Quantitative enhancement washout analysis of solid cortical renal masses using multidetector computed tomography.

PURPOSE: The aim of the study was to prospectively assess the utility of quantitative enhancement washout method in the differentiation of benign solid renal masses from various subtypes of malignant masses using multidetector computed tomography. METHODS: In a prospective investigation from January 2009 to May 2010, 97 patients with solid renal masses underwent CT scan examination with unenhanced, arterial, parenchymal, and delayed phases. The following features were analyzed: the maximum attenuation value in each phase, attenuation difference (enhancement) of the mass in each phase from the unenhanced phase (ΔH), and parenchymal and delayed phases' washout. Of these patients, 82 (85%) underwent unilateral radical nephrectomy, 15 (15%) underwent partial nephrectomy. Group comparison was performed with the Kruskal-Wallis test and Mann-Whitney U test. RESULTS: The masses included in our study were 45 clear cell renal cell carcinomas (CCRCCs); 18 chromophobe renal cell carcinomas, 16 papillary (PRCC), 14 oncocytomas, and 4 minimal fat containing angiomyolipomas. In the arterial phase, the CCRCC was the most enhancing type and could be differentiated from other renal masses (benign or malignant) with high sensitivity and specificity. In the parenchymal phase, the CCRCCs demonstrated the highest washout. Chromophobe renal cell carcinomas showed the second highest washout in this phase. Benign lesions and PRCCs did not exhibit significant washout in this phase. In the delayed phase, the malignant lesions (with the exception of PRCCs) showed the highest washout. Benign lesions showed significant washout but less than malignant lesions. CONCLUSIONS: Multiphasic multidetector CT utilizing arterial-phase attenuation and quantitative enhancement washout method could help in the preoperative differentiation of various types of solid renal masses.

Shock wave lithotripsy of vesical stones in patients with infravesical obstruction: an underused noninvasive approach.

OBJECTIVE: To evaluate the effectiveness and safety of shock wave lithotripsy in the management vesical stones in patients with infravesical obstruction. MATERIALS AND METHODS: From March 2007 to April 2010, 59 male patients with infravesical obstruction were treated using the Dornier Compact Delta II Lithotriptor for urinary bladder stones. The indications for shock wave lithotripsy included patients refusing invasive procedures or those with orthopedic malformations hindering the lithotomy position. The mean age was 61.6 ± 8.6 years (range 44-78), and the mean body mass index was 29 ± 5.1 kg/m(2) (range 20.5-45). The mean stone diameter was 26.6 ± 9.8 mm (range 12-50). All patients underwent an initial session and were re-evaluated using ultrasonography and urinary tract plain radiography at 2-week intervals. RESULTS: All patients were treated in the supine position. The number of shocks ranged from 1910 to 9500. Of the 59 patients, 47 and 11 were cleared by 1 or 2 sessions, respectively; 1 patient required a third session to be cleared of stones. All patients develop mild hematuria and started to pass gravel in the first void after the shock wave lithotripsy session. All patients were rendered stone free within 6 weeks. During follow-up, only 2 male patients developed temporary acute urine retention necessitating urethral catheter fixation. Both patients had a neurologic insult. CONCLUSION: Extracorporeal shock wave lithotripsy is an effective, noninvasive approach to disintegrate vesical stones in patients with infravesical obstruction with adequate fragment clearance.