HIPPOCAMPAL TRANSVERSE RELAXATION-TIMES IN PATIENTS WITH ALZHEIMER-DISEASE

PURPOSE: To determine whether hippocampal relaxation times in magnetic resonance (MR) imaging differ between patients with probable Alzheime r disease and elderly control subjects with normal cognition. MATERIAL S AND METHODS: MR imaging relaxation times were measured in the head a nd body of the right and left hippocampi in 123 subjects: 62 patients with Alzheimer disease (44 women, 18 men; age range, 65-89 years) and 61 elderly control subjects without cognitive impairment (39 women, 22 men; age range, 65-89 years). Hippocampal relaxation times were corre lated with clinical status (patient vs control subject), age, sex, lat erality (right vs left), and location within the hippocampus (body vs head). The hippocampal T2 value was correlated with the severity of di sease in the patients. RESULTS: No statistically significant differenc e in the relaxation times was found between the two clinical groups fo r the analysis of the right versus left hippocampi and the hippocampal head versus body. In both patients and control subjects, no correlati on was found between T2 measurements and age or sex. Twenty-seven pati ents had a clinical dementia rating (CDR) score of 0.5 (very mild deme ntia), 21 patients had a CDR score of 1.0 (mild dementia), and eight p atients had a CDR score of 2.0 (moderate dementia). The CDR score was not available in six patients. No statistically significant associatio n between T2 values and severity of disease was observed. CONCLUSION: MR relaxation time measurements in the hippocampus are not useful for the detection of Alzheimer disease.