The 65-year-old Democrat says he will undergo a PET scan Tuesday at the University of Mississippi Medical Center. PET scans, or positron-emission tomography, use X-rays and a radioactive substance to make images of the inside the body.
Gordon says physicians have found a lesion on his brain and told him he could either undergo laser surgery or take medication.
Gordon was hospitalized at UMC for six days before being released last Friday. He appeared at the Capitol twice last week. He says he left UMC both times without checking out — and without doctors' permission.