OP33.01: Effect of harmonic imaging, SRI‐II, CRI, FFC and coded excitation B‐mode features on fetal bowel echogenicity, studied by computerized image analysis

Abstract

To provide and to compare measurable normal parameters of the fetal bowel echogenicity under predefined B-mode scanning presets. 40 normal fetuses in the 14–17 week scans and 40 normal fetuses in the 21–25 week scans were examined on Voluson 730 Expert (GE, Irvine, CA USA). Sagittal, coronal and axial fetal abdominal images were tested using predefined B-mode presets. The presets differed from the fundamental imaging by isolated activation of harmonic imaging, SRI-II, CRI, FFC and coded excitation features. Transabdominal probe (RAB4-8L) was used in all fetuses. Transvaginal images with RIC5-9H probe were added in 14–17 week scans. The images were studied by the software developed in the Faculty of Electrical Engineering, Technion, Haifa. The software provided gray level analysis of the pixels in the region of interest within the image. Mean brightness (MB) of the pixels from fetal bowel area was calculated. Transabdominal 14–17 week bowel scans showed significantly higher MB on the harmonic imaging compared to the fundamental imaging (104.2 ± 16.5 vs. 111.9 ± 20.3). Activation of coded excitation and CRI in these scans resulted in significant decrease in MB (94.9 ± 17.5 and 81.2 ± 16.2 correspondingly) compared to the fundamental imaging. Transvaginal imaging showed significantly higher MB values compared to the transabdominal one. Bowel MB values in the transabdominal 21–25 week scans did not differ significantly under harmonic imaging, SRI-II, CRI, FFC and coded excitation compared to the fundamental imaging. Calculation of the fetal bowel echogenicity under predefined B-mode presets might be helpful in the diagnosis of echogenic fetal bowel. Using harmonic imaging in the early second trimester abdominal scans may significantly increase mean brightness of the fetal bowel tissue. Contrarily, activation of CRI and coded excitation features produces opposite effect on the bowel echogenicity.