Radiological investigation of renal colic following the introduction of CTKUB
This audit assesses appropriate investigation of first presentation acute renal colic, as well as the diagnostic yield of CTKUB scans in terms of renal calculi and alternative diagnoses.
CT-KUB is the investigation of choice when investigating acute renal colic. This is in keeping with both the Royal College of Radiologists referral guidelines (Ref.1) and the British Association of Urological Surgeon (BAUS) guidelines for acute management of first presentation of suspected acute renal colic (Ref.2)
MDCT is the most accurate investigation in suspected ureteric colic and a low-radiation-dose CT technique can be used in most cases (patients with a high BMI might not be suitable for low dose CT-KUB). However there is still a significant dose involved, and their use should be monitored to ensure that CTKUBs have a reasonable diagnostic yield and are not being used inappropriately for non-specific abdominal pain. It is also important to make sure that inappropriate repeat exams are not carried out (ie if a patient returns the week after initial diagnosis or following treatment such as ESWL – plain x-ray often all that is needed.)
1. CTKUB should be used to investigate acute renal colic unless contra-indicated. Ref.1
2. CTKUB should be performed within 24 hours of presentation. Ref. 2
3. According to published studies conducted at regional centres CTKUB should detect calculi in 44-62% of patients, with alternate diagnoses noted in a further 6-18%. Ref.3-6
1.100%
2.100%
3.Calculi in at least 44%, alternate diagnoses in at least a further 6%. Ref. 3-6
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The indicator
1. Percentage of patients presenting with renal colic who were investigated with CTKUB
2. Percentage of CTKUBs performed within 24 hours of request
3. Percentage of patients undergoing CTKUB with a) confirmed calculi ; b) alternative diagnosis ; c) no radiological diagnosis
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Data items to be collected
1. List of patients referred for investigation from A&E/surgical takes with suspected acute renal colic. (How this is obtained will depend on local coding practices.)
2. Date and time of CTKUB / IVU request form submission, if performed
3. Date and time of CTKUB scan, if performed
4. Referral information ie unilateral loin pain / haematuria/ non-specific abdominal pain
5. Positive findings of CTKUB scan
If wishing to perform subgroup analysis, you can also record the patient age and gender
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Suggested number
75 consecutive patients admitted with acute renal colic
1. Discussions with fellow radiologists, radiographers and the department manager to identify issues affecting CT scan access and capacity. Adapt clinical practice to ensure rapid patient access to CTKUB. Meeting this time target will require access to CTKUB scans at the weekend.
2. If the diagnostic yield of CTKUB is below the standard eg in young female cohort, discuss with A&E and surgical teams the possibility of requesting abdominal USS as a first line investigation in those patients with a lower probability of renal calculi to minimise radiation exposure. Review of diagnostic yield in relation to referral information may highlight referral issues. Emphasise that CTKUB is an inappropriate first line investigation for abdominal pain per se.
1. Request of list of patients referred for CTKUB /IVU / KUB plus US from A&E department/General Surgery Department (45 minutes)
2. Review of request forms to ensure referral reason was for renal colic (2 hours)
3. Review of CTKUB scan reports (2 hours)
4. Analysis (2 hours)
1. Making best use of a Department of Clinical Radiology, Guidelines for Doctors, Sixth Edition 2007, The Royal College of Radiologists, London
2. British Association of Urological Surgeons (BAUS) guidelines for acute management of first presentation of renal/ureteric lithiasis, December 2008. http://www.bauslibrary.co.uk/PDFS/BSEND/Stone_GuidelinesDec2008.pdf
3. Chowdhury FU, Kotwal S, Raghunathan G et al. Unenhanced multidetector CT (CT KUB) in the initial imaging of suspected acute renal colic: evaluating a new service. Clin Radiol. 2007 Oct;62(10):970-7.
4. Meagher T, Sukumar VP, Collingwood J, et al. Low dose computed tomography in suspected acute renal colic. Clin Radiol. 2001 Nov;56(11):873-6.
5. Greenwell TJ, Woodhams S, Denton ER, et al. One year's clinical experience with unenhanced spiral computed tomography for the assessment of acute loin pain suggestive of renal colic BJU Int. 2000 Apr;85(6):632-6.
6. Abramson S, Walders N, Applegate KE, et al. Impact in the emergency department of unenhanced CT on diagnostic confidence and therapeutic efficacy in patients with suspected renal colic: a prospective survey. Am J Roentgenol. 2000 Dec;175(6):1689-95.
It is appreciated that occasionally neither CTKUB or IVU are used as first line investigations, for example in pregnancy, and that ultrasound and AXR may be employed. However these cases are likely to be few in number and may be difficult to identify from RIS/PACS unless data collection is prospective.
Whilst the standard stated above is within 24 hours, depending on local arrangements an alternative standard might be within 4 hours if coming through A&E.
Dr. I Al-Bakir, Dr. Donald Tse, Dr. Horace D'Costa
19 February 2010