Gamble G, Beaumont B, Smith H, Zorn J, Sanders G, Merrilees M, MacMahon S, Sharpe N
Department of Medicine, School of Medicine, University of Auckland, New Zealand.
Atherosclerosis. 1993 Sep;102(2):163-73. doi: 10.1016/0021-9150(93)90158-q.
B-mode ultrasound is being used to assess carotid atherosclerosis in epidemiological studies and clinical trials. Recently the interpretation of measurements made from ultrasound images has been questioned. This study examines the anatomical correlates of B-mode ultrasound of carotid arteries in vitro and in situ in cadavers. Twenty-seven segments of human carotid artery were collected at autopsy, pressure perfusion fixed in buffered 2.5% glutaraldehyde and 4% paraformaldehyde and imaged using an ATL UM-8 (10 MHz single crystal mechanical probe). Each artery was then frozen, sectioned and stained with van Gieson or elastin van Gieson. The thickness of the intima, media and adventitia were measured to an accuracy of 0.01 mm from histological sections using a calibrated eye graticule on a light microscope. Shrinkage artifact induced by histological preparation was determined to be 7.8%. Digitised ultrasound images of the artery wall were analysed off-line. The distance from the leading edge of the first interface (LE1) to the leading edge of the second interface (LE2) was measured using a dedicated programme. LE1-LE2 measurements were correlated against histological measurements corrected for shrinkage. Mean values for the far wall were: ultrasound LE1-LE2 (0.97 mm, S.D. 0.26), total wall thickness (1.05 mm, S.D. 0.37), adventitia (0.35 mm, S.D. 0.16), media (0.61 mm, S.D. 0.18), intima (0.09 mm, S.D. 0.13). Ultrasound measurements corresponded best with total wall thickness, rather than elastin or the intima-media complex. Excision of part of the intima plus media or removal of the adventitia resulted in a corresponding decrease in the LE1-LE2 distance of the B-mode image. Furthermore, increased wall thickness due to intimal atherosclerotic thickening correlated well with LE1-LE2 distance of the B-mode images. B-mode images obtained from the carotid arteries in situ in four cadavers also corresponded best with total wall thickness measured from histological sections and not with the thickness of the intima plus media. In conclusion, the LE1-LE2 distance measured on B-mode images of the carotid artery best represents total wall thickness of intima plus media plus adventitia and not intima plus media alone.
B 型超声正被用于流行病学研究和临床试验中评估颈动脉粥样硬化情况。最近，对超声图像测量结果的解读受到了质疑。本研究在体外和尸体原位研究了颈动脉 B 型超声的解剖学相关性。在尸检时收集了 27 段人类颈动脉，经压力灌注固定于缓冲的 2.5%戊二醛和 4%多聚甲醛中，并用 ATL UM - 8（10MHz 单晶机械探头）成像。然后将每条动脉冷冻、切片，并用范吉森染色法或弹性蛋白 - 范吉森染色法染色。使用光学显微镜上校准的目镜测微尺，从组织学切片测量内膜、中膜和外膜的厚度，精确到 0.01mm。确定组织学制备引起的收缩伪像为 7.8%。对动脉壁的数字化超声图像进行离线分析。使用专用程序测量从第一个界面前缘（LE1）到第二个界面前缘（LE2）的距离。将 LE1 - LE2 测量值与经收缩校正的组织学测量值进行相关性分析。远壁的平均值为：超声 LE1 - LE2（0.97mm，标准差 0.26），总壁厚度（1.05mm，标准差 0.37），外膜（0.35mm，标准差 0.16），中膜（0.61mm，标准差 0.18），内膜（0.09mm，标准差 0.13）。超声测量结果与总壁厚度最相符，而不是与弹性蛋白或内膜 - 中膜复合体相符。切除部分内膜加中膜或去除外膜会导致 B 型图像的 LE1 - LE2 距离相应减小。此外，内膜动脉粥样硬化增厚导致的壁增厚增加与 B 型图像的 LE1 - LE2 距离密切相关。从四具尸体原位颈动脉获得的 B 型图像也与组织学切片测量的总壁厚度最相符，而不是与内膜加中膜的厚度相符。总之，在颈动脉 B 型图像上测量的 LE1 - LE2 距离最能代表内膜加中膜加外膜的总壁厚度，而不仅仅是内膜加中膜的厚度。
