Non-Invasive Assessment of Inflammation and Treatment Response in Patients with Crohn’s Disease and Ulcerative Colitis using Contrast-Enhanced Ultrasonography Quantification

Abstract

ackground & Aim: Novel biological therapies in Crohn’s disease (CD) or Ulcerative colitis (UC) require a proper follow-up for the assessment of bowel inflammation. While endoscopy is the standard method, the imaging techniques using contrast, particularly contrast enhanced ultrasonography (CEUS), are better tolerated by the patients and can be used more frequently. Our aim was to find the usefulness of dynamic CEUS quantification as compared to endoscopy in the assessment of disease activity and in the follow-up under therapy of the patients suffering from either CD or UC.

Method: We have prospectively evaluated 67 patients with UC and 46 with CD, diagnosed by ileo-colonoscopy and biopsy, comparing the endoscopic scores with clinical scores, C reactive protein (CRP), intestinal wall thickness, layer scores after CEUS and TIC parameters (using SonoLiver® software – Imax, RT, TTP, mTT and AUC). For 25 patients with UC and 13 with CD we performed comparisons of the parameters before and after 3 months of treatment and correlated them with the changes in the endoscopic scores.

Results: For UC, time-intensity curves (TIC) volume parameters (AUC) correlated better with endoscopy (ρ=0.64) than the clinical score (ρ =0.62). Other parameters such as CRP and thickness showed significant but less strong correlation, while TIC flow parameters (RT, TTP and mTT) did not show a significant correlation. Results were similar for CD (ρ=0.64 for Imax vs ρ=0.58 for CDAI). The best predictor for endoscopic improvement in both UC and CD was ln(AUC), with a Wilcoxon Z score of 3.76 and 2.61, respectively. There was also a good correlation between the difference of its values and the difference in endoscopic scores before and after the treatment (rho is 0.68 in UC and 0.73 in CD).

Abbreviations: CD: Crohn’s disease; CDAI: Crohn‘s disease activity index; CDEIS: Crohn‘s disease endoscopic index of severity; CEUS: Contrast-enhanced ultrasonography; CICDA: Composite index of CD activity; CRP: C-reactive protein; IBD: Inflammatory bowel disease; Imax: Maximum intensity; ln(AUC): Natural logarithm of AUC; MPI: Maximum peak intensity; mTT: Mean transit time; ROI: Region of interest; RT: Rise time; SES-CD: Simple endoscopic score for Crohn‘s disease; TIC: