Department of Radiology, Västerås, Sweden.
Centre for Clinical Research Uppsala University, Västerås, Sweden.
BJS Open. 2020 Aug;4(4):659-665. doi: 10.1002/bjs5.50290. Epub 2020 May 20.
The aim of this study was to evaluate the diagnostic accuracy of unenhanced low-dose CT (LDCT) in acute colonic diverticulitis in comparison with contrast-enhanced standard-dose CT (SDCT).
All patients with clinically suspected diverticulitis who underwent LDCT followed by SDCT between January and October 2017 were evaluated prospectively. CT examinations were assessed for signs of diverticulitis, complications and other differential diagnoses by three independent radiologists (two consultants and one fourth-year resident) using SDCT as the reference method. Sensitivity and specificity were calculated and Cohen's κ coefficient was used for agreement analyses.
Of the 149 patients included (mean age 66·7 years, M : F ratio 0·4), 107 (71·8 per cent) had imaging consistent with diverticulitis on standard CT. Sensitivity and specificity values for a diverticulitis diagnosis using LDCT were 95-99 and 86-100 per cent respectively, and respective values for identification of complications were 58-73 and 78-100 per cent. The corresponding κ values among the three readers for diagnosis were 0·984, 0·934 and 0·816, whereas κ values for complications were 0·680, 0·703 and 0·354. Of the 26 patients who presented with other causes of abdominal symptoms identified on standard CT, 23 were diagnosed correctly on LDCT. Missed cases included splenic infarction (1) and segmental colitis (2).
The diagnostic accuracy of LDCT was high for the presence of acute diverticulitis. However, as signs of complicated disease can be missed using the low-dose protocol, use of LDCT as a primary examination method should not preclude SDCT when complications may be suspected.
本研究旨在评估与对比增强标准剂量 CT（SDCT）相比，非增强低剂量 CT（LDCT）在急性结肠憩室炎中的诊断准确性。
前瞻性评估 2017 年 1 月至 10 月期间接受 LDCT 后行 SDCT 的所有疑似憩室炎的临床患者。使用 SDCT 作为参考方法，由三位独立的放射科医生（两位顾问和一位四年级住院医师）评估 CT 检查结果中憩室炎的征象、并发症和其他鉴别诊断。计算敏感性和特异性，并使用 Cohen's κ 系数进行一致性分析。
在纳入的 149 例患者中（平均年龄 66.7 岁，M：F 比例为 0.4），107 例（71.8%）在标准 CT 上显示影像学结果符合憩室炎。LDCT 诊断憩室炎的敏感性和特异性分别为 95-99%和 86-100%，诊断并发症的敏感性和特异性分别为 58-73%和 78-100%。三位读者对诊断的相应 κ 值分别为 0.984、0.934 和 0.816，而并发症的 κ 值分别为 0.680、0.703 和 0.354。在标准 CT 上发现其他腹部症状的 26 例患者中，23 例 LDCT 检查结果正确。漏诊病例包括脾梗死（1 例）和节段性结肠炎（2 例）。
LDCT 对急性憩室炎的诊断准确性较高。然而，由于低剂量方案可能会遗漏复杂疾病的征象，因此在怀疑有并发症时，不应将 LDCT 作为主要检查方法而排除 SDCT。
