Additionally, composition of carotid plaque including intraplaque hemorrhage on magnetization-prepared rapid acquisition gradient echo images can be useful predictors of future stroke risk, beyond assessing the degree of luminal narrowing [118,119]. MRA Neck Without IV Contrast MRA of the neck is useful in the initial workup of the asymptomatic patient with a carotid bruit owing to the anatomic assessment of stenosis, which will limit both false-positives and false-negatives. Specifically, MRA of the neck is helpful when multivessel cerebrovascular disease or very severe stenosis is present, which might result Cerebrovascular Diseases-Stroke in artifactual over or underestimation of the degree of disease by carotid Doppler, respectively [113]. Noncontrast MRA of the neck may overestimate the degree of stenosis when severe and/or near occlusive. Contrast administration can reduce the degree of overestimation of the degree of stenosis in some cases. However, contrast- enhanced MRA of the neck has a similar sensitivity for the detection of >70% stenosis of the carotid when 2-D and 3-D techniques of TOF are combined [27,117]. MRA of the neck may also be useful for treatment planning. However, the anatomic definition of the surrounding structures may be inadequate for treatment planning in some cases depending on the sequences used [114]. Additionally, composition of carotid plaque including intraplaque hemorrhage on magnetization-prepared rapid acquisition gradient echo images can be useful predictors of future stroke risk, beyond assessing the degree of luminal narrowing [118,119]. MRI Head Perfusion With IV Contrast Contrast-enhanced MRI head perfusion imaging (or, if available, noncontrast ASL perfusion) may help delineate the hemodynamic significance of a known asymptomatic carotid lesion and the collateral support in each distribution.
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. Additionally, composition of carotid plaque including intraplaque hemorrhage on magnetization-prepared rapid acquisition gradient echo images can be useful predictors of future stroke risk, beyond assessing the degree of luminal narrowing [118,119]. MRA Neck Without IV Contrast MRA of the neck is useful in the initial workup of the asymptomatic patient with a carotid bruit owing to the anatomic assessment of stenosis, which will limit both false-positives and false-negatives. Specifically, MRA of the neck is helpful when multivessel cerebrovascular disease or very severe stenosis is present, which might result Cerebrovascular Diseases-Stroke in artifactual over or underestimation of the degree of disease by carotid Doppler, respectively [113]. Noncontrast MRA of the neck may overestimate the degree of stenosis when severe and/or near occlusive. Contrast administration can reduce the degree of overestimation of the degree of stenosis in some cases. However, contrast- enhanced MRA of the neck has a similar sensitivity for the detection of >70% stenosis of the carotid when 2-D and 3-D techniques of TOF are combined [27,117]. MRA of the neck may also be useful for treatment planning. However, the anatomic definition of the surrounding structures may be inadequate for treatment planning in some cases depending on the sequences used [114]. Additionally, composition of carotid plaque including intraplaque hemorrhage on magnetization-prepared rapid acquisition gradient echo images can be useful predictors of future stroke risk, beyond assessing the degree of luminal narrowing [118,119]. MRI Head Perfusion With IV Contrast Contrast-enhanced MRI head perfusion imaging (or, if available, noncontrast ASL perfusion) may help delineate the hemodynamic significance of a known asymptomatic carotid lesion and the collateral support in each distribution.