CT of kidney stone disease
Revision as of 19:20, 5 December 2018 by Mikael Häggström (talk | contribs) (→Further evaluation in presence of stones: simplified)
Author:
Mikael Häggström [notes 1]
This article deals with acute kidney stone disease. For non-emergent exams, see CT in recurrent kidney stone disease.
Contents
Planning
Need for imaging
Imaging is indicated in cases of flank pain and hematuria.[1]
Choice of modality
File:Algorithm for kidney stone disease.png
Algorithm for kidney stone disease, developed in the US.[2]
- Ultrasonography of kidney stone disease is the first-line imaging modality for patients <14 years of age and those who are pregnant. It is also the first-line investigation for thin (BMI <30) patients and there is a strong suspicion of kidney stone disease.[1] In the algorithm at right, hydronephrosis may count as a diagnostic finding of urolithiasis.
- CT of kidney stone disease is recommended for older patients, as well as those who have higher BMI and/or less specific findings.[1]
Configuration
CT without IV contrast, with low to normal radiation dose as per algorithm at right.
Evaluation
Objectives of the evaluation are mainly:[3]
- Presence of stones within the urinary tract
- Also compare to previous CTs if there is any passage of previous stones.
- Complications such as hydronephrosis (See: Hydronephrosis)
Further evaluation in presence of stones
- Measure the size of stones. Proper sizing of a stone is important at around 5 mm and above, since smaller stones generally pass spontaneously.[notes 2] Sizing of larger stones is also important in order to decide which treatment to choose.[notes 3]
- Assess the stone burden in the kidneys
- 3mmstone.png
CT without contrast, showing a 3-mm stone (marked by an arrow) in the left proximal ureter
- CT measurement of kidney stone in soft tissue and bone window.jpg
Measurement of a 5.6 mm large kidney stone in soft tissue window (at left, with width of 400 HU, and center at 50 HU) versus skeletal window (right, W1800,C400). 145 HU is regarded as an appropriate cutoff to distinguish a stone from surrounding tissue.[4]
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.
- ↑ Ureteric stones less than 5 mm in diameter pass spontaneously in up to 98% of cases, while those measuring 5 to 10 in diameter pass spontaneously in less than 53% of cases.
- Gettman, MT; Segura, JW (2005). "Management of ureteric stones: Issues and controversies ". British Journal of Urology International 95 (Supplement 2): 85–93. doi:. PMID 15720341. - ↑ Small proximal ureteral calculi of less than 10 mm are best treated with shock wave lithotripsy and ureteroscopy, while those larger than 10 mm are best treated with flexible ureteroscopy combined with holmium laser lithotripsy.
- Glenn M Preminger, Section Editors:Stanley Goldfarb, Michael P O'Leary. Deputy Editor:Albert Q Lam (2018-01-19). Management of ureteral calculi. UpToDate.
References
- ↑ 1.0 1.1 1.2 Brisbane, Wayne; Bailey, Michael R.; Sorensen, Mathew D. (2016). "An overview of kidney stone imaging techniques ". Nature Reviews Urology 13 (11): 654–662. doi:. ISSN 1759-4812.
- ↑ Brisbane, Wayne; Bailey, Michael R.; Sorensen, Mathew D. (2016). "An overview of kidney stone imaging techniques ". Nature Reviews Urology 13 (11): 654–662. doi:. ISSN 1759-4812.
- ↑ J Kevin Smith, Mark E Lockhart, Nicole W Berland and Philip J Kenney (2015-10-27). Urinary Calculi Imaging. Medscape.
- ↑ Lidén, Mats; Thunberg, Per; Broxvall, Mathias; Geijer, Håkan (2015). "Two- and three-dimensional CT measurements of urinary calculi length and width: a comparative study ". Acta Radiologica 56 (4): 487–492. doi:. ISSN 0284-1851.
