摘要:
BACKGROUND: Fiber tracking with diffusion-weighted MRI has become an essential tool for estimating in vivo brain white matter architecture. Fiber tracking results are sensitive to the choice of processing method and tracking criteria. PURPOSE: To assess the variability for an algorithm in group studies reproducibility is of critical context. However, reproducibility does not assess the validity of the brain connections. Phantom studies provide concrete quantitative comparisons of methods relative to absolute ground truths, yet do no capture variabilities because of in vivo physiological factors. The ISMRM 2017 TraCED challenge was created to fulfill the gap. STUDY TYPE: A systematic review of algorithms and tract reproducibility studies. SUBJECTS: Single healthy volunteers. FIELD STRENGTH/SEQUENCE: 3.0T, two different scanners by the same manufacturer. The multishell acquisition included b-values of 1000, 2000, and 3000 s/mm(2) with 20, 45, and 64 diffusion gradient directions per shell, respectively. ASSESSMENT: Nine international groups submitted 46 tractography algorithm entries each consisting 16 tracts per scan. The algorithms were assessed using intraclass correlation (ICC) and the Dice similarity measure. STATISTICAL TESTS: Containment analysis was performed to assess if the submitted algorithms had containment within tracts of larger volume submissions. This also serves the purpose to detect if spurious submissions had been made. RESULTS: The top five submissions had high ICC and Dice >0.88. Reproducibility was high within the top five submissions when assessed across sessions or across scanners: 0.87-0.97. Containment analysis shows that the top five submissions are contained within larger volume submissions. From the total of 16 tracts as an outcome relatively the number of tracts with high, moderate, and low reproducibility were 8, 4, and 4. DATA CONCLUSION: The different methods clearly result in fundamentally different tract structures at the more conservative specificity choices. Data and challenge infrastructure remain available for continued analysis and provide a platform for comparison. LEVEL OF EVIDENCE: 5 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2020;51:234-249.
作者机构:
[Chen Hai-ting; Wang Zhi-yuan] Univ South China, Sch Architecture, Hengyang 421001, Hunan, Peoples R China.;[Wang Zhi-yuan] Cent South Univ, Sch Architecture & Art, Changsha 41007, Hunan, Peoples R China.;[Ou Yang-mei] Hunan Inst Traff Engn, Hengyang 42100, Hunan, Peoples R China.
会议名称:
4th International Workshop on Renewable Energy and Development (IWRED)
会议时间:
APR 24-26, 2020
会议地点:
ELECTR NETWORK
会议主办单位:
[Wang Zhi-yuan;Chen Hai-ting] Univ South China, Sch Architecture, Hengyang 421001, Hunan, Peoples R China.^[Wang Zhi-yuan] Cent South Univ, Sch Architecture & Art, Changsha 41007, Hunan, Peoples R China.^[Ou Yang-mei] Hunan Inst Traff Engn, Hengyang 42100, Hunan, Peoples R China.
会议论文集名称:
IOP Conference Series-Earth and Environmental Science
摘要:
Regional urban connection is mainly reflected in the connection between transportation and economy.Using accessibility and improved gravity model, this paper studies the traffic and economic relations and spatial pattern analysis among districts and counties in Hengyang based on the shortest travel time data and socio-economic data of 12 districts and counties in Hengyang, China.The results show that: firstly, in terms of traffic accessibility, there are 8 districts and counties in Hengyang that have higher accessibility than the average level of the city, and 4 districts and counties that have lower accessibility than the average level. Secondly, the accessibility of districts and counties in Hengyang generally presents an irregular circular distribution pattern, forming a core edge distribution feature with five districts in Hengyang as the core and gradually decreasing outward enclosure.Thirdly, from the perspective of economic connection, the 12 districts and counties in Hengyang are divided into five levels. The first level is the connection between Shigu District and Yanfeng District in the central city. The second level connection intensity is between Shigu District and Zhengxiang District in the central city and between Zhengxiang District and Hengyang County. The intensity of the three-level connection is the connection between the counties near the central urban area and the districts in the central urban area, as well as the connection between the counties near the central urban area and the neighboring counties. The fourth level connection refers to the connection between districts and counties far away from the central urban area and counties near the central urban area. The fifth level connection refers to the connection between districts and counties far away from the central urban area. Last but not least, the economic connection of Hengyang District and county forms the center-peripheral radiation pattern which diffuses from the area with the core of Shigu District, steamed Xiang District, Yanfeng District and Zhuhui District as the core, which presents the pattern of "one core and two centers" in space.
作者机构:
Sun Yat Sen Univ, Guangzhou, Peoples R China.;Sun Yat Sen Univ, Affiliated Hosp 3, Guangzhou, Peoples R China.;Chinese Univ Hong Kong, Sch Life Sci, Hong Kong, Peoples R China.;Foshan First Municipal Peoples Hosp, Foshan, Peoples R China.;Univ South China, Affiliated Hosp 1, Hengyang, Peoples R China.
会议名称:
Annual Meeting of the American-Society-of-Clinical-Oncology (ASCO)