人手部皮下微循环特性随深度变化的研究

A Study of Changes in the Characteristics of Subcutaneous Microcirculation of Human Hand

本研究使用手持式扫频光学相干层析(SSOCT)系统分别在人左手无名指指甲上方、无名指指腹和手掌大拇指根部选取3 mm×3 mm区域进行了在体成像,使用指数补偿方法还原血流信息,获取不同深度的血流正面光学断层图像(en face图像),从血管灌注密度(PD)、血管直径(VD)两个方面分析了微循环随深度的变化特性。试验结果证明,在上述三个成像位置中,随着成像深度的增加,血管PD与血管VD均增大,血流信息的丰富程度增加,但同时en face图像的清晰度有所下降。其中左掌大拇指根部微血管最为细密,血流信息较为丰富,比较适宜作为微循环疾病诊断研究的成像部位。分层投影结果显示,左手无名指指甲上方部位在成像深度较浅(220~660μm)时,血管PD明显小于其他两个成像部位,说明此处在该范围内血流信息丰富程度不够。本文测量了随深度变化的手部血流几何学特征,验证了光学相干层析(OCT)技术基于手部皮下微循环光学断层图像进行疾病诊断的可行性。许多微循环疾病早期就已经产生了微血管病变,因此对这种微循环变化的探测在疾病的早期诊断方面具有临床指导意义。

A hand-held sweep source optical coherence tomography(SSOCT)system was used to image three areas on human hands,including nail,fingertip,and palm.The imaging area size is 3 mm×3 mm.The index compensation algorism was used to reconstruct blood information en face images at different depths.The changes in both the blood vessel perfusion density(PD)and blood vessel diameter(VD)with the imaging depth were then calculated to reveal the characteristics of the microvasculature of human hand.The experimental results showed that in the above three imaging positions,as the imaging depth increases,the blood vessel PD and blood VD both increase,and contains more information about the blood flow.At the same time,the en face image clarity decreases with the increase of the depth.It was also observed that the microvascular at palm are the densest one,and the blood flow information is more abundant,which is more suitable as an imaging site for the diagnosis of microcirculation diseases.The layered projection results showed that when the imaging depth of the area above the nail is relatively shallow(220~660μm),the blood vessel PD is significantly smaller than the other two imaging sites,indicating that the blood flow information is not abundant in this range.In this work,we measure the geometric characteristics of hand blood flow that varies with depth,and verify the feasibility of applying OCT technology to the diagnosis of subcuta neous microcirculation in the hand.In the early stages of microcirculation disease,microvascular changes have already occurred.Therefore detection of microvascular changes has clinical significance in early diagnosis of the disease.