Diagnostic Imaging for Vertebral Artery Dissection

Introduction to Diagnostic Imaging

The American College of Radiology recommends CT angiography (CTA) of the head and neck with IV contrast as the preferred initial diagnostic modality for investigating vertebral artery dissection due to its highest reported sensitivity (100%) compared to MRA (77%) and Doppler ultrasound (71%) 1, 2

CT Angiography (CTA) of the head and neck with IV contrast has the highest sensitivity (100%) for vertebral artery dissection compared to other modalities, and allows evaluation of the course and luminal caliber of arteries, detection of luminal filling defects, and should include the entire vertebral artery from origin at aortic arch to basilar artery 1, 2
The American College of Radiology suggests that MR Angiography (MRA) of the head and neck has a sensitivity of approximately 77% compared to conventional angiography, and MRA of the neck is best performed with contrast for better evaluation of vessels with increased spatial resolution 1, 3, 4
The American Heart Association indicates that Doppler ultrasonography may identify dissection flap and differential flow in true and false lumens, but has limited utility for dissections beginning above the angle of the mandible, and is more operator-dependent than CTA or MRA 5
Catheter-based Digital Subtraction Angiography is the traditional gold standard but now largely supplanted by CTA and MRA, and may be necessary in select cases to delineate collateral filling via circle of Willis, and is reserved for cases where non-invasive imaging is inconclusive or when endovascular intervention is being considered 5, 6

The American College of Radiology advises that because symptomatic dissection may involve any portion of the vertebral artery, imaging should include the entire vessel from origin to basilar artery 1, 2
The American Heart Association recommends maintaining a high index of suspicion in younger patients with posterior circulation stroke symptoms, as vertebral artery dissection accounts for 10-15% of ischemic strokes in patients under 45 years 5, 6