In cases of vertebral artery dissection confirmed by conventional angiography, CTA has the highest reported sensitivity (100%), followed by MRA (77%) and Doppler US (71%). The addition of nonluminal vessel wall imaging sequences likely improves the detection of nonstenotic arterial dissection, but it is unclear whether these types of lesions would result in VBI. Because symptomatic dissection may involve any portion of the vertebral artery, from the origin at the aortic arch branch vessels to the basilar artery, the entirety of the vessel should be included for evaluation [14]. MRA Head and Neck Without and With IV Contrast MRA allows for the evaluation of the course and luminal caliber of the arteries. MRA can also detect luminal filling defects, which may include thrombus, embolus, atherosclerotic plaque, dissection flap, or vascular web. MRA of the head and neck can be performed without IV contrast, with IV contrast, or as a combination of without and with IV contrast. Although 3-D time-of-flight MRA of the head is typically diagnostic without the use of IV gadolinium- based contrast agents, MRA of the neck is often best performed with contrast for better evaluation of the vessels with increased spatial resolution and decreased flow-related artifacts. In a study comparing the diagnostic performance of contrast-enhanced MRA of the neck to digital subtraction angiography in evaluation of vertebral artery origin stenosis, the sensitivity, specificity, and accuracy of MRA were shown to be as high as 97%, 98%, and 93%, respectively in 49 patients [69]. However, MRA has not demonstrated significant differences in the degree of arterial stenosis between symptomatic patients with VBI and asymptomatic controls [13]. In cases of vertebral artery dissection confirmed by conventional angiography, CTA has the highest Dizziness and Ataxia reported sensitivity (100%), followed by MRA (77%) and Doppler US (71%).
Dizziness and Ataxia. In cases of vertebral artery dissection confirmed by conventional angiography, CTA has the highest reported sensitivity (100%), followed by MRA (77%) and Doppler US (71%). The addition of nonluminal vessel wall imaging sequences likely improves the detection of nonstenotic arterial dissection, but it is unclear whether these types of lesions would result in VBI. Because symptomatic dissection may involve any portion of the vertebral artery, from the origin at the aortic arch branch vessels to the basilar artery, the entirety of the vessel should be included for evaluation [14]. MRA Head and Neck Without and With IV Contrast MRA allows for the evaluation of the course and luminal caliber of the arteries. MRA can also detect luminal filling defects, which may include thrombus, embolus, atherosclerotic plaque, dissection flap, or vascular web. MRA of the head and neck can be performed without IV contrast, with IV contrast, or as a combination of without and with IV contrast. Although 3-D time-of-flight MRA of the head is typically diagnostic without the use of IV gadolinium- based contrast agents, MRA of the neck is often best performed with contrast for better evaluation of the vessels with increased spatial resolution and decreased flow-related artifacts. In a study comparing the diagnostic performance of contrast-enhanced MRA of the neck to digital subtraction angiography in evaluation of vertebral artery origin stenosis, the sensitivity, specificity, and accuracy of MRA were shown to be as high as 97%, 98%, and 93%, respectively in 49 patients [69]. However, MRA has not demonstrated significant differences in the degree of arterial stenosis between symptomatic patients with VBI and asymptomatic controls [13]. In cases of vertebral artery dissection confirmed by conventional angiography, CTA has the highest Dizziness and Ataxia reported sensitivity (100%), followed by MRA (77%) and Doppler US (71%).