Ultrasound Imaging Of Renal Tumors After A Preliminary Study Of Three-dimensional Reconstruction

Objective:The goal of this study was to evaluate the feasibility of three-dimensional contrast-enhanced ultrasound (3D-CEUS) in diagnosing renal tumors.Material and methods:A total of 121 renal lesions referred between May 2009 and January 2010 were studied, including clear cell renal cell carcinoma (CCRCC) (n=91), papillary renal cell carcinoma (PRCC) (n=5), chromophobe renal cell carcinoma (CRCC) (n=5), renal angiomyolipoma (RAML) (n=19), and cystic nephroma (n=1) (pathologically confirmed). We performed the examinations with transducer C5-2 and volume transducer V6-2 of Philips iU22 ultrasound scanner. The patients underwent conventional grey-scale ultrasound combined with color Doppler ultrasound, and then were taken contrast-enhanced ultrasound (CEUS) with a contrast agent Sonovue. Then transducer V6-2 was used to take the three-dimentional Color Power Angiography (CPA) and 3D-CEUS. QLAB was used to perform the reconstruction of 3D-CPA and 3D-CEUS with all the records stored. We divided the lesions into 5 types according to the characteristics of color Doppler imaging,4 types to the 3D-CPA performance, and 4 types to the 3D-CEUS. And the data was analyzed by STATA7.0.Results:The conventional ultrasound results indicated some difference between benign and malignant renal tumors. Most renal cell carcinoma were slightly hyperechoic or hypoechoic,heterogeneous internal, and with pseudocapsules; while most RAML were hyperechoic or partially hypoechoic,homogeneous internal,and with no pseudocapsule. There was no statistical significance of both color Doppler and 3D-CPA between benign and malignant renal tumors. However, the perfusion performance of 3D-CPA was better than the color doppler. The characteristics of CEUS were different between benign and malignant renal tumors. The RCCs enhanced synchronously with the renal cortex, and decreased rapidly. They were isoechoic or hyperechoic in peak time, with filling defect areas and pseudocapsules partially. Benign renal tumors enhanced slowly and centripetally, were isoechoic or hypoechoic in peak time, with no filling defect areas nor pseudocapsules.The three-dimensional ultrasonography of a particular tumor could be a mixture of different basic types. The features of blood supply are different between benign and malignant renal tumors in 3D-CEUS.The feature of RCCs was tortuous expansion and coarsely reticulate or irregular messy branches frequently, with filling defect areas and pseudocapsules partially. The blood supply of benign renal tumors was usually nebulous or thin uniform reticular, and the internal structure was homogeneous with messy branches in part. The blood supply of 3D-CEUS was shown the best among all the examination techniques above mentioned.The features of CEUS were discrepant between the subtypes of RCCs. CRCCs were isoechoic or hyperechoic in peak time, whereas PRCCs and ChRCCs were often hypoechoic. But the performances of 3D-CEUS showed none significant differences.Conclusions:3D-CEUS can provide clear stereoscopic structures and morphological characteristics of the lesions and supply more information. It is a useful adjuvant of CEUS for the diagnosis of renal tumors.