Computed Tomography Diagnosis of Renal Angiomyolipoma

Abstract

Angiomyolipomas with a high fat content can be diagnosed by CT, thus eliminating the need for angiography. Surgery can then be tailored for maximal renal tissue preservation. One unilateral and two bilateral surgically confirmed cases of renal angiomyolipoma are presented with a typical fourth case in which surgery was cancelled based on the pathognomonic CT findings.

Benign Renal Tumors Detected among Healthy Adults by Abdominal Ultrasonography

“…Thus, preoperative diagnosis has been re garded to be possible for most angiomyolipomas [2], How ever, some renal cell carcinomas have been known to reveal a very hyperechoic pattern indistinguishable from an an giomyolipoma by ultrasonography [3], as also shown in our study. Further, diagnosis of angiomyolipomas has been regarded to be difficult or almost impossible by imaging examinations for those that are small, include a very lim ited amount of fatty tissue or have intratumoral hemor rhage and degeneration which make the fatty tissue ob scure [3][4][5][6], Actually, many of the angiomyolipomas de tected in the present ultrasonographic study were small and diagnosis was occasionally difficult. In such cases, angiog raphy also gave limited diagnostic information.…”

Various radiological appearances of angiomyolipoinas in the same kidney

“…A n g i o m y o l i p o m a can be diagnosed noninvasively with great accuracy by detecting a fat component [3,4]. However, in those lesions composed primarily of smooth muscle or hemorrhage, the diagnosis of an~o m y o l i p o m a is difficult [5].…”

“…The fat c o m p o n e n t accounts for the areas of negative attenuation on CT images, hyperechogenicity on sonograms, and hyperintensity on Tl-weighted M R images [3,4,5,6]. The angiomyolipomas containing an abundant amount of muscle tissue show homogeneously high attenuation on unenhanced CT images, enhance homogeneously on contrast-enhanced CT images, and are isoechogenic on sonograms.…”

Computer-Aided Detection and Diagnosis at the Start of the Third Millennium

“…7 It is not surprising that the first diseases to be diagnosed based on measurements are those in which anatomic changes are subtle or difficult to appreciate in individual images. As quantitative tools become more ubiquitous, it is possible that quantitative criteria for diagnosis will be developed for other diseases whose diagnosis may only be suggested by qualitative impressions today.…”

“…By adjusting to narrow window widths or measuring pixel values, one can diagnose some types of masses. 7 Additional image processing techniques that enhanced image features such as edges were the next step. These enhancement techniques could, for instance, increase lesion conspicuity to make findings more obvious.…”