The subjective assessment of echogenic fetal bowel

Objectives To assess the subjective interpretation of the echogenicity of f etal bowel compared to bone from antenatal ultrasound images taken during e xaminations conducted between 17 and 22 weeks of gestation. Methods Eighty-seven women attending for their antenatal scan were selected in a random prospective manner over a 9-month period. Images of the fetal bowel were taken and evaluated by 10 sonographers, one consultant obstetric ian and one consultant radiologist. Images from a further 13 fetuses, in wh ich the subjective assessment of echogenic bowel was made, were also includ ed. All ultrasound images were acquired on a dedicated ultrasound scanner, with a standard transducer, thermal paper printer and single operator using standardized equipment settings and reproducible image sections. Questionn aires with 100 sets of images of fetal bowel were distributed to the partic ipants. Performance was assessed by means of percentage agreement and level s of chance corrected agreement (Kappa). Results The subjective assessment of fetal bowel echogenicity is very varia ble. Intra- and inter-observer variation discrepancies in the assessment of bowel echogenicity compared to bone were demonstrated between the sonograp hers. Good agreement was identified between the consultants with good to al most perfect intra-observer agreement. Overall, only moderate agreement was observed between the sonographers and the consultants. Conclusions The lack of agreement demonstrated between sonographers when ev aluating the echogenicity of fetal bowel should be addressed if this ultras ound marker is to be incorporated into routine fetal screening programs.