Table 2.

SNR of the segmented liver in the NRFP fetal specimen over the 22-week staining period

Time point	Mean Hounsfield unit (MHU) (HU)	Standard deviation (σ)(HU)	Signal-to-noise ratio (SNR)
Week 0	31.55	22.69	1.39
Week 2	103.56	58.90	1.76
Week 4	161.06	47.74	3.37
Week 6	186.95	52.88	3.53
Week 8	333.69	86.96	3.84
Week 10	231.92	52.77	4.39
Week 12	546.15	90.37	6.04
Week 14	716.81	96.75	7.41
Week 16	936.61	100.08	9.36
Week 18	1116.11	119.47	9.34
Week 20	1244.16	132.64	9.38
Week 22	1391.53	148.99	9.34