Segmental Enhancement Inversion at Biphasic Multidetector CT: Characteristic Finding of Small Renal Oncocytoma

Abstract

http://radiology.rsnajnls.org/cgi/content/full/2522081180/DC1.

Multiparametric MRI of solid renal masses: pearls and pitfalls

“…66 p-RCCs enhance more slowly than AMLs using a wash-in arterial index 13 ; therefore, the combination of homogeneous low T2W SI and rapid arterial enhancement is suggestive of minimal-fat AML rather than p-RCC. 7,66 A single study demonstrated that oncocytoma could be differentiated from chromophobe and cc-RCCs based on delayed enhancement with high specificity 13 and the imaging finding of segmental enhancement inversion has been described as a specific imaging finding of oncocytoma 67 ; however, other studies have been unable to Figure 16 A 61-year-old man with previous bladder cancer status post-total cysto-prostatectomy and neo-bladder formation and severe allergy to iodinated contrast medium imaged with conventional extracellular gadolinium-enhanced MRU demonstrates excellentquality MRU. Prior to the examination, the patient received 500 ml of normal saline intravenously and just prior to the injection of diluted (half-dose) gadolinium, furosemide was also administered intravenously.…”

The expanding role of imaging in the management of renal cell carcinoma

“…Renal oncocytomas have two components, one of which highly enhances on corticomedullary phase; the other is less enhanced. This pattern reverses on the excretory phase with the highly enhancing component on corticomedullary phase becoming less enhancing on the excretory phase and the less enhancing component becoming highly enhancing on the excretory phase (sensitivity of 80% and specificity of 99%) [16]. This CT 'yin-yang' sign of segmental enhancement may help to differentiate small renal oncocytomas from RCCs.…”

“…Oncocytomas are benign renal tumors comprising 3-7% of all primary renal neoplasms [16]. The eosinophilic variants of chromophobe RCCs are frequently difficult to distinguish from renal oncocytomas histologically.…”

“…Currently there are also no reliable imaging features to differentiate oncocytomas from RCC (Figures 10 & 11). One study reported a characteristic enhancement pattern of small renal oncocytomas called segmental enhancement inversion that may help to differentiate them from small RCCs [16]. This is a finding on biphasic CT using both corticomedullary and excretory phases.…”

Quantitative assessment of solid renal masses by contrast-enhanced ultrasound with time–intensity curves: how we do it

“…chRCCs often show homogenous enhancement [32,33,44]. However, an interesting enhancement pattern seen in a minority of chRCCs and oncocytomas termed ''segmental enhancement inversion'' has been recently described [45,46]. With this pattern, at the CMP some portions of the tumor hyperenhance, while other portions hypoenhance, and at early excretory phase this pattern is reversed.…”