Comparison of imaging modalities for the accurate delineation of arteriovenous malformation, with reference to stereotactic radiosurgery

Purpose: To investigate the discrepancy between the arteriovenous malformations seen on magnetic resonance angiography (MRA) and on stereotactic digital subtracted angiography (DSA). Methods and Materials: The target volume on stereotactic DSA (V-DSA) and the target volume on MRA (V,(MRA) rA) were separately delineated in 28 intracranial arteriovenous malformations. The coordinates of the center and the outer edges of V-DSA and V-MRA,A were calculated and used for the analyses. Results: The standard deviations (mean value) of the displacement of centers of V-MRA from V-DSA were 2.67 mm (-1.82 mm) in the left-right direction, 3.23 mm (-0.08 mm) in the anterior-posterior direction, and 2.16 mm (0.91 mm) in the craniocaudal direction. V-MRA covered less than 80% of V-DSA, in any dimensions in 9 cases (32%), although no significant difference was seen in the target volume between each method, with a mean value of 11.9 cc for V-DSA and 12.3 cc for V-MRA (p = 0.948). Conclusion: The shift of centers between each modality is not negligible. Considering no significant difference between V-DSA and V-MRA, but inadequate coverage of the V-DSA by V (MRA), it is reasonable to consider that the target on MRA might include the feeding artery and draining vein and possibly miss a portion of the nidus. (c) 2005 Elsevier Inc.