Prevalence of alternative diagnoses in patients with suspected uncomplicated renal colic undergoing computed tomography: a prospective study

Abstract

Objectives: Unenhanced computed tomography (CT) has become a standard imaging technique for uncomplicated renal colic in many countries. The appropriate timing of CT imaging has not been established, and guidelines recommend that this imaging be performed between 1 and 7 days of presentation. The primary objective of this study was to determine the prevalence of alternative diagnosis identified with low-dose unenhanced CT in the emergency department (ED) in patients with suspected uncomplicated renal colic. Methods: This prospective single-centre study was carried out in a large university hospital ED. Over a 6-month period, all patients with clinically diagnosed renal colic and a plan to be discharged underwent low-dose unenhanced CT in the ED. Pregnant women, women of childbearing age not willing to have a pregnancy test, and patients who had already undergone diagnostic imaging were excluded. The primary outcome was the number and nature of the alternative diagnosis. Univariate analyses were performed to assess factors associated with the primary outcome. Results: A total of 178 patients were screened, and 155 underwent CT in the ED. The mean age was 42.2 years; 69% were male. The diagnosis of uncomplicated renal colic was confirmed in 118 participants (76%); 27 (17%) had an inconclusive CT scan. Overall, 10 patients (6%; 95% confidence interval [CI] 3-10) had an alternative diagnosis, 5 of whom were subsequently hospitalized. Conclusion: Low-dose unenhanced CT in the ED detects alternative diagnoses in 6% (95% CI 3-10) of patients with suspected uncomplicated renal colic, half of whom are subsequently hospitalized. Our prospective findings, which were similar to those reported in retrospective studies, are a potential argument for a systematic approach to ED imaging in suspected renal colic. Future research involving intervention and control groups would be helpful. RÉ SUMÉObjectif: La tomodensitomé trie (TDM) sans densification est devenue, dans de nombreux pays, une technique d'imagerie courante dans les cas de colique né phré tique sans complications. Toutefois, le moment propice pour faire passer cet examen n'est pas é tabli, et, d'aprè s les lignes directrices, l'examen devrait ê tre effectué entre le premier et le septiè me jour de la consultation. L'é tude avait pour objectif principal de dé terminer la pré valence d'autres diagnostics que celui de colique né phré tique sans complications, posé s dans des cas pré sumé s, à l'aide de la TDM sans densification à faible dose, au service des urgences (SU). Mé thode: Il s'agit d'une é tude prospective, unicentrique, qui a é té mené e dans un SU d'un important centre hospitalier universitaire. Sur une pé riode de 6 mois, tous les patients chez qui un diagnostic clinique de colique né phré tique avait é té posé et pour lesquels la sortie é tait pré vue ont passé une TDM sans densification à faible dose au SU. Les femmes enceintes, celles en â ge de procré er qui ne souhaitaient pas passer un test de grossesse et les patients qui avaient dé jà subi de...

Low-Dose (10%) Computed Tomography May Be Inferior to Standard-Dose CT in the Evaluation of Acute Renal Colic in the Emergency Room Setting

“…Poletti et al reported the same detection rate of alternative diagnosis in their series, 8 but it is more common that LDCT reports lower rates of detection for alternative diagnosis. 7–9 , 14 , 15 Nonetheless, imaging to evaluate nephrolithiasis does not require evaluation of alternate soft tissue diagnoses, for example, the use of KUB X-rays for renal stones.…”

Management of urinary stone disease in general practice: A French Delphi study

“…This is in accordance with most of the existing guidelines, [9][10][11][12][13] probably because CT can eliminate most of the alternative diagnoses and shows better diagnostic performances. [17] However, in a recent large multicentre randomized trial, Smith-Bindman et al found that initial ultrasonography for suspected renal colic was associated with lower cumulative radiation exposure than initial CT without significant differences in missing high-risk diagnoses, which emphasizes that controversies regarding this question are still ongoing. [18] Analgesics…”

Imaging patients with renal colic—consider ultrasound first

“…However, most hospitals do not have this technology, which in addition has very limited usefulness in case of ureteral stones. CT can identify the presence and size of stones with a very high accuracy of >95 % and is able to detect alternative diagnoses that simulate renal colic in 5–10 % of patients [ 16 , 17 ]. Nonetheless, in spite of its high accuracy, there is increasing concern about the increase of health care costs and radiation risk that accompanies CT scans, since the use of CT rarely changes the treatment plans of these patients [ 18 ].…”