Giovanni Zimbaro

Harmonic US imaging of vesicoureteric reflux in children: usefulness of a second generation US contrast agent

Background: Contrast-enhanced voiding urosonography (VUS) is largely accepted both for the diagnosis and follow-up of vesicoureteric reflux (VUR) in children. Objective: To evaluate the usefulness of contrast-enhanced second-harmonic VUS in the diagnosis and grading of VUR, using a second-generation contrast agent. Materials and methods: Eighty consecutive children were prospectively studied with contrast-enhanced second-harmonic VUS. All children received a second-generation contrast medium, constituted by phospholipid-stabilized microbubbles of sulphur-hexafluoride (SonoVue, Bracco, Milan, Italy). US monitoring of the bladder, of the retrovesical space and of the kidneys was performed using, alternatively, both tissue-harmonic and contrast-harmonic modes. In those young boys where VUR was depicted at VUS, examination was completed with transperineal, sagittal urethral exploration during micturition. VUR was graded in five steps and diagnoses were compared with voiding cystourethrography (VCUG). Results: VUR was diagnosed in 52 reno-ureteral units with VUS. In 49 of these reno-ureteral units, VCUG confirmed the presence of VUR. In comparison to VUS, sensitivity and negative predictive value of VCUG were inferior. The grade of VUR detected at VUS was higher than that detected at VCUG in three units. In no case was the grade of VUR detected at VCUG higher than the one detected at VUS. The differences between VUS and VCUG in grading VUR were statistically significant (p=0.02). Imaging of the normal posterior urethra was skilfully demonstrated with US in 15 young boys with VUR. No statistically significant differences were found between tissue-harmonic and contrast-harmonic mode (p=0.102). Conclusions: Contrast-enhanced second-harmonic VUS is a sensitive and easy technique for the evaluation of VUR. A second-generation US contrast medium such as SonoVue, if available, should be the first choice as the dose required for one examination is much lower and consequently significant reduction of contrast agent cost is possible.

Usefulness of power Doppler and contrast-enhanced sonography in the differentiation of hyperechoic renal masses

AbstractBackground: In a prospective study, we compared power Doppler with and without contrast medium in the depiction of vascularity for the characterization of hyperechoic renal lesions. Methods: Forty-one hyperechoic renal expansive lesions (29 benign, 12 malignant) in 32 patients were studied with power-Doppler ultrasonography before and after administration of an echo-enhancing agent (Levovist Schering AG, Berlin, Germany). Vascular architecture of the lesions was categorized into five different patterns. Results: Power Doppler ultrasonography showed vascular structures in 25 lesions. The study enhanced with Levovist showed vascularity in eight of 16 lesions not seen on the unenhanced study. The characterization of vascular patterns with unenhanced power Doppler ultrasonography improved diagnostic accuracy compared with gray-scale ultrasonography (59% vs. 32%). The combination of B mode and power Doppler produced even greater diagnostic accuracy (78%), independent of the administration of echo-enhancing agent. Levovist administration was useful in the differential diagnosis between pseudotumor and neoplasm. Conclusion: The use of songraphic contrast agent did not increase the diagnostic accuracy of power Doppler in the differential diagnosis of hyperechoic renal lesions but was advantageous for the characterization of suspected pseudomasses.

Prenatal testicular torsion: ultrasonographic features, management and histopathological findings.

Aim:  To highlight the ultrasonographic features of prenatal torsion of the testis in utero (IUTT) at presentation, the neonatal management and the histological findings postorchiectomy or biopsy.

Potential role of colour-Doppler cystosonography with echocontrast in the screening and follow-up of vesicoureteral reflux.

Primary vesicoureteral reflux is a predisposing factor for urinary tract infections in children. The first‐choice technique for the diagnosis of vesicoureteral reflux is voiding cystourethrography, followed by cystoscintigraphy; cystoscintigraphy, however, has the advantage of only minor irradiation of the patient, but it does not allow the morphological evaluation of bladder and vesicoureteral reflux grading. Colour‐Doppler cystosonography with echocontrast is a recently introduced method for imaging vesicoureteral reflux. The aim of our study is to evaluate the role of colour‐Doppler cystosonography with echocontrast in the diagnosis of vesicoureteral reflux. Twenty children (11M, 9F) aged between 0.4 and 4.9 y underwent colour‐Doppler cystosonography using a diluted solution of Levovist® (Schering, Germany), after filling up the bladder with saline. In all patients, vesicoureteral reflux diagnosis and grading had been performed previously by voiding cystourethrography within 5 d from ultrasonography. Our data showed high accuracy in the detection of medium to severe vesicoureteral reflux (grades III‐V), confirmed by radiological features in 9/9 patients. Conversely, in the 11 patients with mild vesicoureteral reflux (grades I‐II), this technique showed extremely low sensitivity, allowing diagnosis in only four cases.

Vesicoureteral reflux: comparison between urosonography and radionuclide cystography

Our aim was to compare contrast-enhanced color Doppler voiding urosonography (VUS) and direct radionuclide voiding cystography (DRVC) to determine the usefulness of ultrasonography (US) in the detection and grading of vesicoureteral reflux (VUR). In this study, the two techniques were performed simultaneously on a group of 64 children referred for the evaluation of VUR. DRVC detected VUR in 54/128 ureterorenal units, and VUS confirmed reflux in 44 (81%). Only in two cases was the reflux not confirmed by DRVC (97% specificity). Ten units with minimal grade I VUR detected by DRVC were not identified by VUS. For identification of grade II and III reflux, sensitivity of VUS reached 100%. Ten units with grade I VUR at DRVC presented grade II at VUS. Eleven units with grade II VUR at DRVC presented grade III at VUS. In conclusion, contrast-enhanced VUS is a useful diagnostic tool for the detection of VUR in children. Our data suggest a higher diagnostic accuracy of urosonography compared to radionuclide cystography in the determination of the grade of VUR; this may have significant consequences on the management of young patients affected by VUR.

Contrast-enhanced ultrasonography (voiding urosonography) of vesicoureteral reflux: State of the art

Three methods are currently used to identify vesicoureteral reflux (VUR) in children, namely, radiographic voiding cystourethrography, radionuclide voiding cystography and, more recently, echo-enhanced voiding urosonography (VUS). Recent advances in tissue-harmonic and contrast-specific imaging techniques, together with the development of second-generation contrast agents, have improved the potential of ultrasonography both in the diagnosis and grading of VUR in children. Today, VUS is able to accurately assess the grade of reflux and the state of the urethra, previously considered fundamental limitations to the extensive use of this technique. The aim of our paper is to review the role of ultrasonography in the diagnosis of VUR, from the initial experiences up to the recent use of second-generation microbubbles combined with contrast-specific low-mechanical-index software. We discuss the advantages and limits of VUS with respect to radiographic and radionuclide imaging in the light of an analysis of the most recent literature, and we described the new VUS study technique using second-generation contrast media. Growing requests by paediatric nephrologists and surgeons require that even general radiologists become familiar with this technique.RiassuntoLa diagnostica per immagini del reflusso vescico-ureterale (RVU) si avvale oggi di tre metodiche: la uretrocistografia minzionale, la cistoscintigrafia diretta e, più recentemente, la urosonografia con mezzo di contrasto (VUS). Il recente sviluppo tecnologico dell’imaging armonico tissutale e contrasto-specifico, unitamente alla disponibilità di mezzi di contrasto ecografici di seconda generazione, ha comportato un significativo miglioramento della ecografia nella diagnosi e nella stadiazione in gradi del RVU. Oggi la VUS consente un’accurata stadiazione in gradi del reflusso ed una valutazione dello stato dell’uretra, in passato considerate le principali limitazioni all’uso estensivo della metodica. Lo scopo di questo lavoro è quello di rivisitare il ruolo dell’ecografia nella diagnosi del RVU dalle esperienze iniziali sino ai più recenti sviluppi tecnologici costituiti dall’impiego di microbolle di ultima generazione accoppiato a sistemi contrasto-specifici a basso indice meccanico. Vengono discussi i vantaggi ed i limiti della VUS rispetto alle metodiche radiografica e radioisotopica, anche alla luce dell’analisi della più recente letteratura e viene descritta la tecnica di studio VUS con contrasto di ultima generazione. Considerata la crescente domanda da parte di nefrologi e chirurghi pediatri, riteniamo utile che anche il radiologo generale acquisisca familiarità con questa nuova tecnica.

US power Doppler of hepatic angiomyolipoma with low fat content.

Hepatic angiomyolipoma (AML) is a rare tumor containing a variable amount of fat. Angiomyolipoma prevalently constituted by vessels can be difficult to differentiate from other hypervascular hepatic tumors containing a small amount of fat. We describe US power Doppler findings in a case of hepatic AML with minimal fat content.

Intrahepatic portal vein aneurysm: three-dimensional power Doppler demonstration in four cases.

Wedescribe four cases of portal vein aneurysm that were studied with ultrasonography, color Doppler, computed tomography, and magnetic resonance imaging as well as three-dimensional power Doppler. Three-dimensional ultrasonography showed the portal aneurysm and its relationship to its portal branches in all patients and showed the portosystemic communication in three. In all cases, computed tomography or magnetic resonance imaging confirmed the three-dimensional ultrasonographic findings.

Virological profiles in hepatitis B virus inactive carriers: monthly evaluation in 1-year follow-up study

Abstract: Study subject: We longitudinally evaluated the virological behaviour and the hepatitis B virus (HBV) genomic variability in inactive HBV surface antigen (HBsAg) chronic carriers.

Bone scan in patient with horseshoe-kidney mimicking skeletal lumbar metastasis.

A 66-year-old man with prostatism had Tc-99m MDP bone scintigraphy that showed, on anterior imaging, increased uptake in the lumbar spine, suggestive of a skeletal metastasis of L3. Additional SPECT imaging demonstrated that focal radionuclide accumulation was located anterior to the spine and was interpreted as the bridge of functioning renal tissue in a horseshoe-kidney. This diagnosis was confirmed by ultrasonography and pyelography.