Investigation of juxtasellar and cerebellopontine angle meningiomas and neurogenic tumours: two-phase helical CT

We performed two-phase helical CT in 31 patients with juxta-sellar region a nd cerebellopontine angle tumours to evaluate its usefulness in differentia ting meningiomas from neurogenic tumours. After the intravenous injection o f 90 ml contrast medium at 3 ml/s, axial helical images were obtained with delays of 30 and 120 s. After the delayed axial images, we acquired coronal images. Changes in attenuation were assessed visually and quantitatively ( by comparing the attenuation in Hounsfield units). There were 17 meningioma s and 14 neurogenic tumours, all pathologically proven. Two-phase helical C T showed a decrease in attenuation in 15 (88 %) meningiomas and an increase in 14 (100 %) neurogenic tumours from early to delayed axial images. Coron al images showed a decrease in attenuation in all 17 meningiomas and an inc rease in 13 (93 %) of the neurogenic tumours. The mean HU and their ratios were significantly different between meningiomas and neurogenic tumours.