X线数字断层融合成像与常规DR成像放射剂量比较

Comparative Study of Digital Tomosynthesis and Radiography for Radiation Dose

目的：比较断层融合成像（DTS）与常规DR的放射剂量。方法：将进行x线检查的连续就诊患者随机分入常规DR组和DTS组．选择14个常规检查部位，每个部位、每组各10人。常规DR及DTS均采用GEVolumeRAD，根据成像质量需要及尽可能减少放射剂量的要求选择主要成像参数。结果：各检查部位DTS放射剂量明显高于常规DR（P〈0．001）．是常规DR的3．73～12．84倍，平均7．7l倍。其中胸椎、腰椎、颅骨、骨盆等部位放射剂量较大，明显高于其他部位（P〈0．001）。胸椎、腰椎侧位放射剂量明显高于正位（P〈0．001），分别是正位的2-35倍和1．44倍。结论：DTS平均放射剂量明显高于常规DR，因此在不影响诊断和病变显示的情况下，应选择合理的成像参数、选择体厚小的投照方向，以尽可能降低放射剂量。

Objective To detect and compare the entrance surface dose of digital tomosynthesis（DTS） and radiography in body imaging. Methods Totally 14 parts of the body were selected for both DTS and radiography imaging. There were 10 patients included in each part of the body for each examination. DTS and radiography were performed by using a unit of Volume RAD（GE Healthcare）. DTS and radiography parameters were selected to ensure a good image quality and a low radiation dose. The mean radiation doses of DTS in each parts of the body were markedly higher than that of radiography（P〈0.O01）, generally 3.73 to 12.84 times or averagely 7.71 times of the latter. The mean radiation doses of DTS in thoracic vertebrae, lumbar vertebrae, skull, pelvis were notably higher than those in other parts of the body（P〈0.001）. The mean radiation doses of lateral projection were markedly higher than that of anterior-posterior projection in thoracic vertebrae（2.35 times of that of anterior-posterior projection） and lumbar vertebrae（1.44 times of that of anterior-posterior projection）. Conclusion The mean radiation dose of DTS is markedly higher than that of radiography. In order to reduce the radiation dose and keep good image quality simultaneously, reasonable DTS parameters and projective direction should be selected.