Function and Safety of SlowflowHD Ultrasound Doppler in Obstetrics

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.

Volumetric B-mode ultrasound and Doppler Imaging: Automatic Tracking With One Single Camera

Vascular diseases may occur in the upper extremities, and the lesions can span the entire length of the blood vessel. One of the most popular methods to identify vascular disorders is ultrasound Doppler imaging. However, traditional two-dimensional (2D) ultrasound Doppler imaging cannot capture the entire length of a long vessel in one image. Medical professionals often have to painstakingly reconstruct three-dimensional (3D) data using 2D ultrasound images to locate the lesions, especially for large blood vessels. 3D ultrasound Doppler imaging can display the morphological structure of blood vessels and the distribution of lesions more directly, providing a more comprehensive view compared to 2D imaging. In this work, we propose a wide-range 3D volumetric ultrasound Doppler imaging system with dual modality, in which a high-definition camera is adopted to automatically track the movement of the ultrasound transducer, simultaneously capturing a corresponding sequence of 2D ultrasound Doppler images. We conducted experiments on human arms using our proposed system and separately with X-ray computerized tomography (X-CT). The comparison results prove the potential value of our proposed system in the diagnosis of arm vascular diseases.

Topography of the Heart: Mapping the Fetal Heart Through SlowflowHD

SlowflowHD is a Doppler Ultrasound modality that is typically geared toward visualization of small-size vessels and low velocity blood flow. In this commentary, we emphasize the importance of implementing the use of SlowflowHD as an adjunct to traditional Doppler modalities in the echocardiography screening in both the first and second trimester. This modality carries many characteristics that allow it to overcome the limitations of our current ultrasound modalities and facilitate mapping of the entirety of the fetal heart. The clinical implications are significant in regard to earlier acquisition of diagnostic information to guide decision-making and patient counseling.