Progressive multifocal leukoencephalopathy in a renal transplant recipient. Increased diagnostic sensitivity of computed tomographic scanning by double-dose contrast with delayed films.

A progressive, deteriorating neurologic disorder developed in a 28-year-old white man 10 years after he successfully received a living related donor kidney transplant. An extensive neurologic evaluation was unrevealing, including normal results of computed tomographic scanning of the brain with and without contrast medium. Repeated computed tomographic scanning after a double dose of radiocontrast medium in conjunction with delayed imaging revealed multiple areas of abnormal enhancement. This technique helped to direct brain biopsy, which led to the early diagnosis of progressive multifocal leukoencephalopathy and the institution of specific therapy.