Measuring fetal adipose tissue using 3D water-fat magnetic resonance imaging: a feasibility study

Purpose: Analysis of fetal adipose tissue volumes may provide useful insight towards assessment of overall fetal health, especially in cases with abnormal fetal growth. Here, we assess whether fetal adipose tissue volume can be reliably measured using 3D water-fat MRI, using a quantitative assessment of the lipid content of tissues. Materials and methods: Seventeen women with singleton pregnancies underwent a fetal MRI and water-only and fat-only images were acquired (modified 2-point Dixon technique). Water and fat images were used to generate a fat signal fraction (fat/(water + fat)) from which subcutaneous adipose tissue was segmented along the fetal trunk. Inter-rater (three readers) and intrarater reliability was assessed using intraclass-correlation coefficients (ICC) for 10 image sets. Relationships between adipose tissue measurements and gestational age and estimated fetal weight percentiles were examined. Results: The ICC of the inter-rater reliability was 0.936 (p < .001), and the ICC of the intrarater reliability was 0.992 (p < .001). Strong positive correlations were found between adipose tissue measurements (lipid volume, lipid volume/total fetal volume, mean fat signal fraction) and gestational age. Conclusions: 3D water-fat MRI can reliably measure volume and quantify lipid content of fetal subcutaneous adipose tissues.