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Thesis Format



Master of Engineering Science


Biomedical Engineering


de Ribaupierre, Sandrine


Insight into the rapidly developing brain in utero is scarce. Fetal functional magnetic resonance imaging (fMRI) is a technique used to gain awareness into the developmental process. Previous auditory task-based fMRI studies employed an external sound stimulus directly on the maternal abdomen. However, there has since been recommendation to cease doing so. We sought to investigate a reliable paradigm to study the development of fetal brain networks and postulate that by using an internal stimulus, such as the mother singing, it would result in activation of the fetal primary auditory cortex. Volunteers carrying singleton fetuses with a gestational age of 33-38 weeks underwent two stimulus-based block design BOLD fMRI series. All of the nine fetal subjects analyzed had activation in the right Heschl’s gyrus, and seven out of the nine fetal subjects had activation in the left Heschl’s gyrus when exposed to the internal acoustic stimulus. Ultimately, this internal auditory stimulus can be used to analyze the developing fetal brain.

Summary for Lay Audience

Functional MRI (fMRI) is a safe and non-invasive method to investigate the brain. Fetal fMRI provides the ability to investigate the developing brain of a fetus in utero. This thesis investigates areas of the fetal brain that are involved in auditory development such as the primary auditory cortex, putamen, and the middle cingulate cortex. Previous studies investigating fetal response to sound have placed magnetic resonance (MR) safe headphones on the abdomen of the mother. However, there has since been a recommendation to no longer do so. Thus, we proposed that by having the mother sing, representing the auditory stimulus, will activate the fetal primary auditory cortex. Nine pregnant volunteers underwent a stimulus-based fMRI. Our results suggest that out of the nine subjects analyzed, all nine had activation on the right primary auditory cortex and seven out of nine subjects had activation on the left. It can be concluded that this internal auditory stimulus of having the mother sing, can be used to analyze the developing fetal brain.