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 is useful in the initial screening examination for suspected cervical vascular dissection owing to high tissue contrast, especially incorporating fat-saturated T1-weighted sequences, which may be helpful in the delineation of subtle intramural hematomas, improving visibility to the examiner. The sensitivity of MRI neck is similar to CTA neck for cervical carotid dissections. However, the sensitivity for the detection of cervical vertebral artery dissections is significantly reduced compared with CTA neck to as low as 60%, with some variability depending on the technique and sequences employed [129]. Limitations of MRA neck include longer acquisition times and lower spatial resolution, which may delay care or miss subtle intimal irregularities associated with suspected cervical vascular dissections, particularly those involving the vertebral artery. Additionally, an 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]. MRI Head Perfusion With IV Contrast There is no literature to support the use of MRI head perfusion as the initial imaging test in the detection of a suspected cervical artery dissection. MRI Head Without and With IV Contrast There is no relevant literature to support the use of contrast-enhanced MRI of the head in the initial imaging of suspected cervical vascular dissection or injury.
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. 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 is useful in the initial screening examination for suspected cervical vascular dissection owing to high tissue contrast, especially incorporating fat-saturated T1-weighted sequences, which may be helpful in the delineation of subtle intramural hematomas, improving visibility to the examiner. The sensitivity of MRI neck is similar to CTA neck for cervical carotid dissections. However, the sensitivity for the detection of cervical vertebral artery dissections is significantly reduced compared with CTA neck to as low as 60%, with some variability depending on the technique and sequences employed [129]. Limitations of MRA neck include longer acquisition times and lower spatial resolution, which may delay care or miss subtle intimal irregularities associated with suspected cervical vascular dissections, particularly those involving the vertebral artery. Additionally, an 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]. MRI Head Perfusion With IV Contrast There is no literature to support the use of MRI head perfusion as the initial imaging test in the detection of a suspected cervical artery dissection. MRI Head Without and With IV Contrast There is no relevant literature to support the use of contrast-enhanced MRI of the head in the initial imaging of suspected cervical vascular dissection or injury.