Liang Zhigang, Du Xiangying, Liu Jiabin, Yao Xinyu, Yang Yanhui, Li Kuncheng
Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Acta Radiol. 2008 Jul;49(6):618-22. doi: 10.1080/02841850802014610.
Medical film digitizers play an important transitory role as digital-analogue bridges in radiology. Digitized mammograms require evaluation of performance to assure medical image quality.
To compare the diagnostic accuracy in the interpretation of breast masses using original screen-film mammograms versus digitized images.
A total of 72 female patients between 55 and 81 years of age suspected of having breast cancer were selected by two non-observing radiologists. Of these, 31 cases were benign lesions and 41 cases were cancer. The mammography films were digitized using a laser film digitizer. Three radiologists, each with more than 10 years of experience in mammography, interpreted the screen-film mammograms and digitized images respectively. The time interval was 4 weeks. A four-point malignancy scale was used, with 1 defined as definitely not malignant, 2 as probably not malignant, 3 as probably malignant, and 4 as definitely malignant. Receiver operating characteristic (ROC) curves, sensitivity, and specificity were compared.
The average area-under-the-curve (Az) value of the original screen-film mammograms was 0.921, and the average Az value of the digitized images was 0.859. This difference was not statistically significant (P=0.131). The detection specificity of extremely dense breasts was lower than that for other breast compositions for both digitized images and screen-film mammograms. No statistical significance in sensitivity and specificity was observed between digitized images and mammograms for each breast composition. Original screen-film mammograms were observed to perform better than digitized images.
Digitized images with a spatial resolution of 175 microm can be used instead of screen-film mammograms in the diagnosis of breast cancer.
医学胶片数字化仪在放射学中作为数字 - 模拟桥梁发挥着重要的过渡作用。数字化乳腺钼靶照片需要评估性能以确保医学图像质量。
比较使用原始屏 - 片乳腺钼靶照片与数字化图像解读乳腺肿块的诊断准确性。
两名非参与观察的放射科医生挑选了72名年龄在55至81岁之间疑似患有乳腺癌的女性患者。其中，31例为良性病变，41例为癌症。使用激光胶片数字化仪对乳腺钼靶照片进行数字化处理。三名各自拥有超过10年乳腺钼靶摄影经验的放射科医生分别解读屏 - 片乳腺钼靶照片和数字化图像。时间间隔为4周。采用四点恶性程度量表，1定义为肯定不是恶性，2为可能不是恶性，3为可能是恶性，4为肯定是恶性。比较了受试者操作特征（ROC）曲线、敏感性和特异性。
原始屏 - 片乳腺钼靶照片的平均曲线下面积（Az）值为0.921，数字化图像的平均Az值为0.859。这种差异无统计学意义（P = 0.131）。对于数字化图像和屏 - 片乳腺钼靶照片，极度致密乳腺的检测特异性均低于其他乳腺组成类型。对于每种乳腺组成类型，数字化图像和乳腺钼靶照片在敏感性和特异性方面未观察到统计学差异。观察发现原始屏 - 片乳腺钼靶照片的表现优于数字化图像。
空间分辨率为175微米的数字化图像可用于替代屏 - 片乳腺钼靶照片进行乳腺癌诊断。
