الفهرس 
Anatomy of the posterior cranial fossaOnly 14 pages are availabe for public view
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Abstract
The head is considered the first anatomic area for which both CT and MRI were extensively applied. More experience has been acquired from imaging the central nervous system with MRI than any other area of the body, and its clinical utility has been proved beyond doubt. Now, MRI is considered the primary imaging procedure for CNS and will continue for sometime. With the availability of Gd-DPTPA as a contrast agent, indications for enhanced MR are being clarified.The axial and sagittal planes are preferable for midline lesions; hemispheric cerebellar masses are shown best with axial and coronal scans.The majority of intra-axial posterior fossa tumors occur in children. Intra-axial lesions are more likely to obstruct the ventricles than the extra-axial lesions, most of these tumors have a higher water content than normal brain, resulting in non specific prolongation of T1 and T2 relaxation times.