1. 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

2. 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

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

5. 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

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

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

8. 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

10. 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)

11. 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

13. Multiple para pelvic cysts
DDx
Multiple para pelvic cysts

14. 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

15. 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

16. 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…

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

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

19. 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.)

20. 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

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

25. Questions?