- 期刊
High Resolution Optical Doppler Tomography for in vivo Blood Flow Dynamics with Pharmacological Intervention
高解析度光學式都卜勒斷層攝影術偵測血流動力與藥物作用之試管內實驗
摘要
非侵入性高空間解析度技術來偵測血流影像及臨床診斷尚未被運用。相信這樣的技術對生醫研究及臨床診斷將是一大衝擊。而光學式都卜勒斷層攝影術便是此概念的實現。本研究之目的便是在運用高空間解析度（2至15微米）非侵入性的斷層影像，光學式都卜勒斷層攝影術來偵測血流及顯微血管結構。光學式都卜勒斷層攝影術的設計是結合雷射都卜勒流量計與光學式相干斷層攝影術而成，故其俱高解析斷層流速測量能力及高光散射之特點。故可同時偵測靜態與動態生物組織。而本實驗模型為雞胚絨毛膜上血流偵測之試管內實驗。過程中並局部使用硝酸甘油，且同時偵測使用前與使用後其所造成血流之變化。結果顯示在雞胚絨毛膜上之靜脈血流在血管中央之流速較近血管壁處為快。另外也可見到動脈在局部使用硝酸甘油後明顯擴張的情形，其最高流速升高約為3000至4000微米/秒。與動脈相反，受局部硝酸甘油的作用，靜脈擴張後，其最高流速降低約2000至1000微米/秒。總結而言，在試管內實驗中，光學式都卜勒斷層攝影術對雞胚絨毛膜血管結構與速度均俱高解析能力。其臨床運用在依各生體組織特性與使用部位特點之改進後將指日可待。
並列摘要
High spatial resolution noninvasive techniques for in vivo blood flow imaging are currently not available as a diagnostic tool in clinical medicine. Such techniques could have a significant impact for biomedical research and clinical diagnosis. The rationale for using Optical Doppler Tomography (ODT) to characterize the underlying microvasculature is that the technique will be able to probe user-specified discrete spatial locations with high spatial resolution. The objective of our research is to use a noninvasive tomographic imaging technique with high spatial resolution (2-15μm) to characterize and monitor fluid flow and microvasculature in highly scattered biological tissues at user-specified discrete locations. ODT combines Laser Doppler Flowmetry (LDF) with optical coherence tomography (OCT) to obtain high-resolution tomographic velocity and structural images of static and moving constituents biological tissue with high light scattering properties. ODT demonstrates the ability to simultaneously record structure and velocity in images. We present ODT images of structure and velocity using in vivo blood flow in the Chick Chorioallantoic Membrane (CAM). ODT images were also recorded before and after topical application of nitroglycerin. ODT images of in vivo CAM blood flow demonstrate that the magnitude of blood flow velocity at the center of the vein is maximal and that it decreases monotonically towards the peripheral wall. The arterial wall can be clearly identified by its dilatation after the application of nitroglycerin. Peak blood flow velocity at the center of the artery increased from 3000 to 4000μm/s after nitroglycerine application. Dilatation of the vein due to nitroglycerine is observed in both the structure and velocity at the center of the vein. It decreased from 2000 to 1000 μm/s after nitroglycerin application. In conclusion, in our in vivo studies on CAM model vasculatures, the application of ODT to characterize and image blood flow with high spatial resolution at discrete user-specified locations in biological tissues with high light scattering properties is feasible.