期刊文献+
共找到71,068篇文章
< 1 2 250 >
每页显示 20 50 100
Optical coherence tomography angiography in diabetic retinopathy:focusing on microvascular changes 被引量:1
1
作者 Yang Xiongyi Yi Guoguo +5 位作者 Chen Yanxia Yang Siyu Ai Shibei Zheng Cong Cao Mingzhe Fu Min 《国际眼科杂志》 2025年第2期179-190,共12页
AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA scree... AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS:A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital,Sun Yat-sen University from 2022 to 2023 were included,including 95 first-diagnosed DR patients and 105 patients without DR,and all patients underwent OCTA examination and a collection of demographics and renal function parameters.After a quality check,automated measurements of the foveal avascular zone area,vessel density(VD),and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS:Using random forest and multivariate Logistic regression methods,we developed a diagnostic model for DR based on 12 variables(age,FBG,SBP,DBP,HbA1c,ALT,ALP,urea/Scr,DM duration,HUA,DN,and CMT).Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window,AUC=0.837 vs 0.819,P=0.03).In the study of DN patients,the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD;outer VD;full VD;outer PD;full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model.Meanwhile,compared with the 3 mm×3 mm window,the microvascular parameters in the 6 mm×6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR. 展开更多
关键词 optical coherence tomography angiography(OCTA) diabetic retinopathy diabetic nephropathy prediction model
在线阅读 下载PDF
Experimental Observing Damage Evolution in Cement Pastes Exposed to External Sulfate Attack by in situ X-ray Computed Tomography
2
作者 WU Min CAO Kailei +4 位作者 XIAO Weirong YU Zetai CAO Jierong DING Qingjun LI Jinhui 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2025年第1期164-170,共7页
The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an ... The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution. 展开更多
关键词 CONCRETE external sulfate attack damage evolution situ X-ray computed tomography
在线阅读 下载PDF
3D tomographic analysis of equatorial plasma bubble using GNSS-TEC data from Indonesian GNSS Network
3
作者 Ihsan Naufal Muafiry Prayitno Abadi +5 位作者 Teguh N.Pratama Dyah R.Martiningrum Sri Ekawati Yuandhika GWismaya Febrylian FChabibi Gatot HPramono 《Earth and Planetary Physics》 EI CAS 2025年第1期127-136,共10页
Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other s... Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other seasons.The phenomenon significantly disrupts radio wave signals essential to communication and navigation systems.The national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB studies.To explore this,we conducted preliminary 3D tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian sector.TEC and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3D tomography program.Their 2D spatial distribution consistently captured the four EPB clusters over time.These tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)profile.Validation of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric density.These findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage. 展开更多
关键词 EPB Indonesian GNSS Network 3D tomography
在线阅读 下载PDF
Computed tomography enterography-based radiomics for assessing mucosal healing in patients with small bowel Crohn's disease
4
作者 Hao Ding Yuan-Yuan Fang +5 位作者 Wen-Jie Fan Chen-Yu Zhang Shao-Fei Wang Jing Hu Wei Han Qiao Mei 《World Journal of Gastroenterology》 SCIE CAS 2025年第3期62-72,共11页
BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significan... BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients. 展开更多
关键词 Crohn’s disease Computed tomography enterography Mucosal healing NOMOGRAM Radiomics
在线阅读 下载PDF
Role of photon-counting computed tomography in pediatric cardiovascular imaging
5
作者 Arosh S Perera Molligoda Arachchige Yash Verma 《World Journal of Clinical Pediatrics》 2025年第1期55-62,共8页
Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible ligh... Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric signals.This direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced artifacts.In pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young age.Enhanced spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart defects.Additionally,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media doses.Initial clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular cases.As PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety. 展开更多
关键词 CARDIOVASCULAR Photon-counting detectors PEDIATRIC Photon-counting computed tomography Computed tomography
在线阅读 下载PDF
Recent progress in the applications of presynaptic dopaminergic positron emission tomography imaging in parkinsonism
6
作者 Yujie Yang Xinyi Li +7 位作者 Jiaying Lu Jingjie Ge Mingjia Chen Ruixin Yao Mei Tian Jian Wang Fengtao Liu Chuantao Zuo 《Neural Regeneration Research》 SCIE CAS 2025年第1期93-106,共14页
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.... Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders. 展开更多
关键词 aromatic amino acid decarboxylase brain imaging dopamine transporter Parkinson’s disease PARKINSONISM positron emission tomography presynaptic dopaminergic function vesicle monoamine transporter type 2
在线阅读 下载PDF
Neural-field-based image reconstruction for bioluminescence tomography
7
作者 Xuanxuan Zhang Xu Cao +2 位作者 Jiulou Zhang Lin Zhang Guanglei Zhang 《Journal of Innovative Optical Health Sciences》 2025年第1期165-179,共15页
Deep learning(DL)-based image reconstruction methods have garnered increasing interest in the last few years.Numerous studies demonstrate that DL-based reconstruction methods function admirably in optical tomographic ... Deep learning(DL)-based image reconstruction methods have garnered increasing interest in the last few years.Numerous studies demonstrate that DL-based reconstruction methods function admirably in optical tomographic imaging techniques,such as bioluminescence tomography(BLT).Nevertheless,nearly every existing DL-based method utilizes an explicit neural representation for the reconstruction problem,which either consumes much memory space or requires various complicated computations.In this paper,we present a neural field(NF)-based image reconstruction scheme for BLT that uses an implicit neural representation.The proposed NFbased method establishes a transformation between the coordinate of an arbitrary spatial point and the source value of the point with a relatively light-weight multilayer perceptron,which has remarkable computational efficiency.Another simple neural network composed of two fully connected layers and a 1D convolutional layer is used to generate the neural features.Results of simulations and experiments show that the proposed NF-based method has similar performance to the photon density complement network and the two-stage network,while consuming fewer floating point operations with fewer model parameters. 展开更多
关键词 Bioluminescence tomography image reconstruction neural field
在线阅读 下载PDF
Three-dimensional reconstruction under computed tomography and myopectineal orifice measurement under laparoscopy for quality control of inguinal hernia treatment
8
作者 Lei Zhang Jing Chen +7 位作者 Yu-Ying Zhang Lei Liu Han-Dan Wang Ya-Fei Zhang Jun Sheng Qiu-Shi Hu Ming-Liang Liu Yi-Lin Yuan 《World Journal of Gastrointestinal Endoscopy》 2025年第3期50-59,共10页
BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are ne... BACKGROUND Inguinal hernias are common after surgery.Tension-free repair is widely accepted as the main method for managing inguinal hernias.Adequate exposure,coverage,and repair of the myopectineal orifice(MPO)are necessary.However,due to differences in race and sex,people’s body shapes vary.According to European guidelines,the patch should measure 10 cm×15 cm.If any part of the MPO is dissected,injury to the nerves,vascular network,or organs may occur during surgery,thereby leading to inguinal discomfort,pain,and seroma formation after surgery.Therefore,accurate localization and measurement of the boundary of the MPO are crucial for selecting the optimal patch for inguinal hernia repair.AIM To compare the size of the MPO measured on three-dimensional multislice spiral computed tomography(CT)with that measured via laparoscopy and explore the relevant factors influencing the size of the MPO.METHODS Clinical data from 74 patients who underwent laparoscopic tension-free inguinal hernia repair at the General Surgery Department of the First Affiliated Hospital of Anhui University of Science and Technology between September 2022 and July 2024 were collected and analyzed retrospectively.Transabdominal preperitoneal was performed.Sixty-four males and 10 females,with an average age of 58.30±12.32 years,were included.The clinical data of the patients were collected.The boundary of the MPO was measured on three-dimensional CT images before surgery and then again during transabdominal preperitoneal.All the preoperative and intraoperative data were analyzed via paired t-tests.A t-test was used for comparisons of age,body mass index,and sex between the groups.In the comparative analysis,a P value less than 0.05 indicated a significant difference.RESULTS The boundaries of the MPO on 3-dimensional CT images measured 7.05±0.47 cm and 6.27±0.61 cm,and the area of the MPO was 19.54±3.33 cm^(2).The boundaries of the MPO during surgery were 7.18±0.51 cm and 6.17±0.40 cm.The errors were not statistically significant.However,the intraoperative BD(the width of the MPO,P=0.024,P<0.05)and preoperative AC(the length of the MPO,P=0.045,P<0.05)significantly differed according to sex.The AC and BD measurements before and during surgery were not significantly different according to age,body mass index,hernia side or hernia type(P>0.05).CONCLUSION The application of this technology can aid in determining the most appropriate dissection range and patch size. 展开更多
关键词 HERNIA INGUINAL Myopectineal orifice Three-dimensional reconstruction Computed tomography Inguinal hernia
在线阅读 下载PDF
Gastric schwannoma: Computed tomography and perigastric lymph node characteristics
9
作者 Yong-Kang Mo Xia-Pu Chen +4 位作者 Liang-Li Hong Yi-Ru Hu Dai-Ying Lin Li-Chun Xie Zhuo-Zhi Dai 《World Journal of Gastrointestinal Oncology》 2025年第4期153-160,共8页
BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM T... BACKGROUND Gastric schwannoma(GS)is often misdiagnosed as gastrointestinal stromal tumors due to the high incidence of the latter.However,these two types differ significantly in pathology and biological behavior.AIM To evaluate the computed tomography characteristics of GS and provide insights into its accurate diagnosis.METHODS Twenty-three cases of GS confirmed between January 2011 and December 2023 were assessed clinically and radiologically.Imaging characteristics,including tumor location,size,contour,ulceration,growth pattern,enhancement degree and pattern,cystic change,calcification,and perigastric lymph nodes(PLNs),were reviewed by two experienced radiologists.RESULTS Our sample included 18 females and 5 males,with a median age of 54.7 years.A total of 39.1%of cases were asymptomatic.GSs appeared as oval and well-defined submucosal tumors,with exophytic(43.5%)or mixed(endoluminal+exophytic;43.5%)growth patterns.The tumors were primarily located in the gastric body(78.3%).Ulcerations were observed in 8 cases(34.5%),and PLNs were observed in 15 cases(65%).The average degree of enhancement was 48.3 Hounsfield units.Twenty cases(87%)showed peak enhancement in the delayed phase.Most GSs were homogeneous,while cystic change(13.0%)and calcification(17.4%)were rare.CONCLUSION GS predominantly showed gradual homogenous enhancement with peak enhancement in the delayed phase.PLNs around GS are helpful in differentiating GS from other gastric submucosal tumors. 展开更多
关键词 Gastric schwannoma STOMACH Computed tomography Perigastric lymph node KI-67
在线阅读 下载PDF
Evaluation of macular and peripapillary structure and microvasculature with optical coherence tomography angiography in migraine in the Indian population
10
作者 Pankti Shah Virna M Shah +2 位作者 Veerappan Rathinasabapathy Saravanan Karthik Kumar Siddharth Narendran 《World Journal of Methodology》 2025年第3期100-107,共8页
BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch a... BACKGROUND Migraine has been proposed as a potential contributing factor to ischemic complications involving the retina and optic nerve.Ophthalmic disorders connected with migraine encompass occlusions of the branch and central retinal arteries and veins,alongside anterior and posterior ischemic optic neuropathy.With the advent of optical coherence tomography angiography(OCTA),it is easy to identify these macular subclinical microvascular and structural changes.AIM To evaluate macular and peripapillary structural and microvasculature changes in patients with migraine with aura(MA),migraine without aura(MW),and healthy control(HC)participants using OCTA.METHODS In this observational cross-sectional study,we studied a total of 100 eyes:(1)32 eyes of 16 patients with MA;(2)36 eyes of 18 patients with MW,recruited based on the International Classification of Headache Disorders;and(3)32 eyes of 16 age and sex-matched healthy participants.Foveal flux,foveal avascular zone(FAZ),peripapillary flux obtained from OCTA,and foveal and peripapillary ganglion cell layer(GCL)thickness calculated via optical coherence tomography were compared among the groups.RESULTS The mean FAZ area measured in patients with MA and MW was significantly larger than that in the control participants(P=0.002).However,there was no significant difference between the FAZ of the MA and MW groups.Macular perfusion in the superficial capillary plexus in patients with MA was significantly lower compared to MW(P=0.0018)and HCs(P=0.002).There was also significant thinning of the GCL in patients with MA and MW(P=0.001)compared to HCs.However,there was no significant difference in temporal GCL thickness between the MA and MW groups.CONCLUSION Significant changes have been found in structural and microvascular parameters in patients with migraines compared with HCs.OCTA can serve as a valuable non-invasive imaging technique for identifying microcirculatory disturbances,aiding in better understanding the pathogenesis of different types of migraine and establishing their link with other ischemic retinal and systemic pathologies. 展开更多
关键词 MIGRAINE AURA Optical coherence tomography angiography Foveal microvasculature Macular perfusion
在线阅读 下载PDF
Predictive factors for liver abscess liquefaction degree based on clinical,laboratory,and computed tomography data
11
作者 Hong-Yu Long Xin Yan +1 位作者 Jia-Xian Meng Feng Xie 《World Journal of Gastrointestinal Surgery》 2025年第4期233-243,共11页
BACKGROUND Effective management of liver abscess depends on timely drainage,which is influenced by the liquefaction degree.Identifying predictive factors is crucial for guiding clinical decisions.AIM To investigate th... BACKGROUND Effective management of liver abscess depends on timely drainage,which is influenced by the liquefaction degree.Identifying predictive factors is crucial for guiding clinical decisions.AIM To investigate the predictive factors of liver abscess liquefaction and develop a predictive model to guide optimal timing of percutaneous drainage.METHODS This retrospective study included 110 patients with pyogenic liver abscesses who underwent percutaneous catheter drainage.Patients were divided into a poor liquefaction group(n=28)and a well liquefaction group(n=82)based on the ratio of postoperative 24-hour drainage volume to abscess volume,using a cutoff value of 0.3.Clinical characteristics,laboratory indicators,and computed tomography imaging features were compared.A predictive model was constructed using logistic regression and evaluated using receiver operating characteristic curves and five-fold cross-validation.RESULTS Independent predictive factors for good liquefaction included the absence of diabetes[odds ratio(OR)=0.339,P=0.044],absence of pneumonia(OR=0.218,P=0.013),left-lobe abscess location(OR=4.293,P=0.041),cystic features(OR=5.104,P=0.025),and elevated preoperative serum alanine aminotransferase(ALT)levels(OR=1.013,P=0.041).The logistic regression model based on these factors demonstrated an area under the curve of 0.814,with a sensitivity of 90.24%and specificity of 67.86%.Five-fold cross-validation yielded an average accuracy of 83.61%and a kappa coefficient of 0.5209.CONCLUSION Pneumonia,diabetes,abscess location,abscess composition,and preoperative serum ALT levels are significant predictors of liver abscess liquefaction.The model can guide clinical decision-making. 展开更多
关键词 Pyogenic liver abscess Percutaneous catheter drainage PNEUMONIA DIABETES Computed tomography
在线阅读 下载PDF
Optimizing Computed Tomography Processing Parameters for Accurate Detection of Internal Defects in Reinforced Concrete
12
作者 Yueshun Chen Yupeng Zhou Cao Yin 《Structural Durability & Health Monitoring》 2025年第3期575-592,共18页
Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and signifi... Computed tomography(CT)can inspect the internal structure of concrete with high resolution,but improving the accuracy of measurements remains a key challenge due to the reliance on complex image processing and significant manual intervention.This study aims to optimize CT scanning parameters to enhance the accuracy of measuring crack widths and rebar volumes in reinforced concrete.Nine sets of specimens,each with varying rebar diameters and concrete cover thicknesses,were scanned before and after corrosion using an Optima CT scanner,followed by three-dimensional reconstructions using Avizo software.The effects of threshold values and“Erosion”coefficients on measurement accuracy were evaluated.The results demonstrated that an optimal lower threshold of 2950,combined with an‘Erosion’coefficient of 6,effectively limits the measurement error of rebar volumes to within 1%.The optimal threshold for measuring crack widths was influenced by the crack width,rebar diameter,and concrete cover thickness.Additionally,an optimized formula for determining crack measurement thresholds was proposed.This study significantly improves the accuracy of CT-based non-destructive testing(NDT)techniques,providing valuable insights for structural health monitoring(SHM). 展开更多
关键词 Computed tomography concrete structure cracks Avizo non-destructive testing 3D visualisation
在线阅读 下载PDF
Assessment of tomographic parameters and detection of subclinical edema in Fuchs’endothelial corneal dystrophy pre-cataract surgery
13
作者 João Alves-Ambrósio Vítor Miranda +2 位作者 Catarina Pestana Aguiar João Chibante-Pedro Inês Almeida 《International Journal of Ophthalmology(English edition)》 2025年第4期590-597,共8页
AIM:To assess tomographic changes and subclinical edema detection in Fuchs’endothelial corneal dystrophy(FECD)through Scheimpflug tomography in a group of phakic patients contemplating cataract surgery.METHODS:A retr... AIM:To assess tomographic changes and subclinical edema detection in Fuchs’endothelial corneal dystrophy(FECD)through Scheimpflug tomography in a group of phakic patients contemplating cataract surgery.METHODS:A retrospective study was conducted on 30 phakic eyes from patients diagnosed with FECD but without clinical edema,and 59 phakic eyes from a control group without corneal alterations.Comprehensive ophthalmic examinations were conducted,including slitlamp biomicroscopy,corneal specular microscopy(CSM),and Scheimpflug tomography.RESULTS:The study encompassed 30 phakic eyes with FECD(mean age 59.8±13.1y)and 59 control eyes(mean age 61.3±7.7y).The best-corrected visual acuity was higher in the control group compared to the FECD group[0(0,0.08)vs 0.05(0,0.15)logMAR;P=0.042].CSM revealed significant differences between the FECD and control groups in several parameters:number of analyzed cells(26±13 vs 135±42,P<0.001),cell density(2049±376 vs 2479±225 cells/mm2,P<0.001),mean cell area[463(434,544)vs 397(383,431)μm2;P<0.001],coefficient of variation(54.8%±18.7%vs 41.0%±7.2%,P<0.001),and hexagonal cells[0(0,47%)vs 47%(40%,53%),P<0.001].Although often used as a clinical parameter for detecting edema,central corneal thickness measured by CSM showed no significant difference between the FECD and control groups(530±57 vs 546±30μm,P=0.179).Significant differences were noted in various Pentacam measurements between the groups.Specifically,parameters like loss of parallel isopachs(13 vs 0 eyes,P<0.001),displacement of the thinnest point(11 vs 0 eyes,P<0.001),posterior focal depression(25 vs 7 eyes,P<0.001),and increased light scatter[21.4(17.6;23.9)vs 18.0(16.8,21.8),P=0.01]were significantly more prevalent in FECD eyes,reflecting the presence of subclinical edema and loss of corneal transparency.CONCLUSION:Scheimpflug tomography allows for an objective assessment of FECD,offering the capability to detect subclinical edema at an early stage,monitor disease progression,and serve as a predictor of corneal decompensation following cataract surgery. 展开更多
关键词 anterior eye segment CORNEA ENDOTHELIUM CORNEAL Fuchs’endothelial dystrophy tomography
在线阅读 下载PDF
High-Precision Sub-Seafloor Velocity Building Based on Joint Tomography and Deep Learning on OBS Data in the South China Sea
14
作者 Guoxin Chen Jun Li +5 位作者 Jinxin Chen Rongsen Du Yutao Liu Yuli Qi Chun-Feng Li Xingguo Huang 《Journal of Earth Science》 2025年第2期830-834,共5页
INTRODUCTION.Crustal velocity model is crucial for describing the subsurface composition and structure,and has significant implications in offshore oil and gas exploration and marine geophysical engineering(Xie et al.... INTRODUCTION.Crustal velocity model is crucial for describing the subsurface composition and structure,and has significant implications in offshore oil and gas exploration and marine geophysical engineering(Xie et al.,2024).Currently,travel time tomography is the most commonly used method for velocity modeling based on ocean bottom seismometer(OBS)data(Zhang et al.,2023;Sambolian et al.,2021).This method usually assumes that the sub-seafloor structure is layered,and therefore faces challenges in high-precision modeling with strong lateral discontinuities. 展开更多
关键词 velocity modeling time tomography marine geophysical engineering xie joint tomography describing subsurface composition structureand high precision velocity modeling offshore oil gas exploration ocean bottom seismometer obs data zhang
原文传递
Multi-bandwidth reconstruction for photoacoustic tomography using cascade U-net
15
作者 Zezheng Qin Lingyu Ma +3 位作者 Zhigang Lei Yiming Ma Weiwei Fu Mingjian Sun 《Journal of Innovative Optical Health Sciences》 2025年第1期181-194,共14页
Photoacoustic imaging(PAI)employs short laser pulses to excite absorbing materials,producing ultrasonic waves spanning a broad spectrum of frequencies.These ultrasonic waves are captured surrounding the sample and uti... Photoacoustic imaging(PAI)employs short laser pulses to excite absorbing materials,producing ultrasonic waves spanning a broad spectrum of frequencies.These ultrasonic waves are captured surrounding the sample and utilized to reconstruct the initial pressure distribution tomographically.Despite the wide spectral range of the laser-generated photoacoustic signal,an individual transducer can only capture a limited segment of the signal due to its constrained bandwidth.Herein,we have developed a multi-bandwidth ring array photoacoustic computed tomography(PACT)system,incorporating a probe with two semi-ring arrays:one for high frequency and the other for low frequency.Utilizing the two semi-ring array PAIs,we have devised a specialized deep learning model,comprising two serially connected U-net architectures,to autonomously generate multi-bandwidth full-view PAIs.Preliminary results from simulations and in vivo experiments illustrate the system's robust multi-bandwidth imaging capabilities,achieving an excellent PSNR of 34.78 dB and a structural similarity index measure(SSIM)of 0.94 in the high-frequency reconstruction of complex mouse abdominal structures.This innovative PACT system is notable for its capability to seamlessly acquire multi-bandwidth full-view PAIs,thereby advancing the application of PAI technology in the biomedical domain. 展开更多
关键词 Multi-bandwidth imaging photoacoustic tomography dual-layer U-net deep learning channel fusion
在线阅读 下载PDF
Macular microvascular and structural changes on optical coherence tomography angiography in atypical optic neuritis
16
作者 Chinmay Mahatme Madhurima Kaushik +2 位作者 Veerappan Rathinasabapathy Saravanan Karthik Kumar Virna M Shah 《World Journal of Methodology》 2025年第1期88-94,共7页
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im... BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases. 展开更多
关键词 Optical coherence tomography angiography Atypical optic neuritis Macular microvascular changes Neuromyelitis optica spectrum disorders Myelin oligodendrocyte glycoprotein antibody disorder
在线阅读 下载PDF
Characterization of gallbladder stones associated with occult pancreaticobiliary reflux using computed tomography
17
作者 Chen Qiu Yu-Kai Xiang +6 位作者 Hai Hu Xuan-Bo Da Gang Li Yue-Yi Zhang Hong-Lei Zhang Cheng Zhang Yu-Long Yang 《World Journal of Gastroenterology》 2025年第12期49-61,共13页
BACKGROUND Occult pancreaticobiliary reflux(OPBR)is characterized by the absence of congenital anomalies at the pancreaticobiliary junction yet leads to altered bile composition and an increased incidence of gallbladd... BACKGROUND Occult pancreaticobiliary reflux(OPBR)is characterized by the absence of congenital anomalies at the pancreaticobiliary junction yet leads to altered bile composition and an increased incidence of gallbladder stones.AIM To explore the computed tomography(CT)imaging characteristics of gallbladder stones in patients diagnosed with OPBR.METHODS We analyzed 362 patients undergoing cholecystectomy(November 2020 to January 2022).Intraoperative bile samples were assayed for amylase(>110 U/L indicated OPBR).CT features,including stone density and visibility,were compared between 54 OPBR and 308 controls.Stone attenuation(HU)was measured under standardized conditions(uCT-780,120 kVp,160 mAs).Logistic regression and receiver operating characteristic curve analysis identified independent OPBR predictors,forming a validated nomogram.RESULTS OPBR patients exhibited significantly higher rates of CT-invisible stones(35.2%vs 12.3%)and uniform stones(87%vs 73.1%)along with lower overall stone density(P=0.01).Logistic regression identified stone visibility,uniformity,and density as independent predictors.A nomogram integrating these features with patient age achieved high diagnostic accuracy(area under the curve=0.71).CONCLUSION CT imaging distinctly identifies gallbladder stone density,indicating a heightened risk of OPBR in patients with uniform and CT-invisible stones.Such imaging is crucial for preoperative assessments to evaluate potential recurrent biliary pathologies post-cholecystectomy. 展开更多
关键词 Occult pancreaticobiliary reflux Pancreaticobiliary maljunction Pancreaticobiliary reflux Computed tomography Diagnostic model
在线阅读 下载PDF
Temporal changes in computed tomography findings of a persimmon bezoar:A case report
18
作者 Masaya Iwamuro Tomoki Yoshikawa +4 位作者 Tomohiro Kamio Shoichiro Hirata Katsunori Matsueda Daisuke Kametaka Motoyuki Otsuka 《World Journal of Clinical Cases》 2025年第18期72-77,共6页
BACKGROUND Gastric bezoars are masses of indigestible material that accumulate in the stomach,causing nausea,abdominal pain,and vomiting.Persimmon bezoars(diospyrobezoars),which comprise tannins and fibers from persim... BACKGROUND Gastric bezoars are masses of indigestible material that accumulate in the stomach,causing nausea,abdominal pain,and vomiting.Persimmon bezoars(diospyrobezoars),which comprise tannins and fibers from persimmons,are relatively rare but may cause significant gastric complications,including gastric outlet obstruction or ileus.Although computed tomography(CT)is a useful ima-ging tool,diagnosing bezoars can be challenging because their density is similar to that of food debris and gastric content.CASE SUMMARY Here,we report the case of a 72-year-old woman with a persimmon bezoar that was diagnosed using serial CT imaging and confirmed by endoscopy.CT perfor-med over several months revealed changes in the internal structure and density of the bezoar,suggesting progressive hardening.The patient had a history of a par-tial gastrectomy and excessive persimmon consumption,both of which are risk factors for bezoar formation.Endoscopic fragmentation of the bezoar successfully resolved symptoms.CONCLUSION Gastric bezoars,particularly persimmon bezoars,present diagnostic challenges because of their variable imaging characteristics.Serial CT can document tem-poral changes in bezoar density,potentially reflecting changes in hardness.Early diagnosis and endoscopic treatment are essential for effective management,particularly in patients with predisposing factors.This case underscores the im-portance of considering bezoars in the differential diagnosis of gastric masses,and highlights the value of CT for monitoring changes in bezoar characteristics over time. 展开更多
关键词 Computed tomography Endoscopic treatment Gastric bezoar Persimmon bezoar Temporal changes Case report
在线阅读 下载PDF
Morphological alterations of macular region in fellow eyes of patients with idiopathic full-thickness macular holes detected by optical coherence tomography
19
作者 Yan-Ting Li Xin-Zhu Chen +5 位作者 Yun-Feng Lu Yue-Qi Liu Tian-Hong Wu Zi-Yue Song Zheng-Gao Xie Pei-Rong Lu 《International Journal of Ophthalmology(English edition)》 2025年第4期642-647,共6页
AIM:To describe the optical coherence tomography(OCT)features in the fellow eyes of individuals with full-thickness macular holes(FTMHs).METHODS:This multicenter retrospective study included observational and validati... AIM:To describe the optical coherence tomography(OCT)features in the fellow eyes of individuals with full-thickness macular holes(FTMHs).METHODS:This multicenter retrospective study included observational and validation groups,incorporating fellow eyes of patients diagnosed with idiopathic FTMH.OCT images were categorized according to International Vitreomacular Traction Study(IVTS)and Gass classification.Age-and sex-related cataract patients were served as control groups.Vertical and horizontal OCT images were chosen for further measurement.OCT parameters including foveal floor width(FFW),central foveal thickness(CFT)and FFW/CFT ratio were assessed and compared between observational and control groups and were validated by validation group.Receiver operating characteristic(ROC)curves were plotted for OCT parameters in identifying macular holes(MHs).RESULTS:A total of 73 patients were included in the observational group,comprising 51 females and 22 males,with an average age of 65.5±7.3y and an axial length of 23.9±0.8 mm.The validated group consisted of 47 patients,including 31 females and 16 males,with an average age of 65.0±7.4y and an average axial length of 23.6±0.8 mm.In the observational group,16.4%of the fellow eyes associated with FTMHs also exhibited MHs,while in the validated group,this prevalence was 12.7%.The 45.2%in the observational group and 44.6%in validated group of these fellow eyes displayed abnormalities including vitreomacular adhesion(VMA),vitreomacular traction(VMT),and MHs.Statistically significant differences were observed in FFW,CFT,and FFW/CFT ratio between control and observational group,as well as validated group(P<0.01),no matter in the vertical or horizontal layer.ROC curves revealed the area under the curve(AUC)for FFW and the FFW/CFT ratio was 0.85 and 0.90,respectively.CONCLUSION:In the case of unilateral idiopathic MHs,it was important to carefully monitor the condition of the fellow eye.The FFW and FFW/CFT ratio may be good metrics for predicting MHs. 展开更多
关键词 optical coherence tomography macular hole FOVEA foveal floor width central foveal thickness
在线阅读 下载PDF
Renal angiomyolipomas:Typical and atypical features on computed tomography and magnetic resonance imaging
20
作者 Andres Labra Giancarlo Schiappacasse +1 位作者 Diego Constenla Joaquin Cristi 《World Journal of Radiology》 2025年第2期11-20,共10页
Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is... Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is to discuss computed tomography(CT)and magnetic resonance imaging findings for both typical and atypical renal AMLs,along with their associated complications.AMLs are typically defined as solid triphasic tumors composed of varying amounts of dysmorphic and tortuous blood vessels,smooth muscle components and adipose tissue.In an adult,a classical renal AML appears as a solid,heterogeneous renal cortical mass with macroscopic fat.However,up to 5%of AMLs contain minimal fat and cannot be reliably diagnosed by imaging.Fat-poor AMLs can appear as hyperattenuating masses on unenhanced CT and as hypointense masses on T2WI;other AMLs may be isodense or exhibit cystic components.Hemorrhage is the most common complication,and AMLs with hemorrhage can mimic other tumors,making their diagnosis challenging.Understanding the variable and heterogeneous nature of this neoplasm to correctly classify renal AMLs and to avoid misdiagnosis of other renal lesions is crucial. 展开更多
关键词 Kidney neoplasms ANGIOMYOLIPOMA Classic angiomyolipoma-fat poor angiomyolipoma tomography X-ray computed Magnetic resonance imaging
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部