Diverticular disease severity score based on CT colonography.

Objective: We propose a diverticular disease severity score (DDSS) based on CT colonography (CTC) findings.

Methods: Seventy-nine patients (62 ± 14.5 years) underwent CTC after recovering from an episode of acute diverticulitis. Two independent readers classified each case using a four-point scale (DDSS), based on maximum sigmoid colon wall thickness (MSCWT) and minimum lumen diameter at CTC: 1 = MSCWT <3 mm, lumen diameter ≥15 mm; 2 = MSCWT 3-8 mm, lumen diameter ≥5 mm; 3 = MSCWT ≥8 mm, lumen diameter ≥5 mm; 4 = MSCWT ≥8 mm, lumen diameter <5 mm. Intra- and interobserver reproducibility was evaluated. Of 79 patients, 32 (40 %) underwent surgery after CTC; MSCWT was directly measured on the pathological specimen.

Results: Intra- and interobserver reproducibility of DDSS were almost perfect (k = 0.90-0.84). DDSS significantly correlated with the probability of surgery (P = 0.001). After surgery, histopathology revealed acute/chronic diverticular inflammation only in 29 cases, and superimposed sigmoid cancer (n = 2) or Crohn's disease (n = 1) in 3 patients with a DDSS of 4. MSCWT at histopathology correlated with DDSS (P = 0.008).

Conclusion: DDSS is highly reproducible and correlates with pathological MSCWT. Nearly 1 in 3 patients with a DDSS of 4 had significant superimposed histopathology. CTC with DDSS can provide colorectal surgeons with valuable information.

Key Points: • A diverticular disease severity score (DDSS) based on CT colonography is proposed. • This DDSS is based on sigmoid colon wall thickness and lumen diameter. • High scores may be associated with relevant coexisting lesions. • A CTC-based DDSS may influence therapeutic decision-making.