Non-visualization of the fetal Gallbladder: A Comparison of ultrasound and MRI follow-up

The aim of this study is to compare the advantages of ultrasound and MRI as follow-up tools for cases of fetal gallbladder non-visualization.

This is a retrospective study that collected cases where the initial ultrasound indicated non-visualization of the fetal gallbladder, with subsequent follow-up results available from both MRI and ultrasound. Follow-up results, including the presence or absence of the gallbladder and the length and thickness of the visualized gallbladder, were recorded and compared with postnatal examination results. The accuracy of both imaging modalities in identifying the gallbladder and the differences in gallbladder size were analyzed.

A total of 90 cases were included in the study. Postnatal examination revealed that 66 cases had a gallbladder, while 24 cases did not. MRI indicated the presence of a gallbladder in 47 cases and absence in 43 cases, resulting in a diagnostic accuracy of 78.9 %. In contrast, ultrasound indicated a gallbladder in 19 cases and absence in 71 cases, with a diagnostic accuracy of 47.8 %. The difference between the two modalities was statistically significant. The gallbladder length seen on MRI was approximately 0.7 ± 0.2 cm, while on ultrasound it was approximately 1.2 ± 0.5 cm, showing a statistically significant difference; the gallbladder thickness on MRI was approximately 0.3 ± 0.1 cm, compared to approximately 0.4 ± 0.1 cm on ultrasound, also demonstrating a statistically significant difference. This suggests that MRI has an advantage over ultrasound in visualizing small gallbladders.

Compared to ultrasound, MRI can identify smaller gallbladders with higher accuracy, which is of significant importance in the follow-up of cases with fetal gallbladder non-visualization.