多発性脳梗塞症例におけるMRIの有用性に関する研究 Study on the Clinical Usefulness of Magnetic Resonance Imaging in Cases of Multiple Cerebral Infarctions
Study on the Clinical Usefulness of Magnetic Resonance Imaging in Cases of Multiple Cerebral Infarctions
学位の種類: 博士（医学）. 報告番号: 乙第1154号. 学位記番号: 新大院博（医）乙第1073号. 学位授与年月日: 平成3年6月6日
新潟医学会雑誌. 1991, 105(9), 601-613.
We investigated the clinical significance of MRI in cases of thrombotic multiple cerebral infarction. In nine patients with recent lacunar stroke, CT and MRI enhancement studies were performed on the same day. In MRI, injection of Gd-DTPA enhanced recent lesions in all patients except for one who was examined 4 weeks after ictus, and the effect was excellent. Recent infarcts could be identified only by Gd-MRI in four of nine patients. In patients with multiple small infarctions, the use of Gd-MRI makes it possible to distinguish recent infarcts from other lesions definitively. In order to clarify the significance of periventricular high intensity lesion (PVH) in T2-weighted (T2w) MRI, hemodynamic and neuropsychological examinations were carried out in 41 patients with multiple cerebral infarctions. All the patients had PVH, which was classified into three grades as follows; grade 1 (n=16) showing only a thin high intensity band along the body of lateral ventricles; grade 2 (n=15) showing a definite high intensity area around the lateral ventricles; grade 3 (n=10) demonstrating diffuse thick and irregular foci around the whole ventricles. In these patients, rCBF was measured by 133Xe inhalation methods. Initial Slope Index (ISI) was calculated for estimating rCBF. Mini-mental State Test (MMT) was also performed for evaluating the grade of psychological abnormality. ISI in patients with grade 3 was significantly higher than ISI in those with grade 1 (p<0.05). The MMT score in patients with grade 1 was significantly higher than MMT in those with grade 2 and 3 (p<0.05). Progression of PVH may be related with the reduction of the cerebral circulation and mental fuction in cases with multiple cerebral infarction. Ischemic and hemorrhagic lesions can be distinguished by MRI, because old intracerebral hemorrhages appear as hypointensity areas with or without hyperintensity areas on T2w images. In 92 patients with multiple infarctions, MRI was used to evaluate the incidence and distribution of coexisting old intracerebral hemorrhages. Old hemorrhages were found in 15 patients (16.3%). All the old hemorrhages were located where hypertensive hemorrhages commonly occur. High-field MRI is useful for assessing the coexistence of hemorrhages in hypertensive patients with mutiple cerebral infarctions.