ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Scientific Session • ASL Methods: From the Neck Down

Wednesday 3 June 2015

Room 701 B

10:00 - 12:00


T.B.A., T.B.A.

10:00 0532.   
Separation of arterial and portal blood supply to mouse liver and tumour tissue using pseudo-Continuous Arterial Spin Labelling (pCASL)
Rajiv Ramasawmy1, Jack Anthony Wells1, Magdalena Sokolska2, James A. Meakin3, Sean Peter Johnson1, Adrienne E. Campbell-Washburn4, Rosamund Barbara Pedley5, Mark Francis Lythgoe†1, and Simon Walker-Samuel†1
1Centre for Advanced Biomedical Imaging, University College London, London, Greater London, United Kingdom, 2Institute of Neurology, University College London, London, Greater London, United Kingdom, 3Oxford University, Oxfordshire, United Kingdom, 4National Heart Lung and Blood Institute, National Institutes of Health, Maryland, United States, 5Cancer Institute, University College London, London, Greater London, United Kingdom

Liver perfusion measurements could be used to monitor hepatic disease progression and therapy in pre-clinical models. This study investigated the feasibility of using pseudo-continuous ASL (pCASL) to measure mouse liver perfusion, in which both the portal venous and arterial supply to the liver were separately tagged: the mean ratio of perfusion estimates agreed well with the expected vascular contributions. Finally, the technique was applied to a mouse model of liver metastasis, which showed tumours to be exclusively arterially supplied.

10:12 0533.   Quantification of liver perfusion using multi-delay Pseudo-Continuous Arterial Spin Labeling
Xinlei Pan1, Robert Smith2, Mayank Jog2, Tianyi Qian3, Holden H Wu2, Kyunghyun Sung2, Kuncheng Li4, Kui Ying5, and Danny JJ Wang2
1Department of Biomedical Engineering, Tsinghua University, Beijing, Beijing, China, 2Department of Bioengineering, UCLA, CA, United States, 3Siemens Healthcare, MR Collaboration NE Asia, Beijing, China, 4Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, China, 5Department of Engineering Physics, Tsinghua University, Beijing, China

This study tested the feasibility of quantitative liver perfusion measurements using a multi-delay pseudo-continuous ASL (pCASL) protocol that selectively labels the hepatic artery and hepatic portal vein respectively. Estimated mean blood flow of hepatic artery labeled (44±14 ml/100ml/min) and hepatic portal vein labeled (140±9 ml/100ml/min) as well as the corresponding transit times (1020±396,1892±164ms) showed good accordance with the literature. The capability of non-invasively and selectively labeling the hepatic artery and portal vein is a unique strength of pCASL for quantitative liver perfusion imaging.

10:24 0534.   
Non-Contrast Pulmonary Perfusion using pseudo-Continuous Arterial Spin Labeling of the Inferior Vena Cava
Joshua S. Greer1,2, Yue Zhang2, Ivan Pedrosa2,3, and Ananth J. Madhuranthakam2,3
1Bioengineering, UT Dallas, Dallas, TX, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States

Recently, pseudo-continuous ASL (pCASL) has been successfully applied to study cerebral and renal perfusion by labeling the carotid arteries and abdominal aorta. The high blood velocity in these anatomies enabled high labeling efficiency. However, the extension of pCASL to study pulmonary perfusion has been non-trivial due to the complex anatomy of the lungs. In this work, we demonstrate pulmonary perfusion using pCASL, specifically targeting the inferior vena cava and optimizing the labeling parameters to achieve high labeling efficiency. This provided higher SNR, reduced pulmonary vasculature signal and more homogeneous perfusion compared to the established pulsed ASL approach (e.g. 2D FAIRER).

10:36 0535.   
Hao Song1, Wenyang Liu2, Dan Ruan2,3, Sungkyu Jung4, and H Michael Gach1,5
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States,3Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States, 4Statistics, University of Pittsburgh, Pittsburgh, PA, United States, 5Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States

A respiratory motion predictor (RMP) was implemented to prospectively correct respiratory motion for arterial spin labeling (ASL) in the abdomen. An artificial neural network (ANN) algorithm predicted the position of the image slices at the time of acquisition. The ASL sequence adjusted the image acquisition in real-time based on the RMP data obtained during the transit delay. The ANN algorithm accurately predicted the diaphragm motion during the ASL acquisition with an error of 0.8 mm. Renal perfusion maps were consistent with maps acquired using breathhold with respiratory feedback, while requiring much less effort from the subject and less exam time.

10:48 0536.   The feasibility of ASL Spinal bone marrow perfusion Imaging with optimized TI - video not available
Dong Xing1, Yunfei Zha1, Lei Hu1, Jiao Wang1, Yuan Lin1, and Hui Lin2
1Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China, 2MR Research, GE Healthcare China, Shanghai, China

Arterial spin labeling (ASL) has been a preliminary application in musculoskeletal perfusion analysis. However, it has not been applied to the spinal bone marrow (SBM) lesions in the literature up to date. First, this study investigate the effects of inversion time(TI) on flow-sensitive alternating inversion recovery(FAIR) perfusion imaging of SBM to find the optimized TI, then the correlation between ASL and dynamic contrast enhanced (DCE) magnetic resonance (MR) imaging in the measurement of SBM perfusion were assessed to analyse the feasibility of ASL SBM perfusion.

11:00 0537.   Quantitative rat lumbar spinal cord blood flow measurements using multi-slice arterial spin labelling at 9.4T - permission withheld
Mohamed Tachrount1, Andrew Davies2, Roshni Desai2, Kenneth Smith2, David Thomas3, Xavier Golay1, and Roshni Desai2
1Department of brain repair and rehabilitation, UCL Institute of Neurology, London, London, United Kingdom, 2Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, 3UCL Institute of Neurology, London, United Kingdom

A new multi-slice ASL technique is detailed and applied to the study of rat spinal cord at 9.4T. The quantification of the spinal cord blood flow was performed using a pre-saturation FAIR Q2TIPS ASL technique based on the use of adiabatic RF pulses with a reduced FOV. The averaged perfusion within the GM (95.1±4.6ml/100g/min) was higher than within the WM (39.7±3.2ml/100g/min).

11:12 0538.   Measuring myocardial blood flow using modified look locker inversion (MOLLI) recovery arterial spin labelling (ASL)
Charlotte E Buchanan1, Eleanor F Cox1, Claire Grant2, Nick M Selby2, Chris W McIntyre3, Maarten W Taal2, and Susan T Francis1
1SPMIC, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2Division of Medical Sciences and Graduate Entry Medicine, Royal Derby Hospital, Nottingham, United Kingdom, 3Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada

A modified look locker inversion (MOLLI) recovery arterial spin labelling (ASL) technique is used to measure myocardial blood flow (MBF) in humans. Cardiac triggering was used with a ‘Trigger-delay’ (TD) prior to the label module to allow data to be collected at a range of post-label delay times. 8 TD values were collected (0 - 350 ms), with 3 readout pulses per Look-Locker set. MBF was 1.25 ± 0.45 and 1.34 ± 0.42 ml/g/min in healthy controls and chronic kidney disease patients. On exercise, the mean increase in MBF was 85 ± 24 % for patients.

11:24 0539.   Feasibility and Repeatability of Human Brown Adipose Tissue Volume and Perfusion Activity Using MRI
Weiying Dai1, Lauren S. Weiner2, David C. Alsop1, and Aaron M. Cypess2
1Radiology, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, United States, 22Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Boston, MA, United States

Brown adipose tissue (BAT) can improve insulin sensitivity and hence may prove to be an important anti-diabetic tissue. The volume and activity of BAT have previously been measured using 18F-FDG PET/CT. Here, we demonstrate the feasibility and repeatability of using Dixon water/fat imaging and ASL imaging to assess BAT volume and perfusion responses to mild cold stimulation in the cervical area of adult humans. The Dixon method can provide a quantitative measurement of the BAT volume. ASL shows great promise for measuring perfusion activity within BAT and can be successful if the vessel signals near the BAT are well suppressed.

11:36 0540.   Large intramuscular vessel artifact in ASL: effect on calf muscle perfusion measurements and a velocity-selective solution
Jeff L Zhang1, Christopher J Hanrahan1, Jason Mendes1, Gwenael Layec2, Corey Hart2, Kristi Carlston1, Michelle Mueller3, Russell S Richardson2, and Vivian S Lee1
1Radiology, University of Utah, Salt Lake City, Utah, United States, 2Division of Geriatrics, University of Utah, Utah, United States, 3Vascular Surgery, University of Utah, Utah, United States

Capable of measuring perfusion rapidly, ASL is suitable for monitoring muscle perfusion during exercise recovery. However, ASL estimated perfusion could be severely erroneous for tissue voxels containing large blood vessels. Inclusion of large-vessel voxels in a muscle ROI could change the magnitude and the temporal pattern of the averaged perfusion dramatically. In this study, we studied ASL signals of blood vessel simulated by a flow phantom, and using the obtained velocity-perfusion relationship, developed a velocity selective method for excluding the large-vessel voxels. The method was shown to be effective for our healthy subjects, and improved the perfusion accuracy.

11:48 0541.   Arterial spin labeling in exercising calf muscle with prospective motion correction
Céline Giraudeau1,2, Benjamin R. Knowles3, Thomas Lange3, Michael Herbst3,4, Maxim Zaitsev3, and Pierre Carlier1,2
1NMR Laboratory, Institute of Myology, Paris, France, 2NMR Laboratory, CEA, I2BM, MIRCen, Fontenay-aux-Roses, France, 3Department of Radiology, University Medical Center Freiburg, Freiburg, Germany, 4John A. Burns School of Medicine, Uni Hawaii, Honolulu, Hawaii, United States

Acquiring clean ASL perfusion data in exercising skeletal muscle is highly desirable and would have significant impact for the pathophysiological mechanisms of many conditions affecting the skeletal muscle, primarily or secondarily. However, studies have been limited to post-exercise data due to motion that dramatically impairs perfusion curves. Recently, real-time prospective motion correction (PMC) with optical tracking has been proposed for brain and knee MRI. In this work we investigated the potential of PMC-augmented ASL to improve the quality of perfusion curves acquired during calf muscle exercise.