OC01.08: Development of an off-line US-MRI fusion imaging tool for fetal brain assessment

US and MRI are two validated techniques in fetal brain expertise. Fusion imaging (FI) allows to obtain an image combining the advantages of both methods and provide an image with more clinical information. The objective is to evaluate the clinical use of the off-line US-MRI FI in the fetal brain development. It was a prospective study in Necker Hospital (NCT04142606) conducted from January to June 2021. We included normal singleton pregnancies between 20 and 36 WG. Each patient underwent an ultrasound scan with volume acquisitions in the 3 planes, followed by a fetal brain T2w MRI (1.5 T) the same day. The US and MRI images were merged using 4 precise landmarks with the 4D view fusion software (GE Healthcare) We have developed a standardised method based on 29 anatomical structures to perform a complete neurosonogram by an expert. A total of 85 patients were included (8 patients per 2 WG). We obtained 31 US and MRI volumes allowing the FI. The FI results in more predefined anatomical landmarks in the neurosonogram than each modality separately. Indeed, for advanced gestational terms the shadowing of the fetal skull, fetal position and attenuation complicate the interpretation of cerebral brain development such as basal ganglia, trigone, Sylvius Acqueduc or cerebellar foliation; whereas on the same slice, MRI gave access to the full brain gyration, brain stem or peri-cerebellar spaces Moreover, Doppler US can provide information on vascularisation in the MR image. This is a promising off-line US-MRI FI tool allowing to navigate within two merged volumes acquired the same day. The interest could be major for educational purpose, brain development follow-up and in case of fetal pathologies at high risk of brain damages such as CMV or TTTS. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.