About a year ago, a 42-year-old male gorilla named Fubo living in the Bronx Zoo's Congo Gorilla Forest suffered a seizure for no apparent reason. Concerned about his condition, zoo veterinarians put him on several seizure-controlling medications, which seemed to work, because he didn't have any more occurrences on the meds. But they were worried about the cause: Did Fubo have a brain tumor, a stroke or perhaps some kind of injury?

To find out, the Wildlife Conservation Society (WCS), which runs the Bronx Zoo in New York City, contacted the Brain Tumor Foundation (BTF), a nonprofit that provides free brain scans to people living in New York's five boroughs—especially those who cannot afford medical care and want to be screened for possible brain tumors.

Furry and weighing 275 pounds (125 kilograms), Fubo was no typical patient, but the BTF was willing to give it a go. On February 25, workers arrived at the zoo in BTF's Bobby Murcer Mobile MRI Unit, a trailer housing a magnetic resonance imaging (MRI) scanner, which uses magnetic fields and radio waves to generate images of structures inside the body. (The MRI-on-wheels is named after the late Bobby Murcer, the New York Yankees All-Star outfielder who went on to become a radio commentator, and who died last year from brain tumor complications.)

The whole process of sedating the gorilla, running the scan, and returning him to the Gorilla Forest took about three and a half hours, says veterinarian Paul Calle, director of the WCS's Zoological Health Program. "He was very stable and did well," Calle says, noting that Fubo is now back with his family and doing just fine.

To see Fubo getting his MRI and find out what his scan revealed, tour this slide show.

Slide Show: Fubo Gets a Brain Scan