OP05.09: Grading the fetal echogenic bowel (EB): correlation between quantitative computerissed gray‐scale analysis and subjective qualitative evaluation

Abstract

To determine the correlation between qualitative assessment of fetal bowel echogenicity and the quantitative measurements obtained by objective computerised Histogram method. This was a retrospective study conducted in 2016 at the University Medical Centre Groningen. We included all fetuses with EB evaluated at 19+0- 21+6 weeks of gestation. The subjective qualitative assessment of fetal bowel echogenicity was reported as mild, moderate and severe by fetal medicine experts. All pictures were stored digitally and retrospectively analysed using the ImageJ software, a program able to identify 256 shades of gray in a specific area of interest. For each patient the bowel [B] and the iliac bone [IB] were analysed, and the Average [A] of the gray-scale was obtained as indicator of the echogenicity. As absolute echogenicity is known to vary with gain and ultrasound intensity, the ratio of the two adjacent structures [B/IB] was used to overcome gain/setting variation and inter-patient variability. Our study population included 70 cases: 31 cases reported by visual judgement as mild EB, 26 as moderate EB and 13 cases as severe FEB. The average B/IB ratio for each group was 0.79 (±0.19 SD), 0.81 (±0.19 SD) and 0.90 (±0.20 SD), respectively. The difference between each of the 3 groups was not significant, but this may be due to the small sample size. The Histogram evaluation of subjectively judged severity of bowel echogenicity confirms the poor reproducibility of the qualitative assessment and stresses the necessity of an objective grading system for increased fetal bowel echogenicity.