A 63-year-old woman presented with sudden onset vertigo and was diagnosed with an acute infarction in the left cerebellum on October 17, 2015. On the brain magnetic resonance imaging (MRI), an acute infarction was observed in the territory of the left superior cerebellar artery (SCA) (). Magnetic resonance angiography showed a mild irregularity in both proximal VAs and an occlusion in the left SCA (). For further evaluation, we performed a diagnostic cerebral angiography. The SCA was completely recanalized, and there was no definite abnormality in both VAs. Incidentally, we observed an unopacified streaming at the level of C5 during the selective catheter angiography of the left VA originated from the left subclavian artery (). And the medial limb of the left VA arising from the aortic arch could be found on the selective catheter angiography, which was not observed on the MRA. The dominant, lateral limb of the left VA was originated from the left subclavian artery () and the small, medial limb was originated directly from the aortic arch between the left common carotid artery and the left subclavian artery (). They joined at the transverse foramen of the fifth cervical vertebra.\nA right-to-left shunt was suspected on the transcranial doppler using an agitated saline solution with blood. A pulmonary arteriovenous malformation (AVM) in the right lung was detected by transesophageal echocardiography and chest computed tomography. With an elevated level of D-dimer with 421 ng/ml, the pulmonary AVM was suspected as a source of embolus causing an acute cerebellar infarction.
A 36 year-old male with a history of dizziness and suspected cerebrovascular pathology was referred to our center for angiographic evaluation of carotid and vertebral arteries. He underwent multidetector 64-row computed tomography (MDCT) angiography. (GE: Optima660,2011, Tokyo, Japan60). Eighty-five milliliter of nonionic iohexolcontrast (Omnipaque, 350 mg I/ml, GE Healthcare, Shanghai, China) was injected at a rate of 5 ml/s by a power injector through the antecubital vein. The acquired images (slice thickness 0.625 mm) were further analyzed in a work station (GE: AW Volume Share 4) to generate volume-rendered (VR) and maximum intensity projection (MIP) images.\nThe left vertebral artery (LVA) had two separate limbs of origin []. The medial limb (2.2 mm in diameter at its origin) originated directly from the aortic arch in between the origins of left common carotid (LCCA) and left subclavian arteries (LSA) []. The lateral limb (2.4 mm in diameter at its origin) emanated from the LSA in its orthodox position and entered the foramen transversarium of C6 vertebra. Both the limbs united to form a single trunk at C5-C6 interval and the single trunk (3.2 mm in diameter) then entered C5 transverse foramen [Figures and ]. Both the limbs of the right vertebral artery (RVA) originated from the right subclavian artery (RSA) []. The medial limb (3.9 mm in diameter at its origin) originated from its orthodox position, whereas the lateral limb (2.4 mm in diameter at its origin) arose more posteriorly close to the origin of thyrocervical trunk. The lateral limb entered the C6 transverse foramen, but the medial limb entered the carotid space lying posteromedial to right common carotid artery (CCA) []. At the interval between the C4 and C5 vertebrae, both the limbs fused to form a single trunk (4.4 mm in diameter) which entered the C4 transverse foramen [Figures and ]. Further distal course of both vertebral arteries was normal and no cerebrovascular pathology could be detected.