期刊
HUMAN BRAIN MAPPING
卷 39, 期 6, 页码 2412-2425出版社
WILEY
DOI: 10.1002/hbm.24011
关键词
7T MRI; cortical thickness; MP2RAGE; quantitative T-1; transmit bias field
资金
- Maastricht University
- Netherlands Organization for Scientific Research (NWO) [452-11-002]
- Technology Foundation STW [12724]
Determination of cortical thickness using MRI has often been criticized due to the presence of various error sources. Specifically, anatomical MRI relying on T-1 contrast may be unreliable due to spatially variable image contrast between gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). Especially at ultra-high field (>= 7T) MRI, transmit and receive B-1-related image inhomogeneities can hamper correct classification of tissue types. In the current paper, we demonstrate that residual B-1(+) (transmit) inhomogeneities in the T-1-weighted and quantitative T-1 images using the MP2RAGE sequence at 7T lead to biases in cortical thickness measurements. As expected, post-hoc correction for the spatially varying B-1(+) profile reduced the apparent T-1 values across the cortex in regions with low B-1(+), and slightly increased apparent T-1 in regions with high B-1(+). As a result, improved contrast-to-noise ratio both at the GM-CSF and GM-WM boundaries can be observed leading to more accurate surface reconstructions and cortical thickness estimates. Overall, the changes in cortical thickness ranged between a 5% decrease to a 70% increase after B-1(+) correction, reducing the variance of cortical thickness values across the brain dramatically and increasing the comparability with normative data. More specifically, the cortical thickness estimates increased in regions characterized by a strong decrease of apparent T-1 after B-1(+) correction in regions with low B-1(+) due to improved detection of the pial surface. The current results suggest that cortical thickness can be more accurately determined using MP2RAGE data at 7T if B-1(+) inhomogeneities are accounted for.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据