A research team from Poland says it used three different MRI techniques to further explore how alcohol use by expectant mothers can affect their children's mental and physical development.

They presented their findings Sunday at the Radiological Society of North America's 98th annual meeting in Chicago.

The study group included 200 children who were exposed to alcohol during their fetal stage and 30 children whose mothers did not drink while pregnant or during lactation. Researchers used magnetic resonance imaging (MRI) to evaluate the size and shape of the corpus callosum, the bundle of nerve fibers that forms the major communication link between the right and left halves of the brain, in the two groups.

The team says MRI results showed statistically significant thinning of the corpus callosum in the children exposed to alcohol compared with the other group.

"These changes are strongly associated with psychological problems in children," Dr. Andrzej Urbanik, chair of the Department of Radiology at Jagiellonian University in Krakow, Poland, said in a statement.

The team also used diffusion weighted imaging (DWI) to study six areas of the central nervous system in the children. Those in the alcohol group exhibited statistically significant increases in diffusion on DWI compared with the other children, the study says.

"The increase of diffusion indicates neurological disorders or damage to the brain tissue," Dr. Urbanik said.

And to non-invasively study metabolism in the children's brains, the researchers used hydrogen magnetic resonance spectroscopy and the results revealed a complex collection of metabolic changes.

According to reports, care for children affected by fetal alcohol syndrome in the U.S. have been estimated at $4 billion annually.