Influence of oral contrast type and volume on patient experience and quality of luminal distension at MR Enterography in Crohn's disease: an observational study of patients recruited to the METRIC trial

Objectives To compare the distention quality and patient experience of oral mannitol and polyethylene glycol (PEG) for MRE. Methods This study is a retrospective, observational study of a subset of patients enrolled in a multicentre, prospective trial evaluating the diagnostic accuracy of MRE for small bowel Crohn's. Overall and segmental MRE small bowel distention, from 105 patients (64 F, mean age 37) was scored from 0 = poor to 4 = excellent by two experienced observers (68 [65%] mannitol and 37 [35%] PEG). Additionally, 130 patients (77 F, mean age 34) completed a questionnaire rating tolerability of various symptoms immediately and 2 days after MRE (85 [65%] receiving mannitol 45 [35%] receiving PEG). Distension was compared between agents and between those ingesting <= 1 L or > 1 L of mannitol using the test of proportions. Tolerability grades were collapsed into very tolerable, moderately tolerable, and not tolerable. Results Per patient distension quality was similar between agents (excellent or good in 54% [37/68] versus 46% [17/37]) with mannitol and PEG respectively. Jejunal distension was significantly better with mannitol compared to PEG (40% [27/68] versus 14% [5/37] rated as excellent or good respectively). There was no significant difference according to the volume of mannitol ingested. Symptom tolerability was comparable between agents, although fullness following MRE was graded as very tolerable in 27% (12/45) of patients ingesting PEG, verses 44% (37/84) ingesting mannitol, difference 17% (95% CI 0.6 to 34%). Conclusion Mannitol-based solutions and PEG generally achieve comparable distension quality and side effect profiles, although jejunal distension is better quality with mannitol. Neither distension quality nor side-effect profile is altered by ingestion of more than 1 L of mannitol.

Automated summary

This study compared the distention quality and patient experience of oral mannitol and polyethylene glycol (PEG) for MRE. The study found that mannitol had better distension quality in the jejunum compared to PEG. However, overall distension quality and side effect profiles were similar between the two agents. Additionally, ingestion of more than 1 L of mannitol did not alter distension quality or side effect profile.