David D Shin¹, Dan Rettmann², Naoyuki Takei³, and Suchandrima Banerjee^1
1GE Healthcare, Menlo Park, CA, United States, ²GE Healthcare, Rochester, MN, United States, ³GE Healthcare, Hino Tokyo, Japan

While there is a growing trend for using volumetric acquisitions for brain MRI, long acquisition times still limit their adoption. There is still a tremendous need to reduce scan time of these volumetric acquisitions to improve workflow productivity and to reduce the likelihood of motion during the scan. MPRAGE sequence is a key 3D brain acquisition because of its excellent gray-white contrast which is ideal for visualization of substructures, segmentation and morphometric measurements. This work takes a rigorous quantitative approach to investigating the effects of compressed sensing and parallel imaging factors on various tissue measurements derived from accelerated MPRAGE images.

Olivier E Mougin¹, Joshua McAteer¹, Matthan Caan², and Penny A Gowland^1
1School of Physics and Astronomy, SPMIC, Nottingham, United Kingdom, ²Department of Biomedical Engineering & Physics, Amsterdam University Medical Center, Amsterdam, Netherlands

High resolution of the dura matter is useful to detect and follow meningeal pathology. We presented 0.5mm isotropic images obtained at 7T, using compressed sensing to reduce the acquisition time and improve the detectability of the dura matter. Acceleration up to a factor of 8 was possible with broadening of the PSF of the dura visible at acceleration factor higher than 6.

Yunyun Duan¹, Yaou Liu¹, and Jiazheng Wang^2
1Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ²Philips (China) Investment Co., Ltd, Beijing, China

A major barrier of clinical application of 3D T1 sequence is the long acquisition time. Compressed SENSE (CS-SENSE) was introduced into the clinical routine and showed reduced scan time without reduced image quality. However, automatically quantitative assessment of brain structure has not been certificated up to date. This study evaluated the different acceleration factors of CS-SENSE or SENSE of a 3D brain T1 sequence with qualitative and quantitative measurements in health volunteers and patients, in order to assess the feasibility of 3D brain structural imaging acceleration.

Fatiha Andoh¹, Marion Tardieu², Claire Barakat Pellot³, and Xavier Maître^1
1Univ. Paris Saclay, IR4M Laboratory, Orsay, France, ²Institut du Cancer de Montpellier, ICM, Montpellier, France, ³INSERM, IMIV Laboratory, Orsay, France

Mechanical parameters may be underestimated by MR-Elastography if data quality is not properly monitored to discarded inaccurate and unprecised biased data. Optimal condition defined by proper spatial data sampling upon λ/a≈[6;9] can alleviate the quality requirements by lowering Q_threshold, which is defined on each dataset at the drop of correlation between the quality factor and the targeted mechanical parameters.
 

Pascal Spincemaille¹, Julie Anderson², Gaohong Wu², Baolian Yang², Maggie Fung², Ke Li², Shaojun Li¹, Ilhami Kovanlikaya¹, Ajay Gupta¹, Doug Kelley, ², Nissim Benhamo², and Yi Wang^1
1Weill Cornell Medicine, New York, NY, United States, ²General Electrical Healthcare, Waukesha, WI, United States

In this work, we compare the performance of QSM at 7T versus 3T in an intra-scanner test-retest experiment with varying echo numbers and in an image quality analysis. QSM was reproducible within fixed field strength when the same number of echoes were used. Across field strengths and with different numbers of echoes, QSM was reproducible between the 3T acquisition with 10 echoes and the 7T acquisition with 5 echoes. The preliminary data suggest that 7T can be used to shorten QSM acquisition time or enable higher resolution QSM in clinically acceptable scan times.

Daniel Güllmar¹, Renat Sibgatulin¹, Stefan Ropele², and Jürgen R Reichenbach^1,3
1Medical Physics Group / IDIR, Jena University Hospital, Jena, Germany, ²Department of Neurology, Medical University of Graz, Graz, Austria, ³Michael-Stifel-Center for Data driven sciences, Friedrich-Schiller-University Jena, Jena, Germany

If quantitative diffusion measures are acquired at different sites but identical hardware and protocol settings, it remains unclear if a site bias would require a data homogenization in order to pool the data for analysis. A traveling volunteer (including four subjects) approach was applied and different complex diffusion measure as well as diffusion tensor metrics were computed based on the measurements at two different sites. Our results suggest that the inter-site differences are much smaller than the inter-subject differences in the ROI based analysis. The voxel-wise analysis was found to be more susceptible to incomplete artifact compensation and registration errors.

Nicholas G Dowell¹, Nourah Alruwais², Paul S Tofts¹, and Jennifer Rusted^2
1CISC, Brighton and Sussex Medical School, Brighton, United Kingdom, ²School of Psychology, University of Sussex, Brighton, United Kingdom

There is increasing interest in measuring leakage across the blood-brain barrier (BBB) to assess its response to pathology, inflammation or ageing. Quantifying permeability of the BBB is typically performed using dynamic contrast enhanced (DCE) MRI which involves repeated T1-weighted imaging following administration of a Gd contrast agent. In this work, we assess the suitability of two popular DCE acquisition approaches to BBB permeability: (1) a slow gradient echo approach and (2) fast T1-weighted imaging using the VIBE technique . We discuss the advantages and disadvantages of both techniques and recommend the optimum technique for quantification of subtle BBB permeability.

Zo Raolison¹, Redha Abdeddaïm², Marc Dubois², Michel Luong³, Luisa Neves¹, Franck Mauconduit³, Stefan Enoch², Kaizad Rustomji¹, Clarence Quinaux¹, Nicolas Malléjac⁴, Pierre Sabouroux², Fawzi Boumezbeur³, Patrick Berthault⁵, Mikhail Zubkov⁶, Anne-Lise Adenot-Engelvin⁴, Lucie Hertz-Pannier³, and Alexandre Vignaud^3
1Multiwave Imaging, Marseille, France, ²Aix Marseille Université, Marseille, France, ³CEA-DRF/Joliot/Neurospin, Gif-sur-Yvette, France, ⁴CEA-DAM Le Ripault, Monts, France, ⁵CEA-DRF/IRAMIS/NIMBE/LSDRM, Gif-sur-Yvette, France, ⁶Faculty of Physics and Engineering, ITMO University, Saint Petersburg, Russian Federation

Dielectric pads have demonstrated to be a simple and yet efficient solution to mitigate locally RF transmission heterogeneities while using classic 7T MRI birdcage. Extensive research has not yet been carried on alternative candidate to water-based perovskites. The grail would be a long-lasting, comfortable, MR invisible, efficient, unalterable and high permittivity soft material. In this study, a novel material based on silicon carbide particles and addressing those requirements was successfully compared to perovskite pads from the literature in terms of B₁⁺ homogeneity and image contrast through in vivo measurements.

Yuxiang Zhou¹, Yuan Le², Kevin J Glaser², Jun Chen², Roger C Grimm², Arvin Arani², Bradley D Bolster, Jr³, Stephan Kannengiesser⁴, John Huston III², Joel P Felmlee², Richard L Ehman², and Joseph M Hoxworth^1
1Radiology, Mayo Clinic, Phoenix, AZ, United States, ²Radiology, Mayo Clinic, Rochester, MN, United States, ³Siemens Medical Solutions USA, Inc., Salt Lake City, UT, United States, ⁴Siemens Healthcare GmbH, Erlangen, Germany

Using MRE to evaluate the brain requires acquisition of the full 3D wave field and application of 3D inversion processing to generate valid stiffness maps.  The goal of this study was to assess the precision and cross-platform reproducibility of whole brain stiffness measurements obtained with prototype 3D SE-EPI-based MRE techniques, as implemented on GE and Siemens MRI platforms, with the goal of standardization. Our data showed excellent intraplatform repeatability and good interplatform agreement.

 

Tie-bao Meng¹, Haoqiang He¹, Huiming Liu¹, Weijing Zhang¹, Chenghui Huang¹, Long Qian², and Chuanmiao Xie^1
1Department of Radiology, Sun Yat-Sen University Cancer Center, Guangzhou, China, ²MR Research, GE Healthcare, Beijing, China

In the field of neuroscience, an emerging technology named relaxation quantitative MRI (RQ-MRI) have demonstrated its great potential in both clinic and research. Among those RQ-MRI related technologies, the synthetic MRI has moved rapidly towards clinical application due to its acceptable acquisition time. However, how the spatial resolution of synthetic MRI impacts the quantitative maps is still largely unclear. To address this question, in current study, a total of 13 normal subjects with four distinct spatial resolutions were applied. Our results demonstrated that both the in-plane resolution and slice thickness have significantly influence on the measured quantitative values.

Si Xu¹, XiaoMing Liu¹, and JiaZheng Wang^2
1Departments of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, WuHan, China, ²Philips Healthcare, BeiJing, China

3D FLAIR TSE imaging can effectively inhibit cerebrospinal fluid flow artifacts, but the scanning time is long, affecting clinical application. Compressed sensing (CS) is a technique to accelerate the acquisition of magnetic resonance imaging (MRI) by using sparsity constraints during readout measurements of k-space. This study aimed to compare the cerebrospinal fluid flow artifacts and overall image quality in CS 3D FLAIR TSE imaging combined and in 2D FLAIR TSE imaging. Results showed that CS 3D FLAIR TSE yielded better image quality, enhanced diagnosis performance, and reduced fluid flow artifacts when compared to the traditional 2D FLAIR TSE sequence.

Sanghoon Kim¹, Ken Sakaie¹, Mark J Lowe¹, and Stephen E Jones^1
1Cleveland Clinic Imaging Institute, CLEVELAND, OH, United States

Postmortem, whole-brain MRI provides an opportunity to investigate anatomy at spatial resolution approaching that of histology without the distortions and limited coverage inherent to histology. Previous work with ex vivo imaging has been done using a sophisticated process with additional steps, such as a custom-built vibration apparatus to remove air bubbles, proton-free oil to eliminate background signal and modifications to the image reconstruction hardware to deal with the large quantity of imaging data as well as a custom RF coil. The results shown here suggest that similar data can be readily acquired without taking extraordinary or costly measures.

Matthias Weigel^1,2,3, Riccardo Galbusera^1,2, Reza Rahmanzadeh^1,2, Muhamed Barakovic^1,2, Po-Jui Lu^1,2, Ludwig Kappos², Wolfgang Brück⁴, Tobias Kober^5,6,7, Peter Dechent⁸, and Cristina Granziera^1,2
1Translational Imaging in Neurology (ThINk) Basel, Department of Medicine and Biomedical Engineering, University Hospital Basel and University of Basel, Basel, Switzerland, ²Neurologic Clinic and Policlinic, Departments of Medicine, Clinical Research and Biomedical Engineering, University Hospital Basel and University of Basel, Basel, Switzerland, ³Radiological Physics, Department of Radiology, University Hospital Basel, Basel, Switzerland, ⁴Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany, ⁵Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, ⁶Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland, ⁷LTS5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, ⁸Department of Cognitive Neurology, MR-Research in Neurology and Psychiatry, University Medical Center Göttingen, Göttingen, Germany

The MP2RAGE sequence provides fast volumetric T1 weighted MR imaging and offers the possibility to reconstruct quantitative T1 maps. Therefore, it is frequently applied for studying Multiple Sclerosis pathologies in recent years. The present work investigates and explains necessary protocol changes for applying MP2RAGE in fixated human brain acquisitions. Using the established protocol, it is shown that strong soft tissue contrast is reinstated and quantitative T1 values can be derived for normal appearing gray matter and lesions. Based on the feasibility of using long scan times, the isotropic resolution of the MP2RAGE could be even increased to 0.75mm.

Nashwan Naji¹, Myrlene Gee¹, Glen C. Jickling², Richard Camicioli², and Alan H. Wilman^1
1Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada, ²Division of Neurology, University of Alberta, Edmonton, AB, Canada

The MPRAGE sequence is commonly included in brain studies for structural imaging using magnitude images; however, its phase images can provide an opportunity to assess microbleed burden using Quantitative Susceptibility Mapping (QSM). In this study, the mean susceptibility and the cross-sectional area of cerebral microbleeds were assessed using a susceptibility map derived from the phase of the MPRAGE sequence, with comparison to QSM measurements based on standard multi-echo gradient-echo. Microbleeds were well visualized on MPRAGE-QSM with susceptibility generally higher on MPRAGE-QSM, mostly due to mismatch in spatial resolution and SNR.

Ke Jiang¹, Jiazheng Wang¹, and Yuefei Ma^1
1Philips Healthcare Greater China, Beijing, China

Diffusion weighted imaging for brachial plexus can provide useful information for clinical applications. However, clinical DWI usually employs single-shot EPI for signal acquisition, which suffers from image distortion or signal loss especially in the imaging in the head-neck regions due to the spatial variation in B0 field. This work demonstrated the application of a multi-interleave DWI sequence that achieves quality brachial plexus imaging with a resolution of 1.9x1.9 mm² at 3T system.

Spencer L. Waddle¹, Maria E. Garza¹, and Manus J. Donahue^1,2,3
1Department of Radiology, Vanderbilt University Medical Center, Nashville, TN, United States, ²Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, ³Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, United States

The asymmetric spin echo technique (ASE) can be used to collect maps of R2’ and calculate cerebral oxygen extraction fraction (OEF). However, these models require extravascular signal only, which is often not fully achieved in standard ASE approaches. Here, a vascular-space-occupancy (VASO) prepulse is used to null intravascular signal in a novel VASO-ASE method, and repeatability measurements of parenchymal versus extravascular R2’ are presented. VASO-ASE was found to provide physiological OEF (34.1±5.3%) and higher reproducibility in controls compared to standard ASE.

Qi Peng¹, Can Wu², Xiaojuan Li³, Michael L Lipton¹, and Craig Branch^1
1Gruss Magnetic Resonance Research Center, Department of Radiology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States, ²Philips Healthcare, Andover, MA, United States, ³Program of Advanced Musculoskeletal Imaging (PAMI), Cleveland Clinic, Cleveland, OH, United States

Quantitative T1rho (T1ρ) mapping MRI has recently gained wider clinical/research application in human brain imaging. However, high resolution 3D brain T1rho mapping on clinical scanners is still time consuming with compromised quantitative accuracy due to image blurring or artifacts. We propose a 3D FLAIR MAPSS T1rho imaging scheme, which combines CSF-suppression with 3D MAPSS sequence for improved quantitative accuracy in T1rho mapping. Phantom, volunteer, and patient studies validated its sensitivity and reliability for isotropic high resolution of voxel size (1.3mm)³ quantitative mapping using continuous-wave or adiabatic RF pulse T1rho preparation, acquired within clinically acceptable scan duration at 3T.

Haruyuki Fukuchi^1,2, Nao Takano³, Yutaka Ikenouchi², Michimasa Suzuki², Osamu Abe¹, and Shigeki Aoki^2
1Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan, ²Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan, ³Department of Radiology, Juntendo University Hospital, Tokyo, Japan

We developed a novel method, Variable TI, to improve the visibility of ASL based UTE 4D-MRA. In the phantom study and the volunteer study, the Variable TI UTE 4D-MRA offered a higher signal intensity and improved visualization of arteries in late phase compared to the conventional method. The Variable TI technique can improve clinical usability of 4D-MRA because this technique not only offered better visibility of arteries but also realized the data efficacy and reduced reconstruction time. 
 

Christine Sze Wan Law¹, Ken Arnold Weber¹, Sean Mackey¹, and Gary Glover^1
1Stanford University, Stanford, CA, United States

Functional activation within brain has been studied extensively via BOLD fMRI.  Limiting investigation to brain alone provides a truncated view of the central nervous system as it does not capture information exchange between brain and spinal cord.  Simultaneously imaging brain, brainstem, and cervical spine provides insight into pain modulation pathways because dorsal horn is the first synapse connecting periaqueductal gray with cortical pain regions.  Sprenger & Finsterbusch (2015) have shown group-level functional connection of brain to spinal cord under noxious thermal stimulus. Here, we investigate subject-level differences in neural activity in brain-spinal cord.    

Myung-Ho In¹, Daehun Kang¹, Hang Joon Jo², Uten Yarach¹, Nolan K. Meyer¹, Joshua D Trzasko¹, Erin M Gray¹, John III Huston¹, Matt A Bernstein¹, and Yunhong Shu^1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, ²Department of Physiology, College of Medicine, Hanyang University, Seoul, Korea, Republic of

A point-spread-function mapping-based reverse-gradient approach was demonstrated as a viable method to correct severe susceptibility artifacts for deep-brain-stimulation fMRI in a pig model, but at the cost of reduced temporal resolution. Interleaved acquisition of the echo-planar-imaging was used with opposite phase-encoding polarities. In this work, feasibility was evaluated in in-vivo resting-state fMRI reliability in high-susceptibility regions. To compensate for the reduced temporal resolution, multi-band imaging was used, and the improved reliability in highly susceptible regions was evaluated on both standard whole-body and high-performance compact 3T scanners.

Jinli Ding¹, Yunyun Duan¹, Zhizheng Zhuo¹, Yawei Yuan², Guiqing Zhang², Qingwei Song³, Bingbing Gao³, Bing Zhang⁴, Maoxue Wang⁴, Linlin Yang⁵, Yang Hou⁵, Fenglian Zheng¹, Xiaoya Chen⁶, Yishi Wang⁷, and Yaou Liu^1
1Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ²Beijing Royal Integrative Medicine Hospital, Beijing, China, ³First Affiliated Hospital of Dalian Medical University, Dalian, China, ⁴Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Jiangsu, China, ⁵Shengjing Hospital of China Medical University, Shenyang, China, ⁶the First Affiliated Hospital of Chongqing Medical University, Chongqing, China, ⁷Philips Healthcare, Beijing, China

Clinical feasibility of using Compressed SENSE (CS-SENSE) technology to shorten the scan time of Time-of-flight (TOF) magnetic resonance angiography (MRA) and optimal acceleration factor were investigated via a multi-center study. Ninety subjects underwent 8 customized TOF-MRA sequences including sequences with CS-SENSE technology, SENSE technology and without acceleration technology. Subjective assessments including evaluations of artery branches and artifacts, and objective measurements including signal-to-noise ratio, contrast-to-noise ratio and peak signal-to-noise ratio were performed. The results indicated that TOF-MRA using CS-SENSE with an optimal acceleration factor (4 to 6) provided comparable results compared with traditional TOF-MRA sequences, and significantly increased the scan efficiency.

Janine M Lupo¹, Javier Villanueva-Meyer¹, Maryam Vareth^1,2, David Shin³, Emma Bahroos¹, Angela Jakary¹, Brian Burns³, and Suchandrima Banerjee^3
1Radiology & Biomedical Imaging, UCSF, San Francisco, CA, United States, ²Berkeley Institute for Data Science, UC Berkeley, Berkeley, CA, United States, ³GE Healthcare, Menlo Park, CA, United States

Compressed Sensing with parallel imaging can allow for an accelerated anatomical imaging protocol for imaging patients with brain tumors, saving ~10 minutes of scan time over standard clinical protocols when incorporated into 3D T2-FLAIR, and 3D T1-weighted pre- and post- contrast imaging.  We first determined the optimal undersampling pattern and acceleration for CS T1-weighted IR-SPGR sequences and then evaluated the quality of the images and lesion definition in patients with brain tumors. This shortened anatomical imaging protocol has the potential to reduce the frequency of motion artifacts and can allow time for more advanced, therapy specific imaging to be acquired.

kong xiangchuang¹, Tianjing Zhang², Jiazheng Wang³, Qian Qi⁴, Zhenyang Zhou¹, and Dingxi Liu^1
1radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, ²Clinical Science, Philips Healthcare, Shenzhen, China, ³Clinical Science, Philips Healthcare, Beijing, China, ⁴Philips Healthcare, Beijing, China

The aim of this study was to reduce the scan time of 3D Nerve-view using Compressed Sensing-Sensitivity Encoding (CS), and evaluate the image quality and capability of diagnosis of accelerated 3D Nerve-view sequences. 3D Nerve-view sequences with 5 different CS (compressed sense technology) accelerating factors (4,6,8,10,15), and a traditional 3D Nerve-view with 4-fold parallel imaging (sense) as a clinical reference were obtained.The 3D-CS sequence offer comparable diagnostic quality to the clinical 3D scan with much less time, potentially increasing the productivity of MR scanners.CS-3D Nervview with factor 6 offer equilibrium between comparable clinical diagnostic quality with less scan time (235seconds).

Ícaro A F de Oliveira^1,2, Thomas Roos¹, Serge O Dumoulin^1,2,3, and Wietske van der Zwaag^1
1Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, ²Experimental and Applied Psychology, VU University, Amsterdam, Netherlands, ³Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, Netherlands

We compared MPRAGE and MP2RAGE at Ultra-High Field (UHF) in terms of signal separability in gray and white matter. Using a k-space shutter, kt-point universal pulses for signal excitation, and an efficient TR-FOCI for signal inversion, we obtained very good signal contrast throughout the brain, including the cerebellum, for the MPRAGE. Nevertheless, gray-white matter contrast was larger in the MP2RAGE data, leading to better segmentation results, especially in areas affected by low B1+. Hence, MP2RAGE appears more suitable for 7T T1-weighted anatomical data, despite the longer acquisition times.       

Dzung L Pham¹, Neville Gai², Yi-Yu Chou³, Abbey Goodyear², Wen-Tung Wang³, and John A. Butman^2
1Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States, ²National Institutes of Health, Bethesda, MD, United States, ³Henry M. Jackson Foundation, Bethesda, MD, United States

Fluid and White Matter Suppression (FLAWS) MRI uses two inversion times within a T1-weighted magnetization-prepared gradient echo sequence to enhance visualization of gray matter structures within the brain.  FLAWS is based on the MP2RAGE sequence, but with different inversion times, followed by a voxel-wise minimum.  In this work, we demonstrate that a variation of the regularized, ratio combination approach of MP2RAGE yields superior gray matter contrast-to-noise and intensity uniformity compared to the originally proposed FLAWS MRI combination based on minimum intensity.

Tatsuhiro Wada¹, Chiaki Tokunaga¹, Osamu Togao², Yasuo Yamashita¹, Kouji Kobayashi¹, Masami Yoneyama³, and Toyoyuki Kato^1
1Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan, ²Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ³Philips Japan, Fukuoka, Japan

Multi-spin echo acquisition cine imaging (MUSACI) is based on the multi-spin echo technique and used for detection of cerebrospinal fluid (CSF) movement. MUSACI detects CSF movement as a signal loss due to proton phase dispersion and flow void. To better detect the CSF loss caused by CSF movement and reduce the CSF signal loss caused by T2 decay, we modified the refocusing flip angle modulation using pseudo steady state sequence (PSS). The modulation of refocusing flip angle in PSS improved the CSF dynamic imaging using MUSACI.

Zenghui Cheng¹, Naying He¹, Pei Huang², Sean K. Sethi³, Kiran Kumar Yerramsetty⁴, Vinay Kumar Palutla⁴, Weibo Chen⁵, Shengdi Chen², Fuhua Yan¹, and E.Mark Haacke^1,3,6
1Radiology, Ruijin Hospital, school of medicine, Shanghai Jiaotong University, Shanghai, China, ²neurology, Ruijin Hospital, school of medicine, Shanghai Jiaotong University, Shanghai, China, ³Magnetic Resonance Innovations, Inc, Bingham Farms, MI, United States, ⁴MR Medical Imaging Innovations India Pvt. Ltd, Telangana, India, ⁵Philips Healthcare, Shanghai, China, ⁶Radiology, Wayne State University, Detroit, MI, United States

Imaging the nigrosome 1 has been reported to be promising in the diagnosis of Parkinson’s disease (PD), however, there is no uniform imaging protocol. This study was designed to create a rapid imaging protocol with high image quality to consistently visualize and characterize the N1 and to evaluate the loss of N1 in the diagnosis of PD. We found that the N1 sign could be consistently visualized using true SWI (tSWI) with a resolution of at least 0.67 x 0.67 x 1.34 mm³ and could be seen in 95% of HCs, while only 21.1% in PD and atypical parkinsonian syndromes.
 

Joelle E. Sarlls¹, Francois Lalonde², Joellyn Stolinski¹, Maxim Zaitsev³, and Lalith Talagala^1
1NMRF, National Institutes of Health, Bethesda, MD, United States, ²NIMH, National Institutes of Health, Bethesda, MD, United States, ³MR Development and Application Center, University Medical Center Freiburg, Freiburg, Germany

Higher resolution anatomical images can provide more accurate estimates of morphometric measures extracted from segmentation algorithms. Acquisition of submillimeter MPRAGE data at 3T requires long scan times making it prone to subject motion. Prospective motion correction (PMC) techniques can mitigate these effects by tracking brain motion and updating scan parameters accordingly.  Here, we compare morphometric measures from 1.0mm and 0.6mm isotropic resolution MPRAGE data obtained at 3T while using PMC.  Results show that good quality 0.6mm MPRAGE data can be acquired with PMC in approximately 30minutes. Increased cortical thickness in some brain regions is seen with higher resolution data.  

Ho-Joon Lee¹, Yeonah Kang¹, Marc Lebel², Min Soo Park³, and Joonsung Lee^3
1Department of Radiology, Haeundae Paik Hospital, Busan, Republic of Korea, ²MR Collaboration and Development, GE Healthcare, Calagary, AB, Canada, ³GE Healthcare Korea, Seoul, Republic of Korea

Sequences that allow volumetric parametric maps are being developed but when these techniques will be available clinically is uncertain. MDME sequence is a robust method, allowing rapid acquisition of T1, T2 relaxation times, PD from which one can generate synthetic multi-contrast images. However, acquisition at thin slices is challenging. With a deep learned reconstruction method, we demonstrate that interleaved thin slice acquisition of MDME, can produce quasi-volumetric synthetic MRI at an isotropic resolution. Limitations  include motion misregistrations between acquisitions, parallel imaging/partial volume/pulsation related artifacts, which we believe can be overcome with technical development. 

Aocai Yang¹, Guangbin Wang¹, Weibo Chen², and Ye Li^1
1Shandong Medical Imaging Research Institute,Shandong University, Jinan, China, ²Philips Healthcare, Shanghai, China

Quantitative susceptibility mapping (QSM) is an important technique for quantifying iron content in the brain. The conventional time of high spatial QSM data is too long. Compressed sensing acceleration (CS) technique can primarily reduce the acquisition time. We sought to evaluate the accuracy and stability of whole brain QSM on both the voxel-wise level and regional level by using several CS accelerations. We found significant differences in the magnetic susceptibility values on voxel-based QSM, but no statistically different in regions of interest. CS acceleration is feasible for QSM acquisition without influence the magnetic susceptibility values obviously.

Satoshi Yatsushiro¹, Tomohiko Horie², Mitsunori Matsumae³, and Kayagaki Kuroda^1
1Department of Human and Information Science, School of Information Science and Technology, Tokai University, Hiratsuka, Kanagawa, Japan, ²Department of Radiological Technology, Tokai University Hospital, Isehara, Kanagawa, Japan, ³Department of Neurosurgery, School of Medicine, Tokai University, Isehara, Kanagawa, Japan

To compare the performance of separating cardiac- and respiratory-driven intracranial CSF motions under free breathing with Stockwell transform (ST), real time phase contrast imaging based on echo planar imaging (EPI-PC) and steady state free precession (SSFP-PC) were compared. In 3 healthy volunteers, 3 patients with idiopathic normal pressure hydrocephalus (iNPH), and 2 patients with Chiari malformation, both PC schemes yielded almost the same image quality, although EPI-PC had relatively higher frame rate than SSFP-PC. These preliminary results indicated that both techniques in conjunction with ST will be useful to seize the CSF motions under free breathing.

Li Chen¹, Duygu Baylam Geleri ¹, Jie Sun ¹, Hiroko Watase ¹, Jiarui Cai¹, Yin Guo¹, Niranjan Balu ¹, Dongxiang Xu ¹, Thomas Hatsukami ¹, Yongjun Wang ², Jenq-Neng Hwang ¹, and Chun Yuan ^1
1University of Washington, Seattle, WA, United States, ²Beijing Tiantan Hospital, Capital Medical University, Beijing, China

A visualization technique (MOCHA) was developed to facilitate intracranial artery review using 3D Magnetic Resonance vessel wall imaging. Multiple intracranial MR scans, either from multiple contrasts or timepoints, are registered, then the artery of interest is traced and straightened using multiplanar reformation. Scans of 15 subjects with intracranial atherosclerosis were reviewed using MOCHA by a novice reader, with the traditional review method as comparison. The results showed higher sensitivity for plaque identification and higher accuracy for quantifying plaque features with MOCHA. MOCHA is promising for artery reviews using multiple scans, such as identifying plaque components and monitoring vessel wall thickening.

Daniel Gallichan^1
1School of Engineering, Cardiff University, Cardiff, United Kingdom

A novel approach for image colorisation is presented, intended for situations where multiple contrasts are available covering the same anatomy. A colormap is created in a PCA-based hybrid parameter space, allowing signals from all contrasts to contribute to the final image colorization. Examples are shown from a dataset of high grade glioma patients, enabling rapid visual comparison between subjects. Within-subject there is clear contrast between healthy and pathological tissue, while contrast between healthy GM/WM/CSF is preserved.

Roman Fleysher¹, Nelson Gil¹, and Michael L Lipton ^1
1Radiology, Albert Einstein College of Medicine, Bronx, NY, United States

Voxel-wise cluster analysis of any MR-derived metric necessitates non-linear registration to a common brain template. Because quality of inter-brain registrations is sensitive to the similarity between the brains, the results of such analyses are sensitive to the choice of the template. Despite judicious selection of the template may reduce registration errors, inherently the results should not depend on template choice. We show that a dramatic reduction in this sensitivity is achieved by filtering out poorly registered images. Consequently, voxel-wise cluster analyses of the remaining data become more robust and less sensitive to the choice of the template.  

Junghun Cho¹, Yuhan Ma², Pascal Spincemaille³, Bruce Pike^2,4, and Yi Wang^1,3
1Biomedical Engineering, Cornell University, New York, NY, United States, ²McConnell Brain Imaging Centre, McGill University, Montreal, QC, Canada, ³Radiology, Weill Cornell Medical College, New York, NY, United States, ⁴Radiology, University of Calgary, Calgary, AB, Canada

In this study, we compare cerebral oxygen extraction fraction (OEF) and metabolic rate of oxygen consumption (CMRO2) maps obtained using dual-gas challenge calibrated-BOLD (DGC) and challenge-free gradient echo quantitative susceptibility mapping plus quantitative blood oxygen level-dependent modeling (QSM+qBOLD or QQ) to explore the important clinical advantage of challenging-free data acquisition. In n=11 healthy subjects, cortical gray matter average OEF was not significantly different (36.4±1.9% and 38.0±9.1%, P=0.63) as was CMRO2 (151.4±17.6 and 168.2±54.1 μmolO2/min/100g, P=0.26), for QQ and DGC, respectively. QQ can measure OEF and CMRO2 at both baseline and hypercapnia independently, showing a 14% CMRO2 decrease in hypercapnia (P=0.039).

Ryan McNaughton¹, Mina Botros², Ning Hua², Xin Zhang¹, and Hernan Jara^2
1Mechanical Engineering, Boston University, Boston, MA, United States, ²Boston University Medical Center, Boston, MA, United States

Purpose: To develop quantitative MRI-based algorithms for correction of signal polarity for measurement of T1. Methods: Two polarity maps of T1 are calculated according to the mixed-TSE acquisition, and repolarized on a voxel-wise basis. The two polarity maps are compared to thresholds for PD and T2. The correct polarity is selected based on which T1 more accurately describes the selected voxel. Maps of the T1/T2 ratio repolarize the remaining unpolarized tissue. Results: Repolarized T1 maps exhibit an accurate bimodal distribution in vivo. Conclusion: A qMRI-based repolarization technique allows T1 measurement from mixed-TSE magnitude data, toward studying the extremely preterm brain.

Khaled Talaat¹, Bruno Sa De La Rocque Guimaraes², and Stefan Posse^2
1Nuclear Engineering, University of New Mexico, Albuquerque, NM, United States, ²Neurology, University of New Mexico, Albuquerque, NM, United States

Assessing the extent of high frequency resting state connectivity (> 0.15 Hz) across different brain networks has been hampered by the presence of physiological noise. Much of the high frequency information is lost when global filters are applied to stop respiratory and cardiac frequency bands. A spatially selective automated filtering method is developed in order to preserve high frequency signal information in regions where physiological contamination is weak. Preliminary results show significant reduction in artifactual correlations compared to unfiltered data.

Yukai Zou^1,2, Wenbin Zhu³, Ho-Ching (Shawn) Yang¹, Nicole L Vike⁴, Diana O Svaldi¹, Trey E Shenk⁵, Victoria N Poole^1,4, Gregory G Tamer, Jr.¹, Larry J Leverenz⁶, Ulrike Dydak⁷, Eric A Nauman^1,4,8, Thomas M Talavage^1,5, and Joseph V Rispoli^1,5
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, ²College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States, ³Department of Statistics, Purdue University, West Lafayette, IN, United States, ⁴Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, United States, ⁵School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States, ⁶Department of Health and Kinesiology, Purdue University, West Lafayette, IN, United States, ⁷School of Health Sciences, Purdue University, West Lafayette, IN, United States, ⁸School of Mechanical Engineering, Purdue University, West Lafayette, IN, United States

Over years of practices and competitions, adolescent collision-sport (American football, soccer) athletes undergo repetitive subconcussive head impacts, and therefore may exhibit a neuroanatomical trajectory different from healthy adolescents in general. Targeting this vulnerable population, we constructed a specific brain atlas that includes templates (T1 and DTI) and semantic labels (cortical and white matter parcellations), and we demonstrated that the unbiased population-specific brain atlas can minimize bias introduced in spatial normalization, improve sensitivity of voxel-wise statistical analysis, and therefore better clarify the mechanisms that lead to traumatic brain injury in adolescent athletes.

Andreia C. Freitas¹, Inês Sousa¹, Andreia S. Gaspar¹, Rui P.A.G. Teixeira², Joseph V. Hajnal², and Rita G. Nunes^1,2
1ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico – Universidade de Lisboa, Lisbon, Portugal, ²Centre for the Developing Brain, King's College London, London, United Kingdom

T₂ mapping provides valuable tissue-specific MR information. To enable shorter scan times, multi spin-echo (MSE) sequences are commonly used but the achieved T₂ accuracy using conventional mono-exponential fitting is poor. Improvements are possible by matching the measured signal to a pre-computed dictionary. Although simultaneous B₁+ estimation is feasible, previous work demonstrated a bimodal behaviour. We investigate further improvements in B₁+ accuracy using an iterative pixel-neighborhood based method (the Fusion Bootstrap Moves Solver), comparing different levels of spatial regularization. Improved B₁+ accuracy and recovery of spatially smooth maps was demonstrated both in simulated and in-vivo brain data.

Victoria Madge^1,2, Philip Novosad^1,2, Daniel A. Di Giovanni^1,3, and D. Louis Collins^1,2,3
1McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC, Canada, ²Department of Biomedical Engineering, McGill University, Montreal, QC, Canada, ³Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada

VoxelMorph is a deep-learning based non-linear diffeomorphic registration algorithm which claims to perform comparably to the state-of-the-art. However, the previous evaluation did not compare against manual gold-standard anatomical segmentations, used only the Dice metric for comparison, and compared against a modified version of a state-of-the-art algorithm, ANTs SyN. Here, VoxelMorph is evaluated against an unmodified version of ANTs SyN using multiple metrics based on manual labels. Results show VoxelMorph is less robust than ANTs SyN and underperforms in the presence of simulated deformations, and in registration of BrainWeb20 images to the VoxelMorph atlas.  

Rupsa Bhattacharjee^1,2, Rakesh Kumar Gupta³, Vijay Kant Dixit⁴, Praveen Gupta⁵, and Anup Singh^1,6
1Center for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India, ²Philips Health Systems, Philips India Limited, Gurugram, India, ³Department of Radiology, Fortis Memorial Research Institute, Gurugram, India, ⁴Department of Interventional Neuroradiology, Fortis Memorial research Institute, Gurugram, India, ⁵Department of Neurology, Fortis Memorial research Institute, Gurugram, India, ⁶Department of Biomedical Engineering, All India Institute of Medical Sciences, New Delhi, India

Objectives are to enhance the PHVS visibility in SWI, quantify stroke penumbra from it and calculate the mismatch ratio between PHVS(SWI) and DWI. For algorithm performance evaluation, 3D non-contrast pCASL as a gold standard was used to calculate true mismatch ratio with DWI. The proposed approach demonstrates high correlation between the two mismatch ratios, suggesting that PHVS and SWI based penumbra quantification has the potential to be used as an alternative for perfusion based methods. If mismatch ratio can accurately be produced from PHVS SWI, it could potentially reduce the scan time for acute stroke.

Jaemin Shin¹, Jungho Cha², Jeffrey McGovern³, Patrick Quarterman¹, Suchandrima Banerjee⁴, and Ki Sueng Choi^2
1GE Healthcare, New York, NY, United States, ²Mount Sinai, New York, NY, United States, ³GE Healthcare, Waukesha, WI, United States, ⁴GE Healthcare, Menlo Park, CA, United States

This work does a quantitative evaluation of the effectiveness of a distortion correction method, clinically available at the scanner console, in diffusion MRI of the brain (N=10). After distortion correction, average cross-correlation coefficient between T1 and DWI was significantly increased. Distortion correction reduced average residual distance error to 1.1 mm or less (average 76% reduction) in all of three anatomical landmarks (frontal pole,lateral ventricle, pons). This on-console distortion correction method could help in the clinical applications that requires fast and accurate distortion correction such as deep brain stimulations surgery and cases with high susceptibility such as postoperative cohorts.

Xue Feng¹, Huitong Pan², Li Zhao³, and Craig H. Meyer^1
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Springbok, Inc., Charlottesville, VA, United States, ³Children's National Health System, Washington DC, DC, United States

High-resolution 3D MRI can provide detailed anatomical information and is favorable for accurate quantitative analysis. However, due to the limited data acquisition time and other physical constraints such as breath-holding, multi-slice 2D images are often acquired. The 2D images usually have a larger slice thickness than the in-plane resolution. To reconstruct the high- resolution 3D MRI, we propose to use a super-resolution network with three orthogonal multi-slice 2D images as the input. We validated the proposed method on brain MRIs and achieved good results in terms of mean absolute difference, mean squared difference and image details with visual inspection.  

Wen-Tung Wang¹, Dzung Pham¹, and John A Butman^1,2
1Center for Neuroscience and Regenerative Medicine, NIH/USU, Bethesda, MD, United States, ²Radiology and Imaging Sciences, NIH, Bethesda, MD, United States

Ultrashort echo-time (UTE) imaging can detect short- and ultrashort-T2 tissue components. e.g. tendons, ligaments, and cortical bone.  Multi-echo UTE is used to generate the tissue attenuation maps required for quantitative MRI PET, as short T2 skull is visible on the first echo but not on the second.  For accurate classification, it is assumed that these are registered.  Here we show that geometric scaling issues of fat and water may be different between the 1st and 2nd echoes – and hence lead to erroneous tissue classification.

Lyna Kamintsky¹, Steven D Beyea^2,3, John D Fisk^4,5, Javeria A Hashmi⁶, Antonina Omisade⁷, Tim Bardouille⁸, Chris Bowen^2,3, Maher Quraan^2,3, Kara A Matheson⁹, Alon Friedman^1,10, and John G Hanly^11,12
1Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada, ²Department of Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada, ³Biomedical Translational Imaging Centre (BIOTIC), QEII Health Sciences Centre, Halifax, NS, Canada, ⁴Departments of Psychiatry, Psychology & Neuroscience and Medicine, Dalhousie University, Halifax, NS, Canada, ⁵Nova Scotia Health Authority, Halifax, NS, Canada, ⁶Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS, Canada, ⁷Acquired Brain Injury (Epilepsy Program), Nova Scotia Health Authority, Halifax, NS, Canada, ⁸Department of Physics, Dalhousie University, Halifax, NS, Canada, ⁹Research Methods Unit, Nova Scotia Health Authority, Halifax, NS, Canada, ¹⁰Department of Physiology and Cell Biology, Medicine, Ben-Gurion University of the Negev, Beer Sheva, Israel, ¹¹QEII Health Sciences Center, Halifax, NS, Canada, ¹²Department of Medicine and Division of Rheumatology, Dalhousie University, Halifax, NS, Canada

This study addresses the need for mechanism-based understanding of cognitive impairment in systemic lupus erythematosus (SLE). Using dynamic contrast-enhanced MRI we identified extensive blood-brain barrier (BBB) leakage in 16 of 46 SLE patients. Extensive BBB leakage was associated with worse overall cognitive performance, affecting primarily information processing speed and executive abilities. Our study provides the first compelling evidence for BBB damage in SLE, and links BBB leakage to cognitive dysfunction. These findings highlight the diagnostic potential of BBB imaging and call for research into BBB-targeting therapies.

Lukas A. Grajauskas^1,2,3, Tory Frizzell^2,4, Sujoy Hajra^2,4, Caressa Liu^2,4, Xiaowei Song^2,3, and Ryan C.N. D'Arcy^4,5
1Cumming School of Medicine, University of Calgary, Calgary, AB, Canada, ²Surrey Memorial Hospital ImageTech Laboratory, Fraser Health, Surrey, BC, Canada, ³Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada, ⁴Faculty of Applied Sciences, Simon Fraser University, Burnaby, BC, Canada, ⁵Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada

Though white matter has a noted role in motor learning, there have been no MRI studies of functional neuroplasticity in this tissue. Therefore, in this work, twelve healthy participants underwent a motor training program designed to drive behavioral changes in the non-dominant hand. Using BOLD fMRI, we noted an associated change in the temporal dispersion of the white matter hemodynamic response over the training period. This is in line with previous DTI studies that show increases in white matter myelination with training, and BOLD investigations that show hemodynamic responses differ between grey and white matter, and between white matter tracts.

Ze Wang^1
1Radiology, University of Maryland School of Medicine, Baltimore, MD, United States

Human brain relies on long-range coherent activity to execute complex function. The long-range coherence can be measured by brain entropy mapping, which has gained increasing research interest in recent years. The purpose of this study is to examine the relationship between brain entropy and brain functions using large data.

Paola Valsasina¹, Maria A. Rocca^1,2, Alessandro Meani¹, Claudio Gobbi³, Chiara Zecca³, Alex Rovira⁴, Xavier Montalban⁵, Hugh Kearney⁶, Olga Ciccarelli⁶, Lucy Matthews⁷, Jacqueline Palace⁷, Antonio Gallo⁸, Alvino Bisecco⁸, Carsten Lukas⁹, Barbara Bellenberg⁹, Frederik Barkhof^10,11, Hugo Vrenken¹⁰, Paolo Preziosa^1,2, and Massimo Filippi^1,2,12
1Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy, ²Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy, ³Department of Neurology, Neurocenter of Southern Switzerland, Civic Hospital, Lugano, Switzerland, ⁴Section of Neuroradiology and MRI Unit, Department of Radiology, Hospital Universitari Vall d'Hebron, Barcelona, Spain, ⁵Department of Neurology/Neuroimmunology, Multiple Sclerosis Centre of Catalonia, Hospital Universitari Vall d'Hebron, Barcelona, Spain, ⁶NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, ⁷Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, ⁸Department of Advanced Medical and Surgical Sciences, and 3T MRI Center, University of Campania “Luigi Vanvitelli”, Naples, Italy, ⁹Department of Radiology and Nuclear Medicine, and Institute of Neuroradiology, St. Josef Hospital, Ruhr-University Bochum, Bochum, Germany, ¹⁰Department of Radiology and Nuclear Medicine, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, location VUmc, Amsterdam, Netherlands, ¹¹Institutes of Neurology and Healthcare Engineering, University College London, London, United Kingdom, ¹²Vita-Salute San Raffaele University, Milan, Italy

In this study, we used source-based morphometry to identify patterns of grey matter tissue loss in a large, multicenter cohort of patients with multiple sclerosis (MS) acquired at 8 European sites. We detected a differential involvement of grey matter networks across the different stages of the disease. Cortical and subcortical grey matter atrophy progressed significantly in MS patients over 1-year of follow-up. Grey matter atrophy, especially in the sensorimotor network, was able to explain patients’ clinical disability, while cerebellar atrophy was able to predict clinical disability worsening over 1-year follow-up.

Sandy Mournet^1,2, Gosuke Okubo^1,2,3, Ismail Koubiyr^1,2, Valentin H Prevost⁴, Clémence Bal², Bei Zhang⁵, Hiroshi Kusahara ⁴, Nobuyasu Ichinose⁴, Bruno Triaire⁴, Bassem Hiba⁶, Vincent Dousset^1,2,7, and Thomas Tourdias^1,2,7
1Neurocentre Magendie, INSERM U1215, Bordeaux, France, ²Université de Bordeaux, Bordeaux, France, ³Department of Radiology, Tenri Hospital, Nara, Japan, ⁴Canon Medical Systems Corporation, Otawara, Japan, ⁵Canon Medical systems Europe, Paris, France, ⁶Centre de neuroscience cognitive, CNRS UMR 5229, Université Claude Bernard Lyon, Lyon, France, ⁷Neuroimagerie diagnostique et thérapeutique, CHU de Bordeaux, Bordeaux, France

In diffusion MRI, the use of very high b-value remains very challenging. In this study, we scanned 9 volunteers with a protocol of dMRI sequences using b values from 1000 to 5000 s/mm². We compared cortical surface map of myelin (T1wi/T2wi) to maps of mean diffusivity (MD) computed from each b value. As opposed to b1000 s/mm², MD maps from b3000 and b5000 inversely mirrored the myelin maps. With increasing b-values, multiple regression models confirmed an increasing negative association between myelin and MD. The MD obtained with high b-value is sensitive to subtle cellular variations such as the cortical myeloarchitecture.   

Fulvia Palesi¹, Roberta Lorenzi¹, Claudia Casellato¹, Petra Ritter², Viktor Jirsa³, Claudia AM Gandini Wheeler-Kingshott^1,4,5, and Egidio D'Angelo^1,5
1Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, ²Department of Neurology with Experimental Neurology, Charité – Universitätsmedizin Berlin, Berlin, Germany, ³Institut de Neurosciences des Systèmes - Inserm UMR1106, Aix-Marseille Université, Marseille, France, ⁴NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, ⁵IRCCS Mondino Foundation, Pavia, Italy

The Virtual Brain(TVB) has been developed to simulate brain dynamics starting from individual structural and functional connectivity(FC) MRI data. Nowadays, only cerebrocortical circuits have been considered. Here, we provided the first TVB simulations including cerebellar nodes on single-subject datasets. The brain dynamics simulated by either including or excluding cerebrocortical-cerebellar connectivity were compared, revealing that the predictive power of empirical FC is not significantly modified by inclusion of cerebro-cerebellar loops. To improve the present results and apply this pipeline to predict disease states involving cerebrocortical-cerebellar loops, specific neural mass models accounting for cerebellar microcircuit physiology need to be integrated in TVB.

Katja Heuer¹, Mélanie Didier², Stéphanie Anastacio², Antoine Burgos², Romain Valabregue², Marc Herbin³, Roberto Toro^1,4, and Mathieu David Santin^2
1Groupe de Neuroanatomie appliquée et théorique, Unité de Génétique humaine et fonctions cognitives, Département de neuroscience, Institut Pasteur, Paris, France, ²Centre de Neuroimagerie de Recherche, Institut Cerveau Moelle – ICM, CENIR, UPMC-Inserm U1127, CNRS 7225, Paris, France, ³Département Adaptations du Vivant, UMR MECADEV 7179 Equipe FUNEVOL Sorbonne Universités-MNHNUPMC- CNRS-IRD, Muséum National d'Histoire naturelle, PAris, France, ⁴Center for Research and Interdisciplinarity (CRI), Université Paris Descartes, Paris, France

This work presents the MR acquisition of 180 post mortem brains from different species coming from a Museum collection. 3D-High resolution images were obtained at 3 and 11.7T, depending on brain size. The images where then preprocessed in order to be available online for dowload on The Brain Catalogue (https://braincatalogue.org) web portal designed for comparative neuroanatomy studies.

Rafael OHalloran¹, Laura Sacolick¹, Hadrien Dyvorne¹, Carole Lazarus¹, Samantha By¹, Brian Welch¹, Bradley A Cahn², Jill T Shah², Mercy H Mazurek², Matthew M Yuen², Gordon Sze², W. Taylor Kimberly³, Matthew S Rosen^4,5, and Kevin N Sheth^2
1Hyperfine Research, Inc., Guilford, CT, United States, ²Yale New Haven Hospital, New Haven, CT, United States, ³Division of Neurocritical Care, Department of Neurology, Massachusetts General Hospital, Boston, MA, United States, ⁴Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, ⁵Department of Physics, Harvard University, Cambridge, MA, United States

Initial evidence of the feasibility of clinical stroke imaging using a portable 64mT MRI system is presented. Twelve patients with a diagnosis of ischemic stroke diagnosis admitted to a neuroscience intensive care unit were imaged with a portable, point-of-care, MRI system.

Nikhil Deveshwar¹ and Peder E. Z. Larson^1
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States

This work presents a study detailing how ultrashort-T₂* measurements can provide new and complimentary characterizations and differentiations of white matter anatomy in comparison to classic DTI measurements. Specifically the magnitude and frequency shift components of the measured signal are significantly different between white matter with thick versus thin myelin sheaths and provides new methods of assessing myelin content in white matter when compared to FA, MD, and V1 values. These results show that this method could be used to better characterize and study demyelinating diseases such as multiple sclerosis.

Itamar Ronen¹, Francesca Branzoli², Alessandro Colasanti³, Iris Asllani³, Riccardo De Marco³, Neil Harrison⁴, and Mara Cercignani^3
1Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, ²Centre for NeuroImaging Research - CENIR, Brain and Spine Institute - ICM, Paris, France, ³Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom, ⁴Cardiff University Brain Research Imaging Centre (CUBRIC), School of Medicine, Cardiff University, Cardiff, United Kingdom

Neuroinflammation is a pathomechanism implicated in several neruological, neurodegenerative and psychiatric disorders and is expressed in activation of microglia, the resident brain macrophages. Currently the only neuroimaging method for detecting microglial activation is PET with translocator protein (TSPO) ligands. A well-known model of experimentally inducing systemic inflammation is the administration of lipopolysaccharides (LPS). Here we report a significant increase in the apparent diffusion coefficient of the glial metabolite choline (tCho) in the human thalamus, following injection of LPS. This finding suggests that the ADC(tCho) is a putative marker for glial activation and may be useful in measuring neuroinflammation in disease.

Ayodeji L Adams¹, Itamar Terem², Allen A Champagne³, Samantha J Holdsworth⁴, and Jaco Zwanenburg^5
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, ²Radiology, Stanford University, Stanford, CA, United States, ³School of Medicine, Queen’s University, Kingston, ON, Canada, ⁴Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand, ⁵University Medical Center Utrecht, Utrecht, Netherlands

aMRI holds great potential for assessing brain motion/strain using images acquired from readily-available sequences. However, registration is needed to extract displacements from the motion-amplified images, which may limit its accuracy. In this study we separately assessed the errors induced by registration limitations and by imperfections in the aMRI amplification. Displacements were extracted from aMRI and DENSE-amplified images using a common registration algorithm, which were then compared to a ground truth. Although significant differences were found between DENSE-amplified images and aMRI, the aMRI-derived displacements were comparable to the ground truth, strengthening the potential of aMRI for investigating brain motion in disease.

Puneet Bagga¹, Laurie J Rich¹, Abigail Cember¹, Ravi Prakash Reddy Nanga¹, Deepa Thakuri¹, Mark Elliott¹, Mohammad Haris^2,3, John A Detre⁴, and Ravinder Reddy^1
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Sidra Medicine, Doha, Qatar, ³LARC, Qatar University, Doha, Qatar, ⁴Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States

Cerebral metabolism is reported to be monitored by various techniques including ¹³C/²H MR spectroscopy and ¹⁸F-FDG Positron emission tomography. It is well known that ¹H MRS allows the non-invasive detection and quantification of neurochemicals. In this study, we performed ¹H MRS in conjuction with the oral administration of [6,6′-²H₂]glucose in a healthy volunteer at 3T and 7T to measure turnover of glutamate in gray and white matter. As ²H is invisible on ¹H MRS, the ²H enrichment of glutamate leads to a corresponding drop in its ¹H MR resonance measured via LCModel.

Julia Cluceru¹, Yannet Interian², Janine M. Lupo³, Riley Bove⁴, Atul Butte⁵, and Jason Crane^3
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, ²Program in Data Science, USF, San Francisco, CA, United States, ³Radiology and Biomedical Imagin, UCSF, San Francisco, CA, United States, ⁴Department of Neurology, UCSF, San Francisco, CA, United States, ⁵Bakar Computational Health Sciences Institute, UCSF, San Francisco, CA, United States

To perform large-scale analyses of disease progression, it is necessary to automate the retrieval and alignment of MR images of similar contrast.  The goal of this study is to create an algorithm that can reliably classify brain exams by MR image contrast. We use two modeling strategies (SVM and CNN) and two training/testing cohorts to compare within-disease and between-disease transferability of the algorithms. For both cohorts, deep ResNets for extract imaging features combined in a random forest with DICOM metadata perform the best, resulting in 95.6% accuracy on the within-disease comparison, and 99.6% overall accuracy on between-disease comparison.

Dogu Baran Aydogan^1
1Department of Neuroscience and Biomedical Engineering, Aalto University, Helsinki, Finland

Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that is widely used in both research and clinical settings. However, state-of-the-art TMS guidance systems do not leverage the valuable structural connectivity in real-time applications. This is mainly due to the limitations of tractography which has been increasingly pointed out in validation studies. In order to address this problem, in this work we propose a novel visualization approach that is capable of providing information about the uncertainty of obtained streamlines. Our technique offers an easy and intuitive way for the TMS operator to interpret the displayed streamlines in real-time.
 

Nan Zhang¹, Qingwei Song¹, Renwang Pu¹, Haonan Zhang¹, Jiazheng Wang², Zhongping Zhang², and Yu Song^1
1The First Affiliated Hospital of Dalian Medical University, Dalian, China, ²Philips Healthcare, Beijing, China

Amide proton transfer (APT) imaging is a novel and promising MRI contrast method, but it can be time-consuming. Common parallel imaging methods, like SENSE, can lead to reduced quality of APT. Here, compressed sensing technique is evaluated for the acceleration of APT in brain. The purpose of the present study is to explore feasibility of different acceleration factors in brain APT.  The results show that it is feasible to apply accelerator factor 5 to APT display of brain tissue and brain tumor, which could reduce the scan time with in 1 min.

Yiming Wang¹, Limin Zhou¹, Joshua S. Greer^1,2, Edward Pan^3,4,5, Marco C. Pinho^1,6, Joseph A. Maldjian^1,6, and Ananth J. Madhuranthakam^1,6
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, ²Pediatrics, UT Southwestern Medical Center, Dallas, TX, United States, ³Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, United States, ⁴Neurological Surgery, UT Southwestern Medical Center, Dallas, TX, United States, ⁵Harold C. Simmons Cancer Center, UT Southwestern Medical Center, Dallas, TX, United States, ⁶Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States

3D arterial spin labeled (ASL) MRI using turbo spin echo (TSE) acquisition suffers from image blurring, due to T₂ decay along the echo train. In this study, a k-space filtering method proposed earlier was optimized to compensate T₂ blurring, incorporating ASL T₂ measurements in healthy volunteers for T₂ decay estimation. This method was then applied to 3D ASL images acquired in healthy volunteers and patients with glioblastoma (GBM) from an ongoing clinical trial. Results showed reduced image blurring in both volunteers and patients.

Sandeep Ganji¹, Nandor Pinter², Jan Petr3³, Bela Ajtai², Joseph V Fritz², Laszlo Mechtler², Shahrukh Husain², Alexander Fischer⁴, Frederik Barkhof^5,6, and Henri‌ Mutsaerts^5,7
1Philips, Gainesville, FL, United States, ²Dent Neurologic Institute, Amherst, NY, United States, ³Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany, ⁴Philips Research, Aachen, Germany, ⁵Dept of Radiology and Nuclear Medicine, Amsterdam University Medical Center, Amsterdam, Netherlands, ⁶Institute of Biomedical Engineering and Neurology, University College London, London, United Kingdom, ⁷Ghent Institute for Functional and Metabolic Imaging, Ghent, Belgium

The use of standardized image processing pipelines is continuously increasing in radiological research with developments in computing power, image processing, and machine learning techniques. Early integration of academic processing methods into clinical research workflow would accelerate the translation of promising novel MRI techniques into the clinic. However, the integration of such tools is both resource and time consuming. While most of neurological imaging takes place in outpatient centers, resource and workflow limitations of such clinics do not allow for the application of advanced image analysis. Here, we present the integration the “ExploreASL” into the PACS-connected research platform IntelliSpace Discovery.

Xiaomeng Zhang¹, Xiaoqing Yang², Karthikeyan Subramanian³, Bradley A Hooker¹, Mark Haacke³, Ivonne Suridjan¹, Qi Guo¹, Robert Comley¹, Adam Ziemann⁴, and Yanping Luo^1
1Translational imaging, iSAT, Abbvie Inc., North Chicago, IL, United States, ²Data & Statistical Sciences, Abbvie Inc., North Chicago, IL, United States, ³Wayne state university, Detroit, MI, United States, ⁴Neuroscience Development, Abbvie Inc., North Chicago, IL, United States

Quantitative brain MRI was used to evaluate 18 RRMS patients and 10 age matched controls at baseline and 6 months. The study aimed to assess test-retest reproducibility in healthy controls, disease variability in the RRMS population, and sensitivity to disease progression of each MRI-derived parameter. The results will inform the selection of MRI measures to be used as biomarkers in future clinical trials. In addition, longitudinal multiparametric assessment of MS lesions may improve our understanding of different pathological components of such lesions (e.g. inflammation, demyelination, and iron accumulation) during disease progression.

Salil Soman¹, Kyuwon Lee², Magdy Selim³, Aristotelis Filippidis⁴, Ajit Thomas⁴, Pascal Spincemaille⁵, and Yi Wang^5
1Beth Israel Deaconess Medical Center / Harvard Medical School, Boston, MA, United States, ²Radiology, Beth Israel Deaconess Medical Center / Harvard Medical School, Boston, MA, United States, ³Neurology, Beth Israel Deaconess Medical Center / Harvard Medical School, Boston, MA, United States, ⁴Neurosurgery, Beth Israel Deaconess Medical Center / Harvard Medical School, Boston, MA, United States, ⁵Radiology, Weill Cornell Medicine, New York, NY, United States

Cerebral microbleeds are bleeds < 1 cm seen on MRI, not visible on CT, which play a role in diagnosing disease and identifying risks of developing multiple diseases. Many susceptibility based techniques, such as SWI require a phase map to distinguish CMB from calcification. However, studies have demonstrated that for non-CMB bleeds on GRE and SWI, the phase dominant sign may differ across slices, preventing clinical interpretation. We compared the dominant sign for candidate CMBs on SWI phase maps and MEDI QSM images, and found that QSM images showed much less change in dominant sign than SWI phase maps.

 

Eberhard Daniel Pracht¹, Philipp Ehses¹, Hankyeol Lee², Kamil Uludag^2,3, and Tony Stoecker^1,4
1German Center for Neurodegenerative Diseases, Bonn, Germany, ²Center for Neuroscience Imaging Research, Institute for Basic Science & Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of, ³Techna Institute & Koerner Scientist in MR Imaging, University Health Network, Toronto, ON, Canada, ⁴Department of Physics and Astronomy, University of Bonn, Bonn, Germany

In this work, we present an optimized, scan-time efficient multi-echo MP2RAGE sequence (ME-MP2RAGE) for improved brain segmentation at ultra-high field. Apart from removing B₁-, M₀, and T₂* dependencies (MP2RAGE features), the proposed method removes susceptibility induced image distortions along the readout direction. Additionally, an optimized reordering scheme was implemented for scan-time optimization.

KAVITA SINGH¹, María Guadalupe García-Gomar¹, and Marta Bianciardi^1
1Brainstem Imaging Laboratory, Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States

Human ventral tegmental area and its parabrachial pigmented nucleus are involved in attention, memory, reward, drug abuse, and motivation. Mesencephalic and isthmic reticular formation nuclei are implicated in the control of head/eye movement and position. Currently, their assessment in radiological investigations is difficult due to the limited-resolution and contrast of clinical MRI. We precisely delineated these nuclei on 7 Tesla MRI of healthy humans and generated a validated in-vivo stereotaxic probabilistic atlas of these structures. Upon coregistration to clinical MRI, this atlas might improve the evaluation of lesions and assessment of connectivity pathways underlying clinical conditions relating to these nuclei.

Chanon Ngamsombat^1,2, Maria Gabriela Figueiro Longo^1,3, Augusto Lio M. Gonçalves Filho^1,3, Stephen F. Cauley^1,4, Kawin Setsompop^1,4,5, Qiyuan Tian¹, Qiuyun Fan¹, Daniel Polak^6,7, Wei Liu⁸, Wei-Ching Lo⁷, Ramon Gilberto González^3,4, Pamela W. Schaefer^3,4, John E. Kirsch^1,3, Otto Rapalino^3,4, John Conklin^1,3, and Susie Y. Huang^1,3,5
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, ²Faculty of Medicine, Siriraj Hospital Mahidol Univerity, Bangkok, Thailand, ³Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, Boston, MA, United States, ⁴Harvard Medical School, Boston, MA, United States, ⁵Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, ⁶Department of Physics and Astronomy, Heidelberg University, Heidelberg, Heidelberg, Germany, ⁷Siemens Healthineers AG, Erlangen, Erlangen, Germany, ⁸Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Shenzhen, China

Quantification of cerebral white matter lesion volume has become increasingly feasible for routine clinical evaluation and research due to the availability of automated segmentation tools and 3D FLAIR sequences. However, these sequences suffer from long acquisition times, limiting their widespread use. We demonstrate that quantitative white matter lesion volumes estimated using ultrafast Wave-CAIPI SPACE-FLAIR obtained in <3 minutes show excellent agreement with standard SPACE-FLAIR requiring >7 minutes of scanning in patients undergoing clinical evaluation for suspected MS and epilepsy. Wave-CAIPI SPACE-FLAIR may facilitate the adoption of 3D FLAIR sequences for lesion evaluation in patients with MS and other white matter diseases.

Augusto Lio Mota Goncalves Filho^1,2, Maria Gabriela Figueiro Longo^1,2, John Conklin^1,2, Stephen Cauley^1,2, Daniel Polak³, Wei Liu⁴, John Kirsch^1,2, Kawin Setsompop^1,2, Ramon Gilberto Gonzalez¹, Pamela Schaefer¹, Susie Yi Huang^1,2,5, and Otto Rapalino^1
1Radiology, Massachusetts General Hospital, Boston, MA, United States, ²Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ³Siemens Healthineers, Erlangen, Germany, ⁴Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, ⁵Harvard Medical School, Boston, MA, United States

We present the first large-scale evaluation of the diagnostic performance and image quality of highly accelerated Wave-CAIPI post-contrast 3D-T1 SPACE (Wave-T1 SPACE) compared to standard post-contrast 3D-T1 SPACE for the detection of intracranial enhancing lesions in patients undergoing 3T MRI scanning. Two neuroradiologists assessed the images in a head-to-head comparison, and found no significant difference between the two sequences for detection of abnormal intracranial enhancement and overall diagnostic quality, despite a nearly 3-fold decrease in acquisition time of post-contrast Wave-T1 SPACE. The application of highly-accelerated 3D imaging may improve use of MRI resources while reducing motion artifacts and patient anxiety. 

Xin Li¹, Yue Qin¹, Shaoyu Wang², Xiang Feng³, Yifan Qian¹, Juan Tian¹, Liyao Liu¹, Yinhu Zhu¹, Boyuan Jiang¹, and Yanqiang Qiao^1
1XI’AN DAXING HOSPITAL, ShaanXi, Xi’an, China, ²Siemens Healthcare Ltd., ShaanXi, Xi’an, China, ³Siemens Healthcare Ltd., Beijing, China

Hypertension is known to be a major risk factor for damage to target organs, including the brain. Hypertension may be associated with increased heme content and non-heme iron contents. QSM is a potent imaging method that can provide a noninvasive and accurate measurement of iron content in the brain for diagnosing diseases and monitoring progression and treatment. This study evaluated the feasibility of QSM in the measurement of brain iron deposition in patients with hypertension. We found increased iron accumulation primarily in the deep gray matter nucleus in hypertensive patients.

Xin Li¹, Yue Qin¹, Shaoyu Wang², Xiang Feng³, Juan Tian¹, Yifan Qian¹, Yinhu Zhu¹, Liyao Liu¹, Yanqiang Qiao¹, and Boyuan Jiang^1
1XI’AN DAXING HOSPITAL, ShaanXi, Xi’an, China, ²Siemens Healthcare Ltd, ShaanXi, Xi’an, China, ³Siemens Healthcare Ltd., Beijing, China

Hypertension is becoming a common health problem worldwide with increasing life expectancy and increasing prevalence of risk factors. Hypertension was positively associated with body mass index. Previous studies have detected that increased iron accumulation mainly in deep gray matter nucleus and CSF in hypertensive patients. There has no study about the correlates of physiological parameters and magnetic susceptibility of brain in hypertension. The present study used Pearson's correlation test to compare the relationship between the magnetic susceptibility of brain tissue and BMI, maximum systolic blood pressure and maximum diastolic blood pressure in hypertensive patients.

Umang Pandey¹, Jitender Saini², Rakesh Gupta³, and Madhura Ingalhalikar^1
1Symbiosis Centre For Medical Image Analysis, Symbiosis International University, Pune, India, ²Department of Radiology, National Institute of Mental Health and Neurosciences, Bengaluru, India, ³Department of Radiology, Fortis Hospital, Gurgaon, India

Radiomics has gained momentum as a non-invasive prediction tool to assess MRI based tumor data in neuro-oncology. However, there’s little understating about the robustness and reproducibility of these features in normative population which is an important first step before translating to pathology. This work investigates and demonstrates the reproducibility of radiomic features on T2-FLAIR images and variation within hemispheres and lobes and its gender and age-related effect. Overall, our findings suggest that care must be taken while interpreting these features for pathological inference.

Khin Khin Tha^1,2, Daisuke Sawamura³, Xinnan Li³, Yuta Urushibata⁴, Keita Ogawa⁵, Kohsuke Kudo^1,2, and Hiroki Shirato^2
1Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan, ²Global Station for Quantum Medical Science and Engineering, Hokkaido University, Sapporo, Japan, ³Department of Biomarker Imaging Science, Hokkaido University Graduate School of Biomedical Science and Engineering, Sapporo, Japan, ⁴Siemens Healthcare, Tokyo, Japan, ⁵Department of Rehabilitation, Hokkaido University Hospital, Sapporo, Japan

This prospective study  was aimed to identify the diffusion imaging correlates of neurocognition. Newly developed diffusion-imaging sequences, i.e., oscillating gradient spin-echo (OGSE), pulsed gradient spin-echo (PGSE), and double diffusion encoding (DDE) sequences, were acquired in 30 healthy adults.  The diffusion imaging indices were tested for correlation with the neuropsychological test scores. The microscopic fractional anisotropy (υFA) and fractional anisotropy (FA) of the right caudate nucleus, the υFA of the right temporal lobe, and the OGSE sequence-derived apparent diffusion coefficient (ADC) of the right sublobar white matter showed significant correlations with forward digit span test or trail-making test part-B. 

Masaaki Hori^1,2, Masanori Ozaki³, Hiroshi Kusahara⁴, Masahiro Abe⁴, Shuji Sato⁵, Seiko Shimizu⁶, Kouhei Kamiya^1,7, Toshiaki Akashi², Koji Kamagata², and Shigeki Aoki^2
1Toho University Omori Medical Center, Tokyo, Japan, ²Radiology, Juntendo University School of Medicine, Tokyo, Japan, ³Research and Development Center, Canon Medical Systems Corporation, Kanagawa, Japan, ⁴Advanced MRI development PJ Team, Canon Medical Systems Corporation, Kanagawa, Japan, ⁵Juntendo University Hospital, Tokyo, Japan, ⁶Canon Medical Systems Corporation, Tokyo, Japan, ⁷Radiology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan

We investigated the values and image contrast of μFA using double diffusion encoding in patients with brain tumors in vivo, as a preliminary study. In general, μFA showed higher values than FA did in the brain tumors.  There is no correlation among μFA and FA and ADC, in the meningiomas and solid part of glioblastoma and malignant lymphoma. However, more investigation will be needed to establish the usefulness of μFA in clinical use.

Jian Shen¹, Chau Vu¹, Soyoung Choi², Aart Nederveen³, and John Wood^1,4
1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, ²Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States, ³Academic Medical Center, Amsterdam, Netherlands, ⁴Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States

This study demonstrated tissue oxygen extraction change in patients with sickle cell disease after Acetazolamide injection using Asymmetric Spin Echo technique, and compared with global oxygen extraction change revealed by TRUST. The results suggested that global oxygen extraction decreased as blood flow increased, while tissue oxygen extraction remained stable. And this mismatch might be a proof to the existence of "physiological shunting".

Qing Fu¹, Xiao-yong Zhang², Ding-xi Liu¹, and Xian-bo Deng^1
1Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, ²MR Collaborations, Siemens Healthcare Ltd., Shenzhen, China

This study compared the clinical utility of the pointwise encoding time reduction with radial acquisition (PETRA) sequence in subtraction-based magnetic resonance angiography (MRA) with conventional time-of-flight MRA (TOF-MRA) for evaluating intracranial saccular aneurysms. The results showed no substantial differences between PETRA-MRA and TOF-MRA in detecting, localizing, and determining the size of aneurysms. Furthermore, PETRA-MRA produced better image quality and provided a higher correlation with computed tomography angiography (CTA) in assessing morphologic parameters of aneurysms than TOF-MRA.

Su Xiaoyun¹, Zheng Chuansheng¹, Kong Xiangquan¹, Lu Zuneng², Osamah Alwalid¹, and Zhang Huiting^3
1Radiology, union hospital, tongji medical college, Huazhong University of science and technology, Wuhan, China, ²Neurology, Renming Hospital of Wuhan University,, Wuhan, China, ³MR Scientific Marketing, Siemens Healthcare, Shanghai, China

Conventional imaging is insufficient for diagnosis and management of patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Brachial and lumbosacral plexus of 37 CIDP patients and 37 age and gender-matched controls were examined by using multi-sequences. Our study showed that fractional anisotropy (FA) had the most sensitivity, while contrast-enhanced ratio (CR) had the most specificity in single-parameter. The combination of FA and CR value had the best diagnostic efficiency. FA had a negative correlation with course duration, and CR positive correlation with CSF protein. SPACE combined with DTI and contrast enhancement sequences serve as a recommended composite protocol.

Su Xiaoyun¹, Wang Jing¹, Chi Bin¹, Zhu Qing², Zhang Huiting³, Zhang Xiaoyong⁴, and Zheng Chuansheng^1
1Radiology, union hospital, tongji medical college, Huazhong University of science and technology, Wuhan, China, ²Neurology, union hospital, tongji medical college, Huazhong University of science and technology, Wuhan, China, ³MR Scientific Marketing, Siemens Healthcare, Shanghai, China, ⁴Shanghai Key Laboratory of Magnetic Resonance,East China Normal University, Shanghai, China

The mean apparent propagator (MAP) MRI is an advanced diffusion model proposed recently for brain microstructure imaging. In this study, the MAP-MRI model was applied in diagnosis of migraineurs patient without aura. The results found that the parameter of MAP-MRI showed significant differences in in superior frontal gyrus, temporal lobe, cingulate gyrus, parahippocampal gyrus, hippocampus and left amygdata in MWoAs between patients and healthy controls. These findings further suggest involvement of the gray matter in pathology of migraine without aura.

Ken Chang¹, James Brown², Praveer Singh¹, Jay Patel¹, Katharina Hoebel¹, Andrew Beers³, Bruce Rosen¹, Jayashree Kalpathy-Cramer¹, and Hakan Ay^1
1Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ²University of Lincoln, Lincoln, United Kingdom, ³University of Washington, Seattle, WA, United States

It is currently not fully known what parts of the human brain predispose to neurogenic organ injury when injured. In this study, we aimed to identify the neuroanatomic correlates of a broad range of cardiac and systemic alterations occurring after ischemic stroke. Using a mapping technique that is free from the bias of a-priori hypothesis as to any specific location, we show that both cardiac and systemic abnormalities occurring after stroke map to specific infarct locations on diffusion-weighted MR. We show that these maps are predictive of the abnormalities as well as patient outcomes.

Antonio Ricciardi^1,2, Francesco Grussu^1,3, Ferran Prados^1,2,4, Baris Kanber², Rebecca S Samson¹, Daniel C Alexander³, Declan T Chard^1,5, and Claudia A M Gandini Wheeler-Kingshott^1,6,7
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, United Kingdom, ²Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, ³Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom, ⁴Universitat Oberta de Catalunya, Barcelona, Spain, ⁵National Institute for Health Research (NIHR) University College London Hospitals (UCLH) Biomedical Research Centre, London, United Kingdom, ⁶Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy, ⁷Brain MRI 3T Research Center, IRCCS Mondino Foundation, Pavia, Italy

Magnetisation transfer ratio (MTR) is a popular MR-modality for the identification of brain anomalies in multiple sclerosis due to its sensitivity to myelin changes. It however requires dedicated sequences with long acquisition times, which make its applicability in clinics less feasible. In this work, deep learning U-net architectures have been used to extract MTR information directly from routine qualitative images, bypassing the need for specialised acquisitions. Results show strong correlation with MTR and agreement between regional distributions in normal appearing tissues, both in healthy controls and multiple sclerosis patients.

Tae Kim¹ and James T Becker^1
1University of Pittsburgh, Pittsburgh, PA, United States

In order to obtain cardiac waveforms in the brain for studies with incomplete measurement by pulse-oximeter, we developed a technique to map cardiac pulsation directly from fMRI data itself. We compared the cardiac-phase from our method with that from pulse-oximeter and found they are highly correlated (r > 0.8).  

Zhehao Hu^1,2, Anthony G. Christodoulou¹, Nan Wang^1,2, Yibin Xie¹, Bin Sun³, Xiaoming Bi⁴, Fei Han⁴, Shlee S. Song⁵, Marcel M. Maya⁶, Debiao Li^1,2,7, and Zhaoyang Fan^1,2,7
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Bioengineering Department, University of California, Los Angeles, Los Angeles, CA, United States, ³Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, China, ⁴Siemens Healthineers, Los Angeles, CA, United States, ⁵Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ⁶Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ⁷Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States

Perfusion MR imaging (i.e. DCE, DSC) has evolved as an increasingly common modality for evaluating a variety of cerebrovascular diseases, such as stroke and brain tumors, and susceptibility weighted imaging (SWI) is suitable for detection of intracranial hemorrhage. In this work, we developed an MR MultiTasking based Dynamic Imaging for Cerebrovascular Evaluation (MT-DICE) technique that can provide DCE, DSC and SWI information simultaneously with one 8-minute scan and a single contrast agent injection. Feasibility of MT-DICE was demonstrated in healthy volunteers and patients with hemorrhagic stroke or brain cancer.

Martijn Nagtegaal¹, Ingo Hermann^1,2, Sebastian Weingärtner¹, Jeroen de Bresser³, and Frans Vos^1
1Department of Imaging Physics, Delft University of Technology, Delft, Netherlands, ²Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ³Department of Radiology, Leiden University Medical Centre, Leiden, Netherlands

We propose a novel multi-component analysis for MR fingerprinting that enables detection of small lesions, while taking partial volume effects into account. The algorithm uses a joint sparsity constraint limiting the number of components in local regions. It is evaluated in simulations and on MRF-EPI data from a patient with multiple sclerosis (MS). MS-lesions are separated from other tissues based on having increased T₂^* relaxation times. The improved sensitivity to multiple components makes it possible to detect components with long relaxation times within the lesion, possibly increasing our insight into these small pathologies.

Ke Gao¹, Yu Luo¹, and Yong Zhou^1
1Department of Radiology, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China

To quantitative assess the differential between cerebral microbleeds and calcification in susceptibility weight imaging mapping. We quantified the magnetic susceptibility value of calcifications and cerebral microbleeds(CMBs) in susceptibility weight imaging mapping. Significant difference of magnetic susceptibility value was found between them. The 95% confidence interval for the magnetic susceptibility value of the calcification and CMBs was different. The optimal threshold to detecting CMBs was selected by receiver operating characteristic. The conclusion was that magnetic susceptibility value can used to differential diagnose cerebral microbleeds and calcification in the susceptibility weighted imaging mapping.

Shabnam Khorasani Gerdekoohi¹, Hsu-Lei Lee¹, Helena Hung-Yin Huang¹, Pankaj Sah¹, and Kai-Hsiang Chuang^1,2
1Queensland Brain Institute, University of Queensland, Brisbane, Australia, ²Centre for Advanced Imaging, University of Queensland, Brisbane, Australia

Neural calcium activity of genetic reporter GCaMP6f was successfully recorded in 9.4T MRI.

Event-related BOLD activation can be measured using short stimuli.

Susceptibility artefacts from the optic fiber and dental cement affect fMRI quality.

Fan Qiuju¹, Tan Hui¹, Yang Zhen¹, Yu Nan¹, Yu Yong¹, Wang Shaoyu², Xue Yu³, and Li Yue^3
1Affiliated Hospital of Shaanxi University of Chinese Medicine, Shaanxi, China, ²MR senior scientific marketing specialist, Shaanxi, China, ³Shaanxi University of Chinese Medicine, Shaanxi, China

This study aimed to quantitative measurement of cerebral blood flow in different brain regions of different levels of blood pressure by mTI ASL. In the first part of this study, we evaluated the reproducibility of mTI-ASL in healthy subjects, and then mTI-ASL was used to evaluate 55 primary hypertension patients. There was no major variation between two consecutive mTI-ASL measurements in healthy volunteers. Furthermore, the rCBF and ATT values provided valuable information for the classification of hypertension, which can be used as a non-invasive quantitative monitoring MRI tool for hypertension progression.

Mayank A Jog¹, Kay Jann¹, Lirong Yan¹, Chenyang Zhao¹, Bhargavi Kannan¹, and Danny JJ Wang^1
1University of Southern California, Los Angeles, CA, United States

High-definition transcranial direct current stimulation (HD-tDCS) is an emerging neuromodulation technique that uses a multi-electrode montage to focally modulate regional brain activities. However, the effects of stimulation have been shown to be variable across subjects, and efforts to investigate this have been hampered by an inability to visualize the electric current distribution in-vivo. To address this, we developed a MR technique that maps the tDCS current induced magnetic fields in-vivo. The measured fields were robust (avg. ICC = 0.69) and show different hotspot-locations between subjects, potentially demonstrating the sensitivity of this technique to track individual differences in responses to HD-tDCS.

Pulkit Khandelwal¹, Carrie E. Zimmerman², Long Xie³, Hyunyeol Lee³, Cheng-Chieh Cheng³, Scott P. Bartlett², Paul Yushkevich³, and Felix W. Wehrli^3
1Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States, ²Division of Plastic Surgery, Children’s Hospital of Philadelphia, Philadelphia, PA, United States, ³Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States

Bone-selective Magnetic Resonance Imaging (MRI) produced by a Dual Radiofrequency (RF), dual‐echo, 3D Ultrashort Echo Time (UTE) pulse sequence and bone‐selective image reconstruction process provides a radiation-free imaging modality with high concordance to computed tomography (CT). This imaging technique is of specific interest to craniofacial surgeons. Here, we pilot the use of an automated segmentation pipeline on the bone-selective MR images with the goal of reducing time required for the 3D segmentation step. This automated segmentation pipeline, used with bone-selective MRI could eliminate the need for radiative CT thereby reducing the risk of malignancy in pediatric craniofacial patients.

Azusa Sakurama¹, Yasutaka Fushimi¹, Satoshi Nakajima¹, Yusuke Yokota¹, Sonoko Oshima¹, Sayo Otani¹, Krishna Pandu Wicaksono¹, Tomohisa Okada², Wei Liu³, and Kaori Togashi^1
1Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, ²Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan, ³Siemens Healthineers AG, Shenzhen, China

This comparison study between MPRAGE with GRAPPA and MPRAGE with Wave-CAIPI has been performed at the clinical MR scanner. MPRAGE with Wave-CAIPI 3×3 shows relatively good contrast despite its short scan time of 1 m 42 s. No segmentation error was found in MPRAGE with Wave-CAIPI 3×3 in our cohort. The correlation of cerebral cortex and cerebral white matter was very high between 2 MPRAGEs. In deep gray matters except pallidum and hippocampus, the correlation of VOIs were also high. These results suggest that volumes derived from automated segmentation of MPRAGE with Wave-CAIPI are reliable measures.

Xiaotian T. Fang¹, Takuya Toyonaga¹, Ansel T. Hillmer^1,2, Patrick D. Worhunsky², and Richard E. Carson^1
1Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, ²Psychiatry, Yale School of Medicine, New Haven, CT, United States

Resting-state networks, functionally connected brain regions, are canonically investigated with resting-state functional-MRI. ¹¹C-UCB-J is a recently developed PET tracer that binds and visualizes synaptic vesicle protein 2A. The aim is to identify networks of coherent ¹¹C-UCB-J covariation patterns using independent component analysis. We find modest similarity between five ¹¹C-UCB-J PET-based synaptic density sources and rs-fMRI template RSNs. In several sources, there are varying rates of age-related change in subject loading weight, consistent with functional changes in RSNs and age-related gray matter decline. Our findings support the independency of such networks and potential physiological links between synaptic density and brain function.

Sina Mansour L.¹, Ye Tian², Vanessa Cropley², and Andrew Zalesky^1,2
1Department of Biomedical Engineering, The University of Melbourne, Melbourne, Australia, ²Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Melbourne, Australia

Neuroimaging-derived brain phenotypes can be used to identify individuals and predict behavior. We investigated the prediction and identification performance of brain structure and connectivity phenotypes derived from structural, functional and diffusion MRI. Five behavioral domains were predicted: cognition, illicit substance use, tobacco use, personality-emotion traits, and mental health. We arranged the phenotypes on a two-dimensional prediction-identification landscape. Functional connectivity performed better at prediction than identification, whereas the converse was found for curvature and other structural phenotypes. Structural connectivity performed well for both tasks. High-resolution measures outperformed atlas-based counterparts. Our work can aid brain phenotype selection in future neuroimaging studies.

Babak Moghadas¹, Arati Sridharan¹, Livia De Mesquita¹, Yuka Sugamura¹, Jitendran Muthuswamy¹, and Vikram D Kodibagkar^1
1Biomedical engineering, Arizona State University, Tempe, AZ, United States

There is a significant need to spatially map the pO2 levels around chronically implanted neural devices to assess the impact on surrounding tissue. Here we apply a quantitative MRI based oximetry approach to map pO2 around neural interfaces. Electrodes were coated with polydimethylsiloxane matrix and soaked in tetradecamethylhexasiloxane, which was characterized and used as a 1H MR pO2 reporter along with the previously developed PISTOL technique. Tissue pO2 in response to air and oxygen breathing was successfully measured from around implanted electrodes. Future studies will combine single-unit electrophysiology with quantitative, high resolution spatial maps of pO2 levels in vivo.

Alessandra Caporale¹, Hyunyeol Lee¹, Hui Lei², Hengyi Rao³, Michael C Langham¹, Alessandra A Caporale², and Felix W Wehrli^1
1Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States, ²Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States, ³Psychiatry, Division of Sleep and Chronobiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States

Radial OxFlow, a technique able of measuring cerebral metabolic rate of oxygen (CMRO₂) dynamically, has been combined with simultaneous electroencephalography (EEG) recording, during the natural onset of sleep and maintenance during a 50-min period of scanning. During sleep, CMRO₂ (measured continuously with an effective temporal resolution of 3.4 seconds) decreased up to 24% with respect to pre-sleep wakefulness. CMRO₂ changes were positively correlated with heart rate (r²=0.25-0.48, P<0.0005), and negatively with changes in EEG slow-wave activity (r²=0.41-0.67, P<0.005), when sleep onset and maintenance occurred. 

Nai-Chi Chen¹, Cheng-Chia Lee^2,3,4, Yo-Tsen Liu^3,5,6, Chien-Chen Chou², Chung-Jung Lin⁷, Wan-Yuo Guo^3,7, Wen-Yuh Chung^2,3, and Chia-Feng Lu^1
1Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan, ²Department of Neurosurgery, Neurological Institute, Taipei Veteran General Hospital, Taipei, Taiwan, ³School of Medicine, National Yang-Ming University, Taipei, Taiwan, ⁴Brain Research Center, National Yang-Ming University, Taipei, Taiwan, ⁵Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ⁶Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, ⁷Department of Radiology, Taipei Veteran General Hospital, Taipei, Taiwan

Cavernous malformation (CM) is one of the common cause for seizure attacks. Till now, the relationships between the structural characteristics of CM and the resultant abnormality of neural activity are still less explored. We employed MR radiomics analysis and EEG functional connectivity analysis to investigate whether quantitative and non-invasive features derived from these approaches can be used to differentiate CM patients with and without seizure. Furthermore, the association between structural and functional characteristics of CM were unraveled.

Bertwin Zhicheng Chen¹, Reuben Chee Cheong Soh^1,2, Septian Hartono^2,3, Chu Ning Ann³, Ming-Ching Wen³, Weiling Lee¹, Soo Lee Lim⁴, Julian Gan⁵, Yew Long Lo^2,3, and Ling Ling Chan^1,2
1Singapore General Hospital, Singapore, Singapore, ²Duke-NUS Medical School, Singapore, Singapore, ³National Neuroscience Institute, Singapore, Singapore, ⁴National Heart Centre Singapore, Singapore, Singapore, ⁵Siemens Healthineers, Singapore, Singapore

The aetiopathogenesis of adolescent idiopathic scoliosis (AIS) remains elusive, with studies suggesting a neurological basis. Using a case control, multimodal approach incorporating volumetry and diffusion tensor imaging, we characterised brain MRI changes in AIS. The pontine volume was significantly larger while left insula was smaller in patients than controls. Whole brain Tract-Based Spatial Statistics (TBSS) showed no difference between subject cohorts. Tractography of the corticoreticular pathway (CRP), which innervates the axial muscles, showed significant differences in mean and axial diffusivity between the left and right CRP only in the patient cohort, but no such asymmetry in the control cohort.

Christian Prinz¹, Fatima Sherazi¹, Ludger Starke¹, Paula Ramos Delgado¹, Andre Kuehne², Thoralf Niendorf^1,2,3, and Sonia Waiczies^1
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, ²MRI TOOLS GmbH, Berlin, Germany, ³Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany

Siponimod is a trifluorinated anti-inflammatory drug indicated for Multiple Sclerosis that could be potentially tracked in pharmacokinetic studies by fluorine-19 (¹⁹F) MR techniques in order to support therapeutic monitoring. In this study, we investigated the ¹⁹F MR properties of siponimod and its dependency on environmental factors. We found a temperature dependence of the relaxation times T₁ and T₂ and identified a T₂-drop in the presence of human serum. We identified UTE as SNR-efficient MR pulse sequence to study siponimod physiologically and show the potential of tailoring MR methods in the future to individual patient therapeutic needs.

shenghui Xie¹, shaoyu Wang², xu Yan², huapeng Zhang², guang Yang³, and yang Gao^1
1Department of radiology, affiliated hospital of Inner Mongolia medical university, Hohhot, China, ²MR Scientific Marketing, Shanghai, China, ³Shanghai Key Laboratory of Magnetic Resonance, Shanghai, China

The purpose of this study was to evaluate the value of diffusion spectrum imaging (DSI) MAP diffusion model in the changes of brain tissue microstructure in patients with primary essential hypertension, as well as the differences of various parameters including RTOP, RTAP, RTPP, QIV and MSD between the hypertensive group and the normal control group. The results showed that there were significant differences between RTOP and QIV. All the MAP-MRI parameters showed obvious differences in detecting the changes of brain structure microstructure in the early stage of hypertension, especially the RTOP and QIV parameters.

Anna Crawford¹, Stephen Jones¹, and Mark Lowe^1
1Imaging Institute, Cleveland Clinic Foundation, Cleveland, OH, United States

Many advanced imaging application require the identification of seed and target ROIs. Due to size, and signal characteristics some brain structures including brainstem nuclei are difficult to identify with MR imaging, while other types of imaging such as PET have other drawbacks such as poor spatial resolution. We have come up with a “recipe” for defining the ventral tegmental area (VTA) as well as the dorsal raphe nucleus (DRN) using three anatomic atlases. The definition of these ROIs were confirmed with PET imaging. Our method allows for robust, reproducible ROIs using only a high resolution T1 weighted image.

Sayo Otani¹, Yasutaka Fushimi¹, Satoshi Nakajima¹, Yusuke Yokota¹, Sonoko Oshima¹, Azusa Sakurama¹, Krishna Pandu Wicaksono¹, Yuichiro Sano², Ryo Matusda², Masahito Nambu², Koji Fujimoto³, Hitomi Numamoto⁴, Kanae Kawai Miyake⁴, Tsuneo Saga⁴, and Kaori Togashi^1
1Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, ²MRI Systems Division, Canon Medical Systems Corporation, Kyoto, Japan, ³Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan, ⁴Department of Advanced Medical Imaging Research, Kyoto University Graduate School of Medicine, Kyoto, Japan

We have demonstrated six-fold accelerated submillimeter whole brain 3D T2-weighted imaging with deep learning reconstruction (DLR) showed better coefficient of variation and signal ratio compared with that without DLR. Scan time of around 2.5 min is clinically feasible and the delineation of fine structure is preserved after DLR processing.

3D T2-weighted image with better image quality derived from DLR will help clinicians and radiologists evaluate CSF space abnormalities, and its short scan time will be feasible for routine clinical examinations.

Kai Laukamp¹, Lenhard Pennig¹, Frank Thiele¹, Robert Reimer¹, Lukas Goertz¹, David Zopfs¹, Georgy Shakirin¹, Marco Timmer¹, Michael Perkuhn¹, and Jan Borggrefe^1
1UKK, Cologne, Germany

We trained an established deep-learning-model architecture (3D-Deep-Convolutional-Neural-Network, DeepMedic) on manual segmentations from 70 meningiomas independently segmented by two radiologists. The trained deep-learning model was then validated in a group of 55 meningiomas. Ground truth segmentations were established by two further radiologists in a consensus reading. In the validation-group the comparison of the automated deep-learning-model and manual segmentations revealed average dice-coefficients of 0.91±0.08 for contrast-enhancing-tumor volume and 0.82±0.12 for total-lesion-volume. In the training-group, interreader-variabilities of the two manual readers were 0.92±0.07 for contrast-enhancing-tumor and 0.88±0.05 for total-lesion-volume. Deep-learning based automated segmentation yielded high segmentation accuracy, comparable to manual interreader-variability.

Cong Xie¹, Yaou Liu¹, Rongkai Ju², Zhiwei Shen², Zhizheng Zhuo¹, Yunyun Duan¹, Xiaobo Wang¹, Qiong Qiu¹, and Fenglian Zheng^1
1Department of Radiology, Beijing Tiantan Hospital, Beijing, China, ²Philips,healthcare,China, Beijing, China

explorer the performance of in APTw with Compress Sense (CS) in the evaluation of glioma with high grade and low grade.

Alan C Seifert^1,2,3, Joseph A Borrello^1,2,3, Jessie Laffey⁴, Etty Cortes⁴, Tamjeed Sikder⁴, Enna Selmanovic⁵, Bradley N Delman², John Crary⁴, Kristen Dams-O'Connor⁵, and Junqian Xu^1,2,3,6
1Biomedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ²Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ³Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ⁴Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ⁵Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ⁶Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States

Whole-brain ex vivo MRI has proven extremely valuable in neuroscience research, but detailed descriptions of the specific preparation and packaging steps to minimize motion, susceptibility artifacts, and background signal are often missing from reports of experimental findings.  We present the design of a reproducible container and a detailed protocol that yield whole-brain images uncorrupted by susceptibility artifacts.  The most important steps to eliminate susceptibility artifacts due to residual air bubbles are removal of the leptomeninges, application of vacuum to dislodge bubbles, immersion in Fluorinert, and rolling of the sealed container, although removal of leptomeninges may be undesirable in some cases.

Evan Hunter Stanton¹, Niklas Daniel Åke Persson¹, Björn Sigurdsson¹, Tuomas Lilius¹, Humberto Mestre², Maiken Nedergaard¹, and Yuki Mori^1,3
1Division of Glial Disease and Therapeutics, University of Copenhagen, Center for Translational Neuromedicine, Copenhagen, Denmark, ²Division of Glial Disease and Therapeutics, University of Rochester Medical Center, Center for Translational Neuromedicine, Rochester, NY, United States, ³Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, Panum NMR Core Facility, Copenhagen, Denmark

The glymphatic system is a brain waste clearance pathway based on cerebrospinal fluid (CSF) and interstitial fluid exchange. As such, this pathway plays important roles in both acute and neurodegenerative conditions. With 3D-FISP-based fast imaging, we investigated how anesthetic regiments, i.e., ketamine-xylazine (K/X) versus isoflurane, influences the movement of tracer through the brain. This was achieved by conducting acute cisterna magna cannulations, tracer scanning using 3D-FISP, and calculating dynamic tracer distribution maps. Our analysis demonstrates that anesthesia alters the spatial and temporal distribution of CSF tracer, with K/X showing higher influx, and isoflurane shunting CSF out via deep cervical nodes.

fei gao¹, fuxin ren¹, weibo chen², and guangbin wang^1
1Shandong Medical Imaging Research Institute, Shandong University, Jinan, China, ²Philips Healthcare, shanghai, China

Distinguishing relapsing-remitting multiple sclerosis (RRMS) and neuromyelitis optica (NMO) is clinically important because they differ in prognosis and treatment. Edited magnetic resonance spectroscopy (MRS), using the MEGA-PRESS sequence, is the most widely used technique for detecting GABA in the human brain. However, none of the existing studies are performed to compare the brain GABA levels between patients with MS and NMO. In this study, we found GABA levels differences in the LHC and PCC between the RRMS and NMO patients, which may be helpful in distinguishing RRMS from NMO after further validation.

Oun Al-iedani^1,2, Karen Ribbons², Saadallah Ramadan^1,2, Rodney Lea², and Jeannette Lechner-Scott^2,3,4
1School of Health Sciences, University of Newcastle, Newcastle, Australia, ²Hunter Medical Research Institute (HMRI), Newcastle, Australia, ³School of Medicine and Public Health, University of Newcastle, Newcastle, Australia, ⁴Department of Neurology, John Hunter Hospital, Newcastle, Australia

This novel study evaluated the amount of axonal injury with neurometabolite in RRMS patients on fingolimod(N=52) and injectable(N=46) treatments compared with 51 HCs in hippocampus using advanced MRS. PRESS-MRS of the hippocampal voxel(30x15x15mm3) and clinical assessments for RRMS and HCs were acquired. Hippocampal MR-spectra were analysed by LCModel. Hippocampal-NAA/tCr decreased (fingolimod:-17%,p=0.001;injectables:-15%,p=0.01) and in Glx/tCr increased (fingolimod:+16%,p=0.001;injectables:+15%,p=0.02) in RRMS compared to HCs. Total-ARCS (r=0.402) and memory in particular (r=0.428) displayed associations with hippocampal NAA/tCr. This study is the first cross-sectional in-vivo investigation comparing the impact of fingolimod and injectable treatments on the hippocampal metabolism in RRMS patients.

Matthew Rogan^1,2, Alexander Friend², Gabriella Rossetti², Jamie Macdonald², Sam Oliver², and Paul Mullins^1
1The Bangor Imaging Centre, School of Psychology, Bangor University, Bangor, United Kingdom, ²Extremes Research Group, School of Sport Health and Exercise Science, Bangor University, Bangor, United Kingdom

Acute exposure to a moderate hypoxic environment leads to regional specific reduction in cerebral blood flow (rCBF) to the posterior cingulate cortex. Despite this, there is no concomitant reduction in the main excitatory neurotransmitter glutamate, as would be expected if the reductions in rCBF were coupled to neural activity. Our findings obtained using a combined ¹H Magnetic Resonance Spectroscopy and Arterial Spin Labelling paradigm indicate that hypoxia disrupts neurovascular coupling, as it is presently understood, in a regionally specific manner. 

Tomohisa Okada¹, Ravi Prakash Reddy Nanga², Koji Fujimoto¹, Dinh Ha Duy Thuy¹, Ravinder Reddy², Hideto Kuribayashi³, Yuta Urushibata³, Ravi Teja Seethamraju⁴, Sinyeob Ahn⁵, and Tadashi Isa^1
1Kyoto University, Kyoto, Japan, ²University of Pennsylvania, Philadelphia, PA, United States, ³Siemens Healthcare K.K., Tokyo, Japan, ⁴Siemens Healthineers USA, Burlington, MA, United States, ⁵Siemens Healthineers USA, Berkeley, CA, United States

Chemical exchange saturation transfer of the glutamate (GluCEST) contrast is considered from glutamate to be about 70 - 75 %.  Its values at the bilateral hippocampus were compared to those of ¹HMRS in 10 healthy subjects. Correlation between GluCEST contrast and glutamate from ¹HMRS measurements of all subjects was marginally significant (r = 0.44, p = 0.054), but it was statistically significant (r = 0.56, p = 0.030) when analysis was limited to ¹HMRS measurements with SNR ≥ 10. The GluCEST map gives regional difference in glutamate concentration in high resolution and is expected to facilitate investigation of the hippocampus. 

Carl-Johan Boraxbekk^1,2,3, Anna Lind¹, Esben Thade Petersen^1,4, Hartwig Roman Siebner^1,5,6, and Anouk Marsman^1
1Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Hvidovre, Denmark, ²Department of Radiation Sciences, Umeå University, Umeå, Sweden, ³Institute of Sports Medicine Copenhagen (ISMC), Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark, ⁴Center for Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark, ⁵Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, ⁶Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark

Inflammation is proposed as one of the central pillars driving ageing. This study was the first to link peripheral inflammation to brain metabolite differences during normal ageing and to associate this to visuo-spatial working memory performance. Our data shows how peripheral inflammatory markers were associated with performance on visuo-spatial working memory and glial metabolic markers in ACC, Hippocampus, and Thalamus. The findings highlight the role of glial cells as part of the neurobiological link between peripheral inflammation and cognitive performance during ageing.

Anouk Marsman¹, Anna Lind¹, Esben Thade Petersen^1,2, Hartwig Roman Siebner^1,3,4, and Carl-Johan Boraxbekk^1,5,6
1Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark, ²Center for Magnetic Resonance, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark, ³Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, ⁴Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark, ⁵Department of Radiation Sciences, Umeå University, Umeå, Sweden, ⁶Institute of Sports Medicine Copenhagen, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark

Ageing has been associated with widespread neurochemical changes and cognitive decline. The increased sensitivity and resolution of 1H-MRS at 7T could shed new light on the potential relationship between neurochemistry and cognition during ageing. Our data show that primarily levels of glial metabolic markers, and not neuronal markers, differed between younger, middle-aged and older normal individuals and were correlated with visuo-spatial working memory performance across these age groups. This suggests that glial markers may be more affected by ageing than neuronal markers and that there is a potential association between glial markers and visuo-spatial working memory performance during ageing.

Nicola Spotorno¹, Markus Nilsson², Boel Hansson², Felix Andersson³, Antonie Leuzy³, Danielle van Westen², Oskar Hansson³, and Itamar Ronen^4
1Department of Medicine, University of Pennsylvania, Philadelphia, PA, United States, ²Department of Diagnostic Radiology, Lund University, Lund, Sweden, ³Department of clinical sciences Malmö, Lund University, Lund, Sweden, ⁴Department of Radiology, Leiden University Medical Center, Leiden, Netherlands

Intraneuronal tau accumulation is a hallmark of Alzheimer's disease. Currently, positron emission tomography with tau specific ligands (Tau-PET) is the only neuroimaging method for measuring tau in AD. In this study that combines Tau-PET with diffusion weighted MRS we show that the apparent diffusion coefficient of NAA, a neuronal metabolite, is significantly lower in AD patients compared to healthy controls in a brain region that shows elevated levels of uptake of the tau-PET ligand. Standard MRS data shows elevated level of glial metabolites, suggesting concomitant gliosis of neuroinflamation. We propose ADC(tNAA) as a putative marker for tau aggregation in AD. 

Narayan Datt Soni¹, Dipak Roy², Akila Ramesh², and Anant Bahadur Patel^2
1NMR spectroscopy and Microimaging, CSIR-CCMB, Hyderabad, India, ²NMR Spectroscopy and Microimaging, CSIR-CCMB, Hyderabad, India

Alzheimer’s Disease (AD) has been categorized into familial (~5%) and sporadic AD (~95%). Familial cases are genetic whereas sporadic AD (sAD) is acquired during individual’s lifespan. Intracerebroventricular(icv) streptozotocin(stz) administered animals has been shown to resemble AD phenotype through many molecular studies. In this study we have investigated the impact of icv-stz treatment on memory and neurometabolic activity by infusion of [1,6-¹³C₂]Glucose and [2-¹³C]Acetate in conjunction with NMR spectroscopy. Our findings have shown the compromised memory, perturbed neurometabolic homeostasis along with decreased synaptic neurotransmission across glutamatergic and GABAergic synapse in cortical and hippocampal brain regions of icv-stz treated mouse.

Lazar Fleysher¹, Mounir El Mendili², Guilaume Madelin³, Fernando Boada ³, and Matilde Inglese^2
1Mount Sinai Medical Center, New York, NY, United States, ²Icahn School of Medicine at Mount Sinai, New York, NY, United States, ³NYU School of Medicine, New York, NY, United States

We report results of a comparison of three methods of tissue sodium concentration (TSC) quantification which use GRE, FLORET and TPI acquisition techniques at different field strengths. Results demonstrate a good inter-method agreement (better than 10%) in TCS quantification.

Xinnan Li¹, Kagari Abiko², Yuta Urushibata³, Hiroyuki Hamaguchi¹, Sinyeob Ahn⁴, and Khin Khin Tha^5,6
1Department of Biomarker Imaging Science, Hokkaido University Graduate School of Biomedical Science and Engineering, Sapporo, Japan, ²Hokkaido University Hospital, Sapporo, Japan, ³Siemens Healthineers, Tokyo, Japan, ⁴Siemens Healthineers, San Francisco, CA, United States, ⁵Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan, ⁶Global Station for Quantum Medical Science and Engineering, Hokkaido University, Sapporo, Japan

We evaluated the extent of laterality of the diffusion spectrum imaging (DSI) indices, and tested the association of their laterality to laterality of neurometabolite concentrations derived from whole-brain MR spectroscopic imaging (MRSI). Leftward asymmetry was observed mainly in the motor structures and rightward asymmetry in the structures associated with attention and emotion. A similar pattern of GFA, NQA and FA laterality in NAA/Cr and Cho/Cr and a reversed pattern in ADC were observed. The combination of DSI and MRSI can be helpful for a better understanding of ongoing neural processes. Hemispheric lateralization needs to be paid attention when interpreting pathologies.

Jullie W Pan¹, Arun Antony², Victor W Yushmanov¹, Claud W Schirda², and Hoby P Hetherington^1
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, ²UPMC, Pittsburgh, PA, United States

Our group has implemented the rosette trajectory at 3T with 3dimensional phase and Hadamard encoding to achieve multi- and whole-slice spectroscopic images covering a total longitudinal 60mm. These acquisitions are applied in n=25 surgical epilepsy patients (15 medial temporal lobe; 10 neocortical epilepsy), evaluating metabolic dysfunction in terms of overlap with surgical target and outcome. In 19/25 patients the MRSI identified gyral regions of overlap between the abnormal MRSI and surgical therapy. Based on a 4% cut segregation of fractional volume of MRSI abnormalities, the outcome ILAE score was significantly lower (better) in patients with <=4% abnormality compared to >4%.

Reggie Taylor¹, Emma Lynn^1,2, Pierre Blier^1,2, Gerd Melkus^3,4, Verner Knott^1,2, and Natalia Jaworska^1,2
1Institute of Mental Health Research, Ottawa, ON, Canada, ²Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada, ³The Ottawa Hospital, Ottawa, ON, Canada, ⁴Radiology, University of Ottawa, Ottawa, ON, Canada

Cognitive deficits often persist beyond remission in major depressive disorder (MDD). CDP-choline has shown improvements in cognition in other populations characterized by cognitive deficits. These improvements may be due to interactions with the glutamatergic and cholinergic systems. The aim of this ongoing study was to assess the neurochemical response through magnetic resonance spectroscopy to the acute administration of CDP-choline compared with placebo in the anterior cingulate in a group of remitted MDD participants. Early results indicate possible relationships between glutamate and myo-inositol concentrations, and CDP-choline.

Teddy Salan¹, Sameer Vyas², Paramjeet Singh², Sulaiman Sheriff³, Mahendra Kumar⁴, and Varan Govind^1
1Radiology, University of Miami, Miami, FL, United States, ²Postgraduate Institute for Medical Education & Research, Chandigarh, India, ³University of Miami, Miami, FL, United States, ⁴Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, United States

The purpose of this study is to determine whether magnetic resonance spectroscopic imaging (MRSI) can identify  metabolite biomarkers of HIV infection in the brain. Concentrations of N-acetyl aspartate (NAA), choline (CHO), creatine (CR), myo-inositol (MI), and glutamate and glutamine (GLX) were measured at the whole-brain level and compared between HIV+ and healthy control subjects. Significant reductions in NAA and increases in MI are observed throughout the brain, while the concentrations of other metabolites show no significant change.