Special techniques Retrograde and antegrade pyelography (to define level and cause of obstruciton ) Micturating cystogram ( mainly in children for posterior urethral valve or reflux ) Urethrography ( struicture and leak ) Renal arteriography ( define anatomy , stenosis or anomaly 0

URINARY TRACT DISORDERS Urinary tract Calculi : - stones are calcified to varying degree uniform laminated -10-20% are Radiolucent : Xanthine Uric acid) - all stones are seen on CT and US

large : Staghorn calculi Shape of calculi small : round or oval large : Staghorn calculi

which one is used: Plain film or US ? if radioopaque….. plain film is better Always carefully examine preliminary film of IVU ( to see stones , calcification) Stones overly the bones may be obscured

Stones by US Appearance ( echogenic + shadow ) Size: if >5mm usually Seen Site calyces , pelvis and ureter or U. Bladder

Stones by CT Native CT exquisitely sensitive for all types Sometimes ureteric stone need contrast

Nephroclacinosis either Medullary or cortical its Focal or diffuse calcification of the renal parenchyma causes: - disturbance in calcium metabolism : Hypercalcaemia , hypercalciurea , renal tubular acidosis and hyperparathyroidism - Normal calcium metabolism: Medullar sponge kidney or widespread papillary necrosis

Urinary tract Obstruction Its Dilatation of PCS and ureter. the Degree of dilatation should be assessed ( mild , moderate , severe) Level should be assessed ( calyceal, PUJ, ureter , UVJ , bladder outlet)

US in Urinary Tract Obstruction Fluid collection in middle of central sinus Should be differentiated from cysts Cortex ? Should be measured Ureter ( usually only proximal and distal parts seen) Cause ? Stone, bladder mass, pelvic mass

Multiple para pelvic cysts DDx Multiple para pelvic cysts

IVU in obstruction In some centers remains the primary imaging modality of acute ureteric colic . Plain film : calculus After 15 min of contrast injection : if urogram normal it rules out ureteric colic as the cause of the pain

If the urinary system obstructed IVU shows : -dense nephrogram -delayed films usually necessary to seen the level of obstruction ( up to 24 hr or more) obstruction can be intermittent

CT in urinary tract obstruction In Acute obstruction ( do CT KUB) Other DDx can be diagnosed or excluded; A. Appendicitis tumor Ovarian cyst Ectopic pregnancy…

Causes of obstruction obstruction may be at any level down to the urethra Within the lumen In the wall Outside the wall

Causes within the lumen of the urinary tract Calculi Sloughed papilla Blood clot

Causes arising in the wall Transitional cell carcinoma On IVU: in PCS appear as filling defect in ureter ( filling defect or stricture) On Ct : mass forming filling defect on urographic image Stricture ( from : infective, trauma, post op.)

Congenital intrinsic PUJ obstruction Peristalsis not transmitted along this segment Age : usually in children and young adults Diagnoses : Dilated pelvis ( ballooning ) with normal ureter Should be differentiated from baggy pelvis by giving diuretic during IVU

Extrinsic causes of obstruction Best evaluated by CT : Tumors Retroperitoneal fibrosis; usually at the level of L4/5 Lymphnodes Pelvic tumor or mass

Questions?