Multisection CT angiography compared with catheter angiography in diagnosing vertebral artery dissection

Abstract

Background and purpose: Multisection CT angiography is a minimally invasive technique that can provide high-resolution and high-contrast images of the arterial lumen and wall. To our knowledge, the ability of multisection CT angiography in detecting vertebral artery (VA) dissection has never been evaluated. We assessed the sensitivity and specificity of a routine, standardized, multisection CT angiographic protocol for the detection of VA dissection.

Methods: We retrospectively reviewed multisection CT angiograms of 17 patients with VA dissection and 17 control subjects. The acquisition protocol for multisection CT angiography was 1.25-mm nominal section thickness, a table speed of 7.5 mm per rotation (9.4 mm/s), and a 0.8-second gantry rotation period. Two radiologists assessed the maximum intensity projection and axial source images. The sensitivity and specificity of this technique in depicting VA dissection were determined.

Results: Conventional angiography depicted 15 normal and 19 dissected VAs (including five stenotic, seven occlusive, and seven aneurysmal dissections) in the patient group and 28 normal and six atherosclerotic VAs in the control group. Multisection CT angiography enabled successful diagnosis of all 19 dissected VAs and 48 (98%) of 49 nondissected VAs but misidentified a severe atherosclerotic lesion as an aneurysmal-type dissection. The sensitivity, specificity, accuracy, and positive and negative predictive values of multisection CT angiography in diagnosing VA dissection were 100%, 98%, 98.5%, 95%, and 100%, respectively.

Conclusion: Multisection CT angiography was a sensitive and accurate technique for the diagnosis of VA dissection.

Fig 1.

Images obtained in a 53-year-old woman with a sudden onset of occipital pain and unsteady gait. a, Conventional angiogram of the left VA in an oblique projection shows alternating regions of luminal narrowing and dilatation at the V4 segment (arrows). b and c, Axial source CT angiograms show a target appearance (narrowed eccentric lumen surrounded by crescent-shaped mural thickening and an enhanced wall) at the bilateral intracranial VAs (arrows). An associated increased external diameter of the dissected artery is noted. d, MIP CT angiogram demonstrates the same picture of an alternatively narrowed and dilated lumen (black arrows) and the intramural hematoma (white arrows)

Fig 2.

Images obtained in a 57-year-old man with a sudden onset of severe headache and neck stiffness. a, Conventional angiogram of the right VA in a lateral projection shows a dissection aneurysm at the V4 segment (arrow). b and c, MIP CT angiograms more clearly demonstrate the multiple faces of this dissection aneurysm (arrow). d and e, Axial source CT angiograms at the level of the aneurysm and its upper part show no evidence of intramural hematoma (arrow).

Fig 3.

Images obtained in a 51-year-old man with a sudden onset of vertigo, nausea, vomiting, and subsequent loss of consciousness. a, Conventional angiogram of the right VA shows a smoothly tapered occlusion of the VA starting from the proximal V3 segment (arrows). b and c, MIP CT angiograms show the dissection is actually starting from the junction of V3 and V4 (black arrow) with an abrupt occlusion. The faint shadow of intramural hematoma is noted at the junction of V4 and V3-V4 junction (white arrows).

Fig 4.

Images obtained in a 49-year-old man with numbness of the left hand and dizziness for several days. a, Conventional angiogram of the right VA shows luminal irregularities at the intracranial verebrobasilar artery, especially the V4 segment, where alternating regions of narrowing and dilatation are noted (arrows). Luminal irregularities and occlusion were seen at the carotid systems (not shown). This is a case of atherosclerotic vascular disease. b, MIP CT angiogram shows the similar appearance of an alternatively dilated and narrowed lumen (arrows) at the V4 segment. c and d, Axial source CT angiograms at the levels of dilatation and narrowing show no evidence of mural thickening (arrow).