Differentiation of small hyperechoic renal cell carcinoma from angiomyolipoma: Computer-aided tissue echo quantification

To assess the value of computer-aided tissue echo quantification in differe ntiating small hyperechoic renal cell carcinomas from angiomyolipomas, we s tudied ultrasonographic images of 15 renal cell carcinomas and 20 angiomyol ipomas. After digitizing the images, we measured the absolute gray scale va lues of the renal cortex, central echo complex, and mass. The relative gray scale value (%) of the mass was calculated by setting the gray scale value of the cortex as 0% and the central echo complex as 100%. The relative gra y scale value of renal cell carcinomas was in the range of 12 to 73% (mean, 28%), whereas that of angiomyolipomas was 30 to 204% (mean, 130%). The dif ferentiation between small hyperechoic renal cell carcinomas and angiomyoli pomas can be facilitated by computer-aided tissue echo quantification.