This document provides an overview of an intravenous urogram (IVU) procedure. It discusses the terminology, preparation of patients, technique and phases of an IVU, as well as the anatomy visualized through an IVU. Key points include: an IVU shows both nephrogram and pyelogram phases, while a retrograde pyelogram only shows the pyelogram; preparation such as catharsis and dehydration are no longer recommended; the technique involves contrast injection followed by imaging sequences at 1, 3, 10 and 20 minutes both supine and prone; and an IVU can visualize renal size, location, pelvis configuration, calyces, and ureteral anatomy.

1. Intravenous urogram
Sukhdev, CMC Vellore

2. Terminology
• Intravenous urogram
• Pyelogram = RGP
• Intravenous pyelogram ≠ Intravenous urogram

3. RGP vs IVU
IVU RGP
Physiological Non physiological
Nephrogram and pyelogram Only pyelogram
Subjective - depends on injected contrast’s rate and force
Possibility of infection and trauma

4. Physiological effects of IVU
• Osmolar shifts occur and so, influx of water from interstitium to blood
stream – cardiac output increases by 16%
• Peripheral vasodilatation can occur
• Chelation of calcium by the contrast – clinical tetany can occur

5. Preparation of patients
• Catharsis
• Dehydration
• Both are not recommended now
Exceptions:
• In elderly gentlemen with constipation, catharsis – oral and rectal – is
recommended

6. Rationale of dehydration
• Dehydration > ↑ ADH > ↑ water reabsorption in tubules > ↑ density
of contrast in tubules
Risks of dehydration
• AKI - Protein precipitates in tubules
• Renal vein thrombosis

7. Technique and phases
• Scout
• 1 minute film
• 3 minute film followed by ureteral compression
• Three tomograms
• 10 minute film
• 20 minute film – supine
• 20 minute film - prone

8. Scout
Is it necessary?
1.Calculi can be missed in contrast

9. 2. Skeletal abnormalities are well observed in scout
3. Intestinal gas patterns – like ileus- can be well seen
4.Foreign bodies

10. Contrast injection
• Ionic vs non ionic contrast media
• Non ionic contrast media – lesser reactions, but more expensive
Types of administration
1. Bolus
2. Drip infusion

11. Bolus:
• Average adult dose is 20-30 g of iodine
• Do not exceed 30 g
• For e.g: iohexol – 180 mg of iodine/ml
• 100-150 ml of contrast which is injected antecubitally
• Rapid injection α better nephrogram
• Slow injection α less dense nephrogram
• More iodine α more dense nephrogram
• So, nephrogram quality depends on rate and quantity of contrast injection

12. Drip infusion technique:
Advantages:
• Prolonged nephrogram
• Enhanced diuresis which distends the collecting system
• And so, ureteral compression may not be necessary
• Longer collecting system visualisation
• Easy administration
Disadvantages:
• Not advisable in cardiac patients
• False calyceal blunting due to distention
• This can lead to pyelosinus extravasation

13. Post contrast sequences
• 1 minute film
• 3 minute film followed by ureteral compression
• Three tomograms
• 10 minute film
• 20 minute film – supine
• 20 minute film - prone

14. Post contrast sequences
• Calyces fill with contrast in 20 seconds and collecting system in 2
minutes
• So, 1st film in 1 minute and the next in 3 minutes
• Compression device is then placed to compress ureters

15. With and without compression

16. Contraindications of compression:
• Ureteral calculi with obstruction
• Recent surgery
• Nephrostomy
• Severe hypertension
• AAA

17. Tomgrams
Used routinely in patients older than 40
• Average patients : 8,9,10 cm from tabletop
• Heavy patients : 9,10,11 cm from tabletop
• Lean patients : 7,8,9 cm from tabletop

18. Prone film
• Better visualisation of distal ureters
• Lesions on anterior bladder wall well seen
• Bladder hernias well seen
Rationale of a prone film:
Contrast is denser
• Upper pole is posterior than the lower pole in supine position and so,
drainage is hindered. In prone, it is reversed
• Ureters are anterior to renal pelvic plane in supine position and in prone, it
is reversed

19. SUPINE PRONE

20. Delayed films:
• May be obtained 1 hr-2 days after injection
• Valuable ONLY when nephrogram is seen but the collecting system
visualised
Erect film:
• Renal ptosis, bladder hernias, cystoscelces
• Layering of calculi in cysts
Post voiding film:
• Usually not necessary unless you need to know about residual urine

22. Renal ptosis

23. RENAL ANATOMY IN IVU

24. Renal Size
• Average in autopsy : 11.25*(5-7.5)*(2-3.5) cm
• In IVU, apparent nephromegaly due to:
1. Radiographic magnification(18%)
2. Diuresis induced nephromegaly

25. Some numbers
• Men’s kidneys longer than women’s kidneys due to larger BSA
• Average renal length = 3-4 lumbar vertebral bodies
• Right kidney 0.5 cm smaller than left kidney
• To say that a kidney is large:
1. Right kidney should be 0.5 cm larger than left
2. Left kidney should be 0.5 cm larger than right
• Respiratory excursion can occur upto 1-4 cm
• So, urograms are best done in expiratory phase, because inspiration
can kink the ureters

26. • Duplex kidneys are larger than expected by 10%

27. Renal location
• Non visualisation vs non excreting and non functional
• Right renal pelvis is at the level of L2
• Left renal pelvis is 0.5-1 cm higher

28. Variations in renal location
Cephalocaudal axis:
• Excursion of upto 2 lumbar vertebrae is normal
• DD: ectopia vs ptosis
• In ptosis, ureters will be of normal length or might be even kinked
• In ectopia, ureters are short
Coronal axis:
Lateral displaced kidney

29. Cont’d
Transverse axis
• Kidney rotated along its transverse axis to produce a ‘tennis ball’ like
rolled up kidney

30. Anatomical relationship of ureters
• Ureters are lined along tips of transverse processes
• Lateral deviation if >1.5 cm from tip of transverse process
• Medial deviation if ureter overlies the vertebral pedicle

31. Renal pelves
1. Completely intra renal
2. Completely extra renal
3. Combo of both

32. Configuration of pelvis
1. Box
2. Funnel
• In box pelvis, ureter is distinctly seen from the pelvis but not in the
funnel type pelvis

33. Bifid collecting system
• Usually in bifid collecting system,
There is single upper calyceal segment
and
Multiple lower calyceal segments

34. Calyces
• Anatomy textbooks : minor calyces > major calyces > infundibular
• Practically : calyces > infundibula

36. • Average number of calyces : 7-14
• ≥20 – polycalycosis

37. • Calyx is physiologically active
• Larger the papilla, larger is the calyx
• Smaller the papilla, smaller is the calyx

38. Larger calyces Small calyces

39. Microcalyces

40. Infundibular variations
Infundibula may be long and slender or short and stubby or blind
ending

41. 50%
35%
15%
cortex medulla sinus fat

42. The interpapillary line
• Distance between lateral cortex and
IP line should average 2.5 cm
• If <2 cm, parenchymal loss
• If >3.5 cm, renal mass lesions