P171 Reliable assessment of ultrasound parameters during transabdominal ultrasonography in inflammatory bowel disease
Bittl M.*1,2, Petersen F.1,2, Maaser C.1,2, Rath S.3, Roessler A.3, Fischer I.4, Bettenworth D.5, Kucharzik T.1,2
1Klinikum Lüneburg, Gastroenterology, Lüneburg, Germany 2University of Hamburg, Department of Gastroenterology, Lüneburg Hospital, Germany 3Company AbbVie 4University of Tübingen, Department of Biostatistics, Tübingen, Germany 5University of Münster, Department of Gastroenterology, Münster, Germany
The inflammatory activity of chronic inflammatory bowel disease (IBD) may effectively be controlled by means of intestinal ultrasound (IUS). Although IUS is considered to be safe and inexpensive, it is criticised for being dependent on the examiner. The aim of this study was to evaluate whether ultrasound parameters are interpreted in the same way by examiners with experience in this diagnostic procedure.
40 participants (38 IBD specialists, including 27 gastroenterologists with professional experience between <5 years and >10 years) from nationwide IBD centres were included. Using a standardised questionnaire, the participants assessed 20 ultrasound images and videos of IBD patients. In addition, all study participants independently performed “simulator” investigations of 3 IBD-specific pathologica (Schallware simulator, Germany). Overall, the participants all received the same questions for the exact assessment of US image recordings. The questions related to both the assessment of the technical image quality, the methodology of imaging and the evaluation of specific parameters such as bowel wall thickness, vascularisation, etc. were used as reference results for the consensus of a group of experts (n=3). The parameters were evaluated according to the correspondence between the cases and the conformity of the participants. Mann-Whitney U test and Kappa coefficient were used for the statistical evaluation.
The inter-observer variability, as measured by the kappa coefficient, determined moderate agreement between 0.36 to 0.59 with regard to all parameters assessed by the participants. The evaluation of the specific IBD activity parameters revealed a good match with an average of 60.9%. The relevant parameters for an IBD assessment (bowel wall thickness, etc.) were recognised by all participants. The heterogeneity of agreement with regard to interpretation of the findings ranged between 88.5% (item “extraintestinal air”) and 35.6% (item “unevenly altered bowel wall stratification”). Subgroup analyses using the Man-Whitney U test showed that examiners with greater experience reached a higher degree of consensus.
The examiners were able to equally interpret images derived during intestinal ultrasound. In particular, examiners were able to reliably interpret ultrasound parameters relevant for the assessment of IBD activity and complications. The reliability of the assessment increased with the experience of the examiner. Further studies with a larger number of participants to evaluate the reliability of assessment would be meaningful