Published papers

Computed tomography during arterial portography (CTAP) under temporary balloon occlusion of the hepatic artery (BOHA-CTAP) was introduced to evaluate pseudolesions caused by portal venous impairments such as arterioportal shunt and tumor thrombus.

32歳.無月経を主訴とし妊娠反応陽性であったが,超音波検査で明らかな胎嚢を子宮体部に認めなかった為,子宮外妊娠が疑われた.MRIで子宮頸部にT2強調画像によりvery high intensityを示すmassが認められ,胎嚢と考えられた.尿中human chorionic gonadotropin(hCG)高値と合わせ,頸管妊娠と診断した.ただし胎児の心拍は認められず,color Dopplerでも子宮頸部の血流増加は軽度と考えられた.患者が妊孕性温存を希望した為,Actinomycin-D(ACTD)の動注による保存的治療を選択した.hCGが低下し,胎嚢の収縮が認められた後,子宮頸部内膜掻爬術を施行した.術後経過は良好で,大量出血やACTDによる明らかな副作用は認めていない

We present the case of an 86-year-old female with spontaneous spinal epidural hematoma. Although T1- and T2-weighted images showed the dilated posterior epidural space at the cervical spine, this finding was non-specific on conventional magnetic resonance imaging obtained 15 h after the onset of symptoms. Diffusion-weighted imaging with the use of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER), which clearly revealed the high intensity hematoma, was useful for detection and diagnosis of acute spinal epidural hematoma.

We report a case of a 38-year-old man with brain stem hypertensive encephalopathy. MR imaging revealed diffuse hyperintensities in the brain stem. Diffusion-weighted imaging (DWI) was normal, and apparent diffusion coefficient (ADC) values were increased in the brain stem. The supratentorial regions were largely spared, and only subtle high intensities were seen. The lesions completely resolved after stabilization of blood pressure. The findings of normal DWI and high ADC values were compatible with vasogenic edema due to hypertension.

There are a few reports on leptomeningeal high signal intensity (LMHI: ivy sign) on fluid-attenuated inversion-recovery (FLAIR) images in moyamoya disease, but the feature of this finding has not been completely understood. The purpose of this study was to characterize LMHI on FLAIR images in moyamoya disease and to assess usefulness of this finding in the diagnosis of moyamoya disease in conventional MR imaging.

The purpose of the current study is to evaluate the accuracy of MR thermometry for radiofrequency ablation (RFA) with hook-shaped electrodes. The objects were eight extracted bovine livers. The chemical shift change was calculated from MR images acquired with a spoiled gradient echo sequence and compared with the temperature directly measured with a thermocouple. Linear regression was established between them with a coefficient of -0.0110+/-0.0007 ppm/ degrees C and errors were calculated as -0.50+/-7.50 degrees C. MR thermometry is capable of monitoring temperature for RFA.