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T Furusawa

Publications and source records attributed to T Furusawa.

79 records · Page 5Linked to original sources
PubMedDate not supplied

Arachnoid granulations of the posterior fossa: CT and MR findings.

The radiological appearance of typically located arachnoid granulations on craniograms is well known. Arachnoid granulations of unusual size and location should be distinguished from pathological processes. We analyzed six patients with arachnoid granulations in the posterior fossa. Characteristic findings of arachnoid granulations were disclosed by computed tomography (CT) and magnetic resonance (MR) imaging; a punched out-like bone defect from the inner table into the outer table on CT scans and intensity similar to that of the cerebrospinal fluid in all pulse sequences on MR images.

Aged↗
PubMedDate not supplied

Small cortical infarcts mimicking metastatic tumors.

Small cortical enhancing lesions mimicking metastases were demonstrated on contrast imaging in three patients without specific neurologic deficits corresponding to the lesions. One patient had a long carcinoma. However, all had cardiac arrhythmias known as major sources of cerebral emboli. Two had early cerebral infarcts and ischemic heart diseases. The lesions disappeared spontaneously on follow-up studies. They were subsequently presumed to be small infarcts. Clinical information and follow-up examinations are important to differentiate these small cortical lesions from metastases.

Aged↗
PubMedDate not supplied

"Pseudoocclusion" of the internal carotid artery: a pitfall on intracranial MRA.

We report a case showing "pseudoocclusion" of the internal carotid artery as a pitfall on intracranial MRA. Pseudoocclusion was attributed to magnetic susceptibility artifacts with metallic substances located proximal to a slab. The same finding could be reproduced on experimental MRA with a small steel coil applied on the anterior neck of a volunteer at the level of the carotid bifurcation.

Adult↗
PubMedDate not supplied

Focal T2 hyperintensity in the dorsal brain stem in patients with vestibular schwannoma.

BACKGROUND AND PURPOSE: The vestibular nucleus cannot be visualized on MR imaging, but some patients with vestibular schwannoma show a tiny area of hyperintensity in the dorsal brain stem on T2-weighted images. The aim of this study was to determine whether this tiny area is characteristic of vestibular schwannoma. METHODS: We retrospectively reviewed the postoperative MR images of 53 patients with cerebellopontine angle tumor. MR images were obtained with a 1.5T scanner. Spin-echo pre- and postcontrast 3-mm-thick T1-weighted axial images, 3-mm-thick fast spin-echo (FSE) T2-weighted axial images, and 0.8-mm-thick constructive interference in steady state (CISS) axial images were acquired. Surgical and histopathologic diagnosis was vestibular schwannoma (41/53 = 77%), meningioma (7/53 = 13%), epidermoid cyst (3/53 = 6%), glioma with exophytic growth (1/53 = 2%), and chordoma (1/53 = 2%). RESULTS: A tiny area of hyperintensity was observed at the lateral angle of the fourth ventricle floor in 6 patients (3 men, 3 women; age range, 24-54 years; mean age, 43 years) with vestibular schwannoma larger than 2 cm in maximal diameter on both FSE T2-weighted and CISS images. Preoperative MR images with the same pulse sequences showed the same area of hyperintensity in all these patients. CONCLUSION: Because the location of the area of hyperintensity is coincident with the vestibular nucleus, the hyperintensity may represent degeneration of the nucleus. This hyperintensity should not be confused with a postoperative lesion or a small infarction. If such hyperintensity is seen in a patient with a large cerebellopontine angle tumor, a diagnosis of vestibular schwannoma is suggested.

Adolescent↗
PubMedDate not supplied

Primary central nervous system lymphoma presenting as diffuse cerebral infiltration.

We report a case of primary central nervous system lymphoma presenting as diffuse cerebral infiltration. On T2-weighted spin echo MR imaging using a 1.0 Tesla unit, high signal intensity lesions were presented mainly in the bilateral pyramidal tracts and also diffusely extended to white matter with brain swelling. No enhancing lesion was demonstrated after the intravenous injection of Gadolinium-DTPA, during the course of her disease. Radiological diagnosis of gliomatosis cerebri was made because of the characteristic MR appearance. Stereotactic biopsy was performed, and diffusely scattered lymphocytes, probably neoplastic, in the cerebral white matter were demonstrated histopathologically. Oral corticosteroids, radiation therapy, and chemotherapy were applied soon after her admission. The patient's condition improved dramatically. MR imaging using a 1.5 Tesla unit after the treatments showed marked regression and reduction of high intensity lesions on T2-weighted images and improvement of brain swelling. It should be emphasized that brain biopsy is important method for correct diagnosis in case of diffuse non-enhancing brain lesions like our case.

Biopsy↗
PubMedDate not supplied

Investigation of early bone formation using resorbable bioactive glass in the rat mandible.

Recent advances in biomaterial technology have made alloplastic bone substitutes more predictable when used with the proper clinical methodology in carefully selected patients. In this animal study, early bone formation using a novel resorbable bioactive glass in the repair of surgically created bony defects in the rat mandible was investigated. Biopsies taken from the implanted sites after 1, 2, 3, 4, 8, and 16 weeks were examined histologically by means of standard cell-staining techniques. In addition, an electron probe microanalyzer was used to determine the presence and distribution of specific elements in samples taken after 16 weeks. Results indicated the early stage of osteoconductive bone growth after approximately 4 weeks. After 16 weeks, electron probe micro-analyzer scans indicated the formation of a calcium-phosphate shell formed in situ and the resorption of silica to background levels.

Absorbable Implants↗