MRA Neck Without and With IV Contrast MRA of the neck may be useful in the surveillance imaging of known cervical vascular dissections owing to high tissue contrast, especially incorporating fat-saturated T1-weighted sequences, which may better demonstrate subtler intramural hematomas that may not be visible on other noninvasive studies. However, some dissections may be too subtle to follow by MRA of the neck due to lower spatial resolution compared with CTA. Specifically, the sensitivity of MRI is similar to CTA for cervical carotid dissections; however, the sensitivity for the detection of cervical vertebral artery dissections is significantly reduced compared with CTA to as low as 60% with some variability depending on the technique and sequences employed [129]. Unenhanced MRA of the neck may also overestimate the degree of stenosis in more severe dissections, and the anatomic definition of the surrounding structures may be inadequate for treatment planning in some cases depending on the sequences used. Contrast administration can reduce the degree of overestimation of the degree of stenosis in many cases [132]. MRA Neck Without IV Contrast MRA of the neck may be useful in the surveillance imaging of known cervical vascular dissections owing to high tissue contrast, especially incorporating fat-saturated T1-weighted sequences, which may better demonstrate subtler intramural hematomas that may not be visible on other noninvasive studies. However, some dissections may be too subtle to follow by MRA of the neck due to lower spatial resolution compared with CTA. Specifically, the sensitivity of MRI is similar to CTA for cervical carotid dissections; however, the sensitivity for detection of cervical vertebral artery dissections is significantly reduced compared with CTA to as low as 60% with some variability depending on the technique and sequences employed [129].
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. MRA Neck Without and With IV Contrast MRA of the neck may be useful in the surveillance imaging of known cervical vascular dissections owing to high tissue contrast, especially incorporating fat-saturated T1-weighted sequences, which may better demonstrate subtler intramural hematomas that may not be visible on other noninvasive studies. However, some dissections may be too subtle to follow by MRA of the neck due to lower spatial resolution compared with CTA. Specifically, the sensitivity of MRI is similar to CTA for cervical carotid dissections; however, the sensitivity for the detection of cervical vertebral artery dissections is significantly reduced compared with CTA to as low as 60% with some variability depending on the technique and sequences employed [129]. Unenhanced MRA of the neck may also overestimate the degree of stenosis in more severe dissections, and the anatomic definition of the surrounding structures may be inadequate for treatment planning in some cases depending on the sequences used. Contrast administration can reduce the degree of overestimation of the degree of stenosis in many cases [132]. MRA Neck Without IV Contrast MRA of the neck may be useful in the surveillance imaging of known cervical vascular dissections owing to high tissue contrast, especially incorporating fat-saturated T1-weighted sequences, which may better demonstrate subtler intramural hematomas that may not be visible on other noninvasive studies. However, some dissections may be too subtle to follow by MRA of the neck due to lower spatial resolution compared with CTA. Specifically, the sensitivity of MRI is similar to CTA for cervical carotid dissections; however, the sensitivity for detection of cervical vertebral artery dissections is significantly reduced compared with CTA to as low as 60% with some variability depending on the technique and sequences employed [129].