多层螺旋CT对显示泌尿系微小结石的实验研究  

Multislice spiral CT in the detection of urinary calculi

作　　者：洪平[1] 胡道予[1] 万常华[1] 肖明[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院放射科,武汉430030

出　　处：《放射学实践》2004年第9期641-643,共3页Radiologic Practice

摘　　要：目的 :评价多层螺旋CT(MSCT)在不同扫描条件下对泌尿系结石的显示率。方法 :5 1个不同大小取自患者的泌尿系结石 ,将结石分为 3组。A组 :大于 5mm(15个 ) ,B组 :3～ 5mm(9个 ) ,C组 :小于 3mm(2 7个 )。分别经设置不同扫描参数的单层螺旋CT(SSCT)和MSCT扫描。比较不同扫描参数设置下SSCT和MSCT的结石检出率 ,检验不同扫描层厚与检出结石数的关系。结果 :所有序列对A、B组的检出率均为 10 0 % (2 4/ 2 4) ,C组检出的结石数与扫描层厚呈明显负相关(MSCT :r=-0 .947,P <0 .0 1;SSCT :r =-0 .999,P <0 .0 1) ,检出的结石数随着扫描层厚变薄而增多。MSCT 5mm和 10mm层厚扫描 ,然后分别以 0 .62 5mm和 1.2 5mm层厚重建所得的图像 ,其质量及其显示出的结石数与MSCT相应同等薄层扫描 (0 .62 5mm和 1.2 5mm层厚扫描 )所得的结果完全一致。结论 :MSCT因其有效的薄层重建能力、超快的扫描速度以及极高的空间分辨率 ,在检测泌尿系小结石方面较SSCT具有明显优势。运用MSCT检测泌尿系结石值得临床广泛应用。Objective:To evaluate the detection rate of urinary calculi on unenhanced multislice spiral CT (MSCT) images at various settings.Methods:51 urinary calculi of varying size from patients were grouped according to largest dimension of urinary calculi,larger than 5mm in group A (15 cases),3 to 5mm in group B (9 cases) and less than 3mm in group C (27 cases).All urinary calculi were imaged using MSCT and SSCT.The number of calculi visualized on the two type CT images was recorded.Difference in detection rates between MSCT and SSCT was assessed.Results:The detection rate was 100% (24 of 24) in group A and B at all settings.As for group C,the number of detected calculi was reversed proportional to the slice thickness (r=-0.999,P<0.01 for SSCT;r=-0.947,P<0.01 for MSCT).The number of calculi increased with decrease in slice thickness.The quality of reconstruction images with MSCT at the smallest section thickness (0.625mm or 1.25mm) was nearly identical with that of images obtained at 0.625mm or 1.25mm collimation corres- pondingly. Conclusion:Because of its ability of effective reconstruction in thin slices (0.625mm or 1.25mm),ultra high scan speed and higher spatial resolution,MSCT has more advantages than SSCT in detection of small urinary calculi.This technique deserves more clinical practices.

关 键 词：多层螺旋CT 泌尿系结石 MSCT X线计算机 体层摄影术 

分 类 号：R816.7[医药卫生—放射医学]