LEUKOCYTE TRAFFICKING IN RESPONSE TO MAGNETIC-RESONANCE-IMAGING

There were significant increases in total T cells and in T helper cell s in blood samples collected immediately following magnetic resonance imaging (MRI) examinations of brains of male volunteers and patients. Percentages of total lymphocytes and suppressor/cytotoxic T cells decr eased in these same samples. There were no significant changes in any leukocyte subpopulations in males undergoing lumbar MRI and females un dergoing brain MRI. Thus, it is unlikely that stress from the procedur e is the explanation for these changes. Our results show that MRI has specific effects on a brain system(s) that controls lymphocyte subpopu lations.