Application Of Four-phase MDCT In Diagnostic Imaging Of Renal Oncocytoma

Objective:The purpose of this study was to evaluate the Three-phase enhancement CT characteristics of Renal Oncocytomas,including CT value,enhancement degree,enhancement pattern and central radial scar。This research can provide clues for clinician to increase the accuracy of preoperative diagnosis.Methods:Twenty-five patients(15 men and 10 women)who were admitted into Second Hospital of Tianjin Medical University diagnosed Renal Oncocytomas by pathology between August 2011 and January 2019 were included.Six were excluded according to standard procedures.The following CT data were collected: the phase of the largest peak occurring,the central radial scar,necrosis,the CT value of noncontrast computed tomography(NCCT),cortical phase,parenchymal phase and excretory phase.The data of 30 patients with CCRCC and 17 patients with CRCC also were collected and analyzed comparatively and statistically with SPSS22.0statistical software and review relevant literatures.Result: The NCCT value of RO is 33.0Hu(95%CI,29.7～36.0),cortical phase is 102Hu(95%CI,79.9～122.4),parenchymal phase is 120.4Hu(95%CI,98.7～140.5)and excretory phase is 85.9Hu(95%CI,76.9～96.8).The largest peak of CT value is 123.2Hu(95%CI,102.0～142.6).The enhancement degree is 91.0Hu(95%CI,61.7 ～ 111.4).Mean enhancement of RO peaked in the parenchymal phase.The incidence of central scar was 80% in patients with tumor diameter > 4cm(n=5).No patients in this study had a segmental enhancement inversion.The age,sex,BMI,tumor location and tumor size was no statistical difference between RO group and CCRCC group(P>0.05).There was no statistical difference between the two groups in the largest peak of CT value,enhancement degree and the CT value of NCCT,cortical phase,parenchymal phase and excretory phase(P>0.05).The occurrence rate of necrosis in RO group and CCRCC group was statistically different(P <0.001).There was a statistical difference in the phase of the largest peak occurringbetween RO and CCRCC group(P=0.001).The occurrence rate of central radial scar in RO group and CCRCC group was statistically different(P=0.002).The age,sex,BMI,tumor location and tumor size was no statistical difference between RO and CRCC group(P>0.05).There was no statistical difference between the two groups in the occurrence rate of necrosis,the phase of the largest peak occurring,enhancement degree and the CT value of NCCT,cortical phase and excretory phase(P>0.05).CT value in the parenchymal phase of RO group and CRCC group were statistically different(P=0.038).The critical value of parenchymal phase CT value in the differential diagnosis of RO and CRCC was 117.0Hu,which More than 117 Hu was considered for diagnosis as RO,the sensitivity of diagnosis was 70.0%,the specificity was 90.9%,and the area under receiver operating curve(AUC)was 0.745.The maximum CT value of RO group and CRCC group was statistically different(P=0.047).The critical value of maximum CT value in the differential diagnosis of RO and CRCC was 112.0Hu,which more than 112.5Hu was considered for diagnosis as RO,the sensitivity of diagnosis was 70.0%,the specificity was 72.7%,and the area under receiver operating curve(AUC)was 0.718.The enhancement degree of RO group and CRCC group were statistically different(P=0.016).The critical value of enhancement degree in the differential diagnosis of RO and CRCC was 84.0Hu,which more than 84.0Hu was considered for diagnosis as RO,the sensitivity of diagnosis was 70.0%,the specificity was 90.9%,and the area under receiver operating curve(AUC)was 0.800.Conclusion: Four-phase MDCT may assist in the discrimination of RO from CCRCC and CRCC by the CT value of each phase,the phase of largest peak CT value occurring,central radial scar and necrosis.