UNLABELLED: Magnetic resonance (MR) imaging allows minimally invasive autopsy, especially when consent is declined for traditional autopsy. Estimation of individual visceral organ weights is an important component of traditional autopsy.
OBJECTIVE: 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.
METHODS: 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 1.5T using a 3D TSE T2-weighted sequence. These data were analysed offline using the image processing software Mimics 11.0.
RESULTS: 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 (r(2)=0.99, p<0.001). Accuracy was lower when fetuses were less than 20 weeks or less than 300g.
CONCLUSION: Rapid, accurate and reproducible estimation of solid internal organ weights is feasible using the semi-automated 3D volume reconstruction method.
- Image Enhancement/methods
- Image Interpretation, Computer-Assisted/methods
- Infant, Newborn
- Magnetic Resonance Imaging/methods
- Organ Size
- Reproducibility of Results
- Sensitivity and Specificity