The powerful technology could one day be used to generate images of criminals from the minds of witnesses.
The system, developed by US researchers, has been used to accurately reconstruct human faces based only on data from the brain scanner.
The scientists said the same approach could allow them to reconstruct images from people's dreams, memories and imagination in future.
"Our methods yield strikingly accurate neural reconstructions of faces," said Alan Cowen, a neuroscientist at the University of California, Berkeley.
"This represents a novel and promising approach for investigating face perception, but also suggests avenues for reconstructing 'offline' visual experiences - including dreams, memories and imagination," Cowen was quoted as saying by 'The Sunday Times'.
In the study, researchers showed six volunteers 300 faces while they lay in an MRI scanner. This process showed how their brains responded to dozens of different features ranging from blond hair and blue eyes to dark skin and beards.
Once they had built up the database of responses, across several areas of the brain, they showed the volunteers a set of new faces.
Then they measured how each volunteer's brain responded to the new image and, by comparing those responses to the database, reconstructed the image they were looking at.
Cowen and his co- researchers, Brice Kuhl of New York University and Professor Marvin Chun of Yale, believe that extracting facial images from people's brains is just the first step in a process that will one day produce machines able to read minds in a far more detailed way.