优化数字乳腺断层摄影曝光条件的体模显像

目的比较数字乳腺断层摄影(DBT)不同摄影条件下对乳腺体模病灶的检出率。方法对ACR-156体模及MPW-01体模进行DBT,使用有机玻璃板组合模拟5个不同厚度,首先采用自动曝光控制模式(AEC)进行曝光,然后保持相同管电压值,管电流设为AEC曝光时的80%、60%、40%和20%。比较不同厚度、不同曝光条件下辐射剂量及病灶检出率。结果随管电流下降,平均腺体剂量和皮肤吸收剂量及总体病灶检出率下降(P均0.01);相同厚度下,管电流降低20%时,肿块样病灶及钙化样病灶检出率下降平缓甚至无明显变化,纤维样病灶检出率下降较明显,管电流降低20%时,各病灶检出率均随管电流下降而下降;厚度增加对肿块样病灶检出率有一定影响。结论乳腺筛查中适当降低管电流可有效减低辐射剂量而不影响病灶检出率。

Optimization of exposure condition in digital breast tomosynthesis: A phantom study

Objective To compare the detection rate of digital mammography tomosynthesis (DBT) for detecting details in breast phantoms with different exposure conditon. Methods DBT was performed in two different breast phantoms (ACR-156 and MPW-01) with 5 different phantom thickness imtiated by combination of organic glass panel. The automatic exposure control (AEC) was used firstly, and then the current were reduced by 80%, 60%, 40% and 20% of ACE with voltage kept unchanged. The radiation dose and detection rate of the details were compared among different phantom thickness and current. Results With the increase of the current, the average glandular dose, the entrance surfaec dose and the total detection rate of the details decreased. Keeping the phantom thickness unchanged, when the current decreased by 20%, the detection rate of the mass-like and calcification-like details showed a slight decline even had no changed and the detection rate of the fibrous-like details decreased obviously. When the current decreased by >20%, the detection rate of all the details decreased along with the current. The increasing of the phantom thickness had certain impaction on the detection rate of the mass-like details. Conclusion In DBT for screening the breast lesions, reduction of the current properly can effectively reduce the radiation dose without impacting the detection rate of the lesions.