Acute infections of the upper urinary tract

Acute pyelonephritis: Acute pyelonephritis: - usually bacterial ( ascending) - usually bacterial ( ascending) - usually there is predisposing factor: - usually there is predisposing factor: stone stone duplex systems + reflux or obst. duplex systems + reflux or obst. obstructive lesions obstructive lesions DM DM - in Adults only selected patients need imaging - in Adults only selected patients need imaging

If associated with pain and not response to simple measures ………..imaging If associated with pain and not response to simple measures ………..imaging US and Plain film ‘’ stone, obstruction, abscess formation) US and Plain film ‘’ stone, obstruction, abscess formation)

US features of acute infection Normal Normal Diffuse or focal swelling of the kidney + decrease echogenisity. Diffuse or focal swelling of the kidney + decrease echogenisity. If pain sever, IVU or CT KUB …. Stone If pain sever, IVU or CT KUB …. Stone

Following resolution of acute episode, imaging is done in : Following resolution of acute episode, imaging is done in : - women with recurrent UTI. - women with recurrent UTI. - Men : after single confirmed UTI. - Men : after single confirmed UTI. - US of kidneys ….. Stone, obstruction - US of kidneys ….. Stone, obstruction UB … full bladder for stone or mass UB … full bladder for stone or mass Post voiding …..residual urine Post voiding …..residual urine

children Investigation of the renal tract is indicated in all children with a confirmed UTI. Investigation of the renal tract is indicated in all children with a confirmed UTI. US: size, stone, scarring, US: size, stone, scarring, hydronephrosis and hyroureter hydronephrosis and hyroureter Bladder for residual urine Bladder for residual urine Micturating cystography : usually in Micturating cystography : usually in male……….reflux, urethral valve male……….reflux, urethral valve

Renal and Perinephric abscess Usually by US or CT Intrarenal abscesses ; Intrarenal abscesses ; - thick wall, both cystic and solid component - thick wall, both cystic and solid component - but may look like a simple cyst - but may look like a simple cyst -enhancement of the wall in CT -enhancement of the wall in CT simple cyst may become infected …thicker wall with layered debris. simple cyst may become infected …thicker wall with layered debris.

Perinephric abscess : Perinephric abscess : -take the shape of the kidney -take the shape of the kidney - contains solid and cystic parts with debris - contains solid and cystic parts with debris - usually origin form the kidney, so look for renal abnormalities. - usually origin form the kidney, so look for renal abnormalities.

Pyonephrosis Occur only in obstructed systems. Occur only in obstructed systems. Usually Dx by US : demonstrated obstruted system containing echogenic debris Usually Dx by US : demonstrated obstruted system containing echogenic debris

Tuberculosis Blood borne of Mycobacterium tuberculosis, usually from a focus of infection from the lung Blood borne of Mycobacterium tuberculosis, usually from a focus of infection from the lung Usually starts from cortex, then tubels and to other portions of UT. Usually starts from cortex, then tubels and to other portions of UT. Early US and IVU may be normal Early US and IVU may be normal

Later stages best seen on IVU : Later stages best seen on IVU : - earliest change is irregularity of calyx then become a cavity. - earliest change is irregularity of calyx then become a cavity. - calcification are common ( irregular. may involve all the kidney “ autonephrectomy” ). - calcification are common ( irregular. may involve all the kidney “ autonephrectomy” ). -stricture at any part with dilatation, usually multiple -stricture at any part with dilatation, usually multiple - Irregular, thick wall, small volume Bladder. - Irregular, thick wall, small volume Bladder. - multiple urethral stricture. - multiple urethral stricture.

Chronic pyelonephritis ( reflux nephropathy ) Is late appearance of focal or diffuse scarring of the kidney from reflux of infected urine. Is late appearance of focal or diffuse scarring of the kidney from reflux of infected urine. Most damage occur in the 1st years of life. Most damage occur in the 1st years of life. Severity of reflux diminish with age. Severity of reflux diminish with age. Usually bilateral and asymmetrical. Usually bilateral and asymmetrical.

Image finding in reflux: Scar formation ( local reduction in renal paranchymal width ) usually in upper and lower poles. Scar formation ( local reduction in renal paranchymal width ) usually in upper and lower poles. Dilatation of calices in the scarred areas. Dilatation of calices in the scarred areas. Overall reduction in renal size: loss and no growth of the paranchyma Overall reduction in renal size: loss and no growth of the paranchyma Dilatation of the affected collecting system Dilatation of the affected collecting system Best confirmation is by voiding cystography Best confirmation is by voiding cystography

Papillary Necrosis Part or all of the renal papilla sloughs and may fall into the PCS. Part or all of the renal papilla sloughs and may fall into the PCS. May cause obstruction or appear as filling defect. May cause obstruction or appear as filling defect. Associated condition: Associated condition: - high anelgesic intake - high anelgesic intake - DM - DM - Sickle cell disease - Sickle cell disease - infection ( sever, with obstruction) - infection ( sever, with obstruction)

Imaging findings Usually by IVU, although CT uroghraphy may demonstrate it Usually by IVU, although CT uroghraphy may demonstrate it Usually patchy in distribution and severity Usually patchy in distribution and severity Contrast seen around or into the papilla Contrast seen around or into the papilla If papilla sloughed, calyx appear spherical If papilla sloughed, calyx appear spherical May be seen as filling defect or causing obstruction. May be seen as filling defect or causing obstruction. It may calcify. It may calcify.

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