Can “Tumor-to-Cortex Echogenicity Ratio” Differentiate Angiomyolipomas from Other Hyper-Echoic Renal Masses

A retrospective study was performed to evaluate the diagnostic value of tumor-to-cortex echogenicity ratio (TCER) in the characterization of hyper-echoic renal masses. The radiology database was queried between 2012 and 2014 for hyper-echoic renal masses on the basis of defined exclusion and inclusion criteria. Each included mass was characterized as either an angiomyolipoma (AML) or a non-AML based on pre-defined criteria. The ratio of renal mass echogenicity to that of adjacent renal cortex (TCER) was calculated for each mass using commercially available software. A total of 70 masses in 65 patients were identified, including 49 AMLs. TCER values >2.26 were associated with a sensitivity and specificity of 81.6% and 71.4%, respectively, for diagnosis of AML. Moreover, TCER values >3.98 resulted in 100% specificity for AML diagnosis with a sensitivity of 28.6%. These findings suggest that the TCER may be a valuable tool for the characterization of hyper-echoic renal masses.