Irregular surface flattening,which is based on a boundary conforming grid and the transformation between curvilinear and Cartesian coordinate systems,is a mathematical method that can elegantly handle irregular surfac...Irregular surface flattening,which is based on a boundary conforming grid and the transformation between curvilinear and Cartesian coordinate systems,is a mathematical method that can elegantly handle irregular surfaces,but has been limited to obtaining first arrivals only.By combining a multistage scheme with the fast-sweeping method(FSM,the method to obtain first-arrival traveltime in curvilinear coordinates),the reflected waves from a crustal interface can be traced in a topographic model,in which the reflected wavefront is obtained by reinitializing traveltimes in the interface for upwind branches.A local triangulation is applied to make a connection between velocity and interface nodes.Then a joint inversion of first-arrival and reflection traveltimes for imaging seismic velocity structures in complex terrains is presented.Numerical examples all perform well with different seismic velocity models.The increasing topographic complexity and even use of a high curvature reflector in these models demonstrate the reliability,accuracy and robustness of the new working scheme;checkerboard testing illustrates the method's high resolution.Noise tolerance testing indicates the method's ability to yield practical traveltime tomography.Further development of the multistage scheme will allow other later arrivals to be traced and used in the traveltime inversion.展开更多
First-arrival seismic traveltime tomography(FAST)is a well-established technique to estimate subsurface velocity structures.Although several existing open-source packages are available for first-arrival traveltime tom...First-arrival seismic traveltime tomography(FAST)is a well-established technique to estimate subsurface velocity structures.Although several existing open-source packages are available for first-arrival traveltime tomography,most were written in compiled languages and lack sufficient extendibility for new algorithms and functionalities.In this work,we develop an open-source,selfcontained FAST package based on MATLAB,one of the most popular interpreted scientific programming languages,with a focus on ocean bottom seismometer refraction traveltime tomography.Our package contains a complete traveltime tomography workflow,including ray-tracing-based first-arrival traveltime computation,linearized inversion,quality control,and high-quality visualization.We design the package as a modular toolbox,making it convenient to integrate new algorithms and functionalities as needed.At the current stage,our package is most efficient for performing FAST for two-dimensional ocean bottom seismometer surveys.We demonstrate the efficacy and accuracy of our package by using a synthetic data example based on a modified Marmousi model.展开更多
Overt and harmful diabetes mellitus(DM)has detrimental effects on individuals and,by extension,the community.Among the microvascular DM complications is diabetic retinopathy(DR).DR may cause irreversible vision deteri...Overt and harmful diabetes mellitus(DM)has detrimental effects on individuals and,by extension,the community.Among the microvascular DM complications is diabetic retinopathy(DR).DR may cause irreversible vision deterioration in cases of poor blood glucose regulation.Changes in vascular permeability are key trigger points for diabetic macular edema(DME),a condition characterized by the accumulation of fluid in the macula.The development of vascular endothelial growth factor(VEGF)pathway inhibitors has provided a pathogenesis-based treatment approach for DME.Optical coherence tomography(OCT)provides highresolution imaging of the anatomy,including the aging of DME and its structural damage,in distinct morphologic subtypes of macular edema,thereby supporting the assessment of macular edema treatment.The availability of repeated OCT monitoring provides clinical reassurance through the treatment.OCT angiography(OCTA)provides retinal blood flow maps with high spatial resolution.The ability promotes an understanding of disease pathogenesis and facilitates the implementation of new therapeutic methods.This review compares the potential of OCT and OCTA in the diagnosis and treatment of DME,as well as their respective therapeutic applications.展开更多
Photoacoustic-computed tomography is a novel imaging technique that combines high absorption contrast and deep tissue penetration capability,enabling comprehensive three-dimensional imaging of biological targets.Howev...Photoacoustic-computed tomography is a novel imaging technique that combines high absorption contrast and deep tissue penetration capability,enabling comprehensive three-dimensional imaging of biological targets.However,the increasing demand for higher resolution and real-time imaging results in significant data volume,limiting data storage,transmission and processing efficiency of system.Therefore,there is an urgent need for an effective method to compress the raw data without compromising image quality.This paper presents a photoacoustic-computed tomography 3D data compression method and system based on Wavelet-Transformer.This method is based on the cooperative compression framework that integrates wavelet hard coding with deep learning-based soft decoding.It combines the multiscale analysis capability of wavelet transforms with the global feature modeling advantage of Transformers,achieving high-quality data compression and reconstruction.Experimental results using k-wave simulation suggest that the proposed compression system has advantages under extreme compression conditions,achieving a raw data compression ratio of up to 1:40.Furthermore,three-dimensional data compression experiment using in vivo mouse demonstrated that the maximum peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)values of reconstructed images reached 38.60 and 0.9583,effectively overcoming detail loss and artifacts introduced by raw data compression.All the results suggest that the proposed system can significantly reduce storage requirements and hardware cost,enhancing computational efficiency and image quality.These advantages support the development of photoacoustic-computed tomography toward higher efficiency,real-time performance and intelligent functionality.展开更多
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
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
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
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
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
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
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
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
In order to improve the efficiency of 3D near-surface velocity model building, we develop a layer-stripping method using seismic first-arrival times. The velocity model within a Common Mid-Point （CMP） gather is assu...In order to improve the efficiency of 3D near-surface velocity model building, we develop a layer-stripping method using seismic first-arrival times. The velocity model within a Common Mid-Point （CMP） gather is assumed to be stratified into thin layers, and the velocity of each layer var- ies linearly with depth. The thickness and velocity of the top layer are estimated using minimum-offset first-arrival data in a CMP gather. Then the top layer is stripped and the second layer becomes a new top layer. After removing the effect of the top layer from the former first-arrival data, the new first-arrival data are obtained and then used to estimate the parameters of the second layer. In this manner, the velocity model, being regarded as that at a CMP location, is built layer-by-layer from the top to the bottom. A 3D near-surface velocity model is then formed using the velocity models at all CMP locations. The tests on synthetic and observed seismic data show that the layer-stripping method can be used to build good near-surface velocity models for static correction, and its computation speed is approximately hundred times faster than that of grid tomography.展开更多
The precision and reliability of first-arrival picking are crucial for determining the accuracy of geological structure inversion using active source ocean bottom seismometer(OBS)refraction data.Traditional methods fo...The precision and reliability of first-arrival picking are crucial for determining the accuracy of geological structure inversion using active source ocean bottom seismometer(OBS)refraction data.Traditional methods for first-arrival picking based on sample points are characterized by theoretical errors,especially in low-sampling-frequency OBS data because the travel time of seismic waves is not an integer multiple of the sampling interval.In this paper,a first-arrival picking method that utilizes the spatial waveform variation characteristics of active source OBS data is presented.First,the distribution law of theoretical error is examined;adjacent traces exhibit variation characteristics in their waveforms.Second,a label cross-correlation superposition method for extracting highfrequency signals is presented to enhance the first-arrival picking precision.Results from synthetic and field data verify that the proposed approach is robust,successfully overcomes the limitations of low sampling frequency,and achieves precise outcomes that are comparable with those of high-sampling-frequency data.展开更多
We report on tests of combined positron emission tomography(PET)andfluorescence molecular tomography(FMT)imaging system for in vivo investigation on small animals.A nude mouse was inoculated with MD-MB-231 breast canc...We report on tests of combined positron emission tomography(PET)andfluorescence molecular tomography(FMT)imaging system for in vivo investigation on small animals.A nude mouse was inoculated with MD-MB-231 breast cancer cells which expressed redfluorescent protein(RFP).For FMT system,reflective illumination mode was adopted with full-angle data acquisition.[18F]-Fluorodeoxyglucose([18F]-FDG)was used as radioactive tracer for PET.Both data were acquired simultaneously and then reconstructed separately before fusion.Fluorescent tomography results showed exactly where the tumor was located while PET results offered more metabolic information.Results confirmed feasibility for tumor detection and showed superiority to single modality imaging.展开更多
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
Biliary tract cancer(BTC)is a group of heterogeneous sporadic diseases,including intrahepatic,hilar,and distal cholangiocarcinoma,as well as gallbladder cancer.BTC is characterized by high invasiveness and extremely p...Biliary tract cancer(BTC)is a group of heterogeneous sporadic diseases,including intrahepatic,hilar,and distal cholangiocarcinoma,as well as gallbladder cancer.BTC is characterized by high invasiveness and extremely poor prognosis,with a global increased incidence due to intrahepatic cholangiocarcinoma(ICC).The 18Ffludeoxyglucose positron emission tomography(PET)computed tomography(18F-FDG PET/CT)combines glucose metabolic information(reflecting the glycolytic activity of tumor cells)with anatomical structure to assess tumor metabolic heterogeneity,systemic metastasis,and molecular characteristics noninvasively,overcoming the limitations of traditional imaging in the detection of micrometastases and recurrent lesions.18F-FDG PET/CT offers critical insights in clinical staging,therapeutic evaluation,and prognostic prediction of BTC.This article reviews research progress in this field over the past decade,with a particular focus on the advances made in the last 3 years,which have not been adequately summarized and recognized.The research paradigm in this field is shifting from qualitative to quantitative studies,and there have been significant breakthroughs in using 18F-FDG PET/CT metabolic information to predict gene expression in ICC.Radiomics and deep learning techniques have been applied to ICC for prognostic prediction and differential diagnosis.Additionally,PET/magnetic resonance imaging is increasingly demonstrating its value in this field.展开更多
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
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
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
基金financial support for this work contributed by the National Key Research and Development Program of China(grant nos.2016YFC0600302,2016YFC0600101 and 2016YFC0600201)the National Natural Science Foundation of China(grants 41604075,41430213,41574092 and 41474068)
文摘Irregular surface flattening,which is based on a boundary conforming grid and the transformation between curvilinear and Cartesian coordinate systems,is a mathematical method that can elegantly handle irregular surfaces,but has been limited to obtaining first arrivals only.By combining a multistage scheme with the fast-sweeping method(FSM,the method to obtain first-arrival traveltime in curvilinear coordinates),the reflected waves from a crustal interface can be traced in a topographic model,in which the reflected wavefront is obtained by reinitializing traveltimes in the interface for upwind branches.A local triangulation is applied to make a connection between velocity and interface nodes.Then a joint inversion of first-arrival and reflection traveltimes for imaging seismic velocity structures in complex terrains is presented.Numerical examples all perform well with different seismic velocity models.The increasing topographic complexity and even use of a high curvature reflector in these models demonstrate the reliability,accuracy and robustness of the new working scheme;checkerboard testing illustrates the method's high resolution.Noise tolerance testing indicates the method's ability to yield practical traveltime tomography.Further development of the multistage scheme will allow other later arrivals to be traced and used in the traveltime inversion.
基金financially supported by the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (Grant No. GML2019 ZD0207)supported by the Guangzhou Municipal Science and Technology Bureau (Grant No. 202102021054)
文摘First-arrival seismic traveltime tomography(FAST)is a well-established technique to estimate subsurface velocity structures.Although several existing open-source packages are available for first-arrival traveltime tomography,most were written in compiled languages and lack sufficient extendibility for new algorithms and functionalities.In this work,we develop an open-source,selfcontained FAST package based on MATLAB,one of the most popular interpreted scientific programming languages,with a focus on ocean bottom seismometer refraction traveltime tomography.Our package contains a complete traveltime tomography workflow,including ray-tracing-based first-arrival traveltime computation,linearized inversion,quality control,and high-quality visualization.We design the package as a modular toolbox,making it convenient to integrate new algorithms and functionalities as needed.At the current stage,our package is most efficient for performing FAST for two-dimensional ocean bottom seismometer surveys.We demonstrate the efficacy and accuracy of our package by using a synthetic data example based on a modified Marmousi model.
文摘Overt and harmful diabetes mellitus(DM)has detrimental effects on individuals and,by extension,the community.Among the microvascular DM complications is diabetic retinopathy(DR).DR may cause irreversible vision deterioration in cases of poor blood glucose regulation.Changes in vascular permeability are key trigger points for diabetic macular edema(DME),a condition characterized by the accumulation of fluid in the macula.The development of vascular endothelial growth factor(VEGF)pathway inhibitors has provided a pathogenesis-based treatment approach for DME.Optical coherence tomography(OCT)provides highresolution imaging of the anatomy,including the aging of DME and its structural damage,in distinct morphologic subtypes of macular edema,thereby supporting the assessment of macular edema treatment.The availability of repeated OCT monitoring provides clinical reassurance through the treatment.OCT angiography(OCTA)provides retinal blood flow maps with high spatial resolution.The ability promotes an understanding of disease pathogenesis and facilitates the implementation of new therapeutic methods.This review compares the potential of OCT and OCTA in the diagnosis and treatment of DME,as well as their respective therapeutic applications.
基金supported by the National Key R&D Program of China[Grant No.2023YFF0713600]the National Natural Science Foundation of China[Grant No.62275062]+3 种基金Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments[Grant No.2023-SGTTXM-002 and 2024-SGTTXM-005]the Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund)[Grant No.YDZX2023115]the Taishan Scholar Special Funding Project of Shandong Provincethe Shandong Laboratory of Advanced Biomaterials and Medical Devices in Weihai[Grant No.ZL202402].
文摘Photoacoustic-computed tomography is a novel imaging technique that combines high absorption contrast and deep tissue penetration capability,enabling comprehensive three-dimensional imaging of biological targets.However,the increasing demand for higher resolution and real-time imaging results in significant data volume,limiting data storage,transmission and processing efficiency of system.Therefore,there is an urgent need for an effective method to compress the raw data without compromising image quality.This paper presents a photoacoustic-computed tomography 3D data compression method and system based on Wavelet-Transformer.This method is based on the cooperative compression framework that integrates wavelet hard coding with deep learning-based soft decoding.It combines the multiscale analysis capability of wavelet transforms with the global feature modeling advantage of Transformers,achieving high-quality data compression and reconstruction.Experimental results using k-wave simulation suggest that the proposed compression system has advantages under extreme compression conditions,achieving a raw data compression ratio of up to 1:40.Furthermore,three-dimensional data compression experiment using in vivo mouse demonstrated that the maximum peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)values of reconstructed images reached 38.60 and 0.9583,effectively overcoming detail loss and artifacts introduced by raw data compression.All the results suggest that the proposed system can significantly reduce storage requirements and hardware cost,enhancing computational efficiency and image quality.These advantages support the development of photoacoustic-computed tomography toward higher efficiency,real-time performance and intelligent functionality.
基金Project(2023YFB4606200)supported by the National Key Research and Development Program of ChinaProject(2023-SSRF-HZ-503114-2)supported by Shanghai Synchrotron Radiation Facility,Instrument BL16U2,China。
文摘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.
基金supported by the financial support received from the Indian Council of Medical Research-Department of Health Research(ICMRDHR-CoE-5/3/8/5/2019/I-MDMS)Medical Device and Diagnostics Mission Secretariat(MDMS)and Foundation for Centre for Healthcare Entrepreneurship(CfHE).
文摘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.
基金supported by the Guangdong Pharmaceutical University 2024 Higher Education Research Projects(GKP202403,GMP202402)the Guangdong Pharmaceutical University College Students’Innovation and Entrepreneurship Training Programs(Grant No.202504302033,202504302034,202504302036,and 202504302244).
文摘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.
基金supported by the Key Research and Development Program of the Xinjiang Uygur Autonomous Region(No.2020B03006-1)the National Natural Science Foundation of China(Nos.42304069,and 42102275).
文摘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.
文摘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.
基金PEEP titration in ARDS patients using EIT combined with lung ultrasound,Key Laboratory of Emergency Trauma Research,Ministry of Education (KLET-202201)airway clearance protocol in ICU mechanically ventilated patients based on electrical impedance imaging technology,Natural Science Foundation of Hunan Province (2024JJ9148)effects of end expiratory positive pressure on lung re-expansion in patients with ARDS and intra-abdominal hypertension monitored using lung ultrasound,Natural Science Foundation of Hunan Province (2023JJ60308)
文摘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.
文摘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.
基金supported by the Fundamental Research Funds for the Central Universities,Nos.G2021KY05107,G2021KY05101the National Natural Science Foundation of China,Nos.32071316,32211530049+1 种基金the Natural Science Foundation of Shaanxi Province,No.2022-JM482the Education and Teaching Reform Funds for the Central Universities,No.23GZ230102(all to LL and HH).
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.41230318,41074077)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20130132110023)the Fundamental Research Funds for the Central Universities of China(No.201413004)
文摘In order to improve the efficiency of 3D near-surface velocity model building, we develop a layer-stripping method using seismic first-arrival times. The velocity model within a Common Mid-Point （CMP） gather is assumed to be stratified into thin layers, and the velocity of each layer var- ies linearly with depth. The thickness and velocity of the top layer are estimated using minimum-offset first-arrival data in a CMP gather. Then the top layer is stripped and the second layer becomes a new top layer. After removing the effect of the top layer from the former first-arrival data, the new first-arrival data are obtained and then used to estimate the parameters of the second layer. In this manner, the velocity model, being regarded as that at a CMP location, is built layer-by-layer from the top to the bottom. A 3D near-surface velocity model is then formed using the velocity models at all CMP locations. The tests on synthetic and observed seismic data show that the layer-stripping method can be used to build good near-surface velocity models for static correction, and its computation speed is approximately hundred times faster than that of grid tomography.
基金supported by the Major Research Plan on West-Pacific Earth System Multispheric Interactions (Nos.91858215,91958206)the National Natural Science Foundation of China (NSFC)Shiptime Sharing Project (No.41949581)the Key Research and Development Program of Shandong Province (No.2019GHY112019)。
文摘The precision and reliability of first-arrival picking are crucial for determining the accuracy of geological structure inversion using active source ocean bottom seismometer(OBS)refraction data.Traditional methods for first-arrival picking based on sample points are characterized by theoretical errors,especially in low-sampling-frequency OBS data because the travel time of seismic waves is not an integer multiple of the sampling interval.In this paper,a first-arrival picking method that utilizes the spatial waveform variation characteristics of active source OBS data is presented.First,the distribution law of theoretical error is examined;adjacent traces exhibit variation characteristics in their waveforms.Second,a label cross-correlation superposition method for extracting highfrequency signals is presented to enhance the first-arrival picking precision.Results from synthetic and field data verify that the proposed approach is robust,successfully overcomes the limitations of low sampling frequency,and achieves precise outcomes that are comparable with those of high-sampling-frequency data.
基金The authors would like to thank X.Zhang,faculty of XinAoMDT Technology Co.,Ltd.,for the work of system software development.This work is supported by the National Natural Science Foundation of China under Grant Nos.81071191,60831003,30930092,30872633the Tsinghua-Yue-Yuen Medical Science Foundationthe National Basic Research Program of China(973)under Grant No.2011CB707701.
文摘We report on tests of combined positron emission tomography(PET)andfluorescence molecular tomography(FMT)imaging system for in vivo investigation on small animals.A nude mouse was inoculated with MD-MB-231 breast cancer cells which expressed redfluorescent protein(RFP).For FMT system,reflective illumination mode was adopted with full-angle data acquisition.[18F]-Fluorodeoxyglucose([18F]-FDG)was used as radioactive tracer for PET.Both data were acquired simultaneously and then reconstructed separately before fusion.Fluorescent tomography results showed exactly where the tumor was located while PET results offered more metabolic information.Results confirmed feasibility for tumor detection and showed superiority to single modality imaging.
文摘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.
文摘Biliary tract cancer(BTC)is a group of heterogeneous sporadic diseases,including intrahepatic,hilar,and distal cholangiocarcinoma,as well as gallbladder cancer.BTC is characterized by high invasiveness and extremely poor prognosis,with a global increased incidence due to intrahepatic cholangiocarcinoma(ICC).The 18Ffludeoxyglucose positron emission tomography(PET)computed tomography(18F-FDG PET/CT)combines glucose metabolic information(reflecting the glycolytic activity of tumor cells)with anatomical structure to assess tumor metabolic heterogeneity,systemic metastasis,and molecular characteristics noninvasively,overcoming the limitations of traditional imaging in the detection of micrometastases and recurrent lesions.18F-FDG PET/CT offers critical insights in clinical staging,therapeutic evaluation,and prognostic prediction of BTC.This article reviews research progress in this field over the past decade,with a particular focus on the advances made in the last 3 years,which have not been adequately summarized and recognized.The research paradigm in this field is shifting from qualitative to quantitative studies,and there have been significant breakthroughs in using 18F-FDG PET/CT metabolic information to predict gene expression in ICC.Radiomics and deep learning techniques have been applied to ICC for prognostic prediction and differential diagnosis.Additionally,PET/magnetic resonance imaging is increasingly demonstrating its value in this field.
文摘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.
基金supported by the Research Project of the Shanghai Health Commission,No.2020YJZX0111(to CZ)the National Natural Science Foundation of China,Nos.82021002(to CZ),82272039(to CZ),82171252(to FL)+1 种基金a grant from the National Health Commission of People’s Republic of China(PRC),No.Pro20211231084249000238(to JW)Medical Innovation Research Project of Shanghai Science and Technology Commission,No.21Y11903300(to JG).
文摘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.
基金Supported by the 2022 Provincial Quality Engineering Project for Higher Education Institutions,No.2022sx031the 2023 Provincial Quality Engineering Project for Higher Education Institutions,No.2023jyxm1071.
文摘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.
