MRA Head Without and With IV Contrast There is no relevant literature to support the use of contrast-enhanced MRA of the head in the initial imaging of suspected cervical vascular dissection or injury. MRA Head Without IV Contrast MRA of the head may be useful in evaluation for intracranial extension of a known cervical dissection. MRA of the head may also be useful for evaluation of intracranial collaterals of the circle of Willis, which is important in stroke risk stratification and treatment strategies. As such, although an MRA of the head may be useful in the workup of a known cervical dissection, there is no literature to support MRA of the head in the initial imaging of suspected cervical arterial dissection. MRA Neck Without and With 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 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 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 Cerebrovascular Diseases-Stroke 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.
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. MRA Head Without and With IV Contrast There is no relevant literature to support the use of contrast-enhanced MRA of the head in the initial imaging of suspected cervical vascular dissection or injury. MRA Head Without IV Contrast MRA of the head may be useful in evaluation for intracranial extension of a known cervical dissection. MRA of the head may also be useful for evaluation of intracranial collaterals of the circle of Willis, which is important in stroke risk stratification and treatment strategies. As such, although an MRA of the head may be useful in the workup of a known cervical dissection, there is no literature to support MRA of the head in the initial imaging of suspected cervical arterial dissection. MRA Neck Without and With 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 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 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 Cerebrovascular Diseases-Stroke 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.