A new approach from the University of Washington, Seattle, WA, images functional activity in the brains of individual fetuses. The technique allows a better look at how functional networks within the brain develop.

Functional MRI of a fetal brain, showing activated regions (red) of the default mode network.
(Credit: S. Seshamani, et al)

The study, led by Colin Studholme, Ph.D., a professor with joint appointments in pediatrics and bioengineering at the University of Washington, addresses a common problem of functional MRI: if the subject moves during the scanning, the images appear distorted.

By creating a way to correct for motion, the team created a four-dimensional reconstruction of brain activity in moving subjects. The 4D method opens the door for studies of fetuses, small children, and other subjects who do not stay still for long, like fetuses and small children.

The imaging development focused on the default mode network — a collection of regions that are active when the brain is at rest. Fetal brains are often in default mode, but little is known about how the network develops.

To create a four-dimensional movie of fetal default-mode network activity, the researchers used functional MRI — a technique that detects brain activity based on blood flow to the brain's active regions.

While typically just one measurement is collected for each position at each time point, the team collected multiple measurements, each providing slightly different perspectives.

Using the multiple analyses, the team respositioned the images to create an estimate of what the activation over a period of a few minutes would look like.

The new strategy enables investigations into both normal brain development and the effects of a mother’s diet or environment on the functional development of the fetal brain.

"What this is leading to is not just collecting data from individual babies but also understanding and building a four-dimensional map of brain activity and how it should emerge in a normal baby,” said Studholme.

The technique can also be used to compare differences in brain development in premature and full-term babies; detect the effects of alcohol, drug use, or stress during pregnancy; or determine if there are any prenatal differences in babies that go on to develop neurodevelopmental disorders like autism.