Imaging the fetal brain with functional MR can help scientists better understand how functional networks develop, but the images usually get distorted when the fetus moves. Researchers at the University of Washington (UW) have developed a new technique that corrects for motion and generates a 4-D reconstruction of brain activity.

Functional MR can now be used to evaluate normal brain development as well as the impact that a mother’s diet and the environment have on the functional development of the fetal brain.

The UW research is focusing on the default mode network of the brain, which is when someone is daydreaming and not concentrating on a task. It’s not well known how that network develops, but fetal brains are usually in that default mode.
In a study that was published in August in the journal, Human Brain Mapping, the researchers created a 4-D movie of fetal default mode network activity using functional MR. When the fetus moves, it blurs the image and makes it difficult to determine where any signals of activity are coming from.

Only one measurement is captured for each position at each time point, but with the new technique multiple measurements can be captured that provide slightly different perspectives. The researchers were then able to reposition the images to determine an estimate of what the activation would look like over the course of a few minutes.

They tested the method on adults first, by having them purposely move their heads in the MR scanner, and demonstrated that they would successfully quantify brain activity in moving subjects. They then imaged eight fetuses between 32 and 37 weeks of pregnancy and compiled the images to create a 4-D view of the brains over a five-minute time frame.

The technique can also be used to evaluate the differences in brain development in premature and full-term babies, the effects of alcohol, drug use and stress during pregnancy, and babies that develop neurodevelopmental disorders like autism.

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