Diffusion-weighted magnetic resonance imaging is effective to detect ileocolonic ulcerations in Crohn's disease

Abstract

Background: Magnetic resonance entero-colonography enables accurate assessment of ileocolonic Crohn's disease, but the need for bowel cleansing and rectal enema limits considerably its use in daily practice. Aim: We evaluated the accuracy of diffusion-weighted magnetic resonance entero-colonography with neither bowel cleansing nor rectal enema to assess endoscopic activity. Methods: Forty-four Crohn's disease patients underwent prospectively and consecutively diffusion-weighted magnetic resonance entero-colonography [with apparent diffusion coefficient (ADC) and Clermont score calculation] and ileocolonoscopy [with Crohn's Disease Endoscopic Index of Severity (CDEIS) and Simplified Endoscopic score for Crohn's Disease (SES-CD) calculation]. Results: Mean ADC was inversely correlated with total CDEIS (ρ = −0.40; P = 0.0067) and total SES-CD (ρ = −0.33; P = 0.032). Considering the 194 segments, ADC was inversely correlated with segmental CDEIS (−0.48; P < 0.001) and segmental SES-CD (−0.44; P < 0.001). ADC values were lower in segments with deep ulcers (1.30 ± 0.23) or superficial ulcerations (1.75 ± 0.64) than in non-ulcerated segments (2.15 ± 0.5) (P = 0.001). Using a receiver operating curve, we determined that segmental ADC <1.42 detected endoscopic deep ulcerations with sensitivity = 0.91 and specificity = 0.83 (Area under the curve = 0.84; P < 0.001). Segmental ADC <1.88 detected endoscopic superficial ulcerations with sensitivity = 0.64 and specificity = 0.75. The segmental ADC values decreased when the ulcerations size increased (P = 0.0001). Clermont score correlated with ileal CDEIS (0.63; P < 0.05) and ileal SES-CD (0.58; P < 0.05). Clermont score was higher in ulcerated segments (23.3 ± 8.4) than in non-ulcerated segments (12.4 ± 10.0) (P = 0.006) and increased with ulcers size (P = 0.012). Clermont score >18.9 detected ulcerations with sensitivity = 0.79 and specificity = 0.73. Conclusion: Diffusion-weighted magnetic resonance entero-colonography using apparent diffusion coefficient and Clermont score was effective to indirectly detect endoscopic ulcerations in ileocolonic Crohn's disease.