Assessment of referral patterns for CT KUB in a tertiary setting

The proportion of computed tomography kidneys, ureters and bladder (CTKUB) scans that comply with scan extent protocol in an emergency department: a clinical audit and dose ramification study

INTRODUCTION

To assess computed tomography kidneys, ureters and bladder (CTKUB) scan extent protocol compliance and associated doses in the Emergency Department (ED) of an Australian tertiary hospital.

METHODS

A retrospective clinical audit of 150 consecutive ED CTKUB cases was completed. For each patient, scan extent compliance at the superior (kidneys) and inferior (pubic symphysis) borders, in reference to the protocol was recorded. Compliance and non-compliance (over-/under-scanning) was identified, described (superior/inferior), quantified (via IMPAX measurements) and recorded via a purpose-built audit tool. In addition, a PBU40 phantom was scanned to assess the percentage of dose (DLP) increase per centimetre of over-scanning to contextualise results.

RESULTS

A notable non-compliance with department protocol was noted. Eight cases (5.3%) demonstrated overall CT scan extent compliance. The remaining 142 cases (94.7%) demonstrated some form of non-compliance; superiorly, inferiorly or both. Analysing the 150 superior and 150 inferior data points independently, the most common non-compliance was over-scanning at the kidneys by 4 cm to5 cm (19 cases, ~10% extra DLP) beyond tolerance and over-scanning inferiorly at the pubic symphysis by 1 cm to 2 cm (29 cases, ~6.4% extra DLP). Estimated dose increases of up to 35% to 45% were found when clinical audit results were simulated using a PBU40.

CONCLUSIONS

Over-scanning is a predominant occurrence in CTKUB scans in this department. Reasons for over-scanning weren't investigated. It's anticipated this audit will lead to greater awareness of scan extent compliance and dose ramifications of non-compliance. The usage of more easily identified anatomical landmarks and a follow-up audit is suggested.

Routine deferred computed tomography for patients with suspected urolithiasis is low-value healthcare

OBJECTIVE

The aim of this study was to investigate the benefits of deferred routine computed tomography of the kidneys, ureters and bladder (CT KUB) for patients with a self-limiting episode of suspected urolithiasis.

MATERIALS AND METHODS

The study comprised a case series of consecutive patients examined with deferred routine CT KUB for control of suspected urolithiasis. Patients examined with CT KUB at the University Hospital of North Norway, between 1 January 2010 and 31 December 2013, were included. The final analysis included 189 CT KUBs (response rate 48%). All data were extracted from the patient case files. The primary endpoint was the proportion of asymptomatic patients with a confirmed diagnosis of urolithiasis on CT KUB that led to surgical intervention within 1 year from the initial CT scan.

RESULTS

At the time of CT KUB, 171 patients (90%) were asymptomatic, of whom three (1.8%) were treated. Urolithiasis was confirmed on CT KUB in 23% of asymptomatic patients.

CONCLUSION

Deferred CT KUB did not alter the clinical outcome for the great majority of asymptomatic patients. The majority of patients who received adequate pain relief in primary care remained asymptomatic, and did not need specialized healthcare. Refraining from CT KUB involves little risk. Deferred CT KUB for patients with suspected urolithiasis is a low-value healthcare service.

Is CTKUB the gold standard in assessing flank pain with diagnostic uncertainty? A one-year review of 228 cases

The use of computed tomography of the kidneys, ureters and bladder (CTKUB) in a "renal colic pathway" has been reported to yield high diagnosis rates and also identifies other non-urological pathology accounting for patients’ symptoms. Our study explores the diagnostic yield of CTKUB as the first-line investigation for suspected renal colic with regard to urolithiasis and additional findings. All CTKUB performed in cases of suspected renal colic were extracted from our radiology database from 1 April 2010 to 1 April 2011. Extracted information included: demographics, the department ordering the investigation, presence of ureteric calculi, presence of renal calculi and any additional findings that could account for patients’ symptoms, or otherwise. During the study 228 CTKUB were performed. The diagnosis rate of ureteric calculi was 33.7%. In the absence of a ureteric stone, additional findings as well as alternative diagnoses were higher (additional finding 49.7% ( n=75) vs. 35% ( n=27); alternative diagnosis 33.1% ( n=50) vs. 15.6% ( n=12) p < 0.05). In patients with ureteric calculi, the alternative diagnosis yield of 15.6% falls within the range of that previously documented. This study illustrates that when diagnostic clarity is not reached, CTKUB is being overused. This leads to unnecessary radiation exposure and resource wastage.

Rationale use of unenhanced multi-detector CT (CT KUB) in evaluation of suspected renal colic

OBJECTIVE

To assess the yield of non-contrast enhanced CT (CT KUB) across different ordering specialties and need of developing an algorithm for its rationale use.

MATERIALS AND METHODS

We retrospectively reviewed 1550 consecutive CT KUB studies requested for suspected renal colic carried out at a single institution in a calendar year. The data was analyzed for demographic characteristics, referring clinician and final diagnosis. Only patients with CT as primary imaging for clinically suspected reno-ureteral colic were included. Departments ordering these CT KUB examinations were divided into three divisions: Urologist, emergency room (ER) physician and others.

RESULTS

Of 1550 CT KUB performed in the study period 766 met the inclusion criteria. Urologists (57%), followed by ER physicians (30%) mostly ordered the examination. The overall positive yield for urolithiasis was 64% (n = 490), rate of incidental/alternate findings was 15% (n = 116) and 21% (n = 160) were negative. Urologist has the highest positive yield of 67.4% (n = 295) followed by ER physician 67% (n = 152) and others 42.5% (n = 43); p < 0.001. Rate of incidental/alternate findings was highest in CT ordered by other specialties 23.7% (n = 24) followed by ER physician 17.6% (n = 40) and urologist 11.8% (n = 52); p = 0.005.

CONCLUSION

There is statistically significant difference of yield across specialties. CT KUB as an initial imaging modality for suspected urolithiasis should be ordered in consultation with the urologist and ER physicians. Tool of good history taking and physical examination has proved to be essential steps in algorithm of ordering CT KUB, which can avoid unnecessary radiation exposure.