Anatomical Variations of Vertebrobasilar Artery are Closely Related to the Occurrence of Vertebral Artery Dissection—An MR Angiography Study

Basi-parallel anatomical scanning (BPAS)-MRI is a simple MRI technique to reveal the surface contour of the intracranial vertebrobasilar artery. The purpose of this study was to investigate the usefulness of BPAS-MRI for observing the temporal course of unruptured vertebral artery (VA) dissection in patients by means of serial MR examinations. Since April 2003, we performed serial MR examinations in four patients with unruptured acute vertebral artery dissection. The frequency of the MR examinations during the follow-up period in each patient varied from twice within seven months to five times within 19 months. Both MRA and BPAS-MRI were obtained in each MR examination. We investigated the course of morphological changes within the dissected artery on BPAS-MRI (outer contour) and on MRA (inner lumen). Although the initial MRA showed fusiform dilatation, irregular stenosis or normal caliber at the dissected lesion, the initial BPAS-MRI disclosed fusiform dilatation in all of the four patients. In two patients, MRA finding of the VA lesion had changed, though the fusiform appearance had been stationary on BPAS-MRI. Then both dissolution of the fusiform dilatation on BPAS-MRI and normalization of the inner luminal caliber on MRA were confirmed within nine months. In one patient, fusiform dilatation on both BPAS-MRI and MRA resolved simultaneously on the MR examination at eight months after the initial symptom. In another patient, fusiform dilatation of the outer contour was still enlarging on BPAS-MRI ten months after the onset, though the fusiform dilatation on MRA had been stationary since the eighth week. We performed endovascular coil embolization in this patient eleven months after the initial symptom. Resolution of the fusiform dilatation on BPAS-MRI should be a healing sign of VA dissection. Persisting the fusiform dilatation or progressively enlarging outer contour on BPAS-MRI may be an unstable sign. BPAS-MRI provides more information about the instability of the dissected lesion. We should obtain not only MRA but also BPAS-MRI for the course observation of unruptured VA dissection.

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Matsukawa h, Motoharu F, Shinoda M et al. Comparison of clinical characteristics and MR angiography appearance in patients with spontaneous intradural vertebral artery dissection with or without subarachnoid hemorrhage. J Neurosurg 2011; 115: 108 – 112

Neuroradiologie Scan ◽

10.1055/s-0030-1257143 ◽

2012 ◽

Vol 2 (01) ◽

pp. 22-23

Keyword(s):

Subarachnoid Hemorrhage ◽

Vertebral Artery ◽

Mr Angiography ◽

Clinical Characteristics ◽

Vertebral Artery Dissection ◽

Artery Dissection

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Comparison of clinical characteristics and MR angiography appearance in patients with spontaneous intradural vertebral artery dissection with or without subarachnoid hemorrhage

Journal of Neurosurgery ◽

10.3171/2011.2.jns101708 ◽

2011 ◽

Vol 115 (1) ◽

pp. 108-112 ◽

Cited By ~ 8

Author(s):

Hidetoshi Matsukawa ◽

Motoharu Fujii ◽

Masaki Shinoda ◽

Osamu Takahashi ◽

Daisuke Yamamoto ◽

...

Keyword(s):

Subarachnoid Hemorrhage ◽

Vertebral Artery ◽

Mr Angiography ◽

Clinical Characteristics ◽

Univariate Analysis ◽

Vertebral Artery Dissection ◽

Acute Angle ◽

Artery Dissection ◽

Current Smoking ◽

Saccular Aneurysms

Object It is well known that spontaneous intradural vertebral artery dissection (siVAD) is an important cause of nontraumatic subarachnoid hemorrhage (SAH). The factors that influence whether SAH develops, however, remain unclear. The aim of this study was to investigate whether clinical characteristics and imaging findings are different in patients with siVAD with SAH compared to those with siVAD without SAH. Methods The authors conducted a retrospective, single-institution study involving patients in whom siVAD developed with or without SAH, between July 2003 and November 2010. Univariate and multivariate analyses were performed to evaluate clinical characteristics and MR angiography findings. The vertebral-union-basilar angle (VUBA) was defined as the most acute angle between line of the basilar artery trunk and line of the vertebral angle (VA) at the vertebral union on 3D MR angiograms. Results Among 58 patients with siVAD, 21 developed SAH. The presence of siVAD and SAH was significantly associated with higher rates of current smoking (OR 13; 95% CI 3.6–38; p < 0.0001), dissection of the dominant VA (OR 9.2; 95% CI 2.5–19; p = 0.0004), and unruptured supratentorial nondissecting saccular aneurysms (OR 11; 95% CI 2.1–19; p = 0.0025), and the VUBA of the dominant VA was significantly larger (p < 0.0001, univariate analysis). Multivariate analysis showed that these differences were still significant (p < 0.05). Conclusions A larger VUBA of the dominant VA, the presence of unruptured supratentorial nondissecting saccular aneurysms, and current smoking may be factors that predict which patients with siVAD will develop SAH by dominant VAD.

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