低剂量螺旋CT在成人肺结核诊断中的价值

The Diagnosis Value of Low-dose Spiral CT in Adult Pulmonary Tuberculosis

目的研究低剂量螺旋CT扫描技术在成人肺结核诊断中的价值。方法选择150例肺结核患者应用完全随机化法分为2组,分别采用常规剂量及低剂量扫描方式。采用Philips64排螺旋CT机,常规剂量扫描管电流230m A,低剂量扫描依据BMI的不同选择不同管电流:BMI≤18.5采用20m A;18.5<BMI<24.9采用30m A;BMI≥25采用40m A。比较两方式对横断面、冠状面及病灶图像质量的影响。结果肺窗、纵膈窗横断面图像质量在两种扫描方式间具有一致性,肺窗:P=0.539;纵膈窗:P=0.235。冠状面图像质量在两组间无统计学差异(P>0.05)。两种扫描方式所得肺结核CT影像特征比较,结果8项特征的P值均大于0.05。将两组受检者的辐射剂量作两样本均数t检验,P值均远小于0.01。比较两组受检者的平均噪声水平,P<0.01。结论低剂量扫描技术在成人肺结核诊断及随访中的常见影像征象的检测效果与常规剂量扫描无显著差异。低剂量扫描技术显著降低了受检者的辐射剂量。

Objective To investigate the diagnosis value of low-dose spiral CT scanning technology in adullt pulmonary tuberculosis. Methods Choose 150 cases of tuberculosis patients, and divide them into two groups using the completely randomized method. Then adopt conventional-dose and low-dose scanning methods in these patients. Philips 64-slice spiral CT is adopted and electric current of conventional-dose scanning tube is 230mA. According to different BMI, different electric current is available： BMI≤ 18.5, 20mA, 18.5〈BMI〈24.9, 30mA. BMI≥25, 40mA. Compare the differences between the cross sections, coronal planes and the quality of the focuses of infection in these two methods. Results The image quality of cross sections between the lung window and mediastinal window in the two scanning methods are consistent. Lung window： P=0.539; Mediastinal window： P=0.235. The image quality of coronal plane between the two groups is not statistics difference（P〉0.05）. Depented on the comparison of tuberculosis CT images, the P value of eight characteristics are bigger than 0.05. Make two samples of the Radiation dose between the two groups of subjects and take the average test. The result is the P value is more smaUer than 0.01. Compared with the average noise level between the two groups, P value is smaller than 0.01. Conclusion There is no significant difference between conventional-dose and low-dose scanning technology in the aspect of adult tuberculosis diagnosis and the detection effect of common imaging sign. As a result, low- dose scanning technology reduces the radiation dose of subjects significantly.