Quantitative assessment of the reproducibility of functional activation measured with BOLD and MR perfusion imaging: implications for clinical trial design.

摘要: BOLD contrast is the most commonly used functional MRI method for studies of brain activity. However, underlying physiological processes giving rise to measured signal changes (which include contribution from in cerebral blood flow (CBF), volume (CBV) and metabolic rate oxygen consumption (CMRO2)) vary substantially between sessions subjects. To determine whether direct CBF measurement a more reliable technique, we compared localisation activation reproducibility relative change by optimised versus using arterial spin labelling (ASL) technique. Data were collected within primary sensorimotor cortex normal healthy controls performing simple finger-tapping task over three imaging (two on same day one different day). The displacement foci was less than linear dimension voxel (2.4 mm), however, significantly closer nearest draining vein (P=0.030). For measurement, found that has lower inter-subject variation (P<0.05), enabling smaller sample size any given effect size, although intra-subject across not BOLD. provides optimal exploratory mapping, single time-point group study, reduced variance. In addition, reduction variance time measurements (non-significant) suggests it could potentially provide useful approach when assessing longitudinal changes.