Are growth patterns on MRI in small (< 4 cm) solid renal masses useful for predicting benign histology?

Purpose: To evaluate previously described growth patterns in < 4 cm solid renal masses.

Materials And Methods: With IRB approval, 63 renal cell carcinomas (RCC; clear cell n = 22, papillary n = 28, chromophobe n = 13) and 36 benign masses [minimal-fat (mf) angiomyolipoma (AML) n = 13, oncocytoma n = 23) from a single institution were independently evaluated by two blinded radiologists (R1/R2) using T2-weighted MRI for (1) the angular interface sign (AIS), (2) bubble-over sign (BOS), (3) percentage (%) exophytic growth and (4) long-to-short axis ratio. Comparisons were performed using ANOVA, chi-square and multi-variate regression.

Is Ultrasound Useful for Further Evaluation of Homogeneously Hyperattenuating Renal Lesions Detected on CT?

Objective: The purpose of this study was to evaluate the ability of ultrasound (US) to characterize hyperattenuating cysts detected as indeterminate hyperattenuating renal lesions on unenhanced and single phase enhanced CT.

Materials And Methods: A total of 107 consecutive homogeneously hyperattenuating renal lesions underwent gray-scale and Doppler US at our institution between 2010 and 2013. Two radiologists who were unaware of the final diagnosis retrospectively evaluated US images for visibility and diagnosis (simple cyst, intermediate complexity cyst, cystic or solid mass showing internal flow on Doppler US, or indeterminate).