Identification and anatomic description of the anterior choroidal artery by use of 3D-TOF source and 3D-CISS MR imaging

BACKGROUND AND PURPOSE: The importance of the anterior choroidal artery (AC hA) is related to its supply of crucial anatomic structures, such as the in ternal capsule. Angiographically, the AChA can be detected in 71% to 98% of patients, but as yet, its visibility on MR images has not been evaluated. Our goal was to assess the sensitivity of MR imaging in the identification of the AChA and its anatomic characteristics. METHODS: Twenty volunteers underwent MR imaging with a 3D time-of-flight (3 D-TOF) sequence, 10 of them additionally with a 3D Fourier transformation c onstructive interference in steady state (3D-CISS) sequence. The MR angiogr aphic source images and the 3D-CISS images were analyzed independently by t wo neuroradiologists, who evaluated the ability to identify the different s egments of the AChA and the posterior communicating artery (PComA) accordin g to a previously defined scoring system (0 = not identified, 1 = most prob ably identified, 2 = identified with certainty). Additionally, three patien ts were examined who had an arteriovenous malformation (AVM) supplied by th e AChA. RESULTS: In the volunteers, the PComA was identified with certainty in 87.5 % on 3D-TOF sequences and in 95% on 3D-CISS sequences; the AChA was identif ied with certainty in 92.5% on 3D-TOF sequences and in 90% on 3D-CISS seque nces. 3D-CISS images showed additional anatomic information in six of 20 ve ssels. In the three patients, the enlarged AChA was identified with certain ty on both imaging sequences. CONCLUSION: The AChA can be reliably identified using both 3D-CISS sequence s and the source images of the 3D-TOF sequence. MR imaging can be used to a ssess and follow-up AChA-related disorders, especially AVMs.