Spontaneous regression of intracranial arteriovenous malformation on PET.

We report a case of spontaneous regression of intracranial arteriovenous malformation (AVM) detected by PET in a 57-yr-old woman who had suffered repeated ruptures of the AVM at 28, 30 and 31 yr of age associated with pregnancy. The rupture at this hospitalization was the most critical, and after repeated ruptures for 1 mo, the AVM regressed spontaneously. The decreased cerebral blood volume (CBV) in the AVM indicated regression. The flow-to-volume (CBF/ CBV) ratios surrounding the AVM increased. The metabolic rate for oxygen (CMRO2) did not correlate with her improved neurological status, and an imbalance between CBF and CMRO2 was recognized.