Abstract:In this study,we systematically evaluated the iodine quantification accuracy and image noise suppression capabilities of a deep learning reconstruction algorithm(ClearInfinity,CI)under 60 kVp ultra-low tube voltage computed tomography(CT)conditions,comparing it with filtered backprojection(FBP)and hybrid iterative reconstruction(ClearView,CV).A CT performance phantom containing inserts with varying iodine concentrations(40,28,22,12,6,3,and 2 mg/mL)was scanned six times(60 kVp,386 mA)using a NeuViz Epoch Elite CT scanner.Images were reconstructed using FBP,CV(at 20%,40%,60%,and 80%intensities),and CI(at equal intensity).CT values,image noise(standard deviation SD),and coefficients of variation(cv)of the iodine inserts were measured.Absolute percentage bias(APB)and contrast-to-noise ratio(CNR)were calculated.Results show that CI achieved optimal quantitative accuracy at 40%reconstruction intensity and provided the strongest noise reduction at 80%,with a maximum SD reduction of up to 79.59%.At all intensity levels,CI significantly outperformed CV and FBP in terms of APB,noise suppression(especially at low iodine concentrations),measurement stability,and CNR.These findings confirm that CI is an effective solution for producing low-noise,low-bias,and highly stable images in ultra-low-dose CT.

Abstract:X-ray computed tomography(CT)is widely used in clinical practice,and image reconstruction algorithms play a pivotal role in determining image quality.With the increasing diversity of clinical imaging demands and concerns regarding radiation exposure,conventional reconstruction techniques,such as filtered back-projection and iterative reconstruction,have become insufficient for meeting the requirements of low-dose CT imaging and diversified diagnostic scenarios.In recent years,artificial-intelligence(AI)based reconstruction algorithms have been increasingly incorporated into clinical workflows,leading to substantial improvements in image quality and in radiation dose efficiency.In this review,first,the major technical bottlenecks associated with traditional CT reconstruction methods are outlined and the requirement to adopt AI-based reconstruction techniques in clinical practice is highlighted.Then,a systematic overview of the principal categories of AI-based CT reconstruction algorithms is provided,commonly used approaches are summarized,and their performance in clinical applications is described.Finally,the current limitations of AI-based CT reconstruction algorithms are discussed and potential strategies to advance their integration into clinical CT reconstruction are proposed.

Abstract:Objective:To investigate the impact of CARE kV technology on radiation dose in coronary computed tomography angiography(CCTA).Methods:This retrospective study analyzed data from 1,529 patients who underwent CCTA at The First Affiliated Hospital of Chongqing Medical University between December 2023 and December 2024.All scans utilized CARE kV technology,with patients stratified by automatically selected kV values.Radiation dose metrics recorded included the volume CT dose index(CTDIvol),dose-length product(DLP),size-specific dose estimate(SSDE),effective dose derived from DLP(ED_DLP),and Monte Carlo simulation-based effective dose(ED_Radimetrics).Dose ratio differences were characterized by SSDE/CTDIvol and ED_Radimetrics/ED_DLP.Group comparisons were conducted using Kruskal-Wallis H tests with Bonferroni correction,while associations between kV and dose metrics/ratios were assessed with Spearman correlation analysis.Results:Patients were categorized into four kV groups:70 kV(n=815),80 kV(n=541),90 kV(n=67),and 100 kV(n=106).Significant intergroup differences were observed in all dose metrics(CTDIvol,DLP,SSDE,ED_DLP,ED_Radimetrics)and dose ratios(SSDE/CTDIvol,ED_Radimetrics/ED_DLP).Spearman analysis revealed moderate positive correlations between kV and CTDIvol(rs=0.53,P<0.05),DLP(rs=0.49,P<0.05),SSDE(rs=0.54,P<0.05),ED_DLP(rs=0.49,P<0.05),and ED_Radimetrics(rs=0.46,P<0.05).A weak negative correlation was found between kV and SSDE/CTDIvol(rs=-0.30,P<0.05),while a negligible positive correlation was observed between kV and ED_Radimetrics/ED_DLP(rs=0.07,P<0.05).Conclusion:CARE kV technology effectively reduces radiation dose in CCTA.All dosimetric metrics exhibit moderate positive correlations with kV,underscoring kV selection as a critical determinant of dose control.Conventional metrics CTDIvol and ED_DLP systematically underestimate actual radiation dose levels,with the extent of underestimation showing minimal dependence on the CARE kV-selected kV values.We recommend integrating SSDE and ED_Radimetrics into standardized dose management protocols to enhance patient-specific radiation protection and risk stratification.

Abstract:Metal artifacts adversely affect computed tomography(CT)image quality and diagnostic accuracy.Metal-artifact reduction(MAR)in CT images has long been a major focus of research.In recent years,with the advancement and application of deep-learning technologies,new approaches have emerged for research on MAR algorithms,leading to a wealth of outstanding achievements.In this paper,we first introduce the causes and manifestations of metal artifacts in CT images.We then review recent progress in deep-learning-based MAR methods,categorizing them into three approaches:image,projection,and dual domains.Finally,we summarize these methods and discuss future research prospects for MAR technology.

Abstract:In recent years,advancements in geophysical instruments,equipment,and sensitivity have enabled the widespread application of micro-tremor array detection,a natural source geophysical method,in engineering exploration and shallow geological surveys.In this study,we aimed to classify the bedrock relief interface of a pumped storage project site,determine the thickness of its overlying layer,and identify hidden fault structures in the working area.According to the real working conditions at the site,micro-tremor array detection technology featuring strong anti-interference ability and high efficiency and speed was selected.The theoretical simulation results showed that the dispersion curves obtained using a linear array and triangular nested array were consistent with the theoretically calculated values.Therefore,a linear array method was adopted to detect two survey lines arranged in the working area.A data collection method was adopted to obtain abundant geological information in the shallow layer to accomplish high-precision detection of the shallow surface.Based on the SPAC method,the phase-velocity dispersion curves of the fundamental Rayleigh waves were extracted from each measurement point of the two survey lines.The S-wave velocity structural profiles of the two survey lines were obtained via inversion interpolation.The detection results indicated that the thickness of the covering layer in the working area was basically consistent with the verification results of the drilling data,and no shallow geological bodies were found.This provides reliable shallow geological information for the construction of pumped storage projects.

Abstract:Trace detection and X-ray security inspection technology respectively serve as the"nose"and"eyes"of security applications,detecting explosives through"smell"and"vision"perspectives.Following decades of innovation and deployment,they are currently playing critical roles in the integrated aviation security solution.This study explores the prospective fusion of these two technologies for aviation security.Starting with basic technical principles and comparisons,considering security,efficiency,and passenger experience,the study examines industrial trends and discusses the bottlenecks of existing solutions based on standalone security equipment.Subsequently it elaborates the novel concept of fusing trace detection and X-ray computed tomography(X-CT)in security inspection.According to qualitative analysis and discrete event simulation,the study predicts the effectiveness of such fusion.The study further discusses the challenges faced in the development of an automatic trace detection system,elaborates on its concrete innovations and different methods of fusion,and envisions the trends of fusing multiple security detection technologies.According to industry reality,this study analyzes the domestic and international application prospects of this technology in aviation security from a rational and optimistic perspective,aiming to visualize a blueprint for technology developers and end users of security equipment.

Abstract:Flat-panel detector-based cone-beam computed tomography(CBCT)has demonstrated significant potential for applications in medical diagnostics and non-destructive testing.However,the coupling of stronger scatter artifacts and beam hardening effects in CBCT has long limited its quantitative imaging performance.Recently,a novel CBCT imaging technique called"spatial-temporal mixed spectral modulation"has been proposed.It can generate multi-energy spectral data with similar scattering distribution and good alignment of spectral projections,and it has the potential for multi-energy imaging with simultaneously scattering correction capability.This article presents an optimized design of the spectral modulator,which serves as the key hardware for the proposed imaging technique.We first determined the pattern of the spectral modulator based on its physics model and manufacturing difficulty.Subsequently,we selected the material,thickness,and period according to the analysis of the spectral imaging performance and the validation of scatter similarity hypothesis.Finally,we fabricated an overlapped spectral modulator with thicknesses of(0.2+0.4)mm Mo.Physical experiments demonstrated that this modulator can achieve enhanced CBCT quantitative imaging performance using the corresponding spectral-scatter decoupling algorithm.

Abstract:Unilateral absence of the pulmonary vein(UAPV)is a rare congenital anomaly,and computed tomography(CT)angiography can clearly show the anatomical morphology of the pulmonary artery,pulmonary vein,and related lesions.Here,we report the case of an asymptomatic 28-year-old female patient with unilateral interstitial changes in the lungs on plain CT scanning due to UAPV,diagnosed on CT angiography,with no abnormalities in her laboratory tests.This report summarizes and analyzes the imaging manifestations of UAPV in conjunction with related literature to improve our understanding and the diagnosis of this rare disease.

Abstract:Objective:To investigate the diagnostic value of dual-energy computed tomography(DECT)for Stage ⅡA talar osteochondral injuries,with magnetic resonance imaging(MRI)as the reference standard.Methods:Thirty consecutive patients admitted to the orthopedics department of our hospital from January 2023 to December 2023,with long-term ankle pain and diagnosed with an osteochondral lesion of the talus through clinical and MRI examinations,were enrolled.DECT was performed on the patients within 24 hours after the MRI examination.Doctor A diagnosed and staged the 30 MRI images based on the modified MRI staging criteria by Hepple et al.Doctors B and C,independently and blindly,performed visual assessment and staging of the DECT images after post-processing to generate virtual non-calcium images.Doctor D quantitatively assessed images from the patients with a Stage ⅡA injury using the virtual non-calcium technique,based on the MRI results.With MRI as the reference standard,the qualitative assessments of DECT were statistically analyzed by Doctors B and C.Doctor D quantitatively assessed whether there was a statistical difference in CT attenuation values in the lesion area in patients with Stage ⅡA injuries compared with the controls.Results:The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of DECT qualitative diagnosis by Doctors B and C were 84％,91％,89％,83％,and 90％and 85％,89％,88％,83％,91％,respectively(Kappa values of 0.771 and 0.758).The sensitivity and specificity of qualitative assessment of Stage ⅡA lesions by Doctors B and C were 85％,94％,and 84％,93％,respectively(Kappa values of 0.807 and 0.801).The quantitative diagnosis by Doctor D showed a statistical difference,with an optimal cutoff value of-21.85 HU(sensitivity and specificity:92％and 98.9％).Conclusion:DECT and virtual non-calcium imaging techniques have significant diagnostic value for patients with Stage ⅡA talar osteochondral injuries.

Abstract:Objective:To conduct a comparative study on the effects of axial and helical scanning modes on image quality and radiation dose in cranial three-dimensional computed tomography.Methods Phantom study:The CTP515 low-contrast module and CTP528 high-contrast module of a Catphan600 phantom are scanned using clinical scanning protocols,and the image quality is evaluated using the Radia diagnostic software.Clinical study:A total of 297 cranial CT images obtained from five devices in our hospital from August 2024 to January 2025 are randomly selected for retrospective analysis.Among them,147 cases in group A are scanned in the helical mode,and 150 cases in group B are scanned in the axial mode.All CT devices are used in both groups.The contrast-to-noise ratio,which is an objective index of the transverse,coronal,and sagittal plane images of the two groups,is calculated,and the image quality is scored subjectively.Statistical analysis is performed on the subjective and objective indicators,and P<0.05 indicates a statistically significant difference.The radiation dose-related indicators of the patients are analyzed using the Radimetrics software.Results In the transverse plane,the image quality obtained via axial scanning is better than obtained via helical scanning.Meanwhile,in the coronal and sagittal planes,the image quality obtained via helical scanning is slightly better than that obtained via axial scanning.Except for device 4,the volume-rendering images based on helical scanning are better than that based on axial scanning.Among them,the contrast-to-noise ratio(CNR)of the transverse plane of device 1 indicates a statistically significant difference;the subjective scores of the coronal plane of devices 2,3,and 5 show statistically significant differences;the CNR of the sagittal plane of device 4 indicates a statistically significant difference;the subjective scores of devices 2-5 in the sagittal plane show statistically significant differences;and the subjective scores of VR of devices 1,2,3,and 5 indicate statistically significant differences.The differences in scan length,dose length product(DLP),and the effective dose(ED)between the two scanning modes of all devices exceed those of volume CT dose index(CTDIvol),with all being statistically significant.Conclusion When performing cranial CT examinations,the scanning mode selected significantly affects the image quality and diagnostic effectiveness.When only transverse plane images are required,axial scanning can provide an image quality that satisfies the requirements.Meanwhile,patients are exposed to a lower radiation dose if better-quality VR images are required.The transverse,coronal,and sagittal plane images satisfy the clinical diagnostic requirements,and the helical scanning mode is recommended.In certain conditions,a single-rotation axial-scanning mode can be used in conjunction with a wide-body detector.

Abstract:In the southern region of the Ordos Basin,the thin,single-layer distributary channel sands in the Lower Shihezi Formation cause coupling between the sidelobes of the underlying Shanxi-Taiyuan coal seam reflections and the reflections of thin sand bodies within a limited seismic resolution,making it difficult to accurately analyze the reservoir response characteristics.Additionally,challenges in petrophysical analysis arise owing to the poor quality of the logging curves and insufficient shear wave data in this area block,which impede quantitative reservoir prediction.To address these issues,based on the improvement of logging curve quality through multi-parameter fitting this study establishes a three-phase(sand-mud-coal)rock physics modeling workflow by conducting multiple modelings and stepwise integrations in accordance with the theory of the Xu-White rock physics model.This workflow effectively improves the quality of logging curves and enhances the accuracy of shear wave velocity prediction,thereby providing reasonable logging information for subsequent inversions.Furthermore,to address the reservoir prediction problems mentioned above,this study introduces a multidimensional facies-controlled pre-stack geostatistical inversion method suitable for the study area.First,based on the existing geological understanding and well log information,seismic attributes related to channel sands were analyzed,and a two-dimensional lithofacies probability density conforming to sedimentary variation patterns was extracted as a planar constraint for the Shihezi Formation reservoir.Then,using the coal seam inversion volume combined with Bayesian discrimination principles,a three-dimensional coal facies probability density was extracted as a spatial constraint for the underlying coal seam.Finally,both two-and three-dimensional constraints were comprehensively integrated to conduct a pre-stack geostatistical inversion.The prediction results obtained using this method comprehensively considered the coupling characteristics of the underlying coal seams and sandstone reservoirs,effectively reducing the uncertainty in predicting thin reservoirs.This method has shown a good practical application result,with a significant improvement in drilling accuracy.

Abstract:Objective:This study investigates the feasibility and diagnostic value of L1 vertebral computed tomography(CT)attenuation for the opportunistic screening of osteoporosis via routine abdominal CT scans.Methods:Data from 1117 patients who underwent quantitative computed tomography(QCT)and abdominal CT were analyzed retrospectively.The bone mineral density(BMD)and CT attenuation values of the L1 and L2 vertebrae were measured,and patients were divided into three groups according to the BMD:osteoporosis,osteopenia,or normal BMD.The correlation between the two measurements was analyzed.The 30 patients was randomly selected and the L1 attenuation CT value was measured by two observers at two time points separated by at least two weeks.Bland-Altman plots were used to assess the agreement between the predicted and measured QCT values.Receiver operating characteristic(ROC)curves were generated to determine the optimal diagnostic thresholds and the area under the curve(AUC).Results:The L1 and L2 vertebral CT attenuation values correlated well with the QCT BMD values(correlation coefficients of 0.956 and 0.902).There was excellent intra-and interobserver agreement in the L1 vertebral attenuation CT value measurements (ICC=0.995 and 0.985)for the two observers.An analysis of the Bland-Altman plot showed that there was good agreement between the predicted and measured QCT BMD values.The CT attenuation values of the L1 and L2 vertebrae predicted osteoporosis and normal BMD with high accuracy.The AUC of the L1 and L2 vertebrae CT attenuation values and mean CT attenuation values of L1 and L2 for predicting osteoporosis were 0.982,0.977,and 0.984,respectively,and those for predicting normal BMD were 0.969,0.964,and 0.970,respectively.The optimal thresholds of the L1 vertebrae for predicting osteoporosis and normal BMD were 106.33 HU and 149.33 HU,respectively.Conclusion:L1 vertebral CT attenuation values on abdominal CT scans are highly reliable and valuable for opportunistic osteoporosis screening.Thus,the L1 vertebral attenuation CT value can be used for opportunistic osteoporosis screening.

Abstract:The sparse impedance inversion method is widely used in oil and gas exploration.However,traditional sparse constraints capture limited three-dimensional spatial sparse information and often neglect the time-frequency characteristics of seismic data.As a result,the spatial resolution and accuracy of three-dimensional inversion results are often small.To address these limitations,this study proposes a seismic inversion method based on logarithmic three-dimensional total variation sparse constraints under mixed domain conditions.The method introduces a logarithmic penalty factor to extract sparse information.Compared with conventional sparse constraints,the logarithmic penalty allows for the extraction of more effective sparse structures.When combined with a 3D total variation constraint,this method fully exploits the spatial sparsity of wave impedance,thereby improving both spatial resolution and inversion accuracy.In addition,the proposed approach incorporates time-frequency domain information using a short-time Fourier transform(STFT)forward operator.This integration introduces essential time-frequency characteristics of seismic data into the inversion process,further enhancing its accuracy.To improve inversion stability,the method combines initial model constraints,time-frequency domain constraints,and logarithmic 3D total variation sparse constraints within a unified objective function.This objective function is solved using the alternating direction method of multipliers(ADMM).The proposed method was validated on both a three-dimensional thrust body model and real 3D seismic data.Results demonstrates that,compared to conventional methods,the proposed approach significantly improves the spatial resolution and accuracy of 3D inversion results.

Abstract:Objective:To explore the value of myocardial extracellular volume(ECV)measured using dual-energy computed tomography(CT)in preoperative risk stratification for transcatheter aortic valve implantation(TAVI).Methods:We prospectively included 71 patients who underwent CT assessment before TAVI between June 2023 and June 2024,all of whom underwent dual-energy CT-delayed enhancement scans to calculate the ECV.Based on the median ECV,the patients were divided into high-ECV and low-ECV groups.Follow-up was conducted to observe TAVI surgical outcomes and early postoperative recovery among the two patient groups.Results:The median ECV of the 71 patients was(33.92±6.37)%.Of these,49 patients ultimately underwent surgery at our hospital,with 26 patients in the high-ECV group and 23 patients in the low-ECV group.The postoperative hospital stay,intensive care unit(ICU)stay,and incidence of cardiovascular adverse events were significantly greater in the high-ECV group than in the low-ECV group.Correlation analysis showed a positive correlation between ECV and the length of postoperative hospital stay(r=0.446).Multifactorial logistic regression analysis showed that ECV was an independent risk factor for short-term postoperative adverse cardiovascular events(OR=1.399).Conclusion:Cardiac ECV based on dual-energy CT has potential for preoperative risk stratification in patients with aortic valve disease undergoing TAVI.

Abstract:This study aimed to summarize the diagnosis of jejunal diverticulum perforation with hepatic portal venous gas(HPVG)and superior mesenteric vein(SMV)thrombosis using multislice spiral computed tomography(MSCT)and evaluate its curative effect to improve the understanding of this disease.The clinical data,imaging manifestations,treatment,and prognosis of a patient with jejunal diverticulum perforation with HPVG and SMV thrombosis were retrospectively analyzed,and relevant literature were summarized and analyzed.Here,the primary clinical manifestations were persistent abdominal pain and fever.MSCT revealed multiple diverticula in the proximal jejunum.A diverticular wall ruptured and connected to the adjacent SMV branch,resulting in HPVG.Enhanced CT showed thrombus in the SMV.Intraoperatively,multiple jejunal diverticula were observed,of which some showed hyperemia,edema,and exudation.An intraoperative thrombus was observed in the SMV.The pathological manifestations include inflammatory cell infiltration in the jejunal diverticulum and thrombus formation in the SMV.MSCT can clearly diagnose jejunal diverticulum perforation with HPVG and SMV thrombosis and show the exact location of the perforation.Jejunal diverticulum perforation with HPVG and SMV thrombosis suggests that the patient's condition is critical,and active surgical treatment is needed to save the pati-ent's life.

Abstract:Objective:To investigate alterations in glymphatic system function and correlate them with clinical indicators in patients with migraine without aura(MwoA).Methods:A total of 50 MwoA patients and 49 matched healthy controls(HC)were enrolled.Imaging data were acquired using 3.0T MRI.The differences in diffusion tensor imaging analysis along the perivascular space(DTI-ALPS)index and the coupling strength of global blood-oxygen-level-dependent signal and cerebrospinal fluid(CSF)inflow dynamics(gBOLD-CSF)were calculated between the two groups to evaluate the glymphatic system function in MwoA patients;their correlations with clinical scale scores were further analyzed.Results:Compared with healthy controls,MwoA patients exhibited significantly lower left-sided DTI-ALPS index,reduced gBOLD-CSF coupling strength,and diminished-d(gBOLD)/dt-CSF coupling strength.Additionally,the left-sided ALPS index was negatively correlated with the Beck Anxiety Inventory score.Conclusion:MwoA patients demonstrate impaired glymphatic system function,which may contribute to the pathophysiology of migraine and be associated with anxiety symptoms.These findings provide new insights into the mechanisms underlying migraine.

Abstract:The core of vertical seismic profile(VSP)data processing lies in accurately separating upgoing and downgoing waves,and the quality of this separation directly affects the reliability of imaging and inversion of formation parameters.Current mainstream methods include frequency-wavenumber(f-k)filtering,the Radon transform and its improved high-precision algorithms,median filtering,and sparse constraint-based optimization methods.However,these methods incur high trial-and-error costs because of parameter sensitivity and difficulty in balancing fidelity and efficiency in complex wavefields.This study conducted a detailed theoretical analysis and data testing on common methods from the aspects of separation accuracy,processing efficiency,and operation procedures.Considering label generation in deep learning,the study tested the adaptability of different methods for label production,thereby making suggestions for label optimization to improve the quality and production efficiency of training data.In addition,the study constructs a rich label library based on data from multiple work areas,trains a general wavefield separation model,and realizes efficient processing of unknown data,which ultimately improve the accuracy and efficiency of wavefield separation.

Abstract:Objective:This study aimed to explore the efficacy and versatility of contrast enhancement boost(CE-Boost)technology for enhancing blood vessels with varying phases and degrees of enhancement on cranial four-dimensional computed tomography angiography(4D-CTA).Methods:Forty-three patients who underwent cerebral CT perfusion(CTP)were enrolled retrospectively.For each patient,three single-phase images were selected from the 4D-CTA based on subjective scoring criteria:one image was scored as arterial early phase non-diagnostic(insufficient enhancement for clinical diagnosis),and two images were scored as arterial phase diagnostic(sufficient enhancement for clinical diagnosis).Subsequently,the corresponding CE-Boost group images were generated using subtraction software.Measurements were obtained on the normal side in six image groups,including:the middle cerebral artery(MCA)M1 segment,basilar artery(BA),and brainstem(BS).Objective image quality was assessed using the CT value,image noise,signal-to-noise ratio(SNR),and contrast noise ratio(CNR).The subjective image quality was assessed using a five-point Likert scale.Results:The CT attenuation value,noise value,SNR,and CNR of the MCA and BA were significantly higher in the CE-Boost group than in the original images.The subjective score of the CE-Boost group was higher than that of the original image(3.59±1.33 vs.2.92±0.95).Conclusion:The CE-Boost technique can improve the objective image quality of arterial phase diagnostic images of intracranial 4D-CTA while improving the visualization of branch vessels.However,arterial early phase non-diagnostic images only improve the objective evaluation of the trunk and have limited ability to improve the visualization of intracranial branch vessels.This study suggests that the CE-Boost technique is suitable for arterial phase diagnostic images with an intracranial subjective score greater than or equal to 3.

Abstract:Advances in computed tomography(CT)have accelerated scanning speeds and improved the spatial resolution of images.These improvements allow clearer visualization of whole-body fine bone structures,gradually enhancing the understanding of diseases and strengthening confidence in CT-based diagnosis and treatment efficacy evaluation.This review summarizes the clinical applications and research progress of conventional multi-slice spiral CT,cone-beam CT,photon-counting detector CT,and micro-CT in assessing bone quality.

Abstract:The Ganquan Loess Plateau Block in the Ordos Basin exhibits promising hydrocarbon exploration potential in its karst reservoirs.However,the seismic imaging quality obtained using conventional methods remains suboptimal due to challenges posed by thick loess layers and complex karst reservoir structures.This paper proposes a dip-angle domain stationary-phase deabsorption prestack time migration method to enhance imaging quality in this area.By incorporating the effective Q concept,the method compensates for seismic wave energy attenuation and wavelet dispersion caused by medium absorption,significantly improving imaging resolution.Nevertheless,high-frequency energy compensation inevitably amplifies migration noise.The dip-angle domain stationary-phase migration estimates the Fresnel zone based on dip-angle gathers,achieving optimal Fresnel zone stacking imaging in the dip-angle domain,which effectively suppresses migration noise and substantially enhances the signal-to-noise ratio(SNR)of the imaging section.The proposed method integrates the dual advantages of dip-angle domain stationary-phase migration(improving SNR)and viscoelastic prestack time migration(enhancing resolution).After applying this method to the Ganquan Loess Plateau Block,both the SNR and resolution of imaging profiles were markedly improved,with the typical"beaded"structures in karst reservoirs clearly imaged.