Computer-Aided Diagnosis System in Chest Radiography

我们开发了一种计算机辅助诊断(CAD)系统和方案，用于检测数字胸片中的结节、间质性疾病、气胸和心脏肿大。建立了包括胶片数字化机、工作站、激光成像仪、视频打印机和个人计算机在内的计算机辅助设计系统硬件。建立了一种用于肺结节检测的图像差分法。对100个正常肺和100个肺结节异常肺的诊断，以1.0假阳性/图像的灵敏度约为75%。纹理和几何特征分析用于间质病变的检测。对100个正常肺和100个异常肺间质浸润性病变的诊断敏感性约为95%，特异度为95%。建立了Hough变换检测气胸的方法。对60个肺的气胸诊断的敏感性为80%，特异性为70%。提出了一种基于模型函数的心脏大小和形状测量方法。ROC分析显示，对于结节和间质病变，联合使用胸部图像和CAD输出的诊断准确率优于单独使用胸部图像。结果表明，该计算机辅助诊断系统对放射科医生评价胸部X线片是非常有用的。

We have developed a system and schemes of computer-aided diagnosis (CAD) for detection of nodules, interstitial diseases, pneumothorax and cardiomegaly in digital chest radiograph.1. The CAD system hardware was established, which includes a film-digitizer, a workstation, a laser-imager, a video-printer and a personal computer.2. The image-difference method was developed for detection of lung nodules. The performance with approximately 75% of the sensitivity at 1.0 false positive/image was provided for 100 normal and 100 abnormal lungs with lung nodules.3. The texture and geometric feature analyzes were developed for detection of interstitial diseases. The performance with approximately 95% of the sensitivity at 95% of the specificity was provided for 100 normal and 100 abnormal lungs with interstitial infiltrates.4. The method with Hough transform was developed for detection of pneumothorax. 80% sensitivity at 70% specificity was provided for 60 lungs with pneumothorax.5. The method based on a model function was developed for measurement of size and shape of hearts.6. The ROC analysis showed that the diagnostic accuracy with both chest images and CAD outputs was superior to that with chest images alone for detection of nodules and interstitial diseases.7. Our results indicates that this computer-aided diagnosis system is very useful for radiologists to estimate chest radiographs.