Mio Sakai

Silent white matter lesion in linear scleroderma en coup de sabre.

We report a patient with linear scleroderma en coup de sabre without neurological symptoms despite the presence of large white matter lesions. The patient underwent 3.0-T magnetic resonance (MR) examinations including diffusion tensor imaging, time-resolved contrast-enhanced MR angiography, susceptibility-weighted imaging, and proton MR spectroscopy. These imaging findings suggested increased vascular permeability and microbleeding without abnormalities of metabolites. Our observation is consistent with vasculopathy and may be helpful in the proper diagnosis and treatment of linear scleroderma en coup de sabre.

Conventional MRI findings for predicting submandibular pleomorphic adenoma.

Background Although pleomorphic adenomas account for over 90% of all benign submandibular gland tumors, the imaging features of submandibular pleomorphic adenomas have not been reported in a large number of cases. Purpose To assess the conventional magnetic resonance imaging (MRI) findings for predicting the submandibular pleomorphic adenoma. Material and Methods MR studies of 42 pleomorphic adenomas and 28 other types of tumor were reviewed. MR images were assessed for the presence of hyperintense areas on T2-weighted images (first sign), a well-defined margin (second sign), and presence of crescent-shaped compression of the ipsilateral normal submandibular gland (third sign). Results For identifying submandibular pleomorphic adenoma, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 97.6%, 50.0%, 74.5%, 93.3%, and 78.6% for the first sign, 95.2%, 46.4% 72.7%, 86.7%, and 75.7% for the second sign, and 23.8%, 100%, 86.7%, 46.7%, and 54.3% for the third sign, respectively. Combining the first and second findings achieved to 85.7% specificity and 90.9% accuracy. Conclusion Although non-specific, submandibular pleomorphic adenomas usually have hyperintense areas on T2-weighted images and well-defined margins. In addition, crescent-shaped compression of the ipsilateral normal gland seems to represent a highly specific sign.

Follow-up magnetic resonance imaging findings in patients with progressive multifocal leukoencephalopathy: evaluation of long-term survivors under highly active antiretroviral therapy

PurposeThe aim of this study was to clarify the early magnetic resonance imaging (MRI) findings of progressive multifocal leukoencephalopathy (PML) and to evaluate the relations of the clinical course and serial MRI findings in patients with acquired immunodeficiency syndrome (AIDS)-related PML treated with highly active antiretroviral therapy (HAART).Materials and methodsThe clinical course and serial MRI findings in five patients with AIDS-related PML who were treated with HAART are described.ResultsAlthough all five patients were serologically naive to the therapy and alive at the end of the observation period, the lesions showed rapid extension on MRI for up to 3 months after the start of the therapy, and clinical symptoms progressed rapidly for a month after the start of the therapy. Newer margins in spreading lesions showed a diffuse pale hyperintensity and/or many discrete hyperintense dots on T2-weighted imagesConclusionEarly PML lesions may show a characteristic appearance on T2-weighted images. We should be aware of the progression of AIDS-related PML even under serologically effective HAART.

Effect of flip angle on volume flow measurement with nontriggered phase-contrast MR: In vivo evaluation in carotid and basilar arteries

To evaluate the effect of flip angle on volume flow rate measurements obtained with nontriggered phase‐contrast magnetic resonance imaging (MRI) in vivo.