Detailed flow visualization in fetal and neonatal hearts using 2-D speckle tracking

Abstract

Abstract-Two-dimensional blood speckle tracking has shown promise for measuring the complex flow patterns in neonatal hearts when based on linear array and high-frame-rate plane wave imaging. For phased array pediatric imaging, additional challenges emerge due to the reduced lateral bandwidth and increased imaging depth and field-of-view. In this work, a clinically approved setup with pediatric phased array probes and unfocused pulses was used to investigate the potential of blood speckle tracking to acquire 2-D vector velocity maps for neonates, infants and children with congenital heart disease.Promising results were observed for depths < 10 cm, where complex cardiac flow patterns could be visualized. However, due to the small aperture available, diffraction effects could be observed. Further, as the depth dependent lateral resolution and loss in signal-to-noise ratio degrades tracking results for increasing depths, a larger feasibility study is needed to establish clinical viability.Vector velocity maps were also obtained from fetal examinations with the phased array setup as well as with a diverging beam setup on a research scanner, where detailed secondary flows such as the vortex formations in the ventricles of the fetal heart could be observed.

Multidimensional fetal flow imaging with cardiovascular magnetic resonance: a feasibility study

“…7. Complex cardiac flows with vortex formations are observed in both ventricles consistent with previous fetal ultrasound findings [23]. The figure also illustrates flow vortices in the DAo, consistent with adult 4D PC-CMR studies of flow in the proximal aortic arch [24].…”

In Vivo Intracardiac Vector Flow Imaging Using Phased Array Transducers for Pediatric Cardiology

“…For the B-mode images, conventional focused transmit beams were used to obtain sufficient image quality. The resulting duplex frame rate was 40-80 frames/s, depending on the Doppler packet size (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22), image depth (<10 cm), and ROI width.…”

“…Our aim of this paper was to develop and investigate the blood ST methods based on phased array imaging for pediatric cardiology without the use of contrast agents. A clinically approved imaging setup was implemented for phased array probes, utilizing broad pulses to acquire real-time color flow data at high-data acquisition rates, as also described in [11]. Two pediatric patients (one newborn and one 11 years old) were included in the study.…”