应用ROC曲线对比研究数字乳腺机不同靶面/滤过组合的辐射剂量及图像质量

摘要

Objective:To explore radiation and picture quality of doses between different target surface/ filtration combinarions of molybdenum, molybdenum molybdcnum/rhodium tungsten/ thodium targets of the digital breast X-ray machine by ROC curve. Opnmized targct surface/ filtration combination will be applied in the future. Methods: Three different thick phantoms of 15 mm. 30 mm, 45 mm were individually projected by three different target surface/filtration combinations with Siemens MAMMOMAT Novation DR digital breast X-ray machine, and radiation dose was obtained. And then breast TRM model was porjected. the data was analyzed and the curve of ROC was drawn Bilateralis mammary gland of a patiant were individually projected by different target surface/filtration combinations. radiation dose and different of pictures quality were recorded. Results : Radiation dose between three different target surface/filtration combinarions were no significant difference in 15 mm phantom. But radiation dose between three different target surface/filtration combinations were significanr difference in 30 mm and 45 mm phanroms. Radiation dose was the highest in the molybdenum/molybdenum and lowest in the tungsten/rhodium. molybdenum/rhodium medium. The curves of ROC was no significant difference according to the breast TRM model pictures projected by three different target surface/filtration combinations. All the identical magnificat pictures were readed by two associate professor doctor, all the picture quality was no significant difference and had been achieved the request of diagnosis. Conclusion: The tungsten/ rhodium-target surface/filtration combination should be applied in practical work. and sa patient dose will be decreased as far as possible.%目的:应用(receive operating characteristic curve,ROC曲线)ROC曲线对比研究数字乳腺摄影机钼/钼、钼/铑、钨/铑三种不同靶面/滤过组合的辐射剂量及图像质量有无差别.以便在实际工作中对不同靶面/滤过组合进行优化选择.方法:采用西门子Mammomat Novation DR型数字乳腺机,应用上述三种不同靶面/滤过组合分别对15mm、30mm、45mm三种不同厚度乳腺标准体模进行照射,记录其辐射剂量,再对乳腺图像质量检测体模(TRM)进行照射,对数据进行解析并绘制ROC曲线图.同时对同一患者的左右乳房分别采用不同靶面滤过组合进行照射,记录其辐射剂量并观察照片有无差别.结果:模体为15mm时,三种不同靶面/滤过组合辐射剂量差别不大,而在模体为30mm和45mm时,三种不同靶面/滤过组合的辐射剂量差别显著加大,且钼/钼组合辐射剂量最大,钼/铑组合次之,钨/铑组合最小,但三种不同靶面/滤过组合对乳腺图像质量检测体模(TRM)所照照片绘制的ROC曲线图差别不大,所照临床病例照片除放大相同倍数外再不经过任何后处理让2位副主任职称以上医师进行阅读,结果照片无明显差别,全部达到诊断要求.结论:在实际工作中应尽量选择钨/铑这一靶面/滤过组合进行摄影,以尽量减少患者的辐射剂量.