Fetal echocardiography at 11 + 0 to 13 + 6 weeks using four-dimensional spatiotemporal image correlation telemedicine via an Internet link: a pilot study

Ultrasound Obstet Gynecol. 2008 Jun;31(6):633-8. doi: 10.1002/uog.5350.

ABSTRACT

OBJECTIVES: To assess whether spatiotemporal image correlation (STIC) volumes from fetuses at 11 + 0 to 13 + 6 weeks’ gestation can be obtained by a non-expert and whether fetal echocardiography can be performed via a telemedicine link, providing a remote and reproducible diagnosis of the fetal heart condition.

METHODS: STIC volume datasets from 35 fetuses at 11 + 0 to 13 + 6 weeks were obtained prospectively by a general obstetrician, transmitted via the Internet and subsequently analyzed systematically by two different reviewers. Forty-nine pregnancies were initially enrolled into the study, but adequate volumes were not obtained for 14. Thirty-four datasets were obtained on transabdominal and one on transvaginal ultrasound examination. A checklist was used that included 18 structures and views relating to the fetal heart evaluation, and each reviewer assigned the variables as normal, abnormal or unsure. Cohen’s kappa analysis was used to evaluate the agreement between reviewers and the reported findings were compared with the outcome where available.

RESULTS: The mean gestational age was 12 + 3 weeks and the mean (range) crown-rump length was 68 (47-84) mm. The mean maternal age was 33 (range, 26-41) years; 12/35 (34%) were older than 35 years. The four-chamber view obtained was apical in 22/35 (63%) cases and lateral in 13 (37%). Volume datasets were obtained after 12 weeks’ gestation in 30/35 fetuses. Three cases had nuchal translucency thickness above the 99(th) percentile, and two of these had an abnormal heart. Five cases had abnormal outcomes. A mean of 3 (range, 1-6) STIC datasets per patient were acquired. The kappa index obtained confirmed interobserver reliability, with good or very good concordance (kappa > 0.6) in 14/18 structures and views related to the heart.

CONCLUSIONS: STIC volumes acquired between 11 + 0 and 13 + 6 weeks’ gestation could be sent over the Internet and their analysis enabled recognition of most of the structures and views necessary to assess the small fetal cardiac anatomy, with a high degree of interobserver concordance.

PMID:18461551 | DOI:10.1002/uog.5350