PET scanner

PET scans may be able to predict how well patients will recover from severe brain injuries, according to a new study out of Belgium. The new finding provides a reliable method of predicting which patients will wake up from comas, and who will remain unresponsive.

Bedside tests for recovery from comas are currently only about 60 percent accurate. Researchers from the University of Liege examined 126 patients in long-term vegetative states. Using PET scans, the team of researchers was able to correctly predict recovery 74 percent of the time.

Medical researchers looked at victims of brain damage who had been unresponsive for over a year. They found one-third of the patients had hidden levels of consciousness.

Stephen Laureys, who led the study, found 13 of the victims in the study had levels of consciousness that could be detected by PET scans. Within one year, nine of those victims woke from their comas, two died and one remained unconscious.

“This really exciting study suggests for the first time that… PET could be used in the future to predict the likelihood that a patient may wake-up a long time after a severe brain injury,” Michael Bloomfield, from the Medical Research Council Clinical Sciences Centre in London, said.

Positron emission tomography (PET) uses the anti-matter equivalent of electrons, called positrons, to create three-dimensional images of the inside of patients. PET scans are able to measure the energy uptake of various parts of the brain, and areas without much activity are usually damaged. The process is expensive, which has limited use of the machines in diagnosis.

Ethical and legal questions will be raised concerning those victims determined to be permanently unconscious. This development could soon change the practice of medicine and healthcare laws throughout the nation.

PET scans are normally used for cancer patients, and this is the first study to seriously examine use of the technology for victims of brain damage.