MONDAY, Jan. 11 (HealthDay News) -- New research shows that PET brain scans can diagnose which type of Parkinson's-related disease a person has.

Between 1998 and 2006, researchers scanned the brains of 167 patients who had signs of Parkinsonism but hadn't been specifically diagnosed. They used PET (positron emission tomography) technology.

The researchers found that the scans allowed them to differentiate between idiopathic Parkinson's disease, multiple system atrophy and progressive supranuclear palsy, although the diagnoses sometimes differed from those of doctors who assessed the patients.

According to the researchers, who report their findings online in advance of print publication in the February issue of The Lancet Neurology, early diagnosis helps doctors place patients in proper drug trials.

In an accompanying commentary, Professor Angelo Antonini of the IRCCS San Camillo, Venice, and Parkinson Institute in Milan, Italy, wrote: "The clinical and research relevance of these findings should not be underestimated. Neuroprotective and disease-modifying drug research is intensifying, and results mostly rely on accurate early diagnosis."

More information

The National Institutes of Health has more on Parkinson's disease.