借助CT图像评价心脏左右斜位摄影体位

目的 借助ＣＴ图像分析心脏斜位摄影体位的正确性，进一步加强质量控制。方法 将８０例胸部ＣＴ图像按胸厚分为〉２０ｃｍ和〈２０ｃｍ两组经数码相机输入计算机，ＣＴ图像通过计算机处理后得到一组参考数值；并以此分析８０例心脏斜位的摄影体位。结果 １．体形对测量脊柱与前后胸壁比值影响不大。右前斜位两组不同胸厚的平均值均为１．３９～１．４０，左前斜位胸厚〉２０ｍｃ组平均值为１．５０～１．５５，胸厚〈２０ｍｃ组平均值为１．５０～１．５４；２．不符要求的斜位片中，右前斜位主要以角度偏大为主，共８例（１０％）；左前斜位以角度偏小为主，共１１例（１３．８％）。结论 通过测量心脏斜位片脊柱与前后胸壁比值。能评价心脏斜位片摄影体位正确性。

Evaluation of oblique cardiac radiography posiitions with CT images

Purpose To analyze the accuracy of oblique cardiac radiography positions with aid of CT images to further enhance image quality control. Methods Data of 80 cases of thoracic CT images, which were divided into two groups of above and below 20cm in thoracic width, were input into the computer by a digital camera. Through processing of CT images we obtained a set of reference values, which were used as the basis to analyze oblique cardiac radiography posiitions. Results 1. The ratio( R) of the distance between the spine and the anterior thoracic wall upon that between the spine and the posterior thoracic wall was not significanthy affected by body shape. The average R values were 1.39 - 1.40 for the two groups of different thoracic width on right anterior oblique (RAO) views. R valuse was 1.50-1.55 for the group with thoracic width above 20cm and 1.50 - 1.54 for the group below 20cm on left anterior oblique( LAO) views. 2. Among the unqualified oblique cardiac films, too large projection angle was the main cause on RAO views(8 cases, 10%) and too small angle on LAO views (11 case; 13.8% ). Conclusion The quality of oblique cardiac films could be evaluated through measurement of the ratio of the distance between the spine - anterior thoracic wall the spine - posterior thoracic wall.