A comparative fMRI study: T2*-weighted imaging versus R2* mapping.
Functional magnetic resonance imaging experiments were performed in human motor cortex at 1.5 T by sampling two successive gradient recalled echo images in a single shot. Several aspects of brain mapping methods based on T2*-weighted imaging and R2* mapping were quantitatively compared. These include the detected activation volume, functional contrast (FC), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Studies based on the R2* mapping method have the following potential advantages: maximum functional contrast, less dependent on TE; and reduced inflow effects. R2* mapping produced the highest functional contrast, but not the largest activation volume due to the reduced signal-to-noise ratio and inflow effects. The sensitivity for activation detection is significantly correlated with the contrast-to-noise ratio, which is determined by both the SNR and FC.
Department of KARO, Division of Diagnostic Radiology, Karolinska Institutet, Huddinge University Hospital, SE-141 86 Stockholm, Sweden.
A B
AB
Wennerberg
T
T
Jonsson
H
H
Forssberg
T Q
TQ
Li
D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology / Q000502:physiology; D010100:Oxygen / Q000097:blood; D012680:Sensitivity and Specificity; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000502:physiology
D010100:Oxygen