Impact of Vessel Narrowing and Changes in Blood Flow on the Development of Ischemia in Cervical Arterial Dissection Using Quantitative Magnetic Resonance Angiography

Abstract

Background Up to 3% of all ischemic strokes are secondary to dissections; however, cerebral hemodynamic patterns in cervical arterial dissection and their association with cerebral ischemia are unknown. This study represents the first to assess blood flow using quantitative magnetic resonance angiography in patients with cervical arterial dissection and their presentation with ischemia. Methods Retrospective chart review was completed in patients with cervical arterial dissection between 2009 and 2019. Inclusion criteria were adults with dissection of internal carotid artery or vertebral artery who underwent baseline magnetic resonance imaging (MRI) and quantitative magnetic resonance angiography. Cases were reviewed for presentation, management, and imaging findings. Flow index was calculated using ipsilateral vessel flow divided by contralateral flow. Results A total of 37 patients with a mean age of 45.95±11.95 years were included. Of the patients, 19 (51.2%) had internal carotid artery dissections, 17 (45.9%) with vertebral artery dissections, and 1 with both. Patients with ischemia on MRI demonstrated lower flow in the ipsilateral vessel when compared with those patients without ischemia (P=0.003). Using the flow index in receiver operating characteristic analysis to predict ischemia on MRI yielded an area under the curve of 0.833 (P=0.002); receiver operating characteristic analysis of the percent of total flow for ischemia on MRI found an area under the curve of 0.895 (P=0.000), and receiver operating characteristic analysis of percent vessel narrowing calculated an area under the curve of 0.887 (P=0.000). Multivariate analysis identified vessel narrowing as significantly associated with ischemia on MRI (P=0.03). Conclusion This study represents the first to evaluate blood flow in patients with cervical arterial dissection using quantitative magnetic resonance angiography and its relationship with cerebral ischemia. Patients with lower flow as a result of dissection appear to be at higher risk of ischemia on presentation, emphasizing the role of hemodynamics in underlying pathophysiology, and vessel narrowing appears paramount in the association with developing ischemia.

Keywords

• arterial dissection
• cerebral blood flow
• internal carotid artery dissection
• quantitative MR angiography
• vertebral artery dissection