低剂量延迟期扫描在泌尿系统疾病MSCTU中的临床应用

The clinical application of low dose delay scan in MSCTU for urologic disease

目的:探讨MSCT尿路成像(MSCTU)中延迟期低剂量扫描方案(100 k V+CARE Dose 4D)对泌尿系统疾病的诊断价值,并探讨三种不同后处理重组技术(MPR/CPR、MIP、VR)图像对泌尿系统疾病诊断的敏感性。方法:34例MSCTU患者延迟期采用低剂量扫描方案,所有患者延迟期1 mm薄层数据进行CTU图像重组,并与临床、病理诊断进行对照研究。结果:34例中全尿路MSCTU图像的定位诊断准确率为97.1%(33/34),定性诊断准确率为91.2%(31/34)。三组不同图像组合对泌尿系统疾病的定位诊断准确性均高于定性诊断的准确性。其定位、定性诊断敏感性,从高到低依次为:全尿路MSCTU图像>含延迟期CT轴位>常规CT轴位,其中全尿路MSCTU图像与常规CT轴位的诊断差异有显著统计学意义(P<0.012 5),其余组合均无统计学意义(P>0.012 5)。CT尿路造影后处理重组三种技术对泌尿系统疾病的定位、定性诊断准确率从高到低依次为MPR/CPR>MIP>VR图像,定位诊断准确率高于定性诊断准确率。其中MPR/CPR技术与MIP、VR技术对照,差异均有统计学意义(P=0.000),而MIP技术与VR技术比较,两组差异均无统计学意义(P>0.012 5)。结论:MSCTU技术延迟期采用100 k V结合CARE Dose 4D技术方案,不仅能够明显减少单期辐射剂量,而且能提高泌尿系统疾病的定位、定性诊断的准确性,值得临床推广应用。

Objective： To discuss the diagnostic value of low dose delay scan（tube voltage 100 kV＋CARE Dosed 4D） in multi-slice helical computed tomography urography（MSCTU）, and discuss the diagnostic sensitivity of three different post-processing recombinant technologies（MPR/CPR, MIP, VR） in urologic disease. Methods： 34 cases of patients undertook low dose scan protocol in delay phase（100 kV＋CARE Dosed 4D）. The 1 mm-thick CT data in the delay phase were restructed by postprocessing technology and compared with clinical and pathological diagnosis. Results： In 34 cases of patients, the accuracy of localization and qualitative diagnosis of MSCTU image was 97.1%（33/34） and 91.2%（31/34）, respectively. The localization and qualitative diagnostic sensitivity in three different image combinations from high to low was as follows： MSCTU imageCT axial combined with delay imageroutine CT axial, and the diagnostic accuracy of localization was higher than the qualitative diagnosis. There was statistically significant difference（P〈0.0125） between MSCTU image and routine CT axial, but not for the rest of the combinations（P〉0.0125）. Meanwhile, the localization and qualitative diagnostic sensitivity in three different image postprocessing technologies from high to low was as follows： MPR/CPR〉MIP〉VR. There were statistical significant differences（P=0.000） between MPR/CPR and MIP or VR technology, while not between MIP and VR（P〉0.0125）. Conclusion： MSCTU using100 kV with CARE Dosed 4D technology in excretory phase can not only reduce radiation dose in single phase, but also have higher diagnostic accuracy in localization and qualitative diagnosis. The low dose scan protocol is worth to be widely applied in the clinic of urologic disease.