J Korean Radiol Soc.
1996 Nov;35(5):633-643.
Functional Imaging Study of the Human Cerebral Cortex Activation on 1.5-T MR
- Affiliations
-
- 1Department of Radiology, Seoul National University College of Medicine, Korea.
Abstract
- PURPOSE
Adequate image post-processing software, essential for functional magnetic resonance imaging (fMRI)of cerebral cortex activation, is not readily available; this study aimed to evaluate the usefulness of a homemade post-processing system for fMRI and to investigate the physiologic and anatomic sources of activation signals infMRI.
MATERIALS AND METHODS
Twenty nine fMRIs of motor and visual cortices activated by hand movement and photic stimulation were performed using the GRE technique (TR/TE/flip angle : 80/60/40 degrees, 64x128 matrix) in 10 normal volunteers. By using post-processing software, final functional maps were subsequently obtained. In order to investigate physiologic and anatomic sources of activation signals, fMRIs of motor cortices were repeated with different echo times, flip angles and presaturation of adjacent sections. Activation signals were compared tocortical veins on MR venograms.
RESULTS
All fMRIs were successfully performed and those activation signals were detected in regions well known as motor and visual cortices. Mean percentage changes of signal intensities (PCSIs)of activation signals at echo times of 15, 30, and 60 msec were 2.9%, 3.5%, and 12.5%, respectively (p < 0.01).Mean PCSIs of activation signals with 40 degreesnd 10 degreeslip angles were 11.1% and 6.6% (p < 0.01), and those of activation signals without and with presaturation of the adjacent sections were 8.9% and 5.2% (p < 0.01). The shape and location of activation signals corresponded well with those of cortical veins.
CONCLUSION
The imagepost-processing system developed in this study is a useful method for fMRI of cerebral cortex activation. Both BOLD (blood oxygen level-dependent) and inflow effects contribute to the physiologic source of activation signals, and the cortical veins draining activated cortex are the main anatomic source of activation signals.
- Full Text Links
-
- Actions
-
Cited
- CITED
-
- Close
- Share
-
- Similar articles
-
- Functional Imaging of Cerebral Cortex Activation with a 1.5-T IVIR Imaging System
- Development of a System for Functional Mapping of the Human Brain Using 1.5-Tesla Magnet, and Its Applications
- Functional MR Imaging of Cerbral Motor Cortex: Comparison between Conventional Gradient Echo and EPI Techniques
- Functional MRI of Visual Cortex . Correlation between Photic Stimulator Size and Cortex Activation
- Functional MR Imaging of the Motor Cortex in Active and Passive Movement: Qualitative and Quantitative Changes
