CT urography

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Author: Mikael Häggström [notes 1]

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:
  1. Low-radiation-dose of urinary system, without IV contrast
  2. 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:
  1. Low-radiation-dose of whole abdomen, without IV contrast
  2. Normal-radiation-dose of whole abdomen 20 seconds after bolus tracking, for visualization of renal cortex.
  3. Normal-radiation-dose of upper abdomen 40 seconds after the previous, for visualization of all renal parenchyma.
  4. 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:
  • CTs with contrast: Tumors within the kidney, ureters or bladder.
Nodular bladder tumor.
  • 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

  1. 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.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 USA: Raman, Siva P.; Fishman, Elliot K. (2014). "Bladder Malignancies on CT: The Underrated Role of CT in Diagnosis ". American Journal of Roentgenology 203 (2): 347–354. doi:10.2214/AJR.13.12021. ISSN 0361-803X. 
  2. NU Hospital Group, Sweden, 2018