys

The temporal dynamics of ¹²⁹Xe spectroscopy were examined by collecting FIDs during inhalation, breath-hold, and exhalation. These FIDs were fit to a Voigt model to extract four spectral parameters (amplitude, chemical shift, linewidth, and phase) for the airspace, barrier, and RBC ¹²⁹Xe resonances. The RBC resonance parameters exhibited oscillations at the cardiac frequency which were quantified by peak-to-peak amplitudes. IPF subjects exhibited larger signal amplitude, chemical shift, and phase oscillations than healthy or PAH subjects. This indicates that ¹²⁹Xe transfer spectroscopy is differentially affected by cardiopulmonary dynamics such that the causes of gas exchange impairment can be distinguished. 

Andrew Hahn, Jeff Kammerman, Michael Evans, Wei Zha, David Mummy, Robert Cadman, Sean Fain

To advance hyperpolarized Xenon-129 MRI as a robust tool for probing pulmonary gas-exchange in lung diseases, establishing repeatability of quantitative ratios and regional metrics is critical.  Repeatability was assessed using Bland-Altman analysis. Average inter-visit tissue-to-gas, red blood cell-to-gas (RBC-to-gas) and RBC-to-tissue ratios were highly repeatable; the primary source of variation was due to lung inflation volume variations, suggesting consistency of breath-hold coaching and dose delivery is important.  Regional distribution of measures was also qualitatively well-matched between visits.  Demographic factors may also influence these measures; our preliminary data indicate a significant relationship between RBC-to-tissue ratio and subject age.

Naomi Medina, Ziyi Wang, Mu He, Geoffry Schrank, John Nouls, Elianna Bier, Scott Robertson, Ralph Hashoian, John Mugler, Bastiaan Driehuys

Hyperpolarized ¹²⁹Xe-MRI is emerging as a promising method to quantify pulmonary function, but the transient nature of its signal makes routine quality assurance tasks challenging. With increasing interest in multi-center deployment of this technology, it is critical to develop tools to characterize ¹²⁹Xe imaging performance across sites and platforms. Here, we demonstrate a robust, portable, clinical-scale thermally-polarized ¹²⁹Xe phantom and integrated loader shell. Its utility is demonstrated for characterizing human lung imaging coils and enabling routine 2D- QA scans in one-minute. On longer timescales, 3D-imaging is feasible to evaluate ¹²⁹Xe coil sensitivity profiles.

Kai Ruppert, Hooman Hamedani, Faraz Amzajerdian, Luis Loza, Yi Xin, Ian Duncan, Harilla Profka, Sarmad Siddiqui, Mehrdad Pourfathi, Maurizio Cereda, Stephen Kadlecek, Rahim Rizi

Acid aspiration frequently occurs in critically ill patients, and can give rise to severe acute lung injury. In this study, we investigated whether hyperpolarized xenon-129 dissolved-phase MRI provides the necessary sensitivity to assess acid aspiration and associated pneumonitis in a rabbit model. We observed changes that most likely corresponded to the formation of interstitial edema as part of an inflammatory response. In particular, perilesional areas of high xenon uptake may reflect tissue at risk of secondary ventilator-induced injury.

Kai Ruppert, Hooman Hamedani, Faraz Amzajerdian, Luis Loza, Yi Xin, Ian Duncan, Harilla Profka, Sarmad Siddiqui, Mehrdad Pourfathi, Stephen Kadlecek, Rahim Rizi

Several hyperpolarized xenon-129 (HXe) MRI techniques have been developed for characterizing lung function through the observation of parenchymal xenon gas uptake, but these methods tend to provide only a snapshot of a steady-state distribution of the xenon signal within the lung parenchyma. In this study, we investigated the feasibility of extracting gas-transport maps from the relative signal changes between two dissolved-phase images captured with different acquisition parameters. We demonstrated how the acquisition parameters of a suitably-designed HXe MRI pulse sequence can be harnessed for tracing pulmonary gas transport processes, and potentially quantifying them at an unprecedented level.

Kai Ruppert, Hooman Hamedani, Faraz Amzajerdian, Luis Loza, Yi Xin, Ian Duncan, Harilla Profka, Sarmad Siddiqui, Mehrdad Pourfathi, Stephen Kadlecek, Rahim Rizi

Chemical Shift Saturation Recovery MR spectroscopy is becoming a powerful tool for quantifying alveolar gas exchange, but is currently predominantly used for whole-lung assessments. In this study, we investigated the feasibility of regional gas-phase saturation as a tool for coarse spatial localization, testing its utility in a rat model of radiation-induced lung injury. We found a large decrease in the ratio between the red-blood-cell and tissue / plasma peaks in the irradiated lung relative to the lungs in a healthy animal. Our approach might be particularly useful for assessing highly heterogeneous disease patterns (radiation-induced lung injuries, lung transplants, etc.).

Guilhem Collier, Laure Acunzo, Laurie Smith, Paul Hughes, Graham Norquay, Ho-Fung Chan, Alberto Biancardi, Helen Marshall, Jim Wild

This work applies a clustering method developed for image analysis of lung ventilation with hyperpolarized ¹²⁹Xe to data acquired in a different centre with ¹²⁹Xe and ³He. Results show that the current method is not readily transferable using published reference values. A different normalization method that increases the reproducibility of ventilation categorization is proposed. After optimization, the technique was applied in groups of patients with chronic obstructive pulmonary disease and cystic fibrosis. Results show significant differences of ventilation distribution indices between patient and healthy control groups.

Hsin-Yu Chen, Peder Larson, Jeremy Gordon, Robert Bok, Marcus Ferrone, Sue Noworolski, Mark van Criekinge, James Slater, Lucas Carvajal, Natalie Korn, Rahul Aggarwal, Sarah Nelson, Pamela Munster, John Kurhanewicz, Daniel Vigneron

New hyperpolarized-¹³C MRI instrumentation and methods enabled phase II clinical studies on 17 prostate cancer patients using 3D dynamic CS-EPSI with 0.5cm³ spatial and 2s time resolution. New manufacturing processes for ¹³C-pyruvate provided more consistent polarization levels, pyruvate concentrations, radical filtrations for reliable and safe patient injections. Improved quantitative methods were designed and implemented for reproducible kinetic modeling, correction for receiver profile, and peak detection, accounting for B₀ inhomogeneity and noise characteristics. These studies have shown the ability to detect high pyruvate-to-lactate conversion rates in biopsy confirmed prostate cancer.

Jae Mo Park, Stefan Stender, Craig Malloy, Jonathan Cohen, Ralph DeBerardinis, Vlad Zaha

The development of hyperpolarized ¹³C for human patients has refocused interest on radiofrequency (RF) coil design for optimal ¹³C sensitivity. ¹³C NMR spectra were acquired from the human liver using a clamshell transmit and 8-channel paddle receive array in a 3T MRI system. Following a baseline ¹³C liver scan for 15-min, [1-¹³C]glucose was ingested and ¹³C MRS data were acquired for 1-3hrs. [1-¹³C]glucose was observed immediately after ingestion in the stomach, and evolution of [1-¹³C]glycogen was monitored with < 1min temporal resolution.  ¹³C chemical shift imaging data confirmed that the glycogen signals were localized in the liver.

Per Nielsen, Marie Mølmer, Rikke Nørregaard, Christoffer Laustsen

In this study we investigate the metabolic alterations, injury and fibrosis development when combining type 1 diabetes and IRI. We find the anaerobic metabolism is highly upregulated in the diabetic kidney, but this elevation is severely reduced in the reperfusion phase. The reduced injury repair capability of the diabetic kidney leads to high injury induction and fibrosis, which in turn reduces kidney function. Therefore special care should be taken to animals or patients experiencing this combination to avoid renal failure.

Ely Felker, Leonard Marks, Fuad Elkhoury, David Lu, Daniel Margolis, Sepideh Shakeri, Pooria Khoshnoodi, Lorna Herbert, Nathan White, David Karow, Steven Raman

We evaluated the utility of restriction spectrum imaging (RSI), a novel diffusion-based technique to detect and to characterize prostate cancer among men enrolled in a national cancer institute-funded prospective clinical trial of magnetic resonance ultrasound fusion biopsy.  RSI was statistically significantly associated with clinically significant prostate cancer.

Roger Grimm, Adam Froemming, Stephen Riederer

Geometric distortion in echo planar imaging spin echo images caused by a non-uniform B₀ field remains an issue in clinical imaging. The purpose of this work is to combine the reduced-field-of-view echo planar pulse sequence with a blip-up blip-down correction in prostate DWI. We show reduced geometric distortion in prostate imaging and ADC maps with little or no additional acquisition time required over current protocols.

Xiaoxi Chen, Lianming Wu, Weibo Chen, Jinyuan Zhou, Jianrong Xu

We explored the capability of using the amide proton transfer-weighted MR imaging as a molecular imaging biomarker to identify prostate cancer. Results showed that both the amide proton transfer ratio (APTR) and magnetization transfer ratio (MTR) in tumors were higher than in non-tumorous regions. APT-MR imaging may have great value in clinical treatment  and  prognosis of prostate cancer.

Ali Pirasteh, Brian Johnson, Daniel Costa, Ananth Madhuranthakam, Ivan Pedrosa

Diffusion-weighted echo-planar-imaging (DW-EPI) is the cornerstone of multiparametric MRI in evaluation of prostate cancer in the peripheral zone and can help in the detection of transitional zone tumors. However, DW-EPI suffers from significant image distortion and signal loss in men with hip arthroplasty, a population at risk for development of prostate cancer. We have implemented a DWI sequence with turbo spin-echo readout, MultiVane k-space trajectory, and short-tau inversion recovery fat-suppression that provides images without appreciable distortion and promising preliminary results in evaluation of prostate cancer in men with hip implants.

Xinran Zhong, Dapeng Liu, James Sayre, Holden Wu, Kyunghyun Sung

Accurate T₁ estimation is critical for quantitative prostate DCE MRI. B₁⁺ inhomogeneity can introduce significant error into the T₁ quantification, especially for variable flip angle method. Reference region variable flip angle (RR-VFA) method is a promising B₁⁺ and T₁ estimation technique, which requires no separate scans for B₁⁺ mapping and can reduce slice profile and position mismatch between B₁⁺ and T₁ maps. In this study, we investigated both intra-scanner repeatability and inter-scanner reproducibility regarding B₁⁺ corrected T₁ on two 3.0 T scanners to compare RR-VFA to a commercially available B₁⁺ estimation technique. RR-VFA showed comparable intra- and inter-scanner variability to the saturated turbo FLASH based B₁⁺ estimation technique. 

Masamitsu Hatakenaka, Naomi Koyama, Naoya Yama, Maki Onodera, Koichi Onodera, Yurina Onuma, Ryo Taguchi, Mitsuhiro Nakanishi

In prostate cancer, although calculating ADC with b-value combination of 50-100 and 800-1000 sec/mm² is recommended by PI-RADS ver. 2, ADC calculated with b-values of 0 and 1500 sec/mm² may be superior with respect to repeatability and correlation with cancer aggressiveness. 

Stephen Riederer, Eric Borisch, Adam Froemming, Soudabeh Kargar, Akira Kawashima, Joshua Trzasko

A new method is described in which slice profile in 2D multi-slice acquisition is corrected for with k-space-based processing, restoring resolution along the slice select direction.  When used with multiple multi-slice acquisitions the method may allow isotropic 3D resolution.  The method is described, and preliminary results from phantom and prostate MRI exams are presented.   

Eric Stinson, Joshua Trzasko, Soudabeh Kargar, Eric Borisch, Adam Froemming, Akira Kawashima, Phillip Young, Stephen Riederer

The purpose of this work was to adapt our current clinical DCE-MRI protocol to allow for single-echo Dixon fat suppression and maintain image update times <10s. Single-echo Dixon imaging with spatial resolution that matched our current clinical protocol was performed with sub-10s update times and near-optimal Dixon SNR by increasing the readout bandwidth from ±62.5 to ±83.3 kHz. Additionally, pharmacokinetic modelling results look similar to those produced from the standard DCE-MRI protocol. DCE-MRI of the prostate with single-echo Dixon fat suppression provides high spatial and temporal resolution dynamic imaging of contrast uptake without the presence of confounding fat signal.

Mohammed Sunoqrot, Daniel Billdal, Kirsten Selnæs, Mattijs Elschot, Tone Bathen

Computer-aided diagnosis (CADx) systems have been proposed to overcome the limitations of the radiological reading of multiparametric MRI. Fully automated segmentation of the prostate is a crucial step of CADx systems, which can be successfully performed by atlas-based segmentation of T2-weighted (T2W) MR images. For applications like treatment monitoring and active surveillance, the repeatability of automated segmentation method is highly important. In this work, we investigated the repeatability of several fully automated atlas-based prostate segmentation methods. We found that the repeatability of the investigated methods is excellent, which is promising for the further development of CADx systems following patients with multiple measurements over time.

William Devine, Francesco Giganti, Edward Johnston, Eleftheria Panagiotaki, Shonit Punwani, Daniel Alexander, David Atkinson

To investigate if Luminal Water Imaging (LWI), which models multi-compartment T2 decay, can predict the PIRADS 2.0 score of a region of interest (ROI). 52 patients were scanned using both standard mp-MRI and a 32-echo T2 sequence, ROIs were placed in areas of suspected lesion and suspected benign tissue and then these ROIs were each given a PIRADS 2.0 score. The results show that LWI can predict PIRADS 2.0 score as well as the Apparent Diffusion Coefficient (ADC).

William Devine, Francesco Giganti, Edward Johnston, Eleftheria Panagiotaki, Shonit Punwani, Daniel Alexander, David Atkinson

This work aims both to show that using a constrained fitting method for Luminal Water Imaging with fewer echoes produces accurate parameter estimates and that this fitting method is feasible for detecting and grading Prostate Cancer. Simulated signals were produced and the mean LWF across multiple iterations was calculated for two models. Then 19 patients were imaged and the images were contoured in both cancerous and benign regions. The simulation showed that the proposed constrained method is accurate and the in-vivo imaging reinforced the idea that multi-echo T2 modelling shows promise in detecting and grading PCa.

Elisa Roccia, Rohini Vidya Shankar, Radhouene Neji, Gastao Cruz, Rene Botnar, Claudia Prieto, Vicky Goh, Isabel Dregely

Quantitative T₂ mapping has potential for prostate cancer discrimination. However, current methods are typically 2D, require long scan times and may lead to inaccuracies if using an oversimpli?ed exponential model. We propose rapid 3D T₂ mapping based on accelerated 3D multi shot T₂-prepared bSSFP acquisition combined with dictionary-based matching. The dictionary of signals was generated using a simulation framework taking into account the specifics of the acquisition, and was then matched to the acquired images to retrieve T₂ values. The proposed approach was tested in healthy subjects enabling the acquisition of 3D T₂ mapping of the whole prostate in 4min.

Zhitao Li, Ali Bilgin, Kevin Johnson, Hina Arif, Diego Martin, Maria Altbach

A 3D IR radial FLASH technique and a model-based iterative algorithm for the reconstruction of undersampled data are demonstrated for efficient high-resolution T₁ mapping of the prostate. The method is insensitive to B₁ inhomogeneity and provides full coverage of the prostate volume within the time constrains of a clinical examination.

Sean McGarry, Matthew Budde, Sarah Hurrell, Kenneth Ickzowski, Michael Griffin, Petar Duvnjak, Kenneth Jacobsohn, William Hall, Mark Hohenwalter, Andrew Nencka, Peter LaViolette

The Medical College of Wisconsin 39 (MCW39) template provides a common space for the analysis of prostate cancer images. The template was generated through iterative spatial registration of T2-weighted images starting with manually drawn contours as a reference point. Expert annotations of Gleason Grade were transformed into the template space, and maps of tumor probabilities reveal the spatial localization of cancer across the cohort for each grade. 

Yousef Mazaheri, Andreas Hötker , Amita Shukla-Dave, Oguz Akin, Hedvig Hricak

We present a systematic approach to characterize differences in pre- and post-contrast diffusion and perfusion parameters.  In addition to measuring ADC values before and after contrast injection, we extended the mono-exponential model to incorporate the contribution of pseudo-perfusion to the signal intensity and evaluated the impact of contrast injection on molecular diffusion (D) and perfusion fraction (f).  We find in PCa, the coefficient D, like ADC, was significantly lower on post-contrast as compared to pre-contrast DWI, while the perfusion fraction coefficient was significantly higher on post-contrast acquisitions. In PZ, ADC and D did not differ significantly between post- and pre-contrast acquisitions, but f was significantly higher after contrast injection. 
 

Yousef Mazaheri, Maggie Fung, Duane Nicholson, Amita Shukla-Dave, Hedvig Hricak, Oguz Akin

In this study, we evaluated a 2D combined simultaneous multi-contrast acquisition sequence, referred to MAGiC, which allows simultaneously obtaining images to generate, T1, T2, PD, STIR map with acceptable scan duration within a single acquisition. High quality T1- and T2-w images were synthetically generated using mathematical signal models. Prostate images obtained from patients and volunteers showed that T1 and T2 measured by MAGiC were within 16% of the values measured using conventional mapping techniques with reasonable spatial resolution.

Ananya Panda, Yun Jiang, Seunghee Margevicius, Wei-Ching Lo, Mark Schluchter, Chaitra Badve, Mark Griswold, Lee Ponsky, Vikas Gulani

This study presents utility of MRF derived relaxometry, and ADC mapping for differentiating transition zone prostate cancers from non-cancerous lesions. Based on targeted biopsy correlation, T₁, T₂, ADC were compared between cancer, prostatitis and normal transition zone (NTZ). Mean T₁, T₂ and ADC were significantly different between cancer and NTZ. Mean T₁ and ADC were significantly different between prostate cancer and prostatitis. While ADC had an AUC of 0.821 for differentiating cancer and prostatitis, a combination of T₁ and T₂ mapping had an AUC of 0.875. Thus MRF can add significant value to ADC mapping in characterization of TZ lesions.

Wei-Ching Lo, Yun Jiang, Leonardo Bittencourt, Junichi Tokuda, Ravi Seethamraju, Clare Tempany-Afdhal, Ananya Panda, Katherine Wright, Mark Griswold, Nicole Seiberlich, Vikas Gulani

MRF enables rapid collection of multiple tissue properties simultaneously. For clinical applications, the T₁ and T₂ values must be repeatable over time and on different MRI scanners so that any observed relaxivity difference can be assumed to be due to differences in physiology rather than scanner instability, differences in pulse sequence or map reconstruction implementations. This study evaluated multicenter repeatability and reproducibility of T₁ and T₂ estimates of MRF in the ISMRM/NIST MRI system phantom and normal prostate regions in patients. The intra-scanner variation was less than 2% for MRF T₁ and 4.7% for T₂ within the biological range.

jie bao, ximing wang, zhongshuai zhang, su hu, xiaoxia ping, chunhong hu

In this study, we propose to evaluate histogram analysis of ADC derived by traditional DWI model, diffusion related parameters calculated by using intravoxel incoherent motion (IVIM) model and PI-RADS V2 for the detection of the prostate cancer (PCa) in the transition zone (TZ). Our results show that the highest classification accuracy was achieved by the mean ADC (0.841) and mean D (0.809, acquired by the IVIM model). Our findings suggest that Monoexponential DWI and biexponential IVIM model could potentially improve the accuracy of the pathological grading of prostate cancer in TZ.

seiichiro noda, nobuyuki toyonari, yukari horino, kazuhiro katahira, masami yoneyama, yasutomo katsumata

We study on Compressed SENSE in prostate T2map at 3T The imaging sequence used spin echo type multi echo. In case of SENSE, increase Factor resulted in an artifact peculiar to parallel imaging and an error occurred in T2 value measurement of the prostate. However, in the case of CSENSE, artifacts were reduced and T2 value measurement was also possible. Prostate T2map can reduce imaging time using CSENSE.

Nolan Broeke, Justin Peterson, Adam Farag, Aaron Ward, Stephen Pautler, Joseph Chin, Glenn Bauman, Robert Bartha, Timothy Scholl

Over-treatment of prostate cancer is a significant problem in men’s healthcare. Development of non-invasive imaging tools for improved identification of prostate lesions can reduce over-treatment. We have built custom sodium MRI hardware to image and quantify tissue sodium concentration (TSC) in the human prostate. Sodium and multi-parametric MR images are co-registered to Gleason-graded post-prostatectomy histology, the current gold standard for prostate cancer lesion characterization. Our data shows a statistically significant, positive correlation of TSC with Gleason score. These data suggest that TSC measured by sodium MRI, in addition to multi-parametric MRI has utility for non-invasive characterization of prostate cancer. 

Colleen Bailey, Bernard Siow, Roger Bourne, Edward Johnston, Mrishta Brizmohun Appayya, Hayley Pye, Susan Heavey, Thomy Mertzanidou, Hayley Whitaker, Alex Freeman, Dominic Patel, Greg Shaw, Ashwin Sridhar, David Hawkes, Shonit Punwani, Daniel Alexander, Eleftheria Panagiotaki

Quantitative T2 and VERDICT diffusion MRI data were acquired in ex vivo prostate specimens, using a patient-specific mold to allow comparison with registered prostate images. Analysis indicated differences from in vivo T2 spectra, such as a single T2 component dominating the spectrum in most regions, but with longer T2 values where there was generally more lumen space. A small component with T2 of 10-20 ms was observed in some cancerous regions. The geometric mean of the T2 spectrum was inversely correlated with the intracellular fraction parameter from VERDICT and correlated with the diffusion coefficients of the Tensor component modelling the extracellular space.

Daniel Chen Billdal, Mohammed R Sunoqrot, Kirsten Margrete Selnæs, Peter While, Brage Krüger-Stokke, Helena Bertilsson, Tone Bathen, Mattijs Elschot

Relative Enhanced Diffusivity (RED) expresses the relative change in ADC between lower and higher b-value regimes. The purpose of this study was to investigate the diagnostic potential and repeatability of RED as a biomarker for prostate cancer (PCa).

 

Ten (10) healthy volunteers and 28 high-risk patients diagnosed with PCa underwent diffusion-weighted MRI. For the healthy volunteers, the repeatability of RED was good to acceptable. For the patients, RED was able to discriminate tumors from healthy tissue in the peripheral zone using either b=50 or b=400 mm/s² as the intermediate b-value (p < 0.001).

KyungHyun Sung

The MR dispersion imaging (MRDI) has shown great promise in prostate DCE-MRI, but there still exist practical limitations due to the complex model fitting. We evaluate fitting uncertainties and errors in parameter estimation for MRDI and recently proposed modified MRDI (mMRDI). We use the time-concentration curves derived from 94 prostate cancer lesions for fitting uncertainties and errors and assess the ability to delineate between cancerous and normal prostate tissues.