Fetal myocardial wall area: constructing a reference range by means of spatiotemporal image correlation in the rendering mode.

OBJECTIVE: To establish the reference range of the myocardial wall area in the fetus using three-dimensional ultrasound in the rendering mode. METHODS: A prospective, cross-sectional study including 371 singleton, uncomplicated pregnancies at 20 weeks 0 day to 33 weeks 6 days of gestation was carried out. Cardiac volumes were obtained using spatiotemporal image correlation (STIC) at the level of the four-chamber view. The end-diastolic myocardial area of the both ventricles was measured manually. The intraclass correlation coefficient (ICC) was used to assess intra- and interobserver concordance. RESULTS: The mean myocardial area of the fetal right ventricular (RV) wall ranged from 0.86 ± 0.23 cm(2) at 20 weeks 0 day to 2.75 ± 0.69 cm(2) at 33 weeks 6 days of gestation. The mean myocardial area of the fetal left ventricular (LV) wall ranged from 0.82 ± 0.20 cm(2) at 20 weeks 0 day to 2.49 ± 0.59 cm(2) at 33 weeks 6 days of gestation. In addition, intra- and interobserver concordance for the myocardial area of the RV and LV walls was good, with ICC values of 0.94, 0.95, 0.85, and 0.93, respectively. CONCLUSIONS: The reference range for the myocardial area of the RV and LV walls was determined by cardio-STIC in the rendering mode at 20 weeks 0 day to 33 weeks 6 days of gestation, with good concordance between values.

Assessment of the fetal heart at 12-14 weeks of pregnancy using B-mode, color Doppler, and spatiotemporal image correlation via abdominal and vaginal ultrasonography.

This study aimed to evaluate the effect that combining multiple ultrasonographic imaging methods has on the proportion of tests with a satisfactory fetal heart assessment at 12-14 weeks of pregnancy using B-mode, color Doppler, and spatiotemporal image correlation software (STIC) via both the abdominal and vaginal routes. This cross-sectional prospective study involved healthy pregnant women at 12-14 weeks of pregnancy with a crown-rump length (CRL) of 84 mm or shorter. The following four cardiac views were assessed: four-chamber, left and right ventricular outflow tract, and aortic arch views. The same examiner sought to identify these four views using B-mode, color Doppler, and STIC via both the vaginal and abdominal routes. The study determined the proportion of cases and the respective 95 % confidence intervals (CIs) in which all four views were identified. The presence of significant differences in comparisons between methods was analyzed using McNemar's test. Although 57 pregnant women at 12-14 weeks of pregnancy agreed to participate in the study, 4 were not included because they presented with a CRL longer than 84 mm. Thus, 53 pregnant women were thoroughly assessed and included in the analysis. The combination of B-mode, color Doppler, and STIC via both the abdominal and vaginal routes enabled the highest proportion of identification of the four views (90.6 %; 95 % CI, 79.8-95.9 %). The lowest proportions were observed when B-mode was used alone via both the vaginal route (30.2 %; 95 % CI, 19.5-43.5 %) and the abdominal route (37.7 %; 95 % CI, 25.9-51.2 %). The abdominal route showed results slightly better than those of the vaginal route with all the methods, but the differences were not statistically significant. In the vast majority of the cases, the fetal hearts were properly assessed at 12-14 weeks of pregnancy when several methods were combined using both the abdominal and vaginal routes. However, only one-third of them would have had adequate heart assessment if the B-mode via either the abdominal or the vaginal route had been used alone.

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

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.

Prenatal diagnosis of congenital heart disease using four-dimensional spatio-temporal image correlation (STIC) telemedicine via an Internet link: a pilot study.

OBJECTIVE: To assess whether the spatio-temporal image correlation (STIC) acquisition technique can be taught to a general obstetrician by e-mail; whether STIC volume datasets can be transmitted over the Internet; and whether STIC volume datasets analyzed offline at a remote setting can be used to confirm or exclude major cardiac defects (TELE-STIC). METHODS: This was a prospective study involving 50 pregnant women with gestational ages ranging between 20 and 36 weeks. These patients were selected by two general obstetricians (operators) working in geographically remote areas of Chile. Although both obstetricians were users of equipment capable of four-dimensional (4D) ultrasound with STIC, they lacked skill in the performance of fetal cardiac examination. A dedicated web disk was created to upload the acquired volume datasets using an Internet broadband connection. Offline analysis was performed by a single investigator experienced in fetal echocardiography (the administrator). RESULTS: A telemedicine link via the Internet was possible in all cases. Seventy-seven volume datasets were sent to the web server. A complete cardiac examination according to set criteria was achieved by the administrator in 86% of the cases scanned by one operator and 95% of the cases scanned by the other operator. Three patients had cardiac defects confirmed postnatally, two fetuses had extracardiac anomalies and one fetus had a suspected cardiac defect unconfirmed by second-opinion TELE-STIC. There were two isolated major congenital heart defects. Both patients were given advice by e-mail and teleconference using a web camera about the likely outcome and benefits of scheduling in utero transport to a tertiary care center. CONCLUSIONS: STIC volumes can be obtained by operators inexperienced in fetal echocardiography, transmitted via the Internet, and their analysis enables recognition of most of the structures and views necessary to assess fetal cardiac anatomy. The preliminary use of TELE-STIC allowed us to demonstrate that some intracardiac anomalies can be ruled out and others confirmed, allowing perinatal management to be tailored accordingly.