Rong Wang¹, Yuxin Li¹, Jie Lin¹, and Yong Zhang^2
1Huashan Hospital, Shanghai, China, ²GE Healthcare, Shanghai, China, Shanghai, China

This is the first study that used a combined arterial spin labeling (ASL) and resting-state fMRI approach to assess the neurovascular coupling in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), which may provide a new mechanistic perspective into understanding numerous brain diseases.

Andre Monteiro Paschoal¹, Mateus Boaventura¹, Leonie Petitclerc², Matthias J.P. van Osch², Maria Concepcion Garcia Otaduy¹, Samira Luisa Apostolos-Pereira³, Dagoberto Callegaro³, and Carolina de Medeiros Rimkus^1
1Institute of Radiology and Department of Radiology and Oncology, University of Sao Paulo, Sao Paulo, Brazil, ²C.J. Gorter Center for high field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, ³Departamento de Neurologia, Hospital das Clinicas da Faculdade de Medicina, University of Sao Paulo, Sao Paulo, Brazil

Multiple sclerosis is a demyelinating disease affecting the central nervous system. Although MS lesions can be identified by conventional MRI, the evaluation of active lesions in normal appearing gray and white matter requires measures of blood-brain barrier permeability (BBB), which is commonly assessed through the dynamic contrast enhanced (DCE) acquisition. When repeated scans are needed in the MS patients follow-up, repeated gadolinium injection is not recommended. This study successfully showed the feasibility of advanced arterial spin labeling sequences as an alternative to evaluate BBB permeability, whose results of water-exchange times across the BBB were in agreement with DCE measurements.

Yolanda Ohene^1,2, Elizabeth Powell^3,4, Samo Lasič^5,6, Geoff J. M Parker^3,7,8, Laura M Parkes ^1,2, and Ben R Dickie ^2,9
1Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom, ²Geoffrey Jefferson Brain Research Centre, University of Manchester, Manchester, United Kingdom, ³Centre for Medical Image Computing, UCL, London, United Kingdom, ⁴Department of Computer Science, UCL, London, United Kingdom, ⁵Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark, ⁶Random Walk Imaging, Lund, Sweden, ⁷Department of Medical Physics and Biomedical Engineering, UCL, London, United Kingdom, ⁸Bioxydyn Limited, Manchester, United Kingdom, ⁹Division of Informatics, Imaging and Data Sciences, University of Manchester, Manchester, United Kingdom

We have developed a preclinical FEXI sequence optimised to measure water exchange across the blood-brain barrier in the rat brain. Simulated synthetic data estimated an apparent exchange rate (AXR) of 1.22 s^-1, using the in-vivo acquisition parameters and exchange rate constant = 2.5 s^-1, reflecting in-vivo measurements. The experimental normalised AXR in the rat brain was measured at 3.34 ± 1.14 s^-1 (scan) and 3.62 ± 0.96 s^-1 (rescan), with CoV = 26%, n = 10. This technique is a promising non-invasive tool which can be applied to in a wide range of disease models, including neurodegeneration, stroke and neuroinflammation.

Yuriko Suzuki¹, Peter Jezzard¹, Ioannis Koktzoglou^2,3, and Thomas Okell^1
1Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, ²Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States, ³Pritzker School of Medicine, University of Chicago, Chicago, IL, United States

In recent years, magnetic resonance angiography (MRA) using arterial spin labeling (ASL) technique has been developed aiming to be a non-invasive potential alternative to X-ray angiography. When blood flow is slow (e.g. in elderly patients, especially with steno-occlusive diseases), however, ASL-MRA suffers from poor vessel visualization, which hinders its clinical utility in those patients. In this study, instead of using a 3D volume acquisition commonly used in brain MRI, we propose to separately scan multiple 2D slices to reduce the saturation of arterial blood signal and improve the visualization of small peripheral arteries, in combination with a super-resolution reconstruction.

M.B.J. Dijsselhof¹, M. Barboure¹, M. Stritt², W. Nordhøy³, A.M. Wink¹, L.T. Westlye^4,5,6, J.H. Cole⁷, F. Barkhof^1,8, J. Petr⁹, and H.J.M.M. Mutsaerts^1
1Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, Netherlands, ²Mediri GmbH, Heidelberg, Germany, ³Department of Diagnostic Physics, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway, ⁴Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo & Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway, ⁵Department of Psychology, University of Oslo, Oslo, Norway, ⁶KG Jebsen Centre for Neurodevelopmental Disorders, University of Oslo, Oslo, Norway, ⁷Dementia Research Centre, Queen Square Institute of Neurology; Centre for Medical Image Computing, University College London, London, United Kingdom, ⁸Queen Square Institute of Neurology and Centre for Medical Image Computing, University College London, London, United Kingdom, ⁹Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany

The structural brain-age makes predictions based on changes in tissue integrity. Adding cerebrovascular MRI biomarkers may add sensitivity to physiological and metabolic changes, hence complementing structural brain-age, and possibly improving its early pathology sensitivity. Baseline and follow-up T1w, FLAIR, and ASL data of 233 healthy participants and combinations of features and algorithms were used to predict ‘Cerebrovascular brain-age’. 

 The ExtraTrees algorithm utilising T1w, ASL, and FLAIR features performed best and showed good longitudinal reproducibility.

Ethan Danielli^1,2, Beatriz Padrela³, Mitchell Doughty^1,2, Jan Petr⁴, Henk Mutsaerts^3,5, and Michael D Noseworthy^1,2,6
1School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada, ²Imaging Research Centre, St. Joseph's Healthcare Hamilton, Hamilton, ON, Canada, ³Radiology and Nuclear Medicine, Amsterdam University, Amsterdam, Netherlands, ⁴Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany, ⁵Ghent Institute for Functional and Metabolic Imaging, Ghent University, Ghent, Belgium, ⁶Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada

3D PCASL scans were acquired for seventeen aging, retired professional football players with a history of head traumas. Left, right and bilateral CBF and ASL spatial coefficient of variation (sCoV) values were examined for twelve concussion-related ROIs. A Z-scoring approach was applied, with outliers defined as mild, moderate, or severe injury burden (IB). An IB symmetry index was also calculated. Outliers were detected in all 12 ROIs, and the anterior parahippocampal gyrus and inferior frontal gyrus pars opercularis had the highest CBF and ASL sCoV IB, respectively. IB was not biased towards the left or right hemisphere.

Chang Liu¹ and Zhang Yong^2
1Department of Radiology, Southern District, The First Affiliated Hospital of USTC, Division of Life, HEFEI, China, ²MR Research,GE Healthcare,Shanghai,China, Shanghai, China

3D-ASL technology can reflect cerebral blood flow perfusion status,which is helpful for early diagnosis of HIE.The predictive value of ASL for the prognosis of full-term HIE patients is higher than that of DWI.

John McFadden¹, Julian Matthews¹, Lauren Scott¹, Karl Herholz¹, Ben Dickie^2,3, Hamied Haroon¹, Oliver Sparasci^1,4, Saadat Ahmed¹, Natalia Kyrtata^1,5, Geoffrey JM Parker^6,7, Hedley C A Emsley^1,8,9, Maélène Lohezic¹⁰, and Laura M Parkes^1,3
1Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom, ²Division of Informatics, Imaging and Data Science, University of Manchester, Manchester, United Kingdom, ³Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, United Kingdom, ⁴Greater Manchester Mental Health NHS Foundation Trust, Manchester, United Kingdom, ⁵University Hospital of Morecambe Bay NHS Foundation Trust, Lancaster, United Kingdom, ⁶Centre for Medical Image Computing, University College London, London, United Kingdom, ⁷Bioxydyn Limited, Manchester, United Kingdom, ⁸Lancaster Medical School, Lancaster University, Lancaster, United Kingdom, ⁹Department of Neurology, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom, ¹⁰GE Healthcare, Manchester, United Kingdom

We investigated quantitative susceptibility mapping (QSM) and arterial spin labelling (ASL) to measure cerebrovascular parameters in elderly people with a range of vascular disease risk (QRisk) and cognitive impairment. Cerebral blood flow (CBF) and arterial transit time (ATT) were derived from ASL and oxygen extraction fraction (OEF) from QSM. Regional estimates were obtained by matching six large veins to their draining territories. QRisk had a significant positive relationship with ATT. OEF had a significant compensatory increase with altered ATT and CBF. Both OEF and ATT were found to be elevated with impaired cognition.

Moss Y Zhao¹, Kristen Yeom¹, Elizabeth Tong¹, Rui Miguel Duarte^1,2, Michael Moseley¹, and Greg Zaharchuk^1
1Department of Radiology, Stanford University, Stanford, CA, United States, ²Department of Neuroradiology, Hospital Beatriz Ângelo, Lisbon, Portugal

This study compared the CBF measurements using single and multiple delay ASL on 28 children without neurological or cerebrovascular disorders. Results showed that CBF of multiple delay ASL was significantly higher than the values of single delay ASL by a mean of 18%. CBF of both ASL techniques increased with age.

Giannina Rita Iannotti^1,2, Isaure Nadin¹, Quentin Tourdot³, Shahan Momjian¹, Karl Schaller¹, Karl Lovblad², and Frédéric Grouiller^4,5
1Department of Neurosurgery, University Hospital of Geneva, Geneva, Switzerland, ²Department of Radiology and Medical Informatics, University Hospital of Geneva, Geneva, Switzerland, ³Faculty of Pharmacy, University of Montpellier, France, Montpellier, France, ⁴Laboratory of Behavioral Neurology and Imaging of Cognition, Department of Fundamental Neuroscience, University of Geneva, Geneva, Switzerland, ⁵Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland

Brain functional mapping is fundamental in pre-surgical workflow to target areas to be preserved. This work aims at validating ASL as alternative to BOLD to map eloquent cortex, by offering a quantitative measure of the perfusion associated to neuronal activity. Thirty healthy subjects underwent TMS motor mapping and executed a clenching-motor-task in a 3T-MR-scanner, while ASL and BOLD volumes were acquired simultaneously. The comparison between the global maxima of BOLD and ASL activations revealed that ASL localizes significantly deeper and more anteriorly than BOLD. ASL global maximum was found closer than BOLD to the most representative point of TMS mapping.