Variations of the Superior Cerebellar Artery on Magnetic Resonance Angiography

Abstract Introduction: The superior cerebellar artery (SCA) is the most consistent branch of the basilar artery. Its most frequent variations include duplication, hypoplasia, a common trunk of the SCA with the P1 segment of the posterior cerebral artery (PCA), early branching, triplication, and fenestration. Aim: To determine the frequency and characteristics of individual variations of the SCA on magnetic resonance angiography (MRA). Subjects and Methods: This retrospective study included 1000 subjects older than 18 years, who underwent native MRA, which was performed using 1.5 Tesla machines. Patients with cerebrovascular disease, vascular malformations, or brain tumors in the immediate vicinity of the analyzed arteries were excluded from the study. Results: The average internal diameter of the SCA was 1.24 mm. The SCA was symmetrical in 63.4% of cases, and the most common anatomical variation was duplication of the SCA, with 19.8% of cases, where bilateral duplication was more common in men than in women ( P = 0.03). Hypoplasia and fenestration were both present in 0.2% of cases. The frequency of a common SCA and PCA trunk was 14.2%. Conclusion: SCA exhibits a wide range of anatomical variations that may have profound clinical implications, influencing surgical approaches, endovascular interventions, and overall patient management strategies. MRA offers noninvasive, high-resolution visualization of the SCA, making it a superior method for comprehensive assessment of SCA anatomy and possible variations.