Condition number as a measure of noise performance of diffusion tensor data acquisition schemes with MRI.
J Magn Reson
; 147(2): 340-52, 2000 Dec.
Article
en En
| MEDLINE
| ID: mdl-11097823
ABSTRACT
Diffusion tensor mapping with MRI can noninvasively track neural connectivity and has great potential for neural scientific research and clinical applications. For each diffusion tensor imaging (DTI) data acquisition scheme, the diffusion tensor is related to the measured apparent diffusion coefficients (ADC) by a transformation matrix. With theoretical analysis we demonstrate that the noise performance of a DTI scheme is dependent on the condition number of the transformation matrix. To test the theoretical framework, we compared the noise performances of different DTI schemes using Monte-Carlo computer simulations and experimental DTI measurements. Both the simulation and the experimental results confirmed that the noise performances of different DTI schemes are significantly correlated with the condition number of the associated transformation matrices. We therefore applied numerical algorithms to optimize a DTI scheme by minimizing the condition number, hence improving the robustness to experimental noise. In the determination of anisotropic diffusion tensors with different orientations, MRI data acquisitions using a single optimum b value based on the mean diffusivity can produce ADC maps with regional differences in noise level. This will give rise to rotational variances of eigenvalues and anisotropy when diffusion tensor mapping is performed using a DTI scheme with a limited number of diffusion-weighting gradient directions. To reduce this type of artifact, a DTI scheme with not only a small condition number but also a large number of evenly distributed diffusion-weighting gradients in 3D is preferable.
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Base de datos:
MEDLINE
Asunto principal:
Imagen por Resonancia Magnética
/
Cuerpo Calloso
Tipo de estudio:
Health_economic_evaluation
Límite:
Humans
Idioma:
En
Revista:
J Magn Reson
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
Año:
2000
Tipo del documento:
Article
País de afiliación:
Suecia