A novel food-based negative oral contrast agent compared with two conventional oral contrast agents in abdominal CT: a three-arm parallel blinded randomised controlled single-centre trial

Abstract

Background: A negative oral contrast agent (OCA) has been long sought for, to better delineate the bowel and visualise surrounding structures. Lumentin® 44 (L44) is a new OCA formulated to fill the entire small bowel. The aim of this study was to compare L44 with positive and neutral conventional OCA in abdominal computed tomography (CT).

Methods: Forty-five oncologic patients were randomised to receive either L44 or one of the two comparators (MoviPrep® or diluted Omnipaque®). Abdominal CT examinations with intravenous contrast agent were acquired according to standard protocols. The studies were read independently by two senior radiologists.

Results: The mean intraluminal Hounsfield units (HU)-values of regions-of-interest (ROIs) for each subsegment of small bowel and treatment group were -404.0 HU for L44, 166.1 HU for Omnipaque®, and 16.7 HU for MoviPrep® (L44 versus Omnipaque, p < 0.001: L44 versus MoviPrep p < 0.001; Omnipaque versus MoviPrep, p = 0.003). Adverse events, only mild, using L44 were numerically fewer than for using conventional oral contrast agents. Visualisation of abdominal structures beyond the small bowel was similar to the comparators.

Conclusions: L44 is a negative OCA with luminal radiodensity at approximately -400 HU creating a unique small bowel appearance on CT scans. The high bowel wall-to-lumen contrast may enable improved visualisation in a range of pathologic conditions. L44 showed a good safety profile and was well accepted by patients studied.

Trial registration: EudraCT (2017-002368-42) and in ClinicalTrials.gov (NCT03326518).

Keywords: Contrast media; Intestine (small); Iohexol; MoviPrep; Tomography (x-ray computed).

Conflict of interest statement

The authors PL, GS, JM, and KB have nothing to declare. LCD, IA, OB, and TF are together minor shareholders in Lument AB.

© 2022. The Author(s) under exclusive licence to European Society of Radiology.

Figures

Fig. 1

a Freshly prepared Lumentin 44 (L44) poured into a glass. b Optical microscopy image of L44, ready to be administered, which consists of spherical air micro-bubbles dispersed in an aqueous phase that contains protein as foaming agent, stabiliser, buffer agent, and flavouring

Fig. 2

Abdominal computed tomography coronal view after oral administration of Lumentin 44 (a), diluted Omnipaque (b), and MoviPrep (c). Standard abdominal window-setting (window width 400 HU, window level 60 HU)

Fig. 3

Lumentin 44 in small bowel (SB) loops. Close up coronal views showing subtle details in SB walls. a Abdominal window setting (WW 400 HU, WL -15 HU) and 0.7 mm thin-slice reconstruction showing mucosal folds. b Lung window setting (WW 2,000 HU, WL -400) and 0.7 mm thin-slice reconstruction showing SB filled with Lumentin 44 and part of sigmoid colon containing air. c Abdominal window setting (WW 400 HU, WL -15 HU) and 5 mm thick-slice reconstruction showing terminal ileum entering the caecum. WW, Window width; WL, Window level

Fig. 4

Measurements of oral contrast agent (OCA) distribution. Distension: mean ± standard deviation grade of distension by OCA in subsegments of the small bowel. Extension: mean ± standard deviation grade of extension in subsegments of the small bowel by OCA. Grading 1–9 according to Table 1. Number of patients: L44 (n = 17); diluted OP (n = 12); MP (n = 14). L44, Lumentin 44; OP, Omnipaque; MP, MoviPrep