颅神经的影像检查-肖家和ppt课件.ppt

* Figure 52-2 Left optic nerve astrocytoma in a 4-year-old boy. A, Enhanced axial CT scan. The large tumor mass is seen in the left retrobulbar region, with extension into the slightly expanded left optic canal (arrowhead). B, Enhanced axial MRI with contrast and fat saturation. The tumor and its intracanalicular extension are well seen and explain this childs progressive monocular visual loss. * Figure 52-3 Lymphomatous meningitis in a 26-year-old man with AIDS. There is a focal-enhancing lesion at the proximal portion of the right oculomotor nerve in the interpeduncular cistern (arrowhead). The lesion explains the patients third-nerve palsy. The contralateral normal third nerve also is well seen. * Figure 52-4 Right trochlear nerve tumor extending along the course of the nerve from the brainstem to the cavernous sinus. A, Sagittal view showing the nuclear origin of the tumor in the inferior colliculus (arrow). B, Axial image. The deformity of the inferior colliculus is seen (arrow), and there is a separate tumor mass entering the right side of the cavernous sinus (arrowhead). Left sphenoid wing dysplasia and intraorbital extension of the left temporal lobe are incidentally noted in this patient with neurofibromatosis type 1. * Figure 52-5 Parenchymal lymphoma and lymphomatous meningitis in an immunocompromised patient without AIDS. A, Enhanced image at the level of the cerebral peduncles. There are enhancement of the midbrain and enhancement of the left trochlear nerve (arrowhead). B, Axial enhanced scan at the level of the midpons. A similar nodular focus of enhancement is seen in the left CPA (arrowhead). * Figure 52-6 Plexiform neurofibroma of the left fifth nerve in a patient with neurofibromatosis type 1. A and B, Coronal enhanced scans. Note that the tumor involves the left foramen rotundum (arrowhead in A) and extends through the left foramen ovale into the cavernous sinus (arrowhead in B). C and D, Enhanced axial images. Again, the course of the