Vascular imaging findings in 43 patients with cerebral infarction due to spontaneous cerebral artery dissection

Abstract

Objective To investigate the imaging characteristics of spontaneous cerebral artery dissection （CAD） causing cerebral infarction by analyzing the vascular imaging fmdings. Methods The neuroimaging and clinical data in patients with cerebral infarction due to spontaneous CAD were reviewed. The characteristic findings at different sites of CAD in all vascular imaging examinations were analyzed and summarized. Results A total of 43 patients （28 men, 15 women; mean age, 45.1 - 12.3 years） with CAD were included in the study. Twenty-three patients with extracranial internal carotid artery dissection （ICAD）, 5 with intracranial anterior circulation dissection, 7 with extracranial vertebral artery dissection （VAD）, 6 with intracranial VAD, and 2 with basilar artery dissection （BAD）. In patients with extracranial ICAD, occlusion （usually beginning about 1-2 cm above the bifurcation and tapering to a complete occlusion with a flame-like or mouse-tail appearance） was the common imaging findings, luminal stenosis （irregular, elongated, and tapered stenosis） and/or dissecting aneurysms were observed in partial patients, intimal flaps and double-lumen sign were found in a few patients, and vessel tortuosity of ipsilateral or bilateral ICA were observed in 6 patients. Characteristic signs of occlusion or stenosis of extracranial ICAD were observed in computed tomography angiography （CTA） or magnetic resonance angiography （MRA） in partial patients, and magnetic resonance imaging （MRI） could reveal the bright hyperintense crescent-shaped zone that represents the intramural hematoma, and resource imaging of CTA could reveal intimal ,flaps and double-lumen sign at the level of dissection. Occlusion （V1, V4 segnent and V3 segment extending to V4 segment） was the common vascular imaging features in patients with VAD, V1 segment occlusion had a typical appearance： cut-off like or taped occlusion. MRA could reveal VA occlusion, and MRI could show the bright hyperintense of intramural hematoma at the level of VA occlusion. Concomitant dissecting aneurysms and stenosis of intracranial VA were found in 2 patients. Intracranial dissections of anterior circulation were verified mainly by digital subtraction angiography （DSA）, if dissecting aneurysms or intimal flaps were observed, and intimal flaps were revealed by resource imaging of MRA in a patient. In patients with BAD, dissecting aneurysm was found in a patient, concomitant local stenosis in MRA and bright hyperintense of intramural hematoma on MRI were observed in another patients. Vascular imaging follow-up was performed in 7 patients, complete recanalization was found in a patient with extracranial ICA occlusion due to CAD, stenosis disappeared and dissecting aneurysm almost healed in a patient with extracranial ICAD, dissection lesions had no change in 2 patients with extracranial ICAD, dissecting aneurysm further expanded in a patient with extracranial ICAD, degree of stenosis reduced in a patient with intracranial ICAD, dissecting aneurysm healed after stenting in a patient with intracranial VAD. Conclusions Diagnosis of CAD mainly depends on vascular evaluations, and vascular imaging features of CAD, such as flame-like or taped occlusion, dissecting aneurysms, intimal flaps, irregular or/and elongated stenosis, MRI signals of intramural hematoma, doublelumen sign and so on, were the points for diagnosis of CAD. DSA was an important method for diagnosis of CAD, and MRA ＋ MRA, or CTA and resource imaging were very valuable for diagnosis of CAD. CAD should be followed by methods of vascular imaging, because the results of follow-up were very important for adjusting the treatment strategies in patients with CAD. Key words: Carotid artery, intemal, dissection; Vertebral artery dissection; Brain infarction; Angiography, digital subtraction; Magnetic resonance angiography; Tomogaphy, X- ray computed