Relation between the quality of the ultrasound image acquisition and the precision of the measurement of the crown-rump length in the late first trimester: what are the consequences?

Introducing and Validating the Cranial-Dorsal-Hip Angle (∠CDH): A Method for Accurate Fetal Position Assessment in the First Trimester and Future AI Applications

Purpose  To introduce the cranial-dorsal-hip angle (∠CDH) as a novel quantitative tool for assessing fetal position in the first trimester and to validate its feasibility for future AI applications. Materials and Methods  2520 first-trimester fetal NT exams with 2582 CRL images (January-August 2022) were analyzed at a tertiary hospital as the pilot group. Additionally, 1418 cases with 1450 fetal CRL images (September-December 2022) were examined for validation. Three expert sonographers defined a standard for fetal positions. ∠CDH measurements, conducted by two ultrasound technicians, were validated for consistency using Bland-Altman plots and the intra-class correlation coefficient (ICC). This method allowed for categorizing fetal positions as hyperflexion, neutral, and hyperextension based on ∠CDH. Comparative accuracy was assessed against Ioannou, Wanyonyi, and Roux methods using the weighted Kappa coefficient (k value). Results  The pilot group comprised 2186 fetal CRL images, and the validation group included 1193 images. Measurement consistency was high (ICCs of 0.993; P<0.001). The established 95% reference range for ∠CDH in the neutral fetal position was 118.3° to 137.8°. The ∠CDH method demonstrated superior accuracy over the Ioannou, Wanyonyi, and Roux methods in both groups, with accuracy rates of 94.5% (k values: 0.874, 95%CI: 0.852-0.896) in the pilot group, and 92.6% (k values: 0.838, 95%CI: 0.806-0.871) in the validation group. Conclusion  The ∠CDH method has been validated as a highly reproducible and accurate technique for first-trimester fetal position assessment. This sets the stage for its potential future integration into intelligent assessment models.

The impact of optimal dating on the assessment of fetal growth

BACKGROUND

The impact of using the Intergrowth (IG) dating formulae in comparison to the commonly used Robinson dating on the evaluation of biometrics and estimated fetal weight (EFW) has not been evaluated.

METHODS

Nationwide cross-sectional study of routine fetal ultrasound biometry in low-risk pregnant women whose gestational age (GA) had been previously assessed by a first trimester CRL measurement. We compared the CRL-based GA according to the Robinson formula and the IG formula. We evaluated the fetal biometric measurements as well as the EFW taken later in pregnancy depending on the dating formula used. Mean and standard deviation of the Z scores as well as the number and percentage of cases classified as <3rd, < 10th, >90th and > 97th percentile were compared.

RESULTS

Three thousand five hundred twenty-two low-risk women with scans carried out after 18 weeks were included. There were differences of zero, one and 2 days in 642 (18.2%), 2700 (76.7%) and 180 (5%) when GA was estimated based on the Robinson or the IG formula, respectively. The biometry Z scores assessed later in pregnancy were all statistically significantly lower when the Intergrowth-based dating formula was used (p < 10- 4). Likewise, the number and percentage of foetuses classified as <3rd, < 10th, >90th and > 97th percentile demonstrated significant differences. As an example, the proportion of SGA foetuses varied from 3.46 to 4.57% (p = 0.02) and that of LGA foetuses from 17.86 to 13.4% (p < 10- 4).

CONCLUSION

The dating formula used has a quite significant impact on the subsequent evaluation of biometry and EFW. We suggest that the combined and homogeneous use of a recent dating standard, together with prescriptive growth standards established on the same low-risk pregnancies, allows an optimal assessment of fetal growth.

Reproducibility of a quantitative system for assessing the quality of diagnostic ultrasound

Objective

To present a quantitative system for assessing the quality of ultrasound examinations-SQUALUS-and to determine its reproducibility, taking into consideration the images on file, as well as the consistency between the images obtained and the final report.

Materials and Methods

The system includes questions related to the number of images; the appropriateness of images in relation to the protocol established; focus adjustment; depth; gain; and appropriateness of the measurements for B-mode examinations. For Doppler examinations, the system includes questions related to the appropriateness of color images, the spectral analysis, and correction of the insonation angle. To assess the quality of the report, the system includes questions related to the consistency between the images obtained and the contents of the report. An overall numerical score was assigned by averaging the scores for image quality and for the contents of the report. Two independent examiners, each blinded to the evaluation of the other, assessed 30 different types of ultrasound examinations.

Results

There was statistically significant agreement between the two examiners for 8 of the 10 questions related to image quality. For the questions related to the quality of the reports, the interexaminer agreement was almost perfect.

Conclusion

The proposed quantitative system for assessing the quality of ultrasound examinations is a reproducible tool that can be used in audits and accreditation programs.

[Report from the CFEF seminar on fetal biometry (June 2017)]

This article reports the conclusions and recommendations resulting from the seminar organized in Paris on June 15, 2017 by the scientific committee of the French College of Fetal Ultrasound (CFEF). The purpose of this meeting was to audit the practices in screening for SGA and IUGR fetuses in France and to discuss ways to improve ultrasound screening. A review of charts, references, standards and common practices was performed. The potential new biometric tools applicable in France were reviewed and analyzed. Eventually, options and recommendations for improvement are proposed.