The diagnostic yield of computed tomography in the management of acute flank pain and the emergency intervention rate for a proven acute ureteric stone

Abstract

Introduction The diagnostic and management pathways for patients presenting with acute flank pain are complex. Although computed tomography (CT) of the kidneys, ureters and bladder (KUB) is the gold standard investigation for urolithiasis, the multitude of differential diagnoses must also be considered in the context of long-term risk from ionising radiation. This study investigated the integrated role and diagnostic yield of non-contrast CT in cases of acute flank pain. Methods A retrospective cohort study was undertaken of 1,442 consecutive patients investigated with CT KUB between March 2013 and February 2015. The primary outcome was diagnostic yield of CT with secondary outcomes being predictors of need for urological intervention. Results A cause for acute flank pain was identified in 717 patients (50%), there was an incidental finding in 389 patients (27%) and normal imaging was reported in 336 patients (23%). A diagnosis was more commonly made in male than in female patients (70% vs 40%) and with increasing age (46% in patients aged <30 years, 56% in those aged 30–49 years and 63% in those aged ≥50 years). The overall rate for an ipsilateral urinary tract stone was 41%. Factors strongly associated with emergency intervention included stone size >10mm (odds ratio [OR]: 11.7, 95% confidence interval [CI]: 3.3–42.7), stones located at the pelviureteric junction (OR: 7.8, 95% CI: 2.6–22.9), C-reactive protein >50mg/l and ≤100mg/l (OR: 15.2, 95% CI: 5.1–45.3), and estimated glomerular filtration rate ≤30ml/min (OR: 5.8, 95% CI: 1.5–21.8). Conclusions This contemporary study identifies age and sex as independent variables affecting the diagnostic yield of CT KUB in cases of acute flank pain, and highlights factors associated with a need for emergency intervention in proven ureteric stones.

Evaluation, management, and analysis of demographic and radiological characteristics of patients with renal colic at a tertiary hospital in Somalia

“…We found that ultrasound has a high positive rate for ureteral stone detection in 79% of the cases, although detection of ureteral stones less than 5mm in size was 70%. Ultrasound revealed a false negative in stone locations for ureterovesical junction [19] , 14 in distal ureteral stone, six in the mid ureter, and three in the upper ureter.…”

“…Female patients are at the highest risk for developing solid cancer from exposure to ionizing radiation [19] . Ultrasound investigation for flank pain may be relevant to minimize radiation risk.…”

“…Young female cases presenting with flank pain pose a particular diagnostic challenge. Likewise, the significant percentage of negative investigations in females suggests a possibility for revision in the current criteria for using CT KUB [19] .…”

Diagnostic Accuracy of Non-Contrast Computed Tomography in Identification of Renal Calculi in Suspected Patients with Negative Intravenous Pyelogram

“…Recent advancements have introduced low-dose NCCT scanning protocols for detecting urolithiasis/nephrolithiasis, balancing diagnostic efficacy with reduced radiation exposure (8,9). Given the high sensitivity and specificity of NCCT-reported to be between 95-98% and 96-100%, respectively-our hypothesis is that NCCT can accurately detect and measure stones that may be missed by IVP in patients presenting with urolithiasis symptoms (10). This study aims to address the limitations of IVP by using NCCT to accurately diagnose urolithiasis/nephrolithiasis in symptomatic patients who had negative IVP results.…”