Two- and four-dimensional echocardiography with high-definition flow imaging and spatiotemporal image correlation in the diagnosis of fetal isolated partial anomalous pulmonary venous connection

Slow flow HD and traditional CDFI technologies in identifying pulmonary veins in the first trimester

OBJECTIVE

This study aims to assess the feasibility and effectiveness of color doppler flow imaging (CDFI) technology and the Slow Flow HD imaging technique in identifying fetal pulmonary veins (PVs) in the first trimester (11-13 + 6 weeks), and further explore the factors affecting fetal pulmonary vein identification in early pregnancy.

METHODS

Echocardiography and scanning of PVs were performed in 240 normal singleton fetuses in early pregnancy by using CDFI and slow flow HD techniques, to compare the ability of two methods to identify the PVs. Slow Flow HD technology was used to further investigate the difference of PVs identification at different gestational ages [group I (11-11 + 6 weeks), group II (12-12 + 6 weeks), group III (13-13 + 6 weeks)] and with different maternal body mass indices (BMI) (≥ 25 and < 25). In 31 cases of 240 fetuses, transvaginal ultrasonography was added due to maternal habitus or significant retroversion of the uterus, and the difference in PVs identification between transabdominal and transvaginal examination was analyzed.

RESULTS

Successful PVs identification rates via CDFI and Slow Flow HD were 32.0% and 88.3%, respectively (p < 0.05). The identification rate of at least one and two pulmonary veins in Slow Flow HD was 88.3% and 76.2%, and all four pulmonary veins in 11.6% (p < 0.05). The identification rate of group I, II and III were 76.4%, 88.9% and 96.0%, respectively. The identification rate was 45.1% in the transabdominal ultrasound group and 83.8% in the transvaginal ultrasound group. The identification rate was 62.5% in the BMI ≥ 25 group and 94.7% in the BMI < 25 group (p < 0.05).

CONCLUSIONS

Slow Flow HD can detect PVs in early pregnancy more often than using CDFI. Slow Flow HD is a feasible and effective imaging technique for evaluating PVs in early pregnancy.

Feasibility of Transabdominal Real-time CDFI and HDFI Techniques for Fetal Pulmonary Vein Display in the First Trimester

OBJECTIVE

This study aimed to assess the feasibility and usefulness of transabdominal color Doppler flow imaging (CDFI) technology and the high-definition flow imaging (HDFI) technique in detecting fetal pulmonary veins (PVs) in the first trimester (11-13₊₆ weeks).

METHODS

From December 2018 to October 2019, 328 pregnant women with 328 normal singleton fetuses (crown-rump length: 45-84 mm) who had undergone CDFI and HDFI scans for fetal heart and vessel examination were enrolled in this study. The cases were divided into three groups according to the gestational age: group A, 11⁺⁰ -11⁺⁶ weeks; group B, 12⁺⁰ -12⁺⁶ weeks; and group C, 13⁺⁰ -13⁺⁶ weeks. Baseline sonograms and CDFI and HDFI images were analyzed by two senior radiologists independently and blindly. The abilities of CDFI and HDFI to display PVs were compared.

RESULTS

Successful PV display rates via CDFI and HDFI were 2.3% and 68.2% (P<0.01), 22.4% and 82.4% (P<0.01), 41.5% and 91.2% (P<0.01) for group A, group B, and group C, respectively. The total successful display rates for the two methods were 28.9% (CDFI) and 84.8% (HDFI) (P<0.01).

CONCLUSIONS

The HDFI technique is more valuable than CDFI for detecting PVs in early pregnancy (11-13⁺⁶ weeks). HDFI can detect at least one PV in all cases and may be used to detect pulmonary venous anomalies early.

Utility of a modified vascular corrosion casting technique in the diagnosis of fetal total anomalous pulmonary venous connection

Total anomalous pulmonary venous connection (TAPVC) is a rare congenital cardiac malformation, and prenatal detection of TAPVC malformation remains a challenging. TAPVC can be easily missed or misdiagnosed in prenatal examinations. This study was aimed to use the modified vascular corrosion casting technique to prepare fetal cardiovascular casts with TAPVC and investigate the utility of cardiovascular casting for the demonstration of fetal TAPVC. The retrospective study enrolled twenty fetuses (22 to 29 + 4 gestational weeks) with TAPVC diagnosed by prenatal echocardiography and casting technique from May 2015 to May 2020. Pre- and postnatal medical records, including results obtained by prenatal ultrasound, postpartum computed tomography angiography, as well as anatomic and cardiovascular casting findings were carefully reviewed and analyzed. In twenty cases, 80% (16/20) had intra- or extracardiac malformations. The TAPVC types were supracardiac (n = 8), cardiac (n = 6), infracardiac (n = 4), and mixed (n = 2). The diagnosis of 1 case each of supracardiac and cardiac TAPVC was modified to partial anomalous pulmonary venous connection; additionally, 4 malformations were missed and 2 were misdiagnosed, including an anomalous left brachiocephalic vein in supracardiac TAPVC, abnormal inflow of the hepatic vein and a double inferior vena cava in infracardiac TAPVC; and bilateral ductus arteriosus in infracardiac TAPVC; a tetralogy of Fallot in cardiac TAPVC that was corrected to right ventricular double outlet; and an absence of ductus arteriosus that was misdiagnosed as slim ductus arteriosus. Comparing with ultrasound, casting technique has its own superiority in exhibiting TAPVC abnormalities, especially in certain types such as course, origin and absence abnormalities of ductus. Postpartum cardiovascular casts can accurately depict the branch structure of the heart's larger vessels, and may be used as a clinical assessment and teaching method in complex cardiac malformations.