Michele Bertolotto MD, Presenter: Nothing to Disclose

Roberta Zappetti MD, Abstract Co-Author: Nothing to Disclose

Paola Martingano, Abstract Co-Author: Nothing to Disclose

Leonardo Giarraputo MD, Abstract Co-Author: Nothing to Disclose

Massimo Valentino MD, Abstract Co-Author: Nothing to Disclose

Maria Assunta Cova MD, Abstract Co-Author: Nothing to Disclose

To investigate the role of contrast enhanced ultrasound (CEUS) in characterization of renal masses equivocal for enhancement at CT.

From October 2003 to March 2009 13 consecutive patients (11 Men, 2 women, mean age, 58 years, range: 39-83 years) with renal masses that did not present as simple cysts at grey-scale US and had equivocal enhancement at CT underwent CEUS. All patients had at least an unenhanced examination followed by a contrast material-enhanced scan during the nephrographic phase, by using a scanning delay of 90-100 seconds. Equivocal enhancement was defined as a difference of 10-20 HU between the unenhanced and the contrast-enhanced images. After preliminary grey-scale and color Doppler US, CEUS was performed using low acoustic power, contrast specific modes. A bolus of SonoVue was injected to examine the lesion, followed by a saline flush. All examinations were digitally recorded for retrospective evaluation. 10/13 lesions underwent surgery. 3 presumably benign cysts had 1-3 years follow-up.

At grey-scale US 9/13 lesions presented with mixed echotexture, 4/13 as inhomogeneous echogenic lesions. After microbubble administration 4 lesions were characterized as Bosniak category IIF cysts. One was benign at surgery, 3 were stable after a follow-up of 1 and 3 years. 5 Bosniak category IV cystic masses were malignant at surgery. There were 1 clear cell type, and 4 papillary renal cell carcinomas. 4 lesions were characterized as solid vascularised masses at CEUS and surgically removed. There were 2 papillary cancers, 1 chromophobe tumor, and 1 metanephric adenoma.

In our series CEUS allowed a confident characterization of renal lesions presenting with equivocal enhancement at CT. These results need confirmation with a larger number of patients.

CEUS allows differentiation between pseudoenhancement and presence of enhancing tissue in renal lesions presenting at CT with equivocal enhancement (10-20 HU).

Bertolotto, M, Zappetti, R, Martingano, P, Giarraputo, L, Valentino, M, Cova, M, Renal Masses with Equivocal Enhancement at CT: Preliminary Evaluation at CEUS.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8009223.html