Related Experiment Video
Updated: Apr 15, 2026
17:06
Co-analysis of Brain Structure and Function using fMRI and Diffusion-weighted Imaging
Published on: November 8, 2012
27.2K
Changes of the apparent diffusion coefficient in brain diffusion-weighted images due to subject positioning: A
S Kumazawa1, D Ushijima1, H Yabuuchi1
1Department of health sciences, faculty of medical sciences, Kyushu university, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Journal of Neuroradiology = Journal De Neuroradiologie
|April 6, 2015
Summary
Subject positioning impacts brain imaging accuracy. Changes in head angle against the static magnetic field significantly alter cortical apparent diffusion coefficient (ADC) values in diffusion-weighted images.
Area of Science:
- Neuroimaging
- Medical Physics
- Quantitative MRI
Background:
- Apparent diffusion coefficient (ADC) is a key metric in brain diffusion-weighted imaging.
- Accurate ADC measurements are crucial for diagnosing neurological conditions.
Purpose of the Study:
- To determine if subject positioning relative to the static magnetic field affects cortical ADC values.
- Investigate the impact of head tilt angles on ADC measurements.
Main Methods:
- A digital brain phantom was used for magnetic resonance physics simulations.
- Simulated magnetic field inhomogeneities at varying head tilt angles (0-40 degrees).
- Calculated and compared average ADC values across different positions.
Main Results:
- Significant variations in average cortical ADC values were observed with changes in subject positioning (P < 0.05).
- Relative differences in ADC values ranged from approximately 1% to 12% due to positioning changes.
Conclusions:
- Subject positioning is a critical factor influencing the accuracy of cortical ADC measurements.
- Variations in head angle can lead to measurable differences in diffusion-weighted imaging results.
