Quantitative susceptibility mapping for investigating subtle susceptibility variations in the human brain

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• 作者：Ferdin ; Schweser ; Karsten Sommer ; Andreas Deistung ; J¨¹rgen Rainer Reichenbach
• 关键词：COSMOS ; Calculation Of Susceptibility through Multiple Orientation Sampling ; GRE ; gradient (recalled) echo ; HEDI ; Homogeneity Enabled Dipole Inversion ; HEIDI ; Homogeneity Enabled Incremental Dipole Inversion ; MEDI ; Morphology Enabled Dipole Inversion ; QSM
• 刊名：NeuroImage
• 出版年：2012
• 出版时间：September, 2012
• 年：2012
• 卷：62
• 期：3
• 页码：2083-2100
• 全文大小：2925 K

文摘

Quantitative susceptibility mapping (QSM) is a novel magnetic resonance-based technique that determines tissue magnetic susceptibility from measurements of the magnetic field perturbation. Due to the ill-posed nature of this problem, regularization strategies are generally required to reduce streaking artifacts on the computed maps. The present study introduces a new algorithm for calculating the susceptibility distribution utilizing a priori information on its regional homogeneity derived from gradient echo phase images and analyzes the impact of erroneous a priori information on susceptibility map fidelity. The algorithm, Homogeneity Enabled Incremental Dipole Inversion (HEIDI), was investigated with a special focus on the reconstruction of subtle susceptibility variations in a numerical model and in volunteer data and was compared with two recently published approaches, Thresholded K-space Division (TKD) and Morphology Enabled Dipole Inversion (MEDI). HEIDI resulted in susceptibility maps without streaking artifacts and excellent depiction of subtle susceptibility variations in most regions. By investigating HEIDI susceptibility maps acquired with the volunteers' heads in different orientations, it was demonstrated that the apparent magnetic susceptibility distribution of human brain tissue considerably depends on the direction of the main magnetic field.