Evaluation of right ventricular volume and systolic function in normal fetuses using intelligent spatiotemporal image correlation

Table 1 The relationship between normal fetal right ventricular end-diastolic volume, right ventricular end-systolic volume, right stroke volume, right cardiac output, and right ejection fraction with gestational ages from 22 to 35⁺⁶ wk

Gestational age	REDV	RESV	RSV	RCO	REF
r	0.903	0.874	0.866	0.865	0.120
P	< 0.001	< 0.001	< 0.001	< 0.001	0.187

REDV: Right ventricular end-diastolic volume; RESV: Right ventricular end-systolic volume; RSV: Right stroke volume; RCO: Right cardiac output; REF: Right ejection fraction.

Table 2 Measured normal fetal right ventricular end-diastolic volume, right ventricular end-systolic volume, right stroke volume, right cardiac output, and right ejection fraction values with gestational ages between 22 and 35⁺⁶ wk

Gestational age, wk	Case	REDV, mL	RESV, mL	RSV, mL	RCO, mL/min	REF
22–23+6	20	0.99 ± 0.34	0.43 ± 0.18	0.62 ± 0.29	92.23 ± 40.67	0.58 ± 0.12
24–25+6	24	1.43 ± 0.28	0.55 ± 0.15	0.90 ± 0.18	132.10 ± 26.61	0.62 ± 0.58
26–27+6	20	1.66 ± 0.39	0.69 ± 0.20	0.98 ± 0.22	149.25 ± 34.68	0.59 ± 0.06
28–29+6	16	2.06 ± 0.53	0.77 ± 0.15	1.29 ± 0.44	181.12 ± 57.03	0.61 ± 0.06
30–31+6	18	2.61 ± 0.33	1.00 ± 0.14	1.60 ± 0.26	232.58 ± 45.60	0.61 ± 0.05
32–33+6	15	2.98 ± 0.49	1.10 ± 0.17	1.88 ± 0.39	275.86 ± 55.43	0.63 ± 0.04
34–35+6	10	3.69 ± 0.36	1.36 ± 0.22	2.33 ± 0.18	335.83 ± 32.75	0.63 ± 0.03

REDV: Right ventricular end-diastolic volume; RESV: Right ventricular end-systolic volume; RSV: Right stroke volume; RCO: Right cardiac output; REF: Right ejection fraction. RSV = REDV - RESV; RCO = RSV × fetal heart rate; REF = RSV/REDV.

Table 3 Consistency between the same observer and different observers

	n	Observer A	Observer B	t	P	r	P	ICC	95%CI
REDV	30	1.54 ± 0.82	1.51 ± 0.79	1.417	0.167	0.989	< 0.001	0.988	0.975-0.994
RESV	30	0.62 ± 0.36	0.61 ± 0.37	0.384	0.704	0.951	< 0.001	0.951	0.900-0.977
		First measurement	Second measurement
REDV	30	1.54 ± 0.81	1.54 ± 0.84	0.196	0.846	0.990	< 0.001	0.989	0.978-0.995
RESV	30	0.63 ± 0.36	0.61 ± 0.37	1.731	0.094	0.980	< 0.001	0.978	0.955-0.989

REDV: Right ventricular end-diastolic volume; RESV: Right ventricular end-systolic volume; ICC: Intraclass correlation coefficients.