STIMULUS: STillbirth risk Identification using MULtiparametric UltraSound
Annually, around three million children die in utero at a viable gestational age as stillbirths, more than the total number of infant deaths due to all other causes combined. Effective screening tests for stillbirth prediction with an opportunity for adopting appropriate intervention can significantly reduce the occurrences of fetal deaths. In collaboration with the University of British Columbia, we propose STIMULUS (funded by Wellcome Leap In Utero project), an accessible, patient-friendly, inexpensive, and effective screening tool to provide a real-time, non-invasive, objective assessment of the risk of stillbirth at regular intervals. The objectives of the project are: (1) to develop a quantitative ultrasound (QUS) biomarker-based screening tool for predicting stillbirth risk and (2) to translate the screening tool to accessible, portable ultrasound systems. To address the multifactorial, gestational-age dependent etiologies leading to stillbirth, the first objective focuses on the identification of a broad range of QUS parameters obtained from raw radiofrequency (RF) ultrasound (US) data of the placenta, fetus, and cervix, as biomarkers of placental development and fetal growth and wellbeing. Towards improving accessibility to enable regular objective assessment (daily or even hourly), the second objective will focus on the integration of STIMULUS in a handheld US system (with the support from our current partner Clarius).
Research Announcement
SWAVE 2.0: Shear-Wave Absolute Vibro-elastography in the Placenta Ex-vivo
The placenta, being a dynamic organ, undergoes structural and functional change throughout the pregnancy. Antenatal monitoring of placentas could provide a useful clinical tool to predict pregnancy outcome. Correlative imaging acquires and aligns complementary information using multiple multiscale modalities, such as ultrasound (US) and magnetic resonance imaging (MRI) and combines the high axial and lateral resolution achievable using US and the large field-of-view in MRI. More importantly, the quantitative counterparts of these modalities, qMRI (quantitative MRI) and QUS (quantitative ultrasound), can further offer complimentary information regarding the placental micro- and macro- structure, perfusion and function. The combination of the different properties obtained through multimodal imaging and aligned using a correlative registration process would present a unique signature of a tissue type or its pathological state. In Project SWAVE 2.0, we propose a multimodal image acquisition protocol to acquire and align data from ex vivo placenta specimens derived from both healthy pregnancies and pregnancies with preeclampsia and/ or intrauterine growth restriction. In this project, we acquire multimodal image data, including multiparametric quantitative ultrasound (such as elasticity, attenuation coefficient estimate, backscatter coefficient and effective scatterer diameter), multiparametric MRI, and histopathology. We proposed a co-registration method using surface markers and external fiducials to enable alignment and fusion of multimodal data. We also investigate the efficacy of QUS parameters as biomarkers of pregnancy outcomes.