[ 戻る ]
- 1998 Conference Abstracts
- 筆頭
- title
- Abstract
- 筆頭
- title
- Abstract
- 筆頭
- title
- Abstract
- 吉岡大
- 3Tesla MR 装置を用いた膝関節MTC画像の初期検討
- 3Tにおける関節軟骨のMTC画像の最適撮像条件を、MTC効果、軟骨のS/N及び軟骨-蒸留水間のC/Nをもとに検討した。3Tにおいても安全なSARで、十分な関節軟骨の、MTC効果の画像が得られることが示され、FA=20～30°,TE=11,12msの条件が最も適していると考えられた。また、半月板に対しても軟骨同様のMTC効果が得られた。今回用いた短いTRの条件では、撮像時間は短く、2D及び3D画像共に臨床応用は可能であり、今後はヒトへの応用が期待される。
- 中井敏晴
- An fMRI primer
- Functional magnetic resonance imaging (fMRI) is a new tool to evaluate the brain activities by analyzing the time-series of the images obtained by magnetic resonance imaging (MRI) scanners. In the typical fMRI experiments, the dynamic response of the regional cerebral blood flow (rCBF) to the task performed by the subject is detected. The fluctuation of the regional blood oxygenation level induced by the rCBF changes raise the contrast of each pixel of the images between the two or more conditions in the time-series, and the difference is statistically evaluated to represent the brain activation. The role of fMRI is to test the hypothesis of the neurological or cognitive network models. In this paper, the fundamentals of fMRI, history of the technical development, the physiological backgrounds, the basic experiment designs, the methods of data acquisition, statistical data analysis, some recent topics and the limitations of fMRI are reviewed from the view points of medical physics.
- 中井敏晴
- Strategy.for lipid suppression in lactate imaging using STIR-DQCT : A study of hypoxic-ischemic brain injury
- In vivo lactate detection using gradient enhanced double quantum coherence transfer (DQCT) was significantly improved by addition of short-time-inversion-recovery (STIR). Phantom studies demonstrated lipid suppression down to the background noise level with 33% loss of lactate signal. In vivo studies using a rabbit model of hypoxic and unilateral-ischemic brain injury showed reduction down to 29±11 % in lipids with inversion times between 140 and 170ms. Lactate signals on the ischemic side were 51±53 % higher than the non-ischemic side at the peak of hypoxia. STIR-DQCT can be a useful robust method of obtaining metabolic maps of lactate in vivo.
- 1997 Conference Abstracts
- 中井敏晴
- An in vitro 1H-MRS model of oncogene transfection the spectral feature of c-erbB-2 and c-Ha-ras transfected NIH3T3 fibroblast cells
- Purpose: Malignancy is an abnormality of cell division and differentiation based on abnormal expression of oncogenes. This note describes the in vitro 1H-NMR spectral features of oncogene-transfected NIH3T3 fibroblast cells compared to nontransfected cells. Material and Methods: 1H-NMR spectra of cultured NIH3T3 cells and c-erbB-2 or c-Ha-ras gene-transfected cells were obtained by 400 MHz high resolution NMR. The peaks were assigned by 2D-HOHAHA spectra of the cell suspension and the spectral changes were evaluated in 1D and 1D differential spectra. Results: The 1H spectra obtained from both transfected cell lines were broadened over all peaks, suggesting less mobility of plasma membrane lipid molecules. No other differential spectra for characterizing metabolic change was detected. Conclusion: Broadened 1H spectra observed after c-erbB-2 or c-Ha-ras transfection suggest changes of plasma membrane viscosity, which may be related to the oncogene expression.
- 1996 Conference Abstracts
- 筆頭
- title
- Abstract
- 筆頭
- title
- Abstract
- 中井敏晴
- 1H magnetic resonance spectroscopic observation of cultured malignant cells pharmacologically induced to different phenotypes
- Rationale and Objectives: To evaluate the 1H-NMR spectra of malignant cells after the administration of drugs which cause morphologic changes. Methods: 1H spectra of a human lung adenocarcinoma cell line cultured with interferon-g, dexamethasone or sodium butyrate were obtained. The peaks were assigned by 2D-HOHAHA spectra of the cells and their perchloric acid extract. The results were evaluated as relative changes of the peaks by using differential spectra. Results: In the control culture, choline/phosphocholine peaks were increased in the cell growth phase, and the 1.26 ppm peak was increased in the confluent state. Treatment by interferon-g and dexamethasone induced reproducible changes in the peaks of differential spectra corresponding 1.26 ppm, choline/phosphocholine and glutamate/glutamine. Dexamethasone treatment broadened lipid peaks. Changes were obscure after sodium butyrate treatment. Microscopically, cells were induced to morphologically different phenotypes by each drug. Conclusion: Cells induced to morphologically different phenotype present different 1H spectra.
- 中井敏晴
- A model for detecting early metabolic changes in neonatal asphyxia by 1H-MRS
- In newborn rabbits, the early metabolic changes of newborn rabbit brains caused by hypoxic ischemic (H-I) insult was examined by using volume localized 1H-MRS (STEAM). Partial ischemia was caused by unilateral carotid artery ligation and hypoxia was induced by 10% oxygen inspiration for 150 min. Lactate immediately increased after hypoxia induction, and almost disappeared 120 to 150 min after removal of hypoxia in both H-I and hypoxia-only experiments. Lactate production correlated well with decrease of the blood oxygen saturation. More lactate was produced on ischemic side after 50min post hypoxia induction in H-I study. Ischemia alone did not cause any significant lactate production. Lactate caused by hypoxia can be dynamically monitored by localized 1H-MRS. Existence of regional ischemia can induce greater anaerobic glycolysis and may affect the pattern of brain injury under hypoxia. 1H-MRS is a sensitive tool to detect the acute metabolic changes caused by H-I insult.