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volumetric analysis of rock mass instability around haulage drifts in underground mines

Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 60-71页

作者： Shahé Shnorhokian Bryce MacNeil Hani S.Mitri Department of Mining and Materials Engineering McGill University

Haulage networks are vital to underground mining operations as they constitute the arteries through which blasted ore is transported to surface. In the sublevel stoping method and its variations, haulage drifts are excavated in advance near the ore block that will be mined out. Numerical modeling is a technique that is frequently employed to assess the redistribution of mining-induced stresses, and to compare the impact of different stope sequence scenarios on haulage network stability. In this study,typical geological settings in the Canadian Shield were replicated in a numerical model with a steeplydipping tabular orebody striking EW. All other formations trended in the same direction except for two dykes on either side of the orebody with a WNW-ESE strike. Rock mass properties and in situ stress measurements from a case study mine were used to calibrate the model. Drifts and crosscuts were excavated in the footwall and two stope sequence scenarios-a diminishing pillar and a center-out one-were implemented in 24 mining stages. A combined volumetric-numerical analysis was conducted for two active levels by comparing the extent of unstable rock mass at each stage using shear,compressive, and tensile instability criteria. Comparisons were made between the orebody and the host rock, between the footwall and hanging wall, and between the two stope sequence scenarios. It was determined that in general, the center-out option provided a larger volume of instability with the shear criterion when compared to the diminishing pillar one(625,477 m~3 compared to 586,774 m~3 in the orebody; 588 m~3 compared to 403 m~3 in the host rock). However, the reverse was true for tensile(134,298 m~3 compared to 128,834 m~3 in the orebody; 91,347 m~3 compared to 67,655 m~3 in the host rock)instability where the diminishing pillar option had the more voluminous share.

关键词： Haulage drifts Rock mass instability volumetric analysis Stope sequences Numerical modeling

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Quantitative volumetric analysis of the optic radiation in the normal human brain using diffusion tensor magnetic resonance imaging-based tractography

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Neural Regeneration Research 2014年第3期9卷 280-284页

作者： Dong-Hoon Lee Ji-Won Park Cheol-Pyo Hong Center for Medical Metrology Division of Convergence Technology Korea Research Institute of Standards and Science (KRISS) Department of Radiological Science College of Health Science Yonsei University Department of Physical Therapy College of Medical Science Catholic University of Daegu

To attain the volumetric information of the optic radiation in normal human brains, we per- formed diffusion tensor imaging examination in 13 healthy volunteers. Simultaneously, we used a brain normalization method to reduce individual brain variation and increase the accuracy of volumetric information analysis. In addition, tractography-based group mapping method was also used to investigate the probability and distribution of the optic radiation pathways. Our results showed that the measured optic radiation fiber tract volume was a range of about 0.16% and that the fractional anisotropy value was about 0.53. Moreover, the optic radiation probability fiber pathway that was determined with diffusion tensor tractography-based group mapping was able to detect the location relatively accurately. We believe that our methods and results are help- ful in the study of optic radiation fiber tract information.

关键词： nerve regeneration optic radiation diffusion tensor imaging diffusion tensor tractogra-phy magnetic resonance imaging volumetric analysis probability map group mapping visualiza-tion individual variation neural regeneration

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Extravasated contrast volumetric assessment on computed tomography angiography in gastrointestinal bleeding:A useful predictor of positive angiographic findings

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World Journal of Radiology 2024年第5期16卷 115-127页

作者： Laura Maria Cacioppa Chiara Floridi Alessandra Bruno NicolòRossini Tommaso Valeri Alessandra Borgheresi Riccardo Inchingolo Francesco Cortese Giacomo Novelli Alessandro Felicioli Mario Torresi Pietro Boscarato Letizia Ottaviani Andrea Giovagnoni Division of Interventional Radiology Department of Radiological SciencesUniversity Politecnica Delle MarcheAncona 60126Italy Department of Clinical Special and Dental SciencesUniversity Politecnica Delle MarcheAncona 60126Italy Division of Radiology Department of Radiological SciencesUniversity Hospital"Azienda Ospedaliero Universitaria Delle Marche"Ancona 60126Italy Interventional Radiology Unit "F Miulli"Regional General HospitalAcquaviva delle Fonti 70021Italy Department of Radiology IRCCS INRCAAncona 60126Italy

BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed *** tomography angiography(CTA)plays a pivotal role in the early identification of upper and lower GIB and in the prompt treatment of the *** To determine whether a volumetric estimation of the extravasated contrast at CTA in GIB may be a predictor of subsequent positive angiographic *** In this retrospective single-centre study,35 patients(22 men;median age 69 years;range 16-92 years)admitted to our institution for active GIB detected at CTA and further submitted to catheter angiography between January 2018 and February 2022 were ***-three(65.7%)patients underwent endoscopy before *** volumetry was evaluated in both arterial and venous phases via a semi-automated dedicated *** rate was obtained from volume change between the two phases and standardised for unit *** were divided into two groups,according to the angiographic signs and their concordance with *** Upper bleeding accounted for 42.9%and lower GIB for 57.1%.Mean haemoglobin value at the admission was 7.7 g/dL.A concordance between positive CTA and direct angiographic bleeding signs was found in 19(54.3%)*** no significant differences in terms of bleeding volume in the arterial phase(0.55 mL vs 0.33 mL,P=0.35),a statistically significant volume increase in the venous phase was identified in the group of patients with positive angiography(2.06 mL vs 0.9 mL,P=0.02).In the latter patient group,a significant increase in bleeding rate was also detected(2.18 mL/min vs 0.19 mL/min,P=0.02).CONCLUSION In GIB of any origin,extravasated contrast volumetric analysis at CTA could be a predictor of positive angiography and may help in avoiding further unnecessary procedures.

关键词： Gastrointestinal haemorrhage Computed tomography angiography volumetric analysis Computer-assisted image interpretation Therapeutic embolization Transcatheter arterial embolization

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Comparative study of the sectional slice of the anterior commissure and the internal capsule with its MRI images

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中国民康医学 2015年第14期 180-181页

作者：王单单 MA Wenyi Zhang Xiaoyang YUAN Lixiang YUAN Wu LI Yunsheng Department of Anatomy and Histo - embryology Tianjin Medical University Department of Medical Imaging and Nuclear Medicine Tianjin First Center Hospital

Objective:The brain of 100 normal persons were performed MRI scan and image analysis.12adult female brain specimens fixed by formalin,were made into the thickness of 0.5mm by celloidin embedding *** analyzed the anatomical position of the relationship about the anterior limb of internal capsule and the anterior commissure in eollodion-embedded plans,and then compared with the brain MRI of normal *** also further compared the statistical differences of the internal capsule’s *** research aimed to provide a reliable sectional anatomic basis for the study of the central nervous system and deep brain stimulation to treat the mental neurological ***:*** observation of celloid in brain slices horizontal section:Approximately 130 slices of each specimen,from the parietal lobe,the internal capsule was the typical structure"><"on the level of about 35 *** the level of about 41mm,the anterior commissure was"arc"through the bottom head of the caudate nucleus connecting the bilateral anterior limb,which located between the caudate nucleus and the lentiform *** posterior limb of internal capsule situated between the dorsal thalamus and the lentiform nucleus on the level of about 46 *** section:about 150 slices of per specimen,from the former lateral ventricle horn back,on the level of about 16 mm the anterior commissure was"arch"connecting the anterior *** 28 mm dimension,the interior capsule fore limb located between the caudate nucleus and the putamen,the posterior limb of internal capsule located between the globus pallidus and the dorsal thalamus,extending down to the cerebral *** section:about 180 slices of per specimen,from the outside to the inside at the beginning of the temporal lobe,the corona radia taextends between the putamen and dorsal thalamus,and then formsthe posterior limb of the internal capsule at the level of about 21 *** 25 mm level,fore limb located between the caudate n

关键词： Human brain Anterior commissure Internal capsule Celloid in MRI three-dimensional reconstruction volumetric analysis

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