"The most commonly used 3D sequences for intracranial vessel wall imaging use turbo/fast spin-echo with variable low refocusing flip angles, which maintain high spatial resolution during long echo trains. These sequences are known by brand names such as SPACE, Cube, and VISTA 1,2."
"double inversion recovery: a non-selective inversion pulse with a TI near the null point of blood followed by a slice selective inversion pulse recovers signal in stationary tissue but not in flowing blood"
Expected headings
"Spatial resolution"
"Contrast resolution"
"Correlative luminal imaging"
"Enhancement evaluation"
"Clinical uses and interpretation"
"Pitfalls"
"Finally, to depict the vessel wall discretely, signal must also be suppressed from the surrounding tissue. For vessel wall imaging of the extracranial head and neck, for instance, this means suppressing fat signal. For intracranial vessel wall imaging, this means suppressing CSF signal. Fortunately, because CSF flows, many techniques used to suppress signal from flowing blood also suppress CSF signal. Depending on the contrast weighting (CSF signal is low on T1-weighted images but not T2- or proton density-weighted images), dedicated methods to suppress CSF may be needed, such as inversion recovery (FLAIR), antidriven equilibrium, or DANTE 5,6,11."
"slow flow: in laminar flow or intra-aneurysmal circulation, slower blood flow adjacent to the vessel wall may have incompletely suppressed signal, mimicking wall thickening and enhancement; it is helpful to correlate with lumen calibre on MRA or the precontrast medium vessel wall sequence"
"veins: enhancing veins, which have slower flow, mimic arteries with wall enhancement; it is helpful to correlate with time-of-flight MRA to distinguish arteries and veins"
"vasa vasorum: the extracranial carotid and vertebral arteries and sometimes proximal intracranial arteries as well (especially in elderly with severe atherosclerosis), are supplied by the vasa vasorum that appears as diffuse smooth concentric enhancement, which mimics wall enhancement from vasculitis; the distribution and clinical picture helps distinguish"