Combination of MRI hippocampal volumetry and arterial spin labeling MR perfusion at 3-Tesla improves the efficacy in discriminating Alzheimer's disease from cognitively normal elderly adults.

Background: Structural magnetic resonance imaging has been employed for evaluation of medial temporal atrophy in patients with Alzheimer’s disease (AD). Arterial spin labeling (ASL) technique could detect cerebral perfusion abnormalities in AD. Objective: We hypothesized that combination of hippocampal volumetry and cerebral blood flow yield higher accuracy than either method alone in discriminating AD patients from cognitively normal elderly adults. Materials and Methods: 13 AD patients and 15 healthy controls were studied using a 3-tesla scanner. Standardized T1W 3D volumetric Fast Field Echo and QUASAR ASL sequences were employed for cerebral volumetry and perfusion respectively. Manual Right and left hippocampal volumetry was performed manually by ANALYZE software, with total intracranial volume normalization. ASL data were analyzed by institutional specially-design software to calculate cerebral blood flow of region-ofinterests placed at the middle and posterior cingulate gyri. Results: Right and left hippocampal volumes and middle and posterior cingulate gyri cerebral blood flows were significantly lower in the patients than in the controls (independent-samples t-tests, p < 0.05), and prediction accuracies of 89.3%, 82.1%, 75.0% and 71.4% were achieved for each of the above parameters, respectively. In distinguishing patients from controls using corresponding optimized cut-off values, various combinations of these parameters were used to create the Receiver Operating Characteristic curves. The highest area under curve value was 0.944, by combining cerebral blood flow at the middle cingulate gyrus, normalized right and left hippocampal volumes. Conclusions: A ‘one-stop-shop’ magnetic resonance study of combined hippocampal volumetry and cerebral perfusion has improved efficacy in discriminating AD patients from cognitively normal elderly adults.