The Comparison Of Diagnosed Power In Common Small Renal Tumors Between Magnetic Resonance Imaging And Contrast-enhanced Ultrasound

Background:Small renal masses (SRMs) are common renal diseases in clinical practice. Magnetic reasonce imaging (MRI) and contrast-enhanced ultrasound (CEUS) are mainly imaging examination methods to detect renal masses. It is usefull for clinical practice to compare with which is the better method between MRI and CEUS to detect and make a differential diagnosis between benign and malignant SRMs.Objective:To retrospectively determine which MRI findings play the most important role in differential diagnosis between benign and malignant SRMs. And then, basing on the results of diagnosing sensitivity and specificity, the better method will be determine in cost-effectiveness analysis through prospective cohort study.Material and method:This study included seven sections. From first to fourth sections through retrospectively study, these mainly MRI findings of 80 cases containing benign and malignant renal tumors were analyzed using multivariate Logistic regression analysis. Those cases were obtained from January in 2009 to June in 2015. These patients were divided into two groups. Malignant tumors were case group and benign tumors were control group. MRI findings contained two types. One was qualitative findings and the other was quantitative. These qualitative findings included macroscopic fat, pesudocapsule, cystic part and necrosis of lesion, the signal of T2WI, hemorrhage, angular interface, procumbent growth and halo nodule sign. Those quantitative findings contained the decreased degree of tumor’s signal in in-and-out phase imaging, the increased degree of tumor’s signal in cortical phase, croticomedullary and delay phase. Those patients’ age and gender were also included in quantitative dates. Through retrospectively analyzing tumors’ diameters of 94 cases in the fifth section including benign and malignant renal tumors proved by pathology, the detection of different sizes were compared with each other between MRI and CEUS. From sixth to seventh sections, the diagnosing accuracy rates were calculated between MRI and CEUS through prospective cohort study from July 2015 to December 2015,94 cases were included in this cohort. And then, the cost-efficiency analysis was calculated between MRI and CEUS. SPSS 19.0 and CHISS statistical software were utilized to analyze all dates. The mainly statistical method was multivariate Logistic regression anlysis. Student’ test, Pearson χ2 test, Kappa statistic (KS) analysis and single ordinal cortingency date were used as complementary method.Result:The first section showed that fat (the MRI finding of benign tumor), the degree of necrosis of tumors and halo nodule sign (the MRI findings of malignant tumor) were the most important MRI findings in differential diagnosis between benign and malignant tumor. The pesudocapsule and hemorrhage were secondary MRI findings of malignant tumors. The procumbent growth was secondary MRI findings of benign tumors.After comparing with minimal fat angiomyolipoma (AML) and chromophobe renal cell carcinoma (chRCC), the second section demonstrated that the pesudocapsule, the more degree of necrosis and higher signal on T2WI had more probability to diagnosis chRCC’s. If a tumor had either the procumbent growth or angular interface, it had more probability to diagnosis minimal fat angiomyolipoma. In the quantitative findings, the more decreased degree of signal in in-and-out phase and the more enhanced in cortical phase had more chance to diagnosis minimal fat angiomyolipoma.After comparing with minimal fat angiomyolipoma and papillary renal cell carcinoma (pRCC), the third section showed that mixed signal or higher signal on T2WI, the more degree of necrosis and hemorrhage had more probability to diagnosis papillary renal cell carcinoma. And the enhanced degree in cortical phase had more chance to diagnose minimal fat angiomyolipoma.After comparing with clear cell renal cell carcinoma (ccRCC) and chRCC, the fourth section demonstrated that the more degree of necrosis, pesudocapsule and halo nodule sign had more probability to diagnose ccRCC. The more decreased degree of signal in in-and-out phase had more chance to diagnose ccRCC.The fifth section revealed that the detection of MRI was higher than CEUS in the diameter less than 15mm whether these tumors contained fat or not. P value was less 0.008.The sixth and seventh sections demonstrated that the accuracy rate of MRI and CEUS differential diagnosing SRMs were 93.62% and 84.04%, respectively. The cost-effectiveness analysis (CEA) showed that CEUS was higher than MRI. The developed MRI scan protocol had more cost-effectiveness than CEUS.Conclusion:Fat is the mainly MRI finding of benign tumor. The more degree of necrosis of tumor and halo nodule sign had more chance to diagnosis malignant tumors. MRI had more accuracy than CEUS for SRMs. CEUS had more cost-effectiveness than MRI. The developed MRI scan protocol had more cost-effectiveness than CEUS.