CT urography
Author:
Mikael Häggström [notes 1]
Contents
Planning
Indication for CT urography in hematuria
Most patients with macroscopic hematuria, especially when over 50 years, should undergo both cystoscopy and CT urography.[1]
Microscopic hematuria indicates further workup with cystoscopy and/or CT urography if there are significant underlying risk factors, mainly:[1]
- Male sex
- Age, especially being older than 60 years
- Smoking
- Pelvic radiation
Configuration
In Swedish practice,[2] the protocol is determined by age:
- In patients under 40 years, generally:
- Low-radiation-dose of urinary system, without IV contrast
- Normal-radiation-dose with split bolus IV contrast, 7.5 minutes and 90 seconds before image acquisition.
- In patients over 40 years, or younger if suspicion of cancer is high:
- Low-radiation-dose of whole abdomen, without IV contrast
- Normal-radiation-dose of whole abdomen 20 seconds after bolus tracking, for visualization of renal cortex.
- Normal-radiation-dose of upper abdomen 40 seconds after the previous, for visualization of all renal parenchyma.
- Normal-radiation-dose of urinary system 7.5 minutes after IV contrast, for renal pelvises and ureters.
Regardless of age, 1 liter water is given orally 1 hours before the CT, as well as avoiding urination during 1 hour before, in order to increase renal filtration and distend the bladder.[1] If the images show insufficient contrast filling in the renal pelvices and ureters, an additional image is taken after 5 minutes, possibly with the patient lying on the stomach to make gravity help fill the ureters.
If patient has flank pain, a CT of kidney stone disease (without IV contrast) should be done instead.
Evaluation
- CT without contrast: Look for:
Ureteral stones.
If found, see CT of kidney stone disease.
- CTs with contrast: Tumors within the kidney, ureters or bladder.
- If suspected solid renal mass, see: CT of renal tumors
- Signs of bladder tumor:
- Bladder wall thickening, which may indicate a bladder tumor, especially when nodular or irregular.[1] Look both at images 40 seconds after IV contrast and with contrast-containing bladder lumen, since that contrast may both demarcate a tumor as well as obscure one by beam-hardening artifacts.[1] In suspected bladder tumor, see CT of urinary bladder tumors
- Lymph nodes. Enlarged lymph nodes may be metastases. Generalized lymphadenopathy may indicate lymphoma, and in such cases tumors in the urinary system may be lymphomas as well.[1]
Notes
- ↑ For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Radlines:Authorship for details.
