Gadolinium-DTPA enhancement of dural structures on MRI after surgery.

Gadolinium-DTPA enhanced MRI was examined before and after surgery in 14 patients with particular attention to the enhancement of falx cerebri, tentorium cerebelli and dura mater. A marked enhancement was observed in 2 falx and 2 tentorium before surgery, whereas it was observed in 7 falx, 9 tentorium and 11 dura after surgery. Among 6 falx, 7 tentorium and 12 dura showing increased enhancement after surgery, 2 falx, 3 tentorium and 8 dura showed marked enhancement which was not observed before surgery. A small amount of subdural haemorrhage during surgery is known to heal as subdural neomembrane with capillaries. An increased enhancement of dural structures conceivably derives from the extravasation of Gd-DTPA through capillaries involved in the subdural neomembrane. In the postoperative MRI, the enhancement of dural structures should be taken into consideration.