To examine whether a semi-automated can be used for non-invasive internal organ weight measurement using post-mortem MR imaging in fetuses, newborns and children.
Phase 1: In vitro scanning of 36 animal organs (heart, liver, kidneys) was performed to check the accuracy of volume reconstruction methodology. Real volumes were measured by water displacement method. Phase 2: Sixty-five whole body post-mortem MR scans were performed in fetuses (n = 30), newborns (n = 5) and children (n = 30) at 1.5 T using a 3D TSE T2-weighted sequence. These data were analysed offline using the image processing software Mimics 11.0.
Phase 1: Mean difference (S.D.) between estimated and actual volumes were −0.3 (1.5) ml for kidney, −0.7 (1.3) ml for heart, −1.7 (3.6) ml for liver in animal experiments. Phase 2: In fetuses, newborns and children mean differences between estimated and actual weights (S.D.) were −0.6 (4.9) g for liver, −5.1 (1.2) g for spleen, −0.3 (0.6) g for adrenals, 0.4 (1.6) g for thymus, 0.9 (2.5) g for heart, −0.7 (2.4) g for kidneys and 2.7 (14) g for lungs. Excellent co-correlation was noted for estimated and actual weights (r2 = 0.99, p < 0.001). Accuracy was lower when fetuses were less than 20 weeks or less than 300 g.
Rapid, accurate and reproducible estimation of solid internal organ weights is feasible using the semi-automated 3D volume reconstruction method.