Can we renounce performing the intravenous urography in the preoperative evaluation for ESWL treatment?

OBJECTIVE: Our aim was to perform a comparative study between IVP (Intra Venous Pyelography) and Doppler US (Ultras Sound) in assessing the normal renal function. The US assessment of the normal renal function consisted in the evaluation of ureteral flux. MATERIALS AND METHODS: The group of patients consisted in 79 patients with small size urinary stones (5-12 mm). Among them, 58 patients had pelvic stones and 21 patients had ureteral stones. The ultrasound system used in our study was a B&K Medical Panther 2002 equipped with a 3.5 MHz transducer. RESULTS: The sensibility in detecting ureteral flux in patients with pelvic stones and normal IVP was 100%. The sensibility in detecting uretheral flux in ureteral stones with IVP aspect of hydronephrosis was 65%. CONCLUSIONS: In cases of normal aspect of IVP the presence of uretheral flux assessed by ultrasound could substitute the IVP in the preoperative evaluation for ESWL treatment. In cases of hydronephrotic aspect of IVP, the concordance between results based on IVP and those based on Doppler US in good enough for proposing the Doppler US evaluation of renal function in obstructive stones as a new diagnostic imaging modality. Doppler US could be the method of choice for renal function pre ESWL evaluation mainly for patients with known intolerance to contrast media.

US and MRI in renal obstruction evaluation.

OBJECTIVE: To explore the renal obstruction using MRI (Magnetic Resonance Imaging) for anatomical evaluation and Doppler US (Ultra Sound) for functional evaluation. MATERIALS AND METHODS: Thirty-two patients with renal obstruction were investigated. The presence of renal obstruction was subsequently established by excretory urography or surgery. US studies were performed using a B&K Medical ultrasound system Panther 2002 equipped with 3 Mhz transducer. MR urography was done with a magnetic resonance imaging system 0.28T, Tomikon R28-Bruker, Germany. RESULTS: All 30 patients presented increased renal vascular resistance as determined by US evaluation (Resistive Index = 0.74 +/- 0.02). The MR urography proved dilated urinary collecting system in only 20 patients of the group. CONCLUSIONS: Doppler US has a very good sensitivity in detecting the renal obstruction before the dilatation of the collecting system be installed. Used together these methods (US and MR urography) are important for proving anatomical as well as functional changes in renal obstruction. Both methods could be useful mainly in patients with known intolerance to contrast media.