论文信息 - T2* Mapping with Background Gradient Correction Using Different Excitation Pulse Shapes

T2* Mapping with Background Gradient Correction Using Different Excitation Pulse Shapes

SUMMARY: Background gradients induced by magnetic susceptibility variations near air-filled cavities in the brain cause signal-intensity loss in gradient-echo images and shorten T2* considerably. With a correction method in which the exponential decay is restored with section-profile-dependent correction factors, parts of the signal intensity can be recovered. While uncorrected T2* values drop by 20% at a gradient strength of 75 μT/m, with correction and exponential excitation pulses, this boundary is pushed to 220 μT/m.

C. Preibisch | C. Preibisch | N.M. Hirsch | N. Hirsch

[1] R J Ordidge,et al. Rapid T2* mapping using interleaved echo planar imaging , 1999, Magnetic resonance in medicine.

[2] Weili Lin,et al. Quantitative Measurements of Cerebral Blood Oxygen Saturation Using Magnetic Resonance Imaging , 2000, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[3] Christine Preibisch,et al. Rapid single‐scan T 2* ‐mapping using exponential excitation pulses and image‐based correction for linear background gradients , 2009, Magnetic resonance in medicine.

[4] Ralf Deichmann,et al. Quantitative mapping of T1 and T2* discloses nigral and brainstem pathology in early Parkinson's disease , 2010, NeuroImage.

[5] Christine Preibisch,et al. Exponential excitation pulses for improved water content mapping in the presence of background gradients , 2008, Magnetic resonance in medicine.

[6] R. Deichmann,et al. Optimized EPI for fMRI studies of the orbitofrontal cortex: compensation of susceptibility-induced gradients in the readout direction , 2007, Magnetic Resonance Materials in Physics, Biology and Medicine.