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Gamma knife treatment for refractory epilepsy in seizure focus localized by positron emission tomography/CT
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作者 Xia Bai Xuemei Wang +4 位作者 Hongwei Wang Shigang Zhao Xiaodong Han Linjun Hao Xiangcheng Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第36期2937-2943,共7页
A total of 80 patients with refractory epilepsy were recruited from the Inner Mongolia Medical College Affiliated Hospital. The loci of 60% of the patients could be positioned using a combined positron emission tomogr... A total of 80 patients with refractory epilepsy were recruited from the Inner Mongolia Medical College Affiliated Hospital. The loci of 60% of the patients could be positioned using a combined positron emission tomography/CT imaging modality. Hyper- and hypometabolism foci were examined as part of this study. Patients who had abnormal metabolism in positron emission tomography/CT imaging were divided into intermittent-phase group and the seizure-phase group. The intermittent-phase group was further divided into a single-focus group and a multiple-foci group according to the number of seizure foci detected by imaging. Following gamma knife treatment, seizure frequency was significantly lower in the intermittent-phase group and the seizure-phase group. Wieser's classification reached Grade I or II in nearly 40% of patients. Seizure frequency was significantly lower following treatment, but Wieser's classification score was significantly higher in the seizure-phase group compared with the intermittent-phase group. Seizure frequency was significantly lower following treatment in the single-focus group, but Wieser's classification score was significantly higher in the single-focus group as compared with the multiple-foci group. 展开更多
关键词 EPILEPSY SEIZURE positron emission tomography/ct gamma knife radiosurgery METABOLISM 18F-FLUORODEOXYGLUCOSE neural regeneration
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Dynamic ^(18)F-fluorodeoxyglucose positron emission tomography/CT in hibernoma: enhanced tracer uptake mimicking liposarcoma
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作者 Christos Sachpekidis Safwan Roumia +1 位作者 Matthias Schwarzbach Antonia Dimitrakopoulou-Strauss 《World Journal of Radiology》 CAS 2013年第12期498-502,共5页
We report on two cases of patients with fat-equivalent masses in computed tomography(CT),referred to our department for dynamic positron emission tomography/CT(dPET/CT)with18F-fluorodeoxyglucose(18FFDG)in order to inv... We report on two cases of patients with fat-equivalent masses in computed tomography(CT),referred to our department for dynamic positron emission tomography/CT(dPET/CT)with18F-fluorodeoxyglucose(18FFDG)in order to investigate their dignity.Both qualitative and quantitative information,as derived from dPET/CTs,couldn’t exclude a high-grade liposarcoma:Visual evaluation,revealed a large hypermetabolic focus of intense18F-FDG uptake in each patient(average SUVs 8.3 and 11.3).Regression-based parametric imaging demonstrated an enhanced distribution volume,which correlates to perfusion,and a high phosphorylation rate that correlates to cell viability.Kinetic analysis,based on a two-tissue compartment model demonstrated an enhanced FDG transport k1and an enhanced phosphorylation rate k3.A non-compartmental approach based on fractal dimension revealed also enhanced values.However,final diagnosis was based on biopsy,which revealed hibernoma,a benign brown fat tumor.Brown adipose contains increased numbers of mitochondria and a high-rate of glucose metabolism.Therefore,they have increased FDG uptake.The evaluation of lipomatous lesions on CT,with high FDG uptake,should include the possibility of hibernoma as a differential diagnosis. 展开更多
关键词 Hibernoma DYNAMIC POSITRON emission tomography/ct 18F-FLUORODEOXYGLUCOSE Kinetic Modeling Parametric imaging
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Three-dimensional characterization of intermetallic compound formation in magnesium alloys with micro X-ray computed tomography
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作者 SUN Wei HU Xiao-juan +5 位作者 DENG Yang-chao YANG Yang YAO Hu ZHANG Yong-hong ZHANG Rui-feng ZENG Guang 《Journal of Central South University》 2026年第1期160-174,共15页
This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both commo... This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography.By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy,we aim to characterize the nucleation,growth,and distribution of Al-Mn and eutectic intermetallics across various stages of solidification.The non destructive imaging technique employed in this research provides high-resolution,three-dimensional insights into the microstructural development,allowing for a detailed examination of the morphology,spatial arrangement,and interconnectivity of intermetallic phases.This approach overcomes limitations of traditional two-dimensional metallographic methods,offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification. 展开更多
关键词 magnesium alloy X-ray computed tomography SOLIDIFICATION INTERMETALLICS DEFEctS
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Optical coherence tomography for surgical demarcation of GI tumor margins for accelerated decision-making during the surgical resection of tumors
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作者 Mohamed Nijas Veluthedath Anuradha Sekaran +3 位作者 Manjoosha R Yerrapragada Pradeep Rebala Duvvuru Nageshwar Reddy Renu John 《Journal of Innovative Optical Health Sciences》 2026年第2期116-128,共13页
Gastric cancer,including stomach tumors,poses significant health challenges due to late-stage diagnosis and limited early detection methods.Accurate imaging and precise tumor margin demarcation are critical for effect... Gastric cancer,including stomach tumors,poses significant health challenges due to late-stage diagnosis and limited early detection methods.Accurate imaging and precise tumor margin demarcation are critical for effective treatment planning and improved patient outcomes.Conventional imaging techniques,such as endoscopy and histopathology,provide valuable diagnostic information but cannot offer real-time assessment.We aim to explore the application of optical coherence tomography(OCT),combined with statistical and machine learning methods,for rapid tumor margin demarcation in gastrointestinal(GI)cancer tissues in exvivo.GI tumor specimens from 17 patients were imaged intraoperatively with OCT.Quantitative features were extracted from the images,and statistical and machine learning analyses were applied to distinguish tissue types.Subsequent histopathological evaluation was used as the reference standard for validation.The combination of OCT imaging and data-driven analysis enables clear differentiation between healthy,marginal and tumor tissues in near real-time.The KNN model achieved the highest classification accuracy(0.921±0.040),with SVM(0.906±0.038)and Extra Trees(0.901±0.034)also demonstrating robust performance in discriminating tissue margins.OCT findings demonstrate strong agreement with histopathology.Integrated with statistical and machine learning techniques,OCT enables rapid assessment of GI tumor margins.This approach provides quantitative objectivity and real-time feedback,closely approximating histopathological analysis and supporting improved surgical decision-making. 展开更多
关键词 Optical coherence tomography gastrointestinal tumor tumor demarcation optical biopsy
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Characterizing dynamic segregation behavior in cemented paste during pipeline transport through electrical resistance tomography
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作者 Yingjie Chang Aixiang Wu +4 位作者 Zhu’en Ruan Shaoyong Wang Jiandong Wang Shulong Liu Shuangcheng Du 《International Journal of Minerals,Metallurgy and Materials》 2026年第3期798-808,共11页
Cement paste backfill(CPB)technology is a key method for mine waste treatment,and pipeline transport is critical for safe and efficient waste transfer.Variations in raw material properties can cause slurry segregation... Cement paste backfill(CPB)technology is a key method for mine waste treatment,and pipeline transport is critical for safe and efficient waste transfer.Variations in raw material properties can cause slurry segregation,increase pipeline wear and resistance,raise the risk of blockages or bursts,and disrupt operations.To study CPB slurry segregation during transport,CPB was prepared using cement as the cementitious material and unclassified tailings as inert materials.A small annular-tube device using an electrical resistance tomography system was developed to analyze its flow characteristics,and quantitative segregation assessment methods were developed.The results indicated that CPB conductivity increases with transport time but decreases with higher solid mass content,with the latter having a greater impact.At a low solid content,solid particles migrated toward the bottom of the pipe as the flow time increased,and the migratory behavior of the particles diminished as the solid content increased.At a flow rate of 1.25 m/s,the heterogeneity index for CPB with 58wt% solid content increased by 1.24 in 20 min,whereas that for CPB with 62wt% solid content increased by 2.17.Higher solid mass content amplifies the effect of conveying time on segregation,emphasizing the need to balance these factors for minimizing segregation.These insights can guide the optimization of mine pipeline transport systems. 展开更多
关键词 cement paste backfill electrical resistance tomography dynamic segregation pipeline transport
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C-SegNet:a practical approach for automated diabetic macular edema segmentation in optical coherence tomography images
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作者 Zhi-Yuan Guan Ge Deng +6 位作者 Shi-Long Shi Zhen Tang Xian-Kun Dong Qiu-Yi Li Shu-Jing Shen Yong-Ling He Xue-Jun Qiu 《Biomedical Engineering Communications》 2026年第2期15-22,共8页
Background:Diabetic macular edema is a prevalent retinal condition and a leading cause of visual impairment among diabetic patients’Early detection of affected areas is beneficial for effective diagnosis and treatmen... Background:Diabetic macular edema is a prevalent retinal condition and a leading cause of visual impairment among diabetic patients’Early detection of affected areas is beneficial for effective diagnosis and treatment.Traditionally,diagnosis relies on optical coherence tomography imaging technology interpreted by ophthalmologists.However,this manual image interpretation is often slow and subjective.Therefore,developing automated segmentation for macular edema images is essential to enhance to improve the diagnosis efficiency and accuracy.Methods:In order to improve clinical diagnostic efficiency and accuracy,we proposed a SegNet network structure integrated with a convolutional block attention module(CBAM).This network introduces a multi-scale input module,the CBAM attention mechanism,and jump connection.The multi-scale input module enhances the network’s perceptual capabilities,while the lightweight CBAM effectively fuses relevant features across channels and spatial dimensions,allowing for better learning of varying information levels.Results:Experimental results demonstrate that the proposed network achieves an IoU of 80.127%and an accuracy of 99.162%.Compared to the traditional segmentation network,this model has fewer parameters,faster training and testing speed,and superior performance on semantic segmentation tasks,indicating its highly practical applicability.Conclusion:The C-SegNet proposed in this study enables accurate segmentation of Diabetic macular edema lesion images,which facilitates quicker diagnosis for healthcare professionals. 展开更多
关键词 multi-scale input diabetic macular edema image segmentation optical coherence tomography
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Correlation between Optical Coherence Tomography Images and Histological Features in Female Reproductive Tract Lesions
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作者 Xianlin Yuan Yunmiao Chen Rutong Lin 《Journal of Clinical and Nursing Research》 2026年第2期169-175,共7页
Female reproductive tract lesions are diverse,ranging from benign inflammation to malignant tumors,all of which seriously threaten women’s health.Early accurate diagnosis is crucial for improving prognosis.As the“go... Female reproductive tract lesions are diverse,ranging from benign inflammation to malignant tumors,all of which seriously threaten women’s health.Early accurate diagnosis is crucial for improving prognosis.As the“gold standard”for diagnosis,histopathological examination is difficult to meet the needs of clinical screening and dynamic monitoring due to limitations such as invasiveness and sampling restrictions.Optical Coherence Tomography(OCT),as a non-invasive,real-time,and high-resolution imaging technology,can clearly display the microstructure of biological tissues,known as“optical biopsy”,and shows promising application prospects in the diagnosis of female reproductive tract lesions.This article systematically reviews the basic principles of OCT technology,the research progress on the correlation between OCT image features and histological features in lesions of different parts of the female reproductive tract such as the cervix and endometrium,analyzes the diagnostic efficacy,advantages and limitations of OCT technology,and prospects its future development direction,aiming to provide a reference for the clinical application of OCT technology in the diagnosis of female reproductive tract diseases. 展开更多
关键词 Optical Coherence tomography(Oct) HISTOPATHOLOGY Cervical cancer Endometrial cancer
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High-resolution 3D shallow crustal structure of Urumqi foreland thrust tectonic belt,northern Tianshan,based on ambient noise tomography
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作者 Xiang Huang Zhengyang Qiang +1 位作者 Weitao Wang Yuan Yao 《Earthquake Science》 2026年第1期86-96,共11页
The Urumqi foreland thrust tectonic belt exhibits complex geological structures and strong seismicity.Imaging its shallow crustal structure is of great significance for understanding its tectonic mechanism and seismog... The Urumqi foreland thrust tectonic belt exhibits complex geological structures and strong seismicity.Imaging its shallow crustal structure is of great significance for understanding its tectonic mechanism and seismogenic environment.We obtained a high-resolution S-wave velocity model of the shallow crust at depths of 0–8 km using ambient noise tomography applied to data from a dense seismic array.Sediments are generally thinner in the southeast and thicker in the northwest,with a maximum thickness of more than 8 km.Variations in the velocity structure near the Xishan,Wanyaogou,and Yamalike faults indicate that their formation was related to differences in the physical properties on either side of the fault.In addition,the faults exhibit thrusting of the low-velocity sides towards the high-velocity sides.In the study area,earthquakes rarely occur at depths of less than 3 km and are mostly concentrated in the high-velocity zone in the southern part.Below 3 km depth,more earthquakes were observed,mainly distributed near faults or in relatively high-velocity areas in the southern part.This suggests that high-velocity structures are more prone to stress accumulation,resulting in earthquakes.At 6–8 km depth,the densely distributed earthquakes in the northwestern part of the Bogda mountains are well-aligned with the northwest-oriented low-velocity zone observed in this study,suggesting that this weak zone likely controls seismicity in this area. 展开更多
关键词 ambient noise tomography shallow crustal structure thrust fault SEISMICITY Urumqi depression
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Combined multidetector computed tomography and gastrointestinal endoscopy for gastric cancer screening,preoperative staging,and lymph node metastasis detection
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作者 Le-Ping Ye Yan-Ping Zhang +4 位作者 Gang Chen Yi-Xian Wu Cheng-Long He Dong Wang Qiao Mei 《World Journal of Gastrointestinal Oncology》 2026年第1期200-210,共11页
BACKGROUND Early screening,preoperative staging,and diagnosis of lymph node metastasis are crucial for improving the prognosis of gastric cancer(GC).AIM To evaluate the diagnostic value of combined multidetector compu... BACKGROUND Early screening,preoperative staging,and diagnosis of lymph node metastasis are crucial for improving the prognosis of gastric cancer(GC).AIM To evaluate the diagnostic value of combined multidetector computed tomography(MDCT)and gastrointestinal endoscopy for GC screening,preoperative staging,and lymph node metastasis detection,thereby providing a reference for clinical diagnosis and treatment.METHODS In this retrospective study clinical and imaging data of 134 patients with suspected GC who were admitted between January 2023 and October 2024 were initially reviewed.According to the inclusion and exclusion criteria,102 patients were finally enrolled in the analysis.All enrolled patients had undergone both MDCT and gastrointestinal endoscopy examinations prior to surgical intervention.Preoperative clinical staging and lymph node metastasis findings were compared with pathological results.RESULTS The combined use of MDCT and gastrointestinal endoscopy demonstrated a sensitivity of 98.53%,specificity of 97.06%,accuracy of 98.04%,positive predictive value of 98.53%,and negative predictive value of 97.06%for diagnosing GC.These factors were all significantly higher than those of MDCT or endoscopy alone(P<0.05).The accuracy rates of the combined approach for detecting clinical T and N stages were 97.06%and 92.65%,respectively,outperforming MDCT alone(86.76% and 79.41%)and endoscopy alone(85.29% and 70.59%)(P<0.05).Among 68 patients with confirmed GC,50(73.53%)were pathologically diagnosed with lymph node metastasis.The accuracy for detecting lymph node metastasis was 66.00%with endoscopy,76.00%with MDCT,and 92.00% with the combined approach,all with statistically significant differences(P<0.05).CONCLUSION The combined application of MDCT and gastrointestinal endoscopy enhanced diagnostic accuracy for GC,provided greater consistency in preoperative staging,and improved the detection of lymph node metastasis,thereby demonstrating significant clinical utility. 展开更多
关键词 Multidetector computed tomography Gastrointestinal endoscopy Gastric cancer Preoperative staging Lymph node metastasis
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Chronic alcohol consumption on retinal microcirculation in healthy subjects:an optic coherence tomography angiography study
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作者 Dilan Yildiz Tahsin Uzundede +2 位作者 Akin Cakir Gamze Karatas Busra Coban 《International Journal of Ophthalmology(English edition)》 2026年第2期326-332,共7页
AIM:To investigate the effects of chronic alcohol consumption on retinal microcirculation by comparing different alcohol-consuming groups using optical coherence tomography(OCT)and OCT angiography(OCTA).METHODS:This o... AIM:To investigate the effects of chronic alcohol consumption on retinal microcirculation by comparing different alcohol-consuming groups using optical coherence tomography(OCT)and OCT angiography(OCTA).METHODS:This observational clinical study utilized a cross-sectional and prospective design,focusing on chronic alcohol consumers alongside a non-consuming control group.OCT/OCTA imaging parameters including central retinal subfield thickness(CST),subfoveal choroidal thickness(SCT),foveal avascular zone(FAZ)and vessel density(VD)in the superficial and deep capillary plexuses in both the macular and optic disc(OD)regions were recorded.Data were analyzed using SPSS 15.0;descriptive statistics were reported,group comparisons were performed with Chisquare,Kruskal–Wallis,and Bonferroni-corrected Mann–Whitney U tests,and relationships were assessed using Spearman correlation,with statistical significance set at P<0.05.RESULTS:A total of 160 eyes of 160 participants(110 females and 50 males with mean age 38.7±9.9y)who don’t smoke were divided into five groups:never,occasional,monthly,weekly and daily drinkers.The mean CST was 216.6±14.2μm and the mean SCT was 358.9±84.5μm.There was no statistically significantly difference in CST and SCT among the groups(P=0.890,0.799).Foveal superficial capillary plexuses(SCPs)VD was higher in monthly drinkers compared to occasional drinkers(P=0.015).Foveal VD in deep capillary plexus was also higher in monthly drinkers than in never and occasional drinkers(P=0.004,0.006).Nasal SCPs VD at the OD was higher in monthly drinkers compared to never drinkers(P=0.005).There was no significant difference FAZ area among the groups(P=0.071).CONCLUSION:Both superficial and deep microvascular structures in the inferior quadrants of macula are positively correlated with frequency of alcohol use.Also in our study results is that the monthly drinker group has uniquely higher VDs in both macula and OD.This leads us to consider moderate alcohol consumption may also have protective effects on retinal microcirculation. 展开更多
关键词 alcohol consumption foveal avascular zone retinal microcirculation optical coherence tomography angiography vessel density
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Application of electrical impedance tomographyguided PEEP titration in acute respiratory distress syndrome patients with intra-abdominal hypertension
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作者 Hui Wen Maiying Fan +5 位作者 Junliang Xiao Zhiqun Liu Xiaohua Liu Shuzhen Mao Xiaotong Han Fengling Ning 《World Journal of Emergency Medicine》 2026年第1期70-75,共6页
BACKGROUND:Individualized positive end-expiratory pressure(PEEP)titration is a crucial technique in mechanical ventilation therapy for acute respiratory distress syndrome(ARDS)patients with intra-abdominal hypertensio... BACKGROUND:Individualized positive end-expiratory pressure(PEEP)titration is a crucial technique in mechanical ventilation therapy for acute respiratory distress syndrome(ARDS)patients with intra-abdominal hypertension(IAH).This study aimed to evaluate the eff ectiveness of electrical impedance tomography(EIT)-guided PEEP titration in this population.METHODS:This prospective study enrolled 36 ARDS patients,including 22 patients with IAH and 14 without IAH.All the patients underwent EIT-guided PEEP titration at the intersection point between alveolar overdistension and collapse during a decremental PEEP trial.The changes in pulmonary ventilation distribution,respiratory mechanics and hemodynamics during the titration process were observed.RESULTS:After EIT-guided PEEP titration was performed,the PEEP,peak inspiratory pressure and plateau pressure increased significantly(P<0.05).Furthermore,no significant differences were observed in respiratory system compliance,tidal volume,driving pressure,or the 4*DP+RR index between the two groups(P>0.05).The mechanical power increased in the non-IAH(NIAH)group after PEEP titration(P<0.05).Ventilation in gravity-dependent lung regions significantly increased(P<0.05),and the oxygenation index(PaO2/FiO2)improved signifi cantly(P<0.05)in both groups.However,blood pressure,heart rate,respiratory rate,central venous pressure,and lactate levels did not signifi cantly change.In the IAH group,the PaO2/FiO2 ratio improved less than that in the NIAH group did(P<0.05).CONCLUSION:In our study,individualized PEEP titration guided by EIT improved oxygenation in ARDS patients with concomitant IAH without signifi cantly aff ecting hemodynamics.The presence of IAH may limit the improvement of oxygenation during EIT-guided PEEP titration. 展开更多
关键词 Acute respiratory distress syndrome Positive end-expiratory pressure Electrical impedance tomography Intra-abdominal pressure
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Short-period dense linear array ambient noise tomography of shallow crustal structure across the Haichenghe fault zone,China
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作者 Mingruo Jiao Liang Wang +9 位作者 Hongyu Ni Haiyan Wang Lanshu Bai Shuo Liu Zhihong Zhang Zhenpeng Yang Zhengdong Cui Qingshan Sun Rui Qian Mengying Li 《Earthquake Science》 2026年第2期220-234,共15页
The Haicheng region,Liaoning,China,likely hosts a conjugate fault system comprising the NW-trending Haichenghe fault and NE-trending secondary faults.On February 4,1975,at 19:36 CST,an earthquake of M_(S)7.3 and inten... The Haicheng region,Liaoning,China,likely hosts a conjugate fault system comprising the NW-trending Haichenghe fault and NE-trending secondary faults.On February 4,1975,at 19:36 CST,an earthquake of M_(S)7.3 and intensity(MMI)IX hit the city of Haicheng,Liaoning,China.Although deep seismic profiling was previously conducted along the Haichenghe fault,the limited horizontal resolution in the shallow part prevented the recognition of kilometer-scale anomalies.The velocity structure characteristics of the Haichenghe fault and its NE-trending conjugate faults remain unclear.Using the extended range phase shift method,the high-resolution S-wave velocity structures are obtained by deploying a long,dense linear array of 55 short-period seismometers across the fault and NE-trending conjugate faults.The array length was 32 km and inter-station spacing was approximately 600 m,facilitating the collection of approximately 22 days of continuous waveform data.Employing the Extended Range Phase Shift(ERPS)method enabled the extraction of broadband 0.2–5 s Rayleigh wave phase velocity dispersion curves.The broadband dispersion data were used for inversion of the high-resolution S-wave velocity structure to a depth of 8 km from the surface.The velocity structure characteristics and seismicity of the Haichenghe fault and NE-trending conjugate faults were analyzed and compared with nearby fault gas measurements.Results show(1)shallow S-wave velocities show a low-high-low horizontal distribution,corresponding to basin-uplift-basin topography;(2)significant velocity contrasts occur across the Haichenghe fault:its SW segment(0–17 km)exhibits high velocities consistent with Paleoproterozoic crystalline basement(Pt_(1)),while the NE segment(17–32 km)shows low velocities related to Yanshanian intrusions(γ_(5))and Quaternary sediments.NE-trending conjugate faults display sharp velocity gradients marking fracture locations,with all faults being near-vertical to~8 km depth;(3)seismicity at 1–6 km depth mainly clusters in high-velocity zones;at 6–8 km depth,it concentrates beneath the Haichenghe fault in low-velocity areas and along NE-trending faults;(4)the seismic activity characteristics and fault zone width of the Haicheng he fault reflected by velocity imaging results are basically consistent with those obtained by the fault gas measurement method. 展开更多
关键词 dense linear array ambient noise tomography extended range phase shift method S-wave velocity structure Haichenghe fault
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A perspective review of applications of the computed tomography(CT)scan imaging technique for microscopic reservoir rock characterization
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作者 Achinta Bera Bharadwaj Shukla Dhruvikkumar Jogani 《Deep Underground Science and Engineering》 2026年第1期4-27,共24页
In hospitals,a medical computed tomography(CT)scan is used to detect damage to infected areas of the human body.Using this technology,scientists and engineers have found a way to detect the internal pore connections a... In hospitals,a medical computed tomography(CT)scan is used to detect damage to infected areas of the human body.Using this technology,scientists and engineers have found a way to detect the internal pore connections and characterize rock samples of oil and gas reservoirs in the petroleum industry.Nowadays,the micro-CT scan technique is gaining considerable interest in reservoir rock characterization and in situ monitoring of fluid flow through porous media during different flooding experiments.Along with this digital rock physics(DRP)idea,images have been used to accurately describe and model for simulations of rock samples.In this review,the application of micro-CT and medical-CT scanning in the oil and gas industry has been thoroughly discussed.Recent improvements in DRP and modern imaging techniques in the oil and gas industry have been modeled using both experimental and simulation work.The combination of a DRP study and a CT scan has also been discussed as a unique idea for the current scenario of research work in this field.The available literature shows that the modern imaging technique and the DRP concept can enable an understanding of the pore network model.It has also been observed that the visualization of fluid flow behavior through porous media is now possible during fluid movement through the core samples.This review contributes to the new research area and aids those in this field in quickly gaining an understanding of applied image techniques in the oil and gas industry. 展开更多
关键词 computed tomography scanning technology digital rock physics multiphase flow oil and gas industry porous media reservoir characterization
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An effective method toward large field-of-view gamma-ray computed tomography based on an inverse Compton scattering light source
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作者 Zhi-Jun Chi Hong-Ze Zhang +8 位作者 Jia-Yi Sun Hao Ding Jin Lin Xuan-Qi Zhang Qi-Li Tian Zhi Zhang Ying-Chao Du Wen-Hui Huang Chuan-Xiang Tang 《Nuclear Science and Techniques》 2026年第5期252-263,共12页
The quasi-monochromatic,continuously energy-tunable,and high-brightness gamma rays that are produced by an inverse Compton scattering(ICS)light source provide an ideal probe for gamma-ray imaging.However,owing to the ... The quasi-monochromatic,continuously energy-tunable,and high-brightness gamma rays that are produced by an inverse Compton scattering(ICS)light source provide an ideal probe for gamma-ray imaging.However,owing to the influence of the intrinsic energy-angle correlation spectrum of this type of light source,monochromatic computed tomography(CT),especially in the gamma-ray energy region,can only be realized in a low-efficiency manner,similar to first-generation CT.A dual-energy scan scheme with a large imaging field of view(FOV)was developed in this study to improve the imaging efficiency.The effectiveness of this scheme was demonstrated based on the beam parameters of a typical ICS light source using Monte Carlo simulations.By leveraging the principle of basis material decomposition,the influence of the energyangle correlation spectrum on CT reconstruction was corrected,and a monochromatic CT image of the imaging object was accurately reconstructed.Furthermore,the electron density and effective atomic number of the imaging object could be obtained simultaneously. 展开更多
关键词 Gamma-ray computed tomography Energy-angle correlation Basis material decomposition Inverse Compton scattering light source Monte Carlo simulation
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Therapeutic effects of low-intensity transcranial focused ultrasound stimulation on ischemic stroke in rats:An in vivo evaluation using electrical impedance tomography
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作者 Jiecheng Guo Sixuan He +4 位作者 Li Yan Lei Wang Xuetao Shi Huijing Hu Le Li 《Neural Regeneration Research》 2026年第3期1183-1190,共8页
Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance to... Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance tomography enables real-time monitoring of changes in cerebral blood perfusion within the ischemic brain,but investigating the feasibility of using this method to assess post-stroke rehabilitation in vivo remains critical.In this study,ischemic stroke was induced in rats through middle cerebral artery occlusion surgery.Transcranial focused ultrasound stimulation was used to treat the rat model of ischemia,and electrical impedance tomography was used to measure impedance during both the acute stage of ischemia and the rehabilitation stage following the stimulation.Electrical impedance tomography results indicated that cerebral impedance increased after the onset of ischemia and decreased following transcranial focused ultrasound stimulation.Furthermore,the stimulation promoted motor function recovery,reduced cerebral infarction volume in the rat model of ischemic stroke,and induced the expression of brain-derived neurotrophic factor in the ischemic brain.Our results also revealed a significant correlation between the impedance of the ischemic brain post-intervention and improvements in behavioral scores and infarct volume.This study shows that daily administration of transcranial focused ultrasound stimulation for 20 minutes to the ischemic hemisphere 24 hours after cerebral ischemia enhanced motor recovery in a rat model of ischemia.Additionally,our findings indicate that electrical impedance tomography can serve as a valuable tool for quantitatively evaluating rehabilitation after ischemic stroke in vivo.These findings suggest the feasibility of using impedance data collected via electrical impedance tomography to clinically assess the effects of rehabilitatory interventions for patients with ischemic stroke. 展开更多
关键词 animal model brain stimulation electrical impedance tomography evaluation impedance noninvasive treatment real-time monitoring REHABILITATION STROKE transcranial focused ultrasound stimulation
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High-frequency emphasized neural network reconstruction method for in situ synchrotron radiation ultrafast computed tomography characterization
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作者 Jing-Wei Li Yu Xiao +3 位作者 Yong-Cun Li Xiao-Fang Hu Guo-Hao Du Feng Xu 《Nuclear Science and Techniques》 2026年第3期5-17,共13页
There is a contradiction between the evolution rate of materials and the time resolution of SR-CT characterization in the in situ synchrotron radiation computed tomography(SR-CT)characterization of ultrafast evolution... There is a contradiction between the evolution rate of materials and the time resolution of SR-CT characterization in the in situ synchrotron radiation computed tomography(SR-CT)characterization of ultrafast evolution process.The sampling strategy of the ultra-sparse angle is an effective method for improving time resolution.Accurate reconstruction under sparse sampling conditions has always been a bottleneck problem.In recent years,convolutional neural networks have shown outstanding advantages in sparse-angle CT reconstruction given the development of deep learning.However,existing ideas did not consider the expression of high-frequency details in neural networks,limiting their application in accurate SR-CT characterization.A novel high-frequency information-constrained deep learning network(HFIC-Net)is proposed in response to this problem.Additional high-frequency information constraints are added to improve the accuracy of the reconstruction results.Further,a series of numerical reconstruction experiments are conducted to verify this new method,and the results indicate that the reconstruction results of HFIC-Net method effectively improve reconstruction quality.This new method uses only eight-angle projections to achieve the reconstruction effect of the filtered backprojection method(FBP)method in 360 projections.The results of the HFIC-Net method demonstrate clear boundaries and accurate detailed structures,correcting the misinformation caused by using other methods.For quantitative evaluation,the SSIM used to evaluate image structure similarity is increased from 0.1951,0.9212,and 0.9308 for FBP,FBP-Conv,and DDC-Net,respectively,to 0.9620 for HFIC-Net.Finally,the results of actual SR-CT experimental data indicate that the new method can suppress artifacts and achieve accurate reconstruction,and it is suitable for the in situ SR-CT accurate characterization of ultxafast evolution process. 展开更多
关键词 Accurate SR-ct characterization ct reconstruction Sparse-angle ct reconstruction problem High-frequency information constrained Deep learning
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Wave-MambaCT:基于小波Mamba的低剂量CT伪影抑制方法
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作者 崔学英 王宇航 +2 位作者 刘斌 上官宏 张雄 《电子与信息学报》 北大核心 2026年第3期982-993,共12页
低剂量CT(LDCT)图像中的伪影和噪声影响疾病的早期诊断和治疗。基于卷积神经网络的去噪方法在远程建模方面能力有限。与Transformer架构的远程建模方法相比,基于Mamba模型在建模时计算复杂度低,然而现有的Mamba模型存在信息丢失或噪声... 低剂量CT(LDCT)图像中的伪影和噪声影响疾病的早期诊断和治疗。基于卷积神经网络的去噪方法在远程建模方面能力有限。与Transformer架构的远程建模方法相比,基于Mamba模型在建模时计算复杂度低,然而现有的Mamba模型存在信息丢失或噪声残留的缺点。为此,该文提出一种基于小波Mamba的去噪模型WaveMambaCT。首先利用小波变换的多尺度分解解耦噪声和低频内容信息。其次,构建残差模块结合状态空间模型的Mamba模块提取高低频带的局部和全局信息,并用无噪的低频特征通过基于注意力的跨频Mamba模块校正并增强同尺度的高频特征,在去除噪声的同时保持更多细节。最后,分阶段采用逆小波变换渐进恢复图像,并设置相应的损失函数提高网络的稳定性。实验结果表明Wave-MambaCT在较低的计算复杂度和参数量下,不仅提高了低剂量CT图像的视觉效果,而且在PSNR,SSIM,VIF和MSE 4种定量指标上均优于现有的去噪方法。 展开更多
关键词 低剂量ct 伪影抑制 小波变换 Mamba
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基于CT扫描架倾角测量精度的自动分析算法研究
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作者 徐小三 杜翔 +2 位作者 杨春勇 王进 洪君 《中国医学装备》 2026年第3期32-36,共5页
目的:研究提出基于客观评估X射线计算机体层扫描(CT)设备扫描架倾角精度的自动分析算法,为CT扫描架倾角测量提供优化方案。方法:采用南京医科大学附属淮安市第一人民医院的CT设备对江苏省疾病预防控制中心购置的Catphan500型检测模体进... 目的:研究提出基于客观评估X射线计算机体层扫描(CT)设备扫描架倾角精度的自动分析算法,为CT扫描架倾角测量提供优化方案。方法:采用南京医科大学附属淮安市第一人民医院的CT设备对江苏省疾病预防控制中心购置的Catphan500型检测模体进行扫描,以重建后的图像为研究对象,分别采用人工测量方法和Matlab软件自动分析算法(截面线段法和截面积法)对CT扫描架的倾角精度进行测量。将扫描架倾角(θ)的标称角度设置为5°和17°,对比分析两种方法的测量结果,及其与标称角度的偏差。结果:当θ设置为5°和17°时,人工测量实测值分别为4.04°和14.74°,与标称角度的偏差分别为0.96°和2.26°;Matlab自动分析算法中截面线段法测量值分别为4.87°和15.47°,与标称角度偏差分别为0.13°和1.53°,截面积法测量值分别为4.83°和15.47°,与标称角度偏差分别为0.17°和1.53°。当θ为17°时,Matlab自动分析算法中的截面线段法与截面积法测量结果偏差一致,均为1.53°。结论:CT扫描架倾角精度Matlab自动分析算法,无需人为干预便可自动给出CT扫描架倾角测量精度,确保CT扫描架倾角检测结果的客观准确性,能够为CT扫描架倾角测量提供优化方案。 展开更多
关键词 X射线计算机体层扫描(ct)装置 ct扫描架倾角精度 手动分析 自动分析算法
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冠状动脉CTA团注追踪阈值触发时间与CT值预测和对比剂外渗的相关性研究
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作者 付玲 韩菲 +3 位作者 甘良英 刘卓 安备 程瑾 《中国循证心血管医学杂志》 2026年第2期195-200,共6页
目的分析CT冠状动脉造影检查中对比剂团注追踪阈值触发时间、CT值与对比剂外渗的关联性,为临床快速识别并处理对比剂外渗提供科学的参考依据。方法回顾性选取2022年1月至2023年12月于北京大学人民医院接受CT冠状动脉造影检查的1124例门... 目的分析CT冠状动脉造影检查中对比剂团注追踪阈值触发时间、CT值与对比剂外渗的关联性,为临床快速识别并处理对比剂外渗提供科学的参考依据。方法回顾性选取2022年1月至2023年12月于北京大学人民医院接受CT冠状动脉造影检查的1124例门诊患者作为研究对象,收集一般人口学资料。根据患者是否发生对比剂外渗分为外渗组和未外渗组,再根据体重指数(BMI)、对比剂注射剂量及注射速度将患者分为4个亚组(组1:BMI提示偏瘦,注射剂量为48 mL,注射速度为4 mL/s;组2:BMI提示正常,注射剂量为54 mL,注射速度为4.5 mL/s;组3:BMI提示超重,注射剂量为60 mL,注射速度为5 mL/s;组4:BMI提示肥胖,注射剂量为66 mL,注射速度为5.5 mL/s)。统计所有患者的团注追踪阈值触发时间及CT值,比较外渗组和未外渗组患者的性别、年龄、文化程度、体质指数及CT值的变化,以及4个亚组的外渗情况。采用多因素Logistic回归分析对比剂外渗的危险因素,采用多元线性回归分析CT值及触发时间的影响因素。结果在1124例患者中,发生静脉外渗者25例(2.22%)。外渗组和未外渗组患者的性别、年龄、文化程度、BMI比较,差异无统计学意义(P>0.050);两组患者的CT值比较,差异有统计学意义(P<0.050)。4个亚组的外渗情况比较,差异无统计学意义(P>0.050)。多因素回归分析结果显示,性别、年龄、BMI、文化程度、亚组均非对比剂外渗的危险因素(P>0.050)。触发时间及CT值的多元线性回归分析结果显示,性别、文化程度、BMI均非二者的影响因素(P>0.050),年龄、组别是二者的影响因素(P<0.050)。结论基于团注追踪阈值触发时间及CT值预测CT冠状动脉造影检查中的对比剂外渗具有较高的科学性,可为临床评估对比剂外渗风险提供可靠的参考依据。 展开更多
关键词 ct冠状动脉造影 对比剂 团注追踪阈值触发法 外渗 触发时间 ct
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基于CT扫描技术的透水混凝土孔隙特性研究
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作者 徐丽娜 魏超 +2 位作者 丁旭 黄占芳 刘宁 《水电能源科学》 北大核心 2026年第1期114-118,共5页
为深入研究聚丙烯仿钢纤维透水混凝土的微观机理,采用CT扫描技术对试件进行扫描,通过三维数字重构技术建立了孔隙结构的可视化模型。基于图像分析方法对比研究了纤维改性前后材料内部孔隙系统的形态演变特征。结果表明,聚丙烯仿钢纤维... 为深入研究聚丙烯仿钢纤维透水混凝土的微观机理,采用CT扫描技术对试件进行扫描,通过三维数字重构技术建立了孔隙结构的可视化模型。基于图像分析方法对比研究了纤维改性前后材料内部孔隙系统的形态演变特征。结果表明,聚丙烯仿钢纤维的加入可有效提高试件的强度,但会抑制试块的透水性能,试块各层面孔隙率稳定在15%~20%之间,且连通孔隙占总孔隙的97%以上;未添加纤维的试块中大孔数量较少,但其体积占比较大;加入纤维后,部分大孔转化为中孔并抑制孔隙间的连通,从而改变孔隙结构。 展开更多
关键词 聚丙烯仿钢纤维透水混凝土 ct扫描 孔隙结构 透水性能
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