A Case of Fenestrated Basilar Artery Associated with Multiple Aneurysms

Fenestrated basilar artery is a uncommon congenital anomaly. It is seen in approximately 0.3 to 5.26% of autopsy series, but only in 0.1 to 1.9% of angiography series. Because the fenestrated basilar artery is a defect or weakness of muscular and internal elastic lamina, incidence of fenestration of the basilar artery when a vertebrobasilar artery aneurysm is present is reported to be 35.5%. We experienced one case of fenestrated basilar artery associated with multiple aneurysms(fenestrated basilar artery, basilar tip, left posterior communicating artery). We operated the basilar tip aneurysm and the posterior communicating artery aneurysm. Although we didn't operate the fenestrated basilar artery aneurysm, we report one case with review of literature in order to improve the operative result of the fenestrated basilar artery aneurysm.

MR Findings of Trigeminal Neurinoma

PURPOSE: To describe the MRI findings of trigeminal neurinoma. MATERIALS AND METHODS: We retrospectively analyzed the MRI findings of 19 patients with trigeminal neurinomas proven by surgery and pathologic examination. Axial T1-and T2-weighted MR images in all patients and gadolinium-enhanced T1-weighted images in 14 patients were obtained at 2.0T (8 cases), 1.5T (6 cases) or 0.5T (5 cases). These were analyzed in terms of tumor size, signal intensity, degree of contrast enhancement, the presence or absence of cystic change and denervation atrophy of the masticator muscles. RESULTS: Clinical manifestations included sensory abnormality or pain (n=12), headache (n=10), impaired visual acuity or diplopia (n=6), hearing loss or tinnitus (n=3), weakness of masticator muscles (n=2), and mass or nasal obstruction (n=2). On MR images, tumor size was seen to average 4.2 (range 1.5-6)cm; tumors were located in the posterior cranial fossa (n=8), middle cranial fossa (n=4), ophthalmic nerve (n=2), maxillarynerve (n=1), and mandibular nerve (n=1), and in three cases were dumb bell-shaped and extended into both the middle and posterior cranial fossa. On T1-weighted images, signals were isointense with cortical grey matter, in ten cases (53%), and of low intensity in nine (47%); on T2-weighted images, signals were of high intensity in 15 cases (79%) and were isointense in four (21%). Cystic change was seen in 12 cases (63%). After enhancement, all (14/14) the tumors enhanced. Denervation atrophy was seen in nine cases (47%) and all of these involved the trigeminal ganglion or mandibular nerve. CONCLUSION: A trigeminal neurinoma shows similar signal intensity and enhancement to other cranial neurinomas with a higher incidence of cystic degneration. Its location and shape are characteristic, and where there is involvement of the trigeminal ganglion or mandibular nerve, denervation atrophy may be seen.

Dysembryoplastic Neuroepithelial Tumor: MR Imaging Findings

PURPOSE: To describe the characteristic MR imaging findings of dysembryoplastic neuroepithelial tumor(DNT). MATERIALS & METHODS: We retrospectively reviewed MR images and pathologic findings of seven patients(five maleand two female, mean age 22) with surgically proven DNTs. We analyzed the location, size, configuration, signal intensity and contrast enhancement of nodules and accompanying calcifications, surrounding edema and calvarialchanges. RESULTS: All tumors were located in the cortical and subcortical portions of the temporal lobes. Most tumors showed small well-demarcated gyriform cystic nodules with almost the same signal intensity as that of the cerebrospinal fluid. Nodule margins were more sharply delineated on T2 than on T1-weighted images because on the former the peripheral portion of nodules shows high signal intensity. None of the patients showed surrounding edema or mass effect. On contrast-enhanced study, one of five patients showed subtle peripheral enhancement. Two patients showed included dense calcified nodules adjacent to cystic nodules, and two showed overlying calvarial thinning. CONCLUSION: Multiple small gyriform intracortical cystic nodules and occasional dense nodular calcifications are the characteristic findings of DNTs, and these may be differentiated from other focal lesion sin patients with temporal lobe epilepsy with the help of MR imaging.

Growth Hormone-Secreting Pituitary Adenoma: Clinical and MR Imaging Findings

PURPOSE: To describe clinical and MRI findings of growth hormone-secreting pituitary adenoma, to determine ifthere are any characteristic MRI findings different from those of other pituitary adenomas, to evaluate the relationship between tumor size and serum growth hormone level, and to assess the results of immunohistochemical study. MATERIALS AND METHODS: We retrospectively analysed clinical and MRI findings of 29 patients with growth hormone-secreting pituitary adenoma confirmed by serum growth hormone level and surgery. We also evaluated the relationship between the tumor volume and serum growth hormone level, and the results of immunohistochemical study. Coronal and sagittal T1-weighted MR images in all patients and gadolinium enhanced T1-weighted MR images in28 patients were obtained with 2.0 T(24 cases) and 0.5 T(5 cases) MR imagers. The images were analyzed in terms oftumor size, signal intensity, degree of contrast enhancement, extent of tumor growth and the presence or absenceof cystic change, hemorrhage and calcification. RESULTS: Clinical manifestations included facial feature changeand soft tissue swelling of hands and feet(n=29), headache(n=12), impaired visual acuity(n=9), symptoms of hyperprolactinemia(n=8), visual field defect(n=5), and others(n=6). On MR images, all of the 29 cases were seen tobe macroadenomas and the size of the tumors averaged 2.2cm(1-5.2 cm). Supra- and infrasellar extensions were seenin 21 and 22 patients, respectively. Cavernous sinus invasion was noted in seven, and in one this was bilateral.Signal intensity was isointense with cortical grey matter in 26 cases(90%). Cystic change or necrosis was seen ineight cases(28%), hemorrhage in four(14%), and calcification in two(7%). After enhancement, most(25/28) of the tumors enhaned less than mormal pituitary in degree. There was no correlation between serum growth hormone level and tumor size. Immunohistochemical study showed positive growth hormone-secreting cells in only 69%(11/16). CONCLUSION: Clinical findings in patients with growth hormone-secreting pituitary adenomas were various and included acromegaly, headache, visual impairment, and symptoms of hyperprolactinemia, for example. On T1-weightedMR images, all tumor were macroadenoma, and there were no characteristic findings different from those of other pituitary tumors. The volume of a tumor did not correlate with serum hormone level. Immunohistochemical study showed positive growth hormone-secreting cells in a limited number of cases.