B-flow and B-flow spatio-temporal image correlation in visualizing fetal cardiac blood flow

Area of Science:

• Medical imaging
• Fetal cardiology
• Ultrasound technology

Background:

• Accurate visualization of fetal cardiac blood flow is crucial for prenatal diagnosis.
• Traditional two-dimensional ultrasound has limitations in depicting fine vascular structures.

Purpose of the Study:

• To assess the clinical utility of two-dimensional B-flow and four-dimensional (4D) B-flow spatio-temporal image correlation (STIC) for real-time fetal cardiac blood flow imaging.
• To evaluate the capability of these technologies in visualizing small fetal cardiac vessels.

Main Methods:

• Sixty-five normal singleton fetuses (21-39 weeks gestation) were examined using a VOLUSON 730 Expert ultrasound system.
• Two-dimensional B-flow imaging was followed by B-flow STIC acquisition (40-degree angle, 15s acquisition time).
• Cardiac vascular systems were analyzed offline using multiplanar and reconstructed 3D/4D rendered images.

Main Results:

• Extracardiac vessels (aortic arch, descending aorta, vena cava, ductus venosus, hepatic vein) were detected in 38/65 fetuses on 3D/4D images.
• Two or more pulmonary veins were visualized in all 65 cases.
• Detailed visualization of pulmonary veins showed 2 in 52.3%, 3 in 43.1%, and all 4 in 4.6% of cases on reconstructed 4D images.

Conclusions:

• B-flow and B-flow STIC enable visualization of small, low-velocity vessels like pulmonary veins.
• These techniques hold significant potential for detecting abnormalities in small cardiac vessels, including total anomalous pulmonary venous return.