Revisited old and new CT findings in unruptured larger arteriovenous malformations of the brain.

Several papers have already described the computed tomographic (CT) findings in arteriovenous malformations (AVMs) of the brain. In a population of larger and unruptured AVMs, however, improved resolution CT has made it possible to demonstrate findings not previously appreciated: (a) major and minor mass effects in the absence of rupture of an AVM (33 of 60 cases); (b) cisternal enlargement secondary to vessel ectasia and tortuosity; (c) extensive edema of white matter; (d) the detailed features of finer and coarser calcifications of the malformation; (e) gray matter changes, disturbances in the gray-white matter interface, and intrinsic hypodense regions within the AVM; and (f) visualization of small vessels on intravenous enhancement.