The tentorium in axial section. II. Lesion localization.

Most juxtatentorial lesions may be localized accurately on contrast-enhanced axial section CT scans by use of the opacified tentorial bands. Lesions that lie lateral edge of the diverging bands are supratentorial. Lesions that lie medial to the V-shaped tentorial bands are infratentorial and/or incisural. Flattening of the tentorial border of a lesion helps to identify its location. Use of the tentorial bands identifies transincisural extension of meningioma reliably, but does distinguish well between true transtentorial growth of meningioma and marked upward bulging of the tentorium from purely infratentorial meningioma.