Assessment of Motion and F0 Artifacts in 7T High Resolution T2*-Weighted Imaging in Alzheimers Disease Patients, and Application of a Navigator-Based Correction Scheme

Maarten J. Versluis^1,2, Johannes M. Peeters³, Sanneke van Rooden^1,2, Jeroen van der Grond¹, Mark A. van Buchem¹, Andrew G. Webb^1,2, Matthias J. van Osch^1,2

Image quality is decreased substantially in 7T high resolution T2*-weighted images in Alzheimers disease (AD) patients compared to younger volunteers. The source of the image artifacts was investigated in phantom experiments using translational/rotational motion parameters and f0 fluctuations from AD patients. It was found that image degradation by f0 fluctuations was a factor-of-four times larger than artifacts caused by movement typical of AD patients. By implementing a navigator echo correction for f0 fluctuations, the image quality increased considerably. This technique was succesfully applied in four AD patients showing significant image quality improvements.