Correlative investigations of craniospinal anatomy and pathology with computed tomography, magnetic resonance imaging and cryomicrotomy.

A correlative computed tomographic-anatomic method was applied to multiplanar anatomic studies. The method was particularly valuable for comparative anatomic investigations of complex regions of the central nervous system. The description of CT and MR anatomy in this thesis is based either on direct CT-anatomic correlation of the same specimen, or on indirect MR-anatomic correlation with cryosectional images from cadavers. In sagittal partial saturation MR images with short repetition times, the pituitary fossa in 41 normal volunteers appeared inhomogeneous. A postero-inferiorly located high intensity signal correlated with an intrasellar fat pad in sagittal cryosectional images. The height of the pituitary gland in 38 normal volunteers was usually less than 8 mm and its upper surface was flat or concave. The cavernous sinus anatomy was studied in coronal and axial MR planes in seven normal volunteers and 15 patients in correlation with cryosectional images. The intracavernous cranial nerves were best shown in the coronal plane, in partial saturation and inversion recovery sequences and displayed as foci of high signals intensity. MR signs of a parasellar mass included obliteration of intracavernous venous spaces, displacement of the intracavernous portion of the internal carotid artery and bulging of the lateral wall of the cavernous sinus. The topographic anatomy of the cervical neuroforamina was investigated in axial, sagittal, coronal and oblique planes in a correlative CT-anatomic investigation in 19 specimens. In four normal volunteers, the surface coil MR images of the cervical neuroforamina were correlated with cryosectional images. Surface coil MR images in a plane perpendicular to the cervical nerve roots allowed to determine their relationship to intraforaminal structures and the boundaries of the foramen. The dorsal and ventral nerve roots were demonstrated with both CT and MRI. They were located in the lower half of the foramen at and below the intervertebral disc space. The dorsal nerve roots were in contact with the superior articular process. The ventral nerve roots abutted the uncinate process and the inferior portion of the foramen. In a biomechanical cervical spinal trauma study, experimental fractures were studied with CT in axial and sagittal planes. Sagittal anatomic images showed the fractures and soft tissue injuries. Non-displaced and horizontal fractures were generally difficult to detect on axial CT scans alone. In two pathologic spine specimens CT scans in axial, sagittal and coronal planes were compared with reformatted scans and cryosectional images. Direct CT images revealed four cervical spinal fractures whereas the reformatted images only showed one displaced pedicle fracture.(ABSTRACT TRUNCATED AT 400 WORDS)