Variations of the cerebellar arteries at CT angiography.

PURPOSE: There are few studies that investigated variations of the cerebellar arteries, and the prevalence of some variations has not been reported. We aim to identify and evaluate variations of the cerebellar arteries using CTA.

METHODS

The findings in 341 patients who underwent 64-slice CTA were reviewed for anatomical variations of the cerebellar arteries. We assessed variations and classified our findings to describe the results of our analysis. We attempted to create an anatomical model for CTA that is somewhat different from previous studies and described our findings according to vascular anatomy.

RESULTS

Only 11.7% of the 341 patients had all the cerebellar arteries without anatomical variations. Vertebral artery continuation as posterior inferior cerebellar artery (PICA) was found in 4.4% of the patients. Absence of the anterior inferior cerebellar artery (AICA) was observed in 36.1%, and absence of the PICA was observed in 6.7% of the patients. The origin of the PICA was extradural in 71 (20.8%) patients. Double origin of the PICA, PICA duplication, and fenestration were rarely found. Duplication of the AICA (7.9%), and superior cerebellar artery (SCA) (20.5%), and early bifurcation of SCA (9.4%) were frequently observed. Superior cerebellar artery and posterior cerebral artery (PCA) common trunk and SCA originating from PCA were found 9.4 and 8.2%, respectively.

CONCLUSION

Variations of the cerebral arteries can be easily evaluated by CTA. Recognizing and reporting them at cerebral CT angiography may be clinically important.