TUESDAY, July 17, 2018 (HealthDay News) -- People with multiple sclerosis (MS) often live with uncertainty because it's hard to predict how quickly the disease will progress and how disabling it might become.

But researchers hope a new MRI test that tracks iron levels in the brain will help answer those questions.

The test -- called quantitative susceptibility mapping (QSM) -- looks at different areas of the brain and how much iron is deposited in each.

In some brain areas, a higher iron level is linked to longer disease duration, greater disability and disease progression, according to the researchers. One such area is the basal ganglia, a group of structures important for movement.

Surprisingly, in at least one other brain area -- the thalamus -- researchers linked low levels of iron to longer disease duration and greater disability and disease progression.

"Dysregulation of iron is something we know happens in MS. It's thought that iron contributes to the damage to the nervous system in MS, and learning more about how iron is dysregulated will help us understand the disease better," said Bruce Bebo. He's executive vice president of research for the National Multiple Sclerosis Society (NMSS).

"This is a piece of the puzzle that could help us speed diagnosis, but it's not the last piece of the puzzle," Bebo said. He called the study an important contribution from a well-regarded research team.

Study author Dr. Robert Zivadinov was not available for comment. He is a professor of neurology at the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, State University of New York.

Multiple sclerosis is a disease of the central nervous system. It interferes with the messages that nerve cells send within the brain and from the brain to the body, according to NMSS.

The disease is usually diagnosed when people are between 20 and 50 years old. Right now, there's no way to know at diagnosis what course the disease will take. There are four types of MS. Some don't cause lasting disability. Others do, NMSS explains.