Intravenous urography
Updates to Article Attributes
Intravenous urography (IVU), also referred to as intravenous pyelography (IVP) or excretory urography (EU), is a radiographic study of the renal parenchyma, pelvicalyceal system, ureters and the urinary bladder. This exam has been largely replaced by CT urography.
Terminology
Some prefer the more accurate term "urogram" to refer to visualisation of the kidney parenchyma, calyces, and pelvis after intravenous injection of contrast, and reserve the term "pyelogram" to retrograde studies involving the collecting system. In practice, both terms are often used interchangeably.
Procedure
Indications
check for normal function of kidneys
check for anatomical variants or congenital anomalies (e.g. horse-shoe kidney)
check the course of the ureters
detect and localise a ureteric obstruction (urolithiasis)
assess for synchronous upper tract disease in those with bladder transitional cell carcinoma (TCC)
Patient preparation
overnight fasting for 5 hours prior to the date of examination; a laxative is not necessary for bowel preparation as it does not improve image quality 4
on the day of the procedure take a control radiograph to check for radiopaque calculi which may be obscured by the contrast medium
check eGFR (as per hospital guidelines)
take a history of the patient for any known drug allergies followed by written informed consent for the procedure
emergency medications and emergency equipment must always be available in case the patient has a reaction to contrast
Technique
Exposures are ideally in the 65-75 kV range to optimise radiographic contrast, mA of 600-1000, with exposure time of <0.1 sec.
There are a number of techniques for IVU examinations. One is suggested below:
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IV access is required for administration of a water-soluble contrast
nonionic contrast is preferred
dose will vary as per the weight of the patient; generally up to 1.5 ml/kg body weight is well tolerated by patient
the contrast
dosemedium isusually instilled atinjected through afast (bolus) ratewide bore needle4AP film at 2 minutes for the nephrographic phase
Linearlinear tomography is used to see the renal outlines more clearlyAtat 3 minutes contrast medium normally starts to appear in the calicesat 5 minutes
to look for any obstructions inthepelvicalyceal systemcalices are normally seen4if there is no obstruction or
other contraindications, thencontraindication a compression bandiscan be appliedtoover thepatient at the anterior superior iliac spineslower abdomen tocompress the ureters at the pelvic brim and producecause pelvicalycealdistensionsdistension4-
at 10 minutes, the pelvicalyceal system should be adequately distended for imaging
if the pelvicalyceal system is not adequately distended, compression should be checked; an additional 50 mL of contrast can also be administered; after that, another AP film should be taken 4
serial images are taken at 5-20 minutes for visualisation of the pelvicalyceal systems and ureters when required and with operator preference
compression is then released and another AP film is taken to show the flow of contrast into the ureters 4
additional views taken are prone and obliques for ureters
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lastly take a full bladder and post-void film
post void film is taken to show the urinary bladder emptying
during this stage, bladder tumours, ureterovesical junction calculi, and urethral diverticulum can be seen on film 4
Compression is contraindicated in ref:
large abdominal mass
abdominal surgery (post operative)
-<li><p>the contrast dose is usually instilled at a fast (bolus) rate <sup>4</sup> </p></li>- +<li><p>the contrast medium is injected through a wide bore needle<sup>4</sup> </p></li>
-<li><p>Linear tomography is used to see the renal outlines more clearly</p></li>-<li><p>At 3 minutes contrast medium normally starts to appear in the calices</p></li>-<li><p>at 5 minutes to look for any obstructions in the pelvicalyceal system <sup>4</sup></p></li>-<li><p>if there is no obstruction or other contraindications, then a compression band is applied to the patient at the anterior superior iliac spines to compress the ureters at the pelvic brim and produce pelvicalyceal distensions <sup>4</sup></p></li>- +<li><p>linear tomography is used to see the renal outlines more clearly</p></li>
- +<li><p>at 3 minutes contrast medium normally starts to appear in the calices</p></li>
- +<li><p>at 5 minutes the calices are normally seen<sup>4</sup></p></li>
- +<li><p>if there is no obstruction or contraindication a compression band can be applied over the lower abdomen to cause pelvicalyceal distension<sup>4</sup></p></li>