PMC6350027_01
Magnetic resonance angiography performed at admission. (A) Stenosis of the lumen of the right vertebral artery was observed. (B) Basiparallel anatomical scanning performed at admission. The outer diameter of the artery was expanded.
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F1
MR imaging showed a stenosis of the right vertebral artery with an intramural hematoma (Fig. 1A). Basiparallel anatomic scanning revealed widening of the outer diameter of the right vertebral artery (Fig. 1B), leading to the diagnosis of vertebral artery dissection.
Three-dimensional computed tomographic angiography. (A) The right posterior inferior cerebellar artery (PICA) branched from the dissected portion of the right vertebral artery (arrow). The hemispheric branch of the PICA was perfused by some other artery coming from the jugular foramen (arrowhead). As for the left PICA, it entirely came from the left jugular foramen (double arrowhead) instead of branching from the vertebral artery. (B) In the cervical portion, the right ascending pharyngeal artery (APA) branched from the external carotid artery (arrowhead), and the left APA branched from the inside of the bifurcation (arrow).
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F2
As for the left PICA, it did not branch from the left vertebral artery, but entirely came from the left jugular foramen (Fig. 2A). In the cervical portion, the right APA branched from the external carotid artery, while the left APA emerged from the bifurcation of the internal and external carotid arteries (Fig. 2B).
Digital subtraction angiography. (A) Selective angiography of the right ascending pharyngeal artery (APA). The hemispheric branch of the right posterior inferior cerebellar artery (PICA) was perfused by the jugular branch of the APA. The artery is colored red, while the vein is colored blue. (B) Right vertebral angiography. The original PICA from the right vertebral artery (arrow) was supplying only the medial half of the right cerebellar hemisphere. (C) Selective angiography of the left APA. The cortical and medullary segments of the left PICA were perfused by the jugular branch of the APA.
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Digital subtraction angiography revealed that the hemispheric branch of the PICA on the right side originated from the jugular branch of the APA (Fig. 3A). The original PICA from the right VA was supplying only the medial half of the right cerebellar hemisphere (Fig. 3B). On the contralateral side, the PICA did not branch from the vertebral artery, but was perfused only by the jugular branch of the APA (Fig. 3C).
Other anatomical anomalies seen in the patient. (A and B) Angiography of the right (A) and left (B) internal carotid arteries. The right transverse sinus (black arrow) was hypoplastic, while the transverse sinus was absent on the left side. The occipital sinus (white arrowhead) and bilateral marginal sinuses (white arrow) were highly developed. (C and D) Coronal sections of T2-weighted MR images. The A1 segments of the anterior cerebral artery (arrows) on both sides (A: right, B: left) were running under the optic nerves (arrowheads).
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F4
In this patient, the transverse sinus was hypoplastic on the right side and aplastic on the left side, and the occipital and marginal sinuses were substantially enlarged in compensation (Figs. 4A and 4B). The patient also had a rare variation of the anterior cerebral artery, which had an infraoptic course bilaterally (Figs. 4C and 4D).