Assessment of fetal corpus callosum biometry by 3D super-resolution reconstructed T2-weighted MRI

Abstract

AbstractObjectiveTo assess the accuracy of corpus callosum (CC) and its sub-segments’ biometry by super-resolution (SR) 3-dimensional fetal brain MRI in comparison to measurements in 2-dimensional or 3-dimensional ultrasonography (US) and clinical low-resolution T2-weighted MRI sequences (T2WS).MethodWe performed fetal brain biometry of the overall length of the CC, the heights of its sub-segments and its area by two observers (one junior observer, obs1, and one senior pediatric neuroradiologist, obs2) in a cohort of 57 subjects (between 21 and 35 weeks of gestational age (GA), including 11 cases of partial agenesis of CC). Obs1 made measures on US, T2WS, and SR, and obs2 in T2WS and SR. Regression curves of CC biometry with GA were done. Statistical analysis of inter-modality (US vs. T2WS, US vs. SR, and T2WS vs SR) agreement for single observer (obs1) and inter-modality (US vs. T2WS, and US vs. SR) between observers (obs1 vs obs2) were also conducted.ResultsOur study shows a high concordance through GA of CC measurements performed by SR in comparison with US, with a higher agreement than biometry based on T2WS clinical acquisitions. For obs1, SR measurements are highly concordant to US (except for the genu and the CC length) and helps visualizing the splenium. For obs2, SR measurements are highly concordant to US, except for the rostrum and the CC length. Rostrum and Genu (forming the anterior callosum) are the subsegments with larger variability. Regression curves by SR overlay more accurately those from the literature (by US) for the CC length, the splenium and the body than T2WS.ConclusionSuper-resolution MRI could be used in the biometrical assessment of the CC, providing measurements close to US, except for the anterior part of the CC Thanks to its 3D-visualisation capacity and improved through plane spatial resolution, it allows to perform CC biometry more frequently than on T2WS.