With modern computed tomography (CT) and magnetic resonance (MR) imaging equipment, the diagnosis of most renal masses is usually straightforward and accurate. The major question to be answered is whether the mass represents a surgical or nonsurgical lesion or, in some cases, if follow-up studies are necessary. This evaluation usually can be accomplished if a high-quality examination is performed, if the clinical history of the patient is kept in mind, if conditions that mimic a renal neoplasm are considered and excluded, and if there is an awareness of the potential pitfalls and limitations of CT and MR imaging. In this article, the authors present their technique in the performance of CT and MR imaging examinations, summarize their approach to the diagnosis of renal masses, review the imaging findings in these lesions, and stress the limitations in renal mass diagnosis.
The great majority of renal masses are found incidentally as a result of the use of computed tomography (CT), ultrasonography (US), and magnetic resonance (MR) imaging. Fortunately, most of these are simple renal cysts that can be easily diagnosed and do not require treatment. However, solid and complex cystic renal masses are also discovered, many of which are clearly malignant and need to be surgically removed, while others may not require surgical intervention. Therefore, the proper characterization of these masses is essential so that appropriate management is instituted. In this presentation, we summarize our current approach to the imaging evaluation of renal masses, review the pertinent imaging findings in these lesions, and discuss the limitations of CT and MR imaging as well as pitfalls in diagnosis.