[Assessment of the inter- and intraobserver variability for sonographical measurement of intestinal wall thickness in dogs without gastrointestinal diseases].

OBJECTIVE: The aim of the present study was to determine inter- and intraobserver agreement for transabdominal ultrasonographic measurements of the intestinal wall in dogs without gastrointestinal diseases.

MATERIAL AND METHODS: This prospective study included 30 dogs diagnosed with a non-gastrointestinal disease and were evaluated using a transabdominal ultrasound scan in our clinic. Transverse ultrasonographic images for each segment (duodenum, jejunum, colon descendens) were obtained. These images were masked, randomized and imported as DICOM files in the OsiriX® version 5.0 program for Mac Os X. Two observers independently determined the intestinal wall thicknesses using the software inherent measurement tools. The measurements were repeated five times for each segment in all patients on 4 consecutive days. Therefore, each observer performed 1800 measurements, and 3600 measurements in total were analyzed.

RESULTS: The mean values for each intestinal segment were comparable to those in the literature. The statistical analyses showed a significant positive correlation (p  <  0.01) for the inter- and intraobserver measurements at all intestinal locations. There was very high intraobserver repeatability for the measurements, with deviations of <  10%. In addition, the study displayed good interobserver reproducibility for the measurements of all intestinal segments, with variances of <  20% for the duodenum and jejunum, and <  50% for the colonic wall thickness. Even with these variances the interobserver variability for all segments was much less than the mean deviance between normal and diseased dogs.

CONCLUSION AND CLINICAL RELEVANCE: Transabdominal ultrasonography is a practicable tool to assess intestinal wall thickness and integrity in small animal medicine. Our results are comparable to established reference ranges for the normal canine intestinal wall thickness. In addition, we found a good inter- and intraobserver agreement for the measurements of the canine wall thicknesses in dogs without gastrointestinal diseases.