CEREBRAL MAGNETIC-RESONANCE RELAXOMETRY IN HIV-INFECTION

A prospective, cross-sectional study was designed to determine the mag netic resonance relaxation times of cerebral white matter in human imm unodeficiency virus (HIV) infected individuals. T-1 and T-2 were estim ated at 1.5 T using four-point methods. Seventy-five HIV-1 seropositiv e subjects, 48 seronegative blood donors, and 17 seronegative homosexu al men were studied. Associations between relaxometry and clinical cla ssification, neurological status, immunological status, and qualitativ e MRT were investigated. Statistically significant differences in whit e matter T-1 relaxation time were found comparing low-risk control and AIDS groups (p < .005), seropositive subjects with neurological signs and those without (p < .005), and subjects with low (CD4 less than or equal to 200 x 10(6)/1) and high (CD4 > 200 x 10(6)/1) CD4 cell count s (p < .05). These findings add to the body of information that reveal s no HIV-related change in the brain before the onset of symptomatic i mmunosuppression and go someway to validating the previous visually ra ted, qualitative findings, Statistically significant differences in wh ite matter T-2 relaxation time were also found comparing the two contr ol groups (p < .005) highlighting the need for appropriate controls.