MRI Findings of Intracranial IVleningioma: Significance of Gd-DTPA Enhancernent

PURPOSE: To assess the usefulness of Gd-DTPA MRI in the evaluation of the characteristics of intracranial meningiomas and in the correlation with their histopathologic pattern. MATERIALS AND METHODS: We retrospectively analyzed the Gd-DTPA MRI findings in 22 cases of histologicalty-proven intracranial meningiomas. The images were assessed for signal intensity, internal texture, peritumoral edema, and enhancement characteristics. Computed tomograms were obtained in 18 cases and compared with MRI findings. RESULTS: Tl-weighted images were not particularly useful for discriminating pathologic subtype, but signal intensity on T2-weighted images were relatively well correlated with histopathologic findings. A heterogeneous texture produced by tumor vascularity, calcification, cystic foci, hemorrhagic necrosis, or psammoma body was relatively well shown on Gd-DTPA Tl-weighted image compared with that on T1- or T2-weighted image. Gd-DTPA Tl-weighted images revealed a dural tail sign in 19 cases(83%). Angioblastic type was slightly hypointense on Tl-weighted image and markedly hyperintense on T2-weighted image. Psammomatous type and firboblastic type were isointense on both T1- and T2-weighted image. Fibroblastic type was more densely enhanced than the other. The transitional, atypical, and papillary types showed tendency of heterogeneous enhancement. CONCLUSION: Gd-DTPA MRI was a useful imaging modality in evaluation of the characteristics of meningiomas and correlated well with the pathologic patterns.

Head and Neck Tumors and Neck Node Metastasis: Comparison of Ga-67 Scan and CT Findings

PURPOSE: To assess relative diagnostic value of Ga-67 planar, Ga-67 SPECT, and CT images for detection of head and neck tumors and cervical lymph node metastasis. MATERIALS AND METHODS: Thirty eight patients of pathologically proven head and neck tumors including squamous cell carcinomas(n=32), malignant lymphomas(n=3), undifferentiated carcinomas(n=2), adenocarcinomas(n=l) were enrolled in this study. Ga-67 planar and SPECT images were obtained with intravenous injection of 5mCi of Ga-67 citrate. On the basis of 30 and 20 mm in the greatest diameter of cervical lymph nodes, we compared lesion detectability of Ga-67 planar, SPECT, and CT. RESULTS: Thirty eight cases of head and neck tumors were detected in 29 cases(76.3%) with Ga-67 planar image, 37 cases(97.3%) with Ga-67 SPECT, and 32 cases(84.2%) with CT. 25 of 32 squamous cell carcinomas were positive with Ga-67 planar image and all of 32 cases with Ga-67 SPECT. Both of two undifferentiated carcinomas were positive with Ga-67 planar and SPECT images. Two of three malignant lymphomas were positive with Ga-67 planar image and all of three with Ga-67 SPECT. Eight of nine tumors were negative with Ga-67 planar image and those were less than 30ram. One case of adenocarcinoma was negative with Ga-67 planar and SPECT images. Seven of nine lymph nodes greater than 30mm were positive with Ga-67 planar image and all of nine with Ga-67 SPECT. On the basis of 20mm in greatest diameter, 16 of 21 lymph nodes greater than 20 mm were positive with Ga-67 planar and SPECT images. CONCLUSION: CT providing better resolution than Ga-67 scan permitted analysis of size and location of metastatic cervical nodes, however primary tumors of oral cavity, vocal cord, and nasopharynx were often not detected on CT when metallic and motion artifacts were present, where Ga-67 SPECT was useful. Ga-67 SPECT enabled better anatomical localization than Ga-67 planar image and was useful in detection of lymph nodes greater than 30 mm.

Endobronchial IVletastasis of Parosteal Osteosarcoma: A Case Report

Endobronchial metastasis from extrapulmonary carcinoma, both clinically and radiologically similar in appearance to a primary lung cancer, is rare. We present a case of endobronchial metastasis from parosteal osteosarcoma. The first abnormality noted on the chest radiography was tramline calcification with branching pattern along the right upper lobe bronchus and intermediate bronchus. This lesion progressed into a solid calcified nodule which increased in size. Another lesion with same pattern was also observed in the left lower lung zone.

Comparative Evaluation of MR Imaging Findings of Spinal Neurilemmomas and Neurofibromas

PURPOSE:To find out the differential points between spinal neurilemmomas and neurofibromas. MATERIALS AND METHODS: Fourteen patients with pathologically proven neurilemmomas(n--6) and neurofibromas(n=8) of spinal canal were studied using magnetic resonance(MR) imaging. Contrast enhancement was performed with Gd-DTPA in all 14 patients. The size and shape of the tumor, absence or presence of adjacent bone erosion, location and extent of the tumor, signal intensity, degree and pattern of Gd-DTPA enhancement of the tumor were retrospectively analyzed. RESULTS: Rim enhancement was seen in five of six patients(83%) with neurilemmomas and three of eight patients(38%) with neurofibromas. Neurilemmomas showed moderate to marked enhancement in five of six patients(83%), whereas neurofibromas showed moderate to mild enhancement in all 8 cases(100%). The average size in longest diameter of the tumors was 2.8cm in neurilemmomas, while 5.4cm in neurofibromas. Neurilemmomas showed ovoid shape in 5 of 6 patients, no extra- or intradural extension, and erosion of adjacent bone in one patient, whereas neurofibromas showed Iobular shape in 6 of 8 patients, extra- or intradural extension in 6 of 8 patients, and erosion of adjacent bone in 4 of 8 patients. CONCLUSION: In differentiating neurofibroma from neurilemmoma, size, shape, extent of the tumor, absence or presence of adjacent bone erosion, and pattern and degree of enhancement of the tumor may be helpful.