Biomedical subjects
Publications and source records attributed to H Tonami.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
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The magnetic resonance (MR) imaging features of morning glory syndrome are described. In our case, MR demonstrated a colobomatous area in the region of the optic disk, as well as an associated cataract and retinal detachment.
OBJECTIVE: The MR findings of two cases of subperiosteal hematoma of the orbit are described. MATERIALS AND METHODS: We present two cases of subperiosteal hematoma of the orbit following minor head trauma, the first presenting with chronic progressive exophthalmos and the second with acute proptosis. RESULTS: Both cases showed a well-defined biconvex mass with a curvilinear hypointense band in the superior portion of the orbit. In Case 1 chronic hematoma demonstrated high signal on both T1- and T2-weighted imaging, and in Case 2 acute hematoma displayed intermediate signal on T1-weighted imaging and high signal on T2-weighted imaging. Follow-up MRI in Case 2 demonstrated the typical signal changes from acute to subacute hematoma. CONCLUSION: Subperiosteal hematoma has a characteristic appearance on MRI which is virtually diagnostic. In proper clinical settings MRI is the modality of choice for the detection and characterization of this hematoma.
We present a case of chordoid glioma involving the third ventricle in a 42-year-old woman. CT and MR showed a homogeneously enhancing mass occupying the third ventricle, with a cystic component. Chordoid glioma should be included in the differential diagnosis of uncommon masses of the third ventricle in middle-aged women.
We present a case of hypothalamic hamartoma in which the signal intensity of the lesion significantly changed during the course of follow-up. To date, stability of the lesion morphology over time has been considered an important diagnostic criterion of hypothalamic hamartoma. Radiologists should be aware that in hypothalamic hamartoma, signal intensity can change during its natural course.
PURPOSE: The purpose of this work was to compare the diagnostic accuracy of MR sialography with that of salivary gland scintigraphy in Sjögren syndrome. METHOD: One hundred thirty patients clinically suspected of having Sjögren syndrome were examined by MR sialography and salivary gland scintigraphy. A labial gland biopsy was performed in all patients. Imaging findings of MR sialography and salivary gland scintigraphy were compared with the results of labial gland biopsy. RESULTS: From the results of labial gland biopsy, the diagnosis of Sjögren syndrome was established in 80 patients. Abnormally high T2 signal intensity areas on MR sialography and decreased uptake and delayed excretion of [(99m)Tc]pertechnetate on salivary gland scintigraphy were well seen in patients with Sjögren syndrome. For the diagnosis of Sjögren syndrome, salivary gland scintigraphy showed higher sensitivity than MR sialography. On the other hand, MR sialography showed higher specificity and positive predictive value (PPV) than salivary gland scintigraphy. Overall diagnostic accuracy was 83% for MR sialography and 72% for salivary gland scintigraphy. CONCLUSION: The high PPV of MR sialography suggests that MR sialography is the preferred imaging modality in patients suspected of having Sjögren syndrome.
We present serial changes on diffusion-weighted MRI (DWI) in a patient with Creutzfeldt-Jakob disease (CJD). DWI revealed serial changes of abnormal hyperintense lesions that had become more extensive and conspicuous with progression of neurologic findings, more sensitively than conventional MRI. In the late stage, disappearance of abnormal hyperintense lesions on DWI was observed. DWI proved to be particularly useful for monitoring the progression of CJD.
We present a case of advanced oesophageal cancer with cardiac invasion in an 84-year-old male presenting with dysphagia and general malaise. Histological analysis of an endoscopic biopsy specimen revealed a poorly differentiated squamous cell carcinoma. Computed tomography indicated a thickened oesophageal wall that was compressing the left atrium, suggesting invasion of the heart, and oesophagography revealed a polypoid lesion 9 cm in length. No distant metastases were seen on computed tomography. The patient was given chemotherapy with 10 mg/m2 cisplatin on days 1 and 4 every week for 5 weeks and concurrent radiotherapy at a dose of 2 Gy five times per week (total dose 52 Gy). After 4 weeks, the mass was no longer visible on oesophagography or endoscopic examination. The patient was free of recurrence and metastases for 4.5 years. In conclusion, chemoradiotherapy may be curative in elderly patients with unresectable oesophageal carcinoma.
Twenty-one intraocular lesions associated with various systemic diseases in 15 patients were studied by MR imaging. The disorders included diabetes mellitus, cardiovascular disease, Behçet disease, sarcoidosis, and ankylosing spondylitis. MR was performed on a 0.5-T system using a surface-coil technique. Ophthalmoscopic visualization of the fundus was precluded by the presence of opaque media in all cases. MR was found to be effective in demonstrating intraocular bleeding, vitreous opacity, detached lesions of the posterior pole, and eyeball deformity. Surface-coil MR is a useful adjunct in the evaluation of the eyes affected by systemic diseases, especially in patients with opaque media.
Four patients with orbital blowout fractures were evaluated by surface coil MR imaging, and the resulting images were compared with computer reformatted CT scans. The surface coil afforded significant improvement in spatial resolution, resulting in better demonstration of the blowout fracture. Surface coil MR was found superior to CT in the assessment of fracture site, extent of prolapsed orbital fat, and muscle entrapment.