低剂量螺旋CT最大密度投影对肺微小结节的诊断价值

The diagnostic value of MIP reconstructions of low- dose spiral CT for micronodules of lungs

目的研究螺旋CT低剂量扫描图像最大密度投影(MIP)对肺微小结节的诊断价值。方法6例煤工尘肺的尸检离体肺脏制成充气固定肺标本,分别行螺旋CT常规剂量(100mA)和低剂量(65mA,30mA)1.5mm的薄层扫描,并行8.5mmMIP重建,比较不同剂量重建图像对微小结节的显示。结果与常规剂量MIP重建图像比较,65mA和30mA组与常规剂量组对结节的发现无显著性差异,65mA和30mA组的敏感性分别为97.97%、97.29%,阳性预测值分别为96.03%、96.00%。结论低剂量螺旋CT扫描MIP重建能理想地显示常规剂量扫描MIP重建所能显示的结节。

Objective To evaluate the diagnostic value of maximum intensity projection (MIP) reconstructions of low- dose spiral CT for the micronodules of the lungs. Methods 6 inflated and fixed lung specimens of coal pneumoconiosis. Above- mentioned lung specimens underwent routine spiral CT scan, 1.5- mm- thick spiral CT scan( 100 mA, 65 mA, 30 mA) .For each dose 1.5- mm- thick spiral CT, 8.5- mm- thick MIP reconstructins were generated respectively. Comparing the findings of micronodules in MIP imagings of routine- dose and low- dose spiral CT. Result Comparing with routine- dose(100 mA) spiral CT MIP, there are not marked difference for the findings of micronodules in MIP imagings of low- dose(65 mA, 30 mA) spiral CT. The sensitivity of group 65 mA and 30 mA are 97.97% ? 97.29% respectively. The postive predictive value of which are 96.03% ? 96.00% . Conclusion MIP imagings of low- dose(65 mA, 30 mA) spiral CT for the diagnosis of the micronodules are perfectly comparing with MIP imagings of routine- dose(100 mA) spiral CT. [