糖尿病患者の超音波定量的頸動脈血流の測定と脳循環異常に関する研究

Cerebral Blood Flow Disorder in Elderly Patients with Diabetes Mellitus

　超音波定量的血流測定装置（QFM 2000 XA）を用いて健康成人における頸・脳動脈血流の加齢による変化を検討したので報告する。頸動脈血流量，血流速度は加齢とともに減少し，頸動脈血管径は拡大した。頸動脈壁拍動偏位率は加齢とともに減少し，血圧波形のシュミレーションから求めた頸動脈血管抵抗，脳末梢循環抵抗は加齢とともに増加した。高齢健康成人と高齢糖尿病患者の間に，脳血流の有意差はみられなかったが，脳のMRIで脳血管障害が認められた高齢糖尿病患者との間には明らかな差がみられた。脳血流測定において左右差の著しい場合にはMRI上脳内に異常がみられ，若干例で同時に調べた脳血流シンチグラム（SPECT）所見ともよく一致し，CT, MRI検査以前にスクリーニング的に行う検査として臨床上有用と考えた。

We studied changes due to aging in carotic and cerebral arterial blood flows, and compared the difference between healthy adults and diabetics using a ultrasonic quantitative blood flow measure-ment system (QFM 2000 XA). Aging caused the carotic blood flow, blood velocity and diameter excurtion rate on the carotic wall to decrease, and its diameter to enlarge. Both cerebrovascular resis-tance and capacitance obtained from simulation models of blood presure waves, increased with aging. Cerebral blood flows in aged healthy adults was not significantly different from those in aged diabetics, but clearly different from those in aged diabetics with abnormal findings on MRI. When right and left cerebral blood flows were markedly different, abnormality was observed on brain MRI. This well agreed with findings on cerebral blood flow scintigrams (SPECT) obtained from several patients. The ultrasonic quantitative blood flow measurement system is considered a useful screen-ing tool before CT or MRI examinations.