THE URINARY TRACT Methods of examination

1. THE URINARY TRACT Methods of examination Plain film of the abdomen – patient in supine position, kidneys, ureteral and bladder areas. Assessment of the size, shape and position of the kidneys, the presence of calcium, psoas muscle abnormalities. IVU – i.v. injection of radioopaque contrast medium. Serial films are obtained over 25 minutes as the contrast agent is excreted by the kidneys for visualization of the renal collecting system, ureters and bladder (first film obtained after 1 minute and a second film after 5 minutes). Compression – film. Patient preparation – bowel cleansing to remove gas and fecal matter from the colon. Contraindications to injection of i.v. contrast medium : - hypersensitivity to the contrast agent - renal and hepatic disease - asthma - a serum creatinine level higher than 1,5 – 1,8 mg/100ml - multiple myeloma - history of severe allergy

5. US CT MRI Retrograde pyelography – cystoscopy and catheterization of the ureters are necessary. Antegrade pyelography – a needle is placed percutaneously into the renal pelvis from a posterolateral approach and either fluoroscopic or ultrasonic guidance is used. Conventional percutaneous nephrostomy, brush biopsy, stent placement, stone dissolution or extraction, dilation of stenosis can be performed Renal angiography – first global aortography followed by selective renal artery catheterization. Used for renal angioplasty/stenting and renal embolization. Cystography – a urethral catheter is inserted and the bladder is filled with contrast medium. Indications: bladder rupture, tumors, diverticula. Renal scintigraphy – 99Tc. Indication – renal function.

14. Anomalies in number Renal agenesis – single kidney. Method of choice – angiography. Supernumerary kidney –the anomalous kidney is small - the other kidney on the same side is often smaller than the normal kidney on the opposite side. - demonstration of the presence of a separate pelvis, ureter and blood supply is necessary for the diagnosis.

16. Anomalies in size and form • Hypoplasia • – usually associated with hyperplasia on the other side. • The hypoplastic kidney functions normally. • the collecting system is small • there is a normal relation between the amount of parenchyma and the size of calices and renal pelvis. • Differentiai diagnosis - acquired atrophic kidney – small kidney because of vascular or inflammatory disease.

17. Anomalies in size and form • Hyperplasia – is associated with agenesis or hypoplasia • on the opposite side • - more properly termed compensatory hypertrophy. • Conditions that usually cause bilateral renal enlargement: • acute glomerulonephritis, • lymphoma, leukemia in children, • systemic lupus erithematosus, • polycystic disease, • bilateral renal vein thrombosis, • amyloidosis, • sarcoidosis, • lobular glomerulonephritis, • total lipodystrophy.

20. Fusion anomalies • Horseshoe kidney – the lower poles of the kidney are joined by a band of soft tissue, the isthmus. • the long axis of the kidney is reversed  the lower pole is nearer the midline than the upper. • associated rotation anomaly  the calyces are directed backward or posteromedially. • the ureters tend to be streched over the isthmus  partial obstruction is not unusual dilation of the pelvis and calyces. • Crossed ectopy – fusion of the kidneys on the same side; • - the lower kidney is ectopic and its ureter crosses the midline to enter the bladder normally on the opposite side.

24. Anomalies in position Ectopy – pelvis, thorax Nephroptosis – downward displacement and more mobility of the kidney than usual. Malrotation – results from incomplete or excessive rotation and urographic study indicates the degree of anomaly.

26. PA

27. Anomalies of the renal pelvis and ureter Ureteropelvic junction anomalies – bilateral but not always simmetrical. Duplication of the pelvis and ureter Retrocaval ureter – is limited to the right side. - The ureter passes to the left behind the IVC. Ureterocele – intravesical dilation of the ureter immediately proximal to its orifice in the bladder. - resembles a cobra head in shape. - When the ureterocele is not filled with contrast - radiolucent mass within the opacified bladder in the region of the ureteral orifice. - If it is filled, the lesion is outlined by a radiolucent wall that stands out in contrast to the filled bladder and to the filled, dilated, distal ureter. Ureteral diverticula

29. OBSTRUCTIVE UROPATHY Nonobstructive hydronephrosis – diabetes, - infections, - appendicitis, peritonitis Congenital hydronephrosis – obstruction at the UPJ, - vesicoureteral reflux, - congenital ureterocele, - urethral valves, congenital strictures. Acquired hydronephrosis – tumors, - calculi, - strictures, - radiation therapy, - surgery, - prostatic enlargement, - pregnancy in the third trimester.

30. OBSTRUCTIVE UROPATHY • Imaging findings • US method of first choice to evaluate patients with suspected hydronephrosis (mild, moderate, severe). • CT + i.v.contrast medium – useful to assess the cause of obstruction. • Urography • – early : flattening of the normal concavity of the calyx + decrease in the rate of contrast material accumulating in the collecting system. • Calyces then gradually enlarge with progressive destruction of parenchyma. • A prolonged and increasingly dense nephrogram is characteristic of acute renal obstruction. • In severe cases do percutaneous nephrostomy.

33. T

36. CALCULI Incidence – 5% of population; 20% at autopsy. Recurrence of stone disease – 50%. Predisposing conditions – calyceal diverticuli, renal tubular acidosis, hypercalcemia, hypercalciuria. The radiographic density of a calculus depends on its calcium contents: - Calcium calculi (opaque) 75% - calcium oxalate andphosphate. - Struvite calculi (opaque) 15% - magnesium ammonium phosphate:”infection stones”; - Cystine calculi (less opaque) – cystinuria. - Nonopaque calculi – uric acid, xanthine, mucoprotein matrix calculi in poorly functioning, infected urinary tract.

37. Radiographic features Calculus - determine size, number, location Radioopaque calculus are best detected on KUB or helical CT Radiolucent calculi are best detected by IVU US – renal calculi - hyperechoic focus, posterior shadowing IVU - Delayed and persistent nephrogram  ureteral obstruction - Ureter distal to calculus is narrowed (edema, inflammation), may create false impression of stricture - Ureter proximal to calculus is persistently minimally dilated CT - detects most calculi regardless of calcium content - Helical CT is very useful to detect small calculi

38. Location – 3 narrow sites: • UPJ, at crossing of ureter with iliac vessels, UVJ • Complications: • - Forniceal rupture (pyelosinus backflow) • - Chronic calculous pyelonephritis • - XGP • Treatment options: • Small renal calculi ( 2,5cm) – ESWL • (extracorporeal shock wave lithotripsy) • - Large renal calculi ( 2,5 cm) – percutaneous removal • Upper ureteral calculi – ESWL • Lower ureteral calculi – ureteroscopy • Differential diagnosis • - Gallstones • - Calcification of costal cartilage • - Calcified mesenteric nodes • - Calcifications in cysts and tumors • - Vascular calcification

39. Staghorn calculus

43. URINARY TRACT INFECTION Acute pyelonephritis Acute bacterial infection of the kidney and urinary tract – Proteus, Klebsiella, E.Coli Types - focal type – lobar nephronia - diffuse type – more severe and extensive Role of imaging studies: - Define underlying pathology – obstruction, reflux, calculus - Rule out complications – abscess, emphisematous pyelonephritis Radiographic features US - renal enlargement (edema) - loss of corticomedullary differentiation (edema) - IVU – delay of contrast excretion, narrowing of collecting system, striated nephrogram, - CT - areas of decreased perfusion by

44. Chronic pyelonephritis • Criteria for diagnosis: • - Scarring - can affect the entire thickness of renal substance the involved papilla is retracted  secondary dilation of its calyx • the involved area irregular surface depression • The dilated calyx - smooth margin, variable shape • Renal tissue adjacent to the involved area is normal or hypertrophied • unifocal or multifocal, one or both kidneys • decreased size of the involved kidney

46. RENAL ABSCESS Usually caused by gram negative bacteria. Underlying disease – calculi, obstruction, diabetes, AIDS. Radiographic features Well-delineated focal renal lesion Central necrosis Thickened abscess wall with contrast enhancement Perinephric inflammatory involvement Complications: retroperitoneal spread of abscess, renocolic fistula

48. TUBERCULOSIS GU tract is the second most common site of TB involvement after the lung.The disease is typically due to hematogeneous spread. Clinical – history of pulmonary TB, pyuria, hematuria, dysuria Radiographic features Distribution – unilateral involvement is more common – 70% Size – early- kidneys are enlarged - late- the kidneys are small, autonephrectomy Parenchyma - calcifications –curvilinear, mottled, amorphous - Papillary necrosis, parenchymal cavity - Tuberculoma - Parenchymal scarring Collecting system - infundibular stenosis - amputated calyx - Corkscrew ureter – multiple stenosis - “pipestem” ureter - narrow, rigid, aperistaltic segment