Radiological Findings of Vertebral Artery Dissection

PURPOSE: The vertebral artery dissection is rare and increasingly recognized as a source of stroke. The purpose of this study is to describe causes, clinical manifestations, MRI and anglographic findings. MATERIALS AND METHODS: Conventional anglograms(n=7) and magnetic resonance imaging(n=6) were retrospectively analyzed in seven patients of vertebral artery dissection. The classification of the Krayenbuhl and Yasargil for vertebral artery segmentation was used for localization of vertebral artery dissection. Additionally, etiology and clinical manifestations were also retrospectively reviewed. RESULTS: Six cases were spontaneous type and one case was traumatic type. The clinical diagnoses of 6 spontaneous arterial dissection cases were wallenberg syndrome(4 cases), subarachnoid hemorrhage(1 case), and infarction of the cerebellum corresponding to PICA territory(1 case). A linear bright signal caused by thrombus was well visualized at the dissection area on sagittal T1 weighted spin echo MR images in all 6 cases. The characteristic anglographic findings were profound narrowing in 4 cases, pearl and string sign(including dissecting aneurysm) in 3 cases, complete obstruction in 3 cases, and a double density lumen(true and false lumen) extending to proximal basilar artery in one case. Spontaneous dissections were located at the V4 segment in all 6 cases. One traumatic dissection was located at the V2 segment. CONCLUSION: The most common site of the spontaneous dissection of the vertebral artery was V4 portion and a linear bright signal caused by thrombus was well visualized on sagittal T1 weighted spin echo MR images.

MR Findings of Vascular Masses of the Head and Neck: Differential Diagnosis and Interventional Treatment Planning

PURPOSE: To characterize the MR findings for a differential diagnosis and to make a plan for treatment by interventional technique of the vascular masses with/without hypertrophic feeding vessels of the head and neck. SUBJCETS AND METHODS: Seven patients with vascular masses of the head and neck proved by pathology, angiography, clinical findings were included. Vascular masses included 4 venous malformations, a capillary hemangioma, and a hemangiopericytoma, a hemangioma combined with arteriovenous malformation. 7 patients had MR studies with 1.0T and 1.5T using routine TI-, T2- weighted spin echo sequences, and contrast enhancement. 4 MR angiography, 3 inversion recovery, and 6 contrast angiography were studied from 7 patients RESULTS: All vascular masses demonstrated higher than muscle signal intensity on Tl-weighted images, bright signal intensity on T2-weighted images, and prominent enhancement, except AV hemangioma combined with prominent arteriovenous malformation on postcontrast scan. Three hemangiomas demonstrated distinct serpiginous signal voids. Venous malformations demonstrated venous lakes seen as homogenous regions of high signal intensity and phleboliths seen as low signal foci on images. Inversion recovery was the best pulse sequence for evaluation of the extent of lesion. CONCLUSION: MR findings of the vascular masses of the head and neck are useful in delineating the extent of the disease, differentiating venous malformation or cavernous hemangioma from other hemangiomatous lesions including hypertrophic feeding vessels, and making a plan for treatment by interventional technique also.

3D-TOF MR angiography of the lower extremity: normal and arterial occlusive disease

No abstract available.