Right renal angiomyolipoma


Clinical History: 59-year old woman with right lower back pain for more than one year


Diagnosis: Right renal angiomyolipoma


MR Technique:

Upper abdominal imaging was performed on a 3T MR system. (A, B) Axial T1-weighted VIBE in- and out-of-phase (TR/TE 3.88/1.27ms), and (C) axial FS T2-weighted TSE (TR/TE 5814/78ms, with respiratory triggering) scans were acquired prior to the administration of intravenous contrast. Then, arterial (D), venous (E) and delayed phase (F) dynamic contrast-enhanced T1-weighted VIBE (TR/TE 3.22/1.2ms) scans were acquired in the axial plane.


Imaging Findings:

There is a well-defined, round lesion within the upper pole of the right kidney. The lesion has homogeneous high signal intensity on T1WI, and heterogeneous low signal on T2WI. Signal loss between the in-phase and out-of-phase images indicates the presence of fat. On the contrast-enhanced scan, the lesion has marked enhancement on the venous image, with slight wash out on the delayed image. The diagnosis of an angiomyolipoma was confirmed by pathologic examination.