Diagnostic Value Of CEUS,CECT And CEMRI For The Cystic Renal Lesions: A Meta-analysis

Background:The incidence of renal cystic lesions has been steadily increasing,and shows a positive correlation with age.It was reported that approximately 50%of the people over the age of 50 had kidney cysts.The ability to accurately identify those complex renal cystic masses was necessary for the timely treatment of malignant lesions.CT(computed tomography)-based Bosniak classification system,has been routinely used to assess complex cystic renal mass in clinical practice.Besides,it also can be applied to contrast-enhanced ultrasound(CEUS)and contrast-enhanced magnetic resonance imaging(CEMRI).Furthermore,a new version was proposed and incorporated MRI(magnetic resonance imaging)into the Bosniak system in 2019.However,the role of US(ultrasound)in the Bosniak system has not been clearly established.Purpose:To compare the diagnostic ability of CEUS,CECT and CEMRI based on the current Bosniak classification for the evaluation of renal cystic lesions.Materials and Methods:Related studies were searched in PubMed,EMBASE,and the Cochrane Library databases from January 1,2010 to December 10,2020.Key terms for the literature search included“kidney”,“cystic masses”,“contrast-enhanced”,“ultrasound”,“US”,“CEUS”,“CT”,“CECT”,“MRI”and so on.The retrieved results were screened according to the pre-established inclusion and exclusion criteria,then the related data were extracted from the qualified studies.QUADAS-2 was used to assess the study quality.Meta-analysis was performed by“midas modules”of Stata SE 15.0 software.The bivariate mixed-effect model was used.Forest plots and Summary receiver operating characteristic(SROC)curves were drawn.The pooled sensitivity,pooled specificity and AUC-value(the area under the SROC-curve)for these three methods were calculated and compared.The Q test and the I~2 statistic were implemented to detect the heterogeneity.Meta-regression and subgroup analysis were conducted to reveal the source of heterogeneity.A sensitivity analysis was conducted to explore impact of a single study on the overall pooled parameters.Finally,publication bias was assessed by Deek’s test for funnel plot asymmetry.Results:After screening 3783 articles,16 eligible studies were finally included.CEUS showed highest pooled sensitivity and specificity,which were 98%(95%CI:91%～100%)and 80%(95%CI:64%～90%)respectively,and the AUC value of CEUS was also the highest which was 0.97(95%CI:0.95～0.98).CECT and CEMRI showed similar pooled estimates,and the sensitivity and specificity were 88%(95%CI:77%～94%)versus 85%(95%CI:77%～91%),and 79%(95%CI:70%～86%)versus71%(95%CI:52%～85%),respectively.The AUC value of CECT and CEMRI were0.89(95%CI:0.86～0.92)and 0.87(95%CI:0.84～0.90)respectively.The I~2 value for CEUS,CECT and CEMRI were 75%,88%and 83%(p-value=0.010,0.000,0.001)respectively,which meant the heterogeneity of the included studies was significant.Conclusion:Based on the current Bosniak classification,CEUS showed superior diagnostic ability compared to CECT and CEMRI for the complex renal cystic masses,and could serve as an alternative for CECT and CEMRI.Concerning the new version of the Bosniak standard,more studies are needed in future to explore and demonstrate its diagnostic efficacy combined with different imaging methods.