1Medical Physics, Department of Radiology, University Medical Center Freiburg, Freiburg, Germany, 2Dept. of Computer Science and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan, 3Graduate Institute of Applied Physics, National Chengchi University, Taipei, Taiwan, 4Magnetic Resonance Development and Application Center, University Medical Center Freiburg, Freiburg, Germany, 5Dept. of Radiology, Veterans General Hospital Kaohsiung, Kaohsiung, Taiwan