Urinoma perirenal

Fig. 6.2a,b. Prenatal sonography in a 22-week gestational age male fetus, a Megacystis with dilated posterior urethra. Moderately dilated left kidney (not shown), b Huge dilatation of the right kidney with perirenal urinoma (courtesy of D. Eurin)... 

Perirenal urinoma (Fig. 6.2) (ascites or evenhydro-thorax) maybe present. Such fluid collections are the consequence of the rupture of calyceal fornices due to increased pressure. This has been described as the pop-off mechanism (Rittenberg 1988). However, the presence or absence of urinoma does not clearly correlate with renal function impairment. 

Fig.15.2a,b. Infected perirenal urinoma. a US of the left flank the huge urinoma contains echoes resulting from pus. b MR urography (SPIR T2 coronal sequence) showing right side ureterohydronephrosis and left huge urinoma... 

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