Diagnostic accuracy of acute diverticulitis with unenhanced low-dose CT

Abstract

Background: 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). Methods: 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 coefficient was used for agreement analyses. Results: 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 values among the three readers for diagnosis were 0⋅984, 0⋅934 and 0⋅816, whereas 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). Conclusion: 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.

The WSES/SICG/ACOI/SICUT/AcEMC/SIFIPAC guidelines for diagnosis and treatment of acute left colonic diverticulitis in the elderly

“…However, the evidence is insufficient to recommend it as the first-choice examination. Furthermore, in a recent prospective study on patients with suspected diverticulitis, although unenhanced low-dose CT showed good sensitivity (98.6%) for the detection of diverticulitis with excellent intermodality agreement, it had significantly lower sensitivity (61%) for the detection of complications [ 39 ].…”

Iodinated contrast media shortage: Insights and guidance from two major public hospitals

“…Many of the clinical indications (e.g. bowel obstruction, acute appendicitis, diverticulitis and hollow viscus perforation) for an abdominal CT can be addressed with sufficiently high accuracy on NCCT 3,4 . We have also opted to perform abdominal and chest CTs for minor trauma without ICM.…”

Changing Paradigms in the Management of Acute Uncomplicated Diverticulitis

“…However, it can be advantageous in patients with chronic diverticulitis, especially for visualizing a fistula tract ( 29 ). Although low radiation-dose CT without intravenous contrast has a high sensitivity for diverticulitis, smaller perforations and small pericolic or intramural abscesses can be missed using this technique ( 30 ). Therefore, a full-dose CT protocol with intravenous contrast is recommended for patients with suspected acute diverticulitis.…”