3-Dimensional sonographic volumetry of fetal brain, liver and myocardial mass--interdisciplinary clinical validation of the method and application in fetuses with and without structural heart disease.

BACKGROUND

Prenatal 3-dimensional (3D) ultrasound allows volumetry of the fetal brain, liver and measurement of myocardial mass (MM). We studied the reliability of this method in an interdisciplinary approach, defined the relation of the values throughout gestation, and evaluated the results in fetuses with congenital heart disease (CHD).

METHODS

In 104 fetuses (39 with CHD) between 14 and 38 weeks of gestation 3D ultrasound was prospectively performed. Data sets of brain, abdomen and heart were stored for off-line analysis of volumes and MM. Descriptive statistics, coefficients of correlation and of variation (CV) were performed.

RESULTS

Volumetric data set acquirement was feasible in all pregnancies, lasted approximately 10 min, but off-line analysis was feasible in only 66% lasting about 45 min. MM increased in a linear fashion during gestation. CV were 11.0 and 10.8 for the left, 14.39 and 12.66, respectively, for the right MM. Median ratio between right and left MM was 0.88 in normal fetuses, and 8.25 in fetuses with hypoplastic left heart syndrome. Intra- and interobserver variabilities revealed CVs of 2.46 and 11.80, respectively, for brain volumetry, and CVs of 3.16 and 29.2, respectively, for liver volumetry. Both brain and liver volumes were positively associated with gestational age, and did not show different growth patterns in fetuses with CHD.

CONCLUSIONS

Prenatal volumetry is time-consuming, but reliable especially for left MM and brain volume. Linear growth of brain and liver volume is present in utero irrespective of CHD. Application of our reference graphs of MM growth allows early differentiation in CHD.