• Title, Summary, Keyword: 자기공명영상 보상물질

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A Study on Indirect Attachment Method of Compensation Materials to Increase Signal Intensity in Magnetic Resonance Imaging (자기공명영상검사 시 신호강도를 높이기 위한 보상물질의 간접부착 방식에 관한 연구)

  • Son, Soon-Yong
    • The Journal of the Korea Contents Association
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    • v.17 no.7
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    • pp.437-442
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    • 2017
  • Previously, studies on compensation material to increase the signal intensity have been conducted which does not affect the reading of images. However, the compensation material has a concern on patient infection as it is attached directly on the skin. Therefore, in this study, we tested an indirect attachment of the compensation material as an alternative method of the direct attachment. The silicon compensation material was fabricated in the form of a cylindrical bar and attached to each element of the 8 channel head coil. Then the signal intensities of the water phantom pre and post application of the silicon were measured. T1 and T2-weighted images were acquired using an 8-channel head coil and a 3.0T superconducting MRI. Signal intensities were measured by using an image measuring program. Paired t-test was used to verify if there were significant differences. The signal intensity before application of the silicon was significantly increased by 3.39% and 2.62% in T1 and T2 weighted images, respectively. Although the indirect attachment method had a limitation to completely replace the existing method, it was considered to be useful in patients with infectious diseases such as diabetic complications since it had a meaningful improvement in signal intensity based on the filling factor increase.

The review of neural basis for prosocial moral motivation and moral decision-making (친사회적-도덕적 동기 및 도덕적 의사결정의 신경학적 기제에 대한 개관 연구)

  • Jung, Ju-Youn;Han, Sang-Hoon
    • Science of Emotion and Sensibility
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    • v.14 no.4
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    • pp.555-570
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    • 2011
  • In order to do morally right behavior that we cognitively know, prosocial moral motivation is necessary. Previous studies revealed emotion is important for prosocial moral motivation. This was supported by cognitive neuroscience studies using functional magnetic resonance imaging(fMRI) in which the activity of ventral striatum(VS) was observed when people made moral decision. VS was originally known as the core area of reward process but recently VS was found to respond also to social reward and even feeling of prosocial emotion itself. However it is not clear why VS was activated when people experience prosocial moral sentiments. The aims of this review article were to find situations in which people are prosocially and morally motivated and to understand more about the role of emotion as a moral motivator by examining evidence regarding the neural network, including VS, of prosocial moral motivation and moral decision-making.

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Gaussian Filtering Effects on Brain Tissue-masked Susceptibility Weighted Images to Optimize Voxel-based Analysis (화소 분석의 최적화를 위해 자화감수성 영상에 나타난 뇌조직의 가우시안 필터 효과 연구)

  • Hwang, Eo-Jin;Kim, Min-Ji;Jahng, Geon-Ho
    • Investigative Magnetic Resonance Imaging
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    • v.17 no.4
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    • pp.275-285
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    • 2013
  • Purpose : The objective of this study was to investigate effects of different smoothing kernel sizes on brain tissue-masked susceptibility-weighted images (SWI) obtained from normal elderly subjects using voxel-based analyses. Materials and Methods: Twenty healthy human volunteers (mean $age{\pm}SD$ = $67.8{\pm}6.09$ years, 14 females and 6 males) were studied after informed consent. A fully first-order flow-compensated three-dimensional (3D) gradient-echo sequence ran to obtain axial magnitude and phase images to generate SWI data. In addition, sagittal 3D T1-weighted images were acquired with the magnetization-prepared rapid acquisition of gradient-echo sequence for brain tissue segmentation and imaging registration. Both paramagnetically (PSWI) and diamagnetically (NSWI) phase-masked SWI data were obtained with masking out non-brain tissues. Finally, both tissue-masked PSWI and NSWI data were smoothed using different smoothing kernel sizes that were isotropic 0, 2, 4, and 8 mm Gaussian kernels. The voxel-based comparisons were performed using a paired t-test between PSWI and NSWI for each smoothing kernel size. Results: The significance of comparisons increased with increasing smoothing kernel sizes. Signals from NSWI were greater than those from PSWI. The smoothing kernel size of four was optimal to use voxel-based comparisons. The bilaterally different areas were found on multiple brain regions. Conclusion: The paramagnetic (positive) phase mask led to reduce signals from high susceptibility areas. To minimize partial volume effects and contributions of large vessels, the voxel-based analysis on SWI with masked non-brain components should be utilized.