多层螺旋CT后处理图像技术对尘肺小阴影的显示对比

Multi-slice spiral CT post processing study of small shadow of pneumoconiosis

目的:探讨多层螺旋CT之HRCT、MPR、MIP对煤工尘肺小阴影的显示价值。方法:采用Somaton Sensation 16多层螺旋扫描机,对67例0+和1期煤工尘肺患者进行高分辨率螺旋扫描,并进行高分辨1mm层厚轴位及冠状位MPR成像、轴位与冠状位10mm层厚MIP成像。结果:HRCT与10mm层厚CT对照:对p和s型小阴影:P<0.05,对qr、t、、u型阴影:P>0.05。HRCT与MPR联合观察在对p型小阴影的显示上优于单纯轴位HRCT(P<0.01),对其它型小阴影差异无统计学意义(P>0.05)。同层厚MIP与常规CT在显示小圆形阴影肺区数上,对p型阴影有显著差异(χ2=16.7317,P<0.001),对q型阴影有差异(χ2=7.2970,P<0.01),对r型阴影无差异(χ2=0.0290,P>0.05)。结论:多层螺旋CT的HRCT、MPR和MIP重建技术在显示煤工尘肺小阴影方面有重要价值。MIP具有反映小圆形阴影密集度的效果,是在多层螺旋CT各种成像方式中反映小圆形阴影密集度的最好方式。

Objective：To evaluate the techniques of HRCT, MPR and MIP which reconstructed of multi-slice spiral CT scanning in displaying small shadow of the early stage of coal workers pneumoconiosis. Methods： Among 67 coal worker cases, 19 cases is in 0^＋ stage, 44 cases in I stage, 4 cases in I^＋ stage. All the cases were spiral scanned. Images were reconstructed with the techniques of MPR and MIP（thickness, 10mm）. HRCT thickness is 1mm. Results：Compared HRCT with 10-mm-thick CT, there was difference in displaying p and s type shadow （ P 〈 0.05）, and there was no remarkable difference in displaying q, r, t and u type shadow （ P 〉 0.05）. HRCT aided by MPR was superior to HRCT in displaying p type shadow （ P 〈 0.01）, but no difference in displaying other type small shadow. Compared MIP with 10-mm-thick CT, MIP was superior to 10-mm-thick CT in showing p and q type small shadow（p type： X^2 = 16.7317, P 〈 0.001 ; q type： X^2 = 7.2970, P 〈 0.01 ）, and there was no remarkable difference in r type shadow （X^2 = 0.0290, P 〉 0.05）. Conclusion：HRCr and MPR are important in evaluating micro-structure of the early pathological changes of pneumoconiosis. MIP is one of the best method to display the small round nodules and show its density.