제3회 막수 포럼 (The 3rd Last Wednesday Forum)
일시: 2013년 5월 29일, 12:00~13:00
장소: 전산학과(E3-1) 4층 오상수 영상강의실
Metal Artifact Reduction in CT image
Presenter: 전수민 (이창옥 교수님 연구실)
In computed tomography (CT) there is an increasing demand for effective removal of metal artifact since the metallic objects cause the loss of information about biological structures, for example, at the dental surface of the metal restoration and their adjacent biological structures and so on. We consider the methods for reducing the metal artifact in CT image.
Compressed Sensing for fMRI at High Field
Presenter: Paul Kyu Han (박성홍 교수님 연구실)
Conventional functional magnetic resonance imaging (fMRI) technique known as gradient recalled echo (GRE) echo-planar imaging (EPI) is sensitive to image distortion and degradation caused by local magnetic field inhomogeneity at high magnetic fields. Non-EPI sequences such as spoiled gradient echo and balanced steady state free precession (bSSFP) have been proposed as an alternative high-resolution fMRI technique; however, the temporal resolution of these sequences is lower than the typically used GRE-EPI fMRI. One potential approach to improve the temporal resolution is to use compressed sensing (CS). In this study, we tested the feasibility of k-t FOCUSS - one of the high performance CS algorithms for dynamic MRI - for non-EPI fMRI at 9.4T using the model of rat somatosensory stimulation. To optimize the performance of CS reconstruction, different sampling patterns and various k-t FOCUSS variations were investigated. Experimental results show that an optimized k-t FOCUSS algorithm with acceleration by a factor of 4 works well for non-EPI fMRI at high field under various statistical criteria, which confirms that a combination of CS and a non-EPI sequence may be a good solution for high resolution fMRI at high fields.