title: Cerebrovascular MRI: a review of state-of-the-art approaches, methods and techniques.
abstract: Cerebrovascular imaging is of great interest in the understanding of neurological disease. MRI is a non-invasive technology that can visualize and provide information on: (i) the structure of major blood vessels; (ii) the blood flow velocity in these vessels; and (iii) the microcirculation, including the assessment of brain perfusion. Although other medical imaging modalities can also interrogate the cerebrovascular system, MR provides a comprehensive assessment, as it can acquire many different structural and functional image contrasts whilst maintaining a high level of patient comfort and acceptance. The extent of examination is limited only by the practicalities of patient tolerance or clinical scheduling limitations. Currently, MRI methods can provide a range of metrics related to the cerebral vasculature, including: (i) major vessel anatomy via time-of-flight and contrast-enhanced imaging; (ii) blood flow velocity via phase contrast imaging; (iii) major vessel anatomy and tissue perfusion via arterial spin labeling and dynamic bolus passage approaches; and (iv) venography via susceptibility-based imaging. When designing an MRI protocol for patients with suspected cerebral vascular abnormalities, it is appropriate to have a complete understanding of when to use each of the available techniques in the 'MR angiography toolkit'. In this review article, we: (i) overview the relevant anatomy, common pathologies and alternative imaging modalities; (ii) describe the physical principles and implementations of the above listed methods; (iii) provide guidance on the selection of acquisition parameters; and (iv) describe the existing and potential applications of MRI to the cerebral vasculature and diseases. The focus of this review is on obtaining an understanding through the application of advanced MRI methodology of both normal and abnormal blood flow in the cerebrovascular arteries, capillaries and veins.
authors.affiliation: Biomedical Engineering, Radiology, and Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
authors.forename: Matthew Ethan
authors.identifier: http://orcid.org/0000-0001-5421-3536
authors.initials: ME
authors.lastname: MacDonald
authors.affiliation: Biomedical Engineering, Radiology, and Clinical Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Frayne
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: MRI; angiography; arterial spin labeling; cerebral vasculature; phase contrast; time of flight; venography