Laura C. Bell¹, Natenael B Semmineh¹, Sudarshan Ragunathan¹, and C. Chad Quarles^1
1Barrow Neurological Institute, Phoenix, AZ, United States

Clinical adoption of DSC-MRI for brain cancer imaging is plagued by reproducibility concerns. To support and advance reproducible science for DSC-MRI, an anthropomorphic phantom is developed in order to benchmark post-processing pipelines and software platforms. In addition to this anthropomorphic phantom, the technical computation of relative cerebral blood volume (rCBV) is discussed since rCBV is not an absolute measurement in DSC-MRI. In summary, this DRO-based benchmark can then be used to characterize the accuracy of commonly employed DSC-MRI algorithms and clinical software.

Sultan Zaman Mahmud^1,2, Thomas S. Denney^1,2, and Adil Bashir^1,2
1Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States, ²Auburn University MRI Research Center, Auburn University, Auburn, AL, United States

Blood-brain barrier (BBB) is crucial to prevent brain tissue from circulating toxins while allowing the delivery of nutrients from intravascular space to the central nervous system (CNS). Compromised BBB can result in brain dysfunction and degeneration. Development of reproducible non-invasive techniques to assess BBB permeability is of particular interest. Previously we had demonstrated a non-invasive technique to estimate BBB permeability using magnetization transfer (MT) effect on labeled arterial spins at 7T. In this work, we demonstrate the reproducibility of the technique. The feasibility was evaluated in healthy subjects at baseline and after caffeine challenge.

Kay Jann¹, Xingfeng Shao¹, Samantha J Ma^1,2, Karl G Helmer³, Michael Magaletta³, Mitchell J Horn⁴, Andrew D Warren⁴, Vanessa A Gonzalez⁴, Hanzhang Lu⁵, Yang Li⁵, Zixuan Lin⁵, Kaisha Hazel⁵, George Pottanat⁵, and Danny JJ Wang^1
1Laboratory of Functional MRI Technology (LOFT), USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, United States, ²Siemens Medical Solutions USA, Inc., Los Angeles, CA, United States, ³Department of Radiology, Massachusetts General Hospital and Athinoula A Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, United States, ⁴Department of Neurology, Massachusetts General Hospital and Athinoula A Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, United States, ⁵The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States

Standardized acquisition protocols have been recommended for Arterial Spin Labeling perfusion MRI across major MRI platforms. However, there are still vendor and sequence specific differences for ASL implementations that limit the use of ASL for clinical trials. Here we evaluated the repeatability of CBF measurements across 4 different MR platforms on a traveling cohort of 10 volunteers using standardized 3D background suppressed pCASL sequences. We show that while there are differences in global CBF values, relative CBF values are reproducible in major vascular territories across the 4 MRI platforms.

Feng Xu^1,2, Dan Zhu³, Hongli Fan^2,3, Hanzhang Lu^1,2, Dapeng Liu^1,2, Wenbo Li^1,2, and Qin Qin^1,2
11The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, ²F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, ³Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States

Standardized perfusion phantom allows for controlling reproducibility of arterial spin labeling (ASL) techniques across multiple sites, field strength, and vendors. Here using a commercial perfusion phantom, velocity-selective inversion (VSI) prepared ASL was compared with PCASL with an emphasis on velocity-encoding directions. While this effect is amplified on this phantom with feeding channels having only vertical and transverse flow directions, VSI-ASL with a tilted encoding direction achieved higher labeling efficiency through more uniform labeling of the entire feeding tubes. Careful selection of velocity-encoding directions along the major feeding arteries is recommended for VSASL applications to attain optimal labeling efficiency.

Salem Alkhateeb¹, Tales Santini², Tiago Martins², nadim farhat², and Tamer S. Ibrahim^2
1Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, ²University of Pittsburgh, Pittsburgh, PA, United States

A dedicated labeling coil for arterial spin labeling (ASL) technique can alleviate the challenges at 7T MRI, in this work we propose a separate 16-channel RF neck coil for transmit only. Finite-difference time-domain (FDTD) simulations and RF shimming have demonstrated the feasibility of this design to produce a homogeneous B1+ fields in the labeling region (left and right common carotid arteries) while minimizing SAR to within safe limits.      

Kai Wang¹, Samantha J Ma², Xingfeng Shao¹, and Danny JJ Wang^1
1University of Southern California, Los Angeles, CA, United States, ²Siemens Medical Solutions USA, Inc, Los Angeles, CA, United States

The transmit magnetic field (B1+) drop and B0 field inhomogeneity at the labeling plane make it challenging to achieve high labeling efficiency at ultrahigh field for pseudo-continuous Arterial Spin Labeling (pCASL). In this study, we designed the pCASL sequence with “Maxmin” shimming for the labeling and “MinCV” shimming for the acquisition utilizing the parallel transmission (pTx). Phantom and in-vivo experiments suggest MinCV shimming can improve the profile homogeneity within ROI and that Maxmin-shimmed labeling is a promising approach to increase the labeling efficiency for pCASL.

Bashair Alhummiany¹, David Shelley^1,2, Margaret Saysell^1,2, Maria-Alexandra Olaru³, Bernd Kühn³, David L. Buckley¹, Julie Bailey², Michael Mansfield², Steven Sourbron⁴, and Kanishka Sharma^4
1Department of Biomedical Imaging Sciences, University of Leeds, Leeds, United Kingdom, ²Leeds Teaching Hospitals, NHS Trust, Leeds, United Kingdom, ³Siemens Healthcare GmbH, Erlangen, Germany, ⁴Department of Imaging, Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, United Kingdom

Kidney perfusion can be measured using DCE or ASL, but clinical confidence in the assays is undermined by the large variability in published values. In this study, an intra-subject comparison was performed of DCE and ASL against phase-contrast RBF in 25 patients with diabetic kidney disease. Results show that the three techniques agree well on average, but pairwise agreement on the single-subject level remains poor. ASL agreed better with PC than DCE, but the difference was driven by a single DCE outlier. While RBF is a useful biomarker for studies at population level, individual patient management will require further optimization.

Wei-Hao Huang¹, Chia-Ming Shih¹, Po-Wei Cheng¹, and Jyh-Horng Chen^1,2
1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, Taipei, Taiwan, ²Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Taipei, Taiwan

In this study, we aim to combine dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and Wideband technique and use this accelerated sequence to assess the renal function of mice. With temporal resolution improvement, we can get more information in the same scan time, helping to perform a more accurate analysis. The quantitative analysis based on the Tofts model was performed and compare the result to the conventional DCE. All in all, we validate the feasibility of high temporal resolution Wideband DCE.

Paul Han¹, Thibault Marin¹, Yanis Djebra^1,2, Georges El Fakhri¹, Jinsong Ouyang¹, and Chao Ma^1
1Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, ²LTCI, Télécom Paris, Institut Polytechnique de Paris, Paris, France

Renal perfusion imaging with multi-delay arterial spin labeling (ASL) can provide multi-parametric information along with more robust quantification of renal blood flow. However, renal perfusion imaging with ASL is challenging especially due to respiratory motion. This work presents a subspace-based fast MR method for free-breathing multi-delay ASL imaging of the kidney. The feasibility of the proposed method is shown using in vivo data obtained from a healthy volunteer on a 3T MR scanner.

Tzu-Ming Hung¹, Sheng-Min Huang², Yun-Chieh Tsai³, Ting-Yu Chin⁴, and Hsu-Hsia Peng^1
1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, ²Institute of biomedical engineering and nanomedicine, National Health Research Institutes, Miaoli, Taiwan, ³Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan, ⁴Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan, Taiwan

Mice deficient of collapsin response mediator protein 1 (CRMP-1) gene may cause neural disorganization in hippocampus and demonstrate memory and spatial learning dysfunction. Relative cerebral blood volume (rCBV) can reflect the blood volume within the tissue and was served as an index to correlate with psychosis progression. The purpose of this study was to quantify the rCBV of hippocampus and to explore the difference of vascular distribution in wild type (WT) and aging CRMP-1 knockout (KO) mice. KO mice possessed significantly higher rCBV in the hippocampus than WT mice, indicating the increased blood volume in the hippocampus of KO mice.

Amnah Mahroo¹, Nora-Josefin Breutigam¹, Jörn Huber¹, and Matthias Günther^1,2
1MR Physics, Fraunhofer MEVIS, Bremen, Germany, ²MR-Imaging and Spectroscopy, University of Bremen, Bremen, Germany

Improved blood brain barrier integrity measurements in shorter scan times 

Caterina Lapucci^1,2, Marco Fiorelli³, Annunziata Stefanile⁴, Silvana Zannino⁴, Maria Maddalena Filippi⁵, Antonio Cortese³, Carlo Piantadosi⁶, Marco Salvetti⁷, Matilde Inglese^1,8, and Tatiana Koudriavtseva^4
1DINOGMI, University of Genoa, Genoa, Italy, ²Department of Experimental Neurosciences, Ospedale Policlinico San Martino IRCCS, Genoa, Italy, ³Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy, Rome, Italy, ⁴Department of Clinical Experimental Oncology, IRCCS Regina Elena National Cancer Institute, IFO, Rome, Italy, Rome, Italy, ⁵Fatebenefratelli Foundation, Afar Division, Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy, Rome, Italy, ⁶Neurology Unit, San Giovanni-Addolorata Hospital, Rome, Italy, Rome, Italy, ⁷Department Of Neuroscience Mental Health And Sensory Organs (NEMOS), Sapienza University, Sant’Andrea Hospital, Rome, Italy, Rome, Italy, ⁸Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA/, New York, NY, United States

Hemodynamic changes by Dynamic Susceptibility Contrast enhanced perfusion (DSC) in Multiple Sclerosis (MS) have been poorly evaluated. The aim of the study was to compare relapsing and remitting (RR) MS patients by DSC. 45 RRMS patients, 22 with (REL) and 23 without (REM) relapse in the previous 2 months were included. A hyperperfusion of the Normal Appearing White Matter (NAWM) compared to FLAIR lesions was noted. The correlations between NAWM perfusion, disease duration and 1-year before Annualized Relapse Rate in REM patients seemed to suggest that an increased NAWM perfusion may be a radiological marker of higher inflammatory activity.

Hui Liu¹, Gaofeng Shi¹, Qinglei Shi², Weishuai Wang³, Jiangyang Pan¹, and Yang Li^1
1Fourth Hospital of Hebei Medical University, shijiazhuang, China, ²MR Scientific Marketing, Siemens Healthcare, beijing, China, ³CS, Services,, Siemens Healthcare, jinan, China

The sequence that continuously acquired Golden-angle RAdial Sparse Parallel acquisition employing compressed sensing reconstruction (“GRASP”) can acquire high spatial and high temporal resolution as well as motion robustness to DCE MRI in liver imaging. However, there are still some artifacts in abdominal imaging, especially in the early arterial phase. In this study, we proposed an optimization scheme which can significantly improve the image quality both in  plain and all enhanced phases, which may have important value in the study of abdominal disease using GRASP based DCE in future.

Paolo Bosco¹, Laura Biagi¹, Giovanni Cioni², Michela Matteoli³, Alessandro Sale³, Nicoletta Berardi³, Michela Tosetti¹, and the Train the Brain Consortium^4
1FiRMLAB, IRCCS Stella Maris Foundation, Pisa, Italy, ²IRCCS Stella Maris Foundation, Pisa, Italy, ³Institute of Neuroscience of the CNR, Pisa, Italy, ⁴the Train the Brain Consortium, Pisa, Italy

One of the main challenges in identifying people at risk of dementia is their clinical heterogeneity. One hypothesis is that the clinical symptoms may be the result of different biological processes. We applied a data-drive clustering approach on structural and perfusion brain-MR imaging on a cohort of 141 MCI subjects in order to elucidate homogeneous structural and perfusion profiles and we observed the correspondent clinical features. Unsupervised clustering identified 6 different clusters on both ASL and gray matter volume data. Perfusion and atrophy showed to be variable in the different clusters and showed dissimilar patterns at subcortical and cortical levels.

Ke Fang¹, Zejun Wang^2,3, Zhaoqing Li^2,3, Bao Wang⁴, Guangxu Han^2,3, Zhaowei Cheng¹, Zhihong Chen¹, Chuanjin Lan⁵, Yi Zhang⁶, Peng Zhao⁷, Xinyu Jin¹, Yingchao Liu⁸, and Ruiliang Bai^2,3
1College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, China, ²Department of Physical Medicine and Rehabilitation of The Affiliated Sir Run Run Shaw Hospital AND Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou, China, ³Key Laboratory of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China, ⁴Department of Radiology, Qilu Hospital of Shandong University, Jinan, China, ⁵School of Medicine, Shandong University, Jinan, China, ⁶Shandong Medical Imaging Research Institute, Shandong University, Jinan, China, ⁷Department of Neurosurgery, Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China, ⁸Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China

We proposed a customized conventional neural network (CNN) to fasten the computation time of non-linear pharmacokinetic models in DCE-MRI. The results demonstrated that the CNN could shorten the computation time of extended Tofts model of whole-brain data to less than a minute without sacrificing the agreements with conventional non-linear least square (NLLS) fitting. This CNN could serve as an alternative to conventional NLLS fitting for fast assessment of pharmacokinetic parameters in clinical practice.

Thomas Lindner^1,2, Hajrullah Ahmeti³, Dana Voß³, Monika Huhndorf², Friederike Austein^1,2, Michael Helle⁴, Olav Jansen², Michael Synowitz³, and Stephan Ulmer^2,5
1Department of Diagnostic and Interventional Neuroradiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany, ²Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Kiel, Germany, ³Neurosurgery, University Hospital Schleswig-Holstein, Kiel, Germany, ⁴Tomographic Imaging Department, Philips Research Laboratories, Hamburg, Germany, ⁵Radiology, Kantonsspital Winterthur, Winterthur, Switzerland

Arterial Spin Labeling allows to intraoperatively monitor changes in perfusion induced by anesthesia.

Hui-Chieh Yang¹, Cheng-Hao Tu², and Shin-Lei Peng^1
1Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan, ²Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan

Studies on the brain responses to the pain-relieving treatments are relative limited, especially in dysmenorrhea. In this study, we investigated the brain response to acupuncture treatment in dysmenorrhea by using the arterial spin labeling technique. Results showed that after acupuncture treatment, significant decreases in cerebral blood flow were found in the pain-related regions, such as dorsal anterior cingulate cortex in the acupuncture group while orbitofrontal cortex, caudate, and insula in the sham acupuncture group. These findings suggest that acupuncture improves the descending pain modulation system by decreasing the neuronal activity in these brain regions.

Chau Vu¹, Jian Shen¹, Matthew Borzage², Soyoung Choi³, and John Wood^4
1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, ²Fetal and Neonatal Institute, Children's Hospital Los Angeles, Los Angeles, CA, United States, ³Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States, ⁴Pediatrics and Radiology, Children's Hospital Los Angeles, Los Angeles, CA, United States

Dynamic susceptibility contrast MRI is a popular perfusion technique that requires the use of intravenous exogenous contrast. To avoid gadolinium injection, this study proposed a perfusion MRI method based on a CO₂ respiratory challenge, which delivers a sinusoidally-modulated CO₂ stimulus. We evaluated this technique at two different stimulus amplitudes and reported cerebral blood flow (CBF), cerebral blood volume (CBV) and transit time (TT) within the acceptable range of the previous literature.

Eleonora Patitucci¹, Michael Germuska¹, James Kolasinski¹, Valentina Tomassini^1,2,3, and Richard G Wise^1,2
1CUBRIC, Cardiff University, Cardiff, United Kingdom, ²Institute for Advanced Biomedical Technologies (ITAB), Department of Neurosciences, Imaging and Clinical Sciences, University of Chieti-Pescara, Chieti, Italy, ³MS Centre, Neurology Unit, SS. Annunziata University Hospital, Chieti, Italy

Functional MRI can detect modifications in the brain’s resting state with learning-related behavioural improvements. However, the impact of learning on local cerebral blood flow after task execution remains unclear. Here we investigate changes in CBF after the execution of a motor task and demonstrate a sustained increase in resting CBF that is localised in regions relevant for the learning of the task. Our results show that learning induces sustained changes of local cerebral blood flow (over a timescale of minutes).

Michael S Stringer^1,2, Cameron Manning^1,2, Una Clancy^1,2, Alasdair Morgan^1,2, Zahra Shirzadi^3,4, Francesca M Chappell^1,2, Dany Jaime Garcia^1,2, Angela CC Jochems^1,2, Maria Valdes-Hernandez^1,2, Stewart Wiseman^1,2, Eleni Sakka^1,2, Gordon W Blair^1,2, Rosalind Brown^1,2, Bradley MacIntosh^3,4, Ian Marshall^1,2, Fergus Doubal^1,2, and Joanna M Wardlaw^1,2
1Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom, ²UK DRI at the University of Edinburgh, Edinburgh, United Kingdom, ³Hurvitz Brain Sciences Research Program, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, ⁴Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada

Accurate cerebral blood flow (CBF) quantification using arterial spin labelling (ASL) relies on physiological and MR parameters. Longitudinal relaxation time (T₁) of blood, which depends on haematocrit, can be a factor in some patient groups. We determined subject-specific T₁ using the DESPOT-1 HIFI method in a mild stroke cohort, calculating CBF using nominal and subject-specific values. CBF calculated with subject-specific T₁ values was lower in grey and higher in white matter, though there was not a proportional bias. CBF was lower in patients with higher disease burden. Subject-specific T₁ values can reduce variance, potentially improving CBF quantification in clinical ASL.