Clinical Application Of "One-stop" Energy Spectrum-Perfusion CT In Laryngeal And Hypopharyngeal Tumors

BackgroundTumors in the larynx and hypopharynx are among the most common diseases in the upper respiratory tract.In recent years,the incidence and mortality rates of laryngeal and hypopharyngeal cancer have been increasing,and the age of onset is becoming younger,posing a serious threat to patients’ physical and mental health.This greatly reduces the quality of life for patients and has become a major global public health concern.Therefore,early diagnosis and treatment are key to reducing the incidence and mortality rates of laryngeal and hypopharyngeal cancer.CT scans can determine the location of primary tumors preoperatively,analyze the extent of invasion of surrounding tissues and organs,and assess the range of lymph node metastasis,making it the preferred non-invasive auxiliary examination method for clinical physicians.Traditional CT evaluates and measures only the morphological characteristics and CT density values of lesions,which has certain limitations."Onestop" spectral-perfusion CT achieves qualitative and quantitative analysis of tumor lesions with multiple parameters and energies.By simultaneously and instantaneously collecting high and low dual energies,it provides quantitative information parameters for lesions.Patients can obtain functional parameter values including tumor lesion morphology and CT density information in a single examination,providing clinical physicians with multidimensional and valuable tumor lesion characteristics.Therefore,"one-stop" spectral-perfusion CT examination is expected to be an effective supplement to traditional CT examination.In neck CT examinations,the thyroid gland inevitably suffers from radiation damage.Clinically,lead materials are commonly used as radiation protection devices.Although they have good radiation shielding effects on radiation-sensitive organs in the scanning area,they significantly reduce the image quality of CT images and exhibit significant metal artifacts,thereby seriously affecting radiologists’ diagnosis of tumor lesions.In addition,lead-based materials have the drawbacks of high weight,potential toxicity,and easy migration.Moreover,there are serious environmental pollution problems in the production and processing of lead-based protective materials.To address the shortcomings of lead-based radiation protection materials,there is an urgent need to develop lightweight,green,and non-toxic radiation protection materials that can effectively protect radiation-sensitive organs during CT examinations and obtain images that meet diagnostic needs.Section 1.Comparison Study of "One-Stop" Spectral-Perfusion CT Imaging and Traditional CT Imaging: Feasibility Study in Laryngeal and Hypopharyngeal TumorsObjective: This study aims to compare the image quality and radiation dose between the "single-source" spectral CT perfusion imaging technique and traditional CT imaging technique,and to analyze whether the "single-source" spectral CT perfusion imaging technique can be applied to the imaging diagnosis of tumors in the larynx and hypopharynx.Materials and Methods: Three test tubes were arranged in a column with fixed intervals of concentration gradients,and a phantom was made as the object of this study.The concentrations in the test tubes were 5 mg/ml,10 mg/ml,and 20 mg/ml,respectively.The phantom was scanned using both spectral CT perfusion imaging and traditional CT scanning methods.The spectral CT images were automatically reconstructed from 40 ke V to 140 ke V,resulting in 101 monochromatic images.Eleven layers were delineated as regions of interest（ROIs）on both the spectral CT and traditional CT images,and the air in uniform areas at the same layer was measured as background noise.A radiologist measured the CT values of regions with different contrast agent concentrations,and calculated the corresponding CNR and SNR values.The CT values,CNR values,and SNR values of the 101 spectral CT images and traditional CT images were analyzed using Med Calc and SPSS 26.0 statistical software,and presented as mean ± standard deviation（（?）±S）.Additionally,the CTDIvol and DLP of the spectral CT and traditional CT scans were recorded,and the effective dose（E）was calculated.Results: Under the conditions of monochromatic energies ranging from 40 keV to 140 keV,with concentrations of 5 mg/ml,10 mg/ml,and 20 mg/ml as the research objects,it was found that the CT values decreased with increasing ke V values.In the test tubes with higher concentrations（20 mg/ml）,the CNR values initially increased and then decreased with increasing ke V values.However,in the test tubes with lower concentrations（5 mg/ml,10 mg/ml）,it was observed that the CNR values gradually increased and the SNR values gradually decreased with increasing ke V values.When 5 mg/ml was used as the research object,the spectral images obtained in the range of 66 ke V to 77 ke V were of higher quality than the CT images obtained under 120 k Vp conditions.When 10 mg/ml was used as the research object,the spectral images obtained in the range of 63 ke V to 132 ke V were of higher quality than the CT images obtained under 120 k Vp conditions.After spectral CT perfusion scanning,the total DLP was 1584.45 m Gycm,and the radiation dose was 9.348 m Sv.After traditional CT scanning at 120 k Vp,the total DLP was 1371.30 m Gycm,and the radiation dose was 8.091 m Sv.Conclusion: Although spectral CT perfusion combined with CT examination increases the radiation dose to some extent compared to traditional CT scanning,it remains within the standard radiation dose range for adults.Moreover,within a certain energy range,the image quality obtained is superior to that obtained from traditional CT examinations.Additionally,spectral CT perfusion examination offers multiple parameters and powerful post-processing capabilities,enabling analysis of lesion contours,tumor perfusion,and surrounding microvascular infiltration,providing favorable imaging support for in-depth research on tumors in the larynx and hypopharynx.Section 2 Clinical Study of "One-stop" Dual-energy CT Angiography-Perfusion Imaging in Laryngeal and Hypopharyngeal Tumors: Differential Diagnosis between Benign and Malignant TumorsObjective: The aim of this study is to conduct preoperative auxiliary examinations of laryngeal and hypopharyngeal tumors using "single-source" spectral CT perfusion imaging technology,obtain quantitative and qualitative parameters related to lesions,explore the diagnostic value of spectral and perfusion parameters in distinguishing between benign and malignant tumors in the larynx and hypopharynx,and thereby provide more reliable and scientific clinical evidence for formulating surgical plans and treatment strategies.Materials and Methods: This study prospectively collected data from patients at the Second Hospital of Jilin University from March 2023 to February 2024.These patients underwent "one-stop" spectral-perfusion enhanced CT scans of the neck or larynx,were clinically suspected of having laryngeal or hypopharyngeal space-occupying lesions after laryngoscopy,and were pathologically confirmed post-surgery.There were 20 cases in the benign lesion group and 82 cases in the malignant lesion group.A 256-slice CT scanner was used to perform "one-stop" spectral-perfusion CT scans of the neck or larynx for patients clinically suspected of having laryngeal or hypopharyngeal spaceoccupying lesions.After the scan,74 ke V single-energy images from the arterial and venous phases were reconstructed as images equivalent to those obtained under 120 k Vp tube voltage conditions,termed 120 k Vp-like images.These 120 k Vp-like images,along with arterial and venous phase spectral and perfusion images,were analyzed using an AW 4.7 post-processing workstation.A head and neck tumor imaging diagnostic physician with five years of experience independently reviewed all images in a double-blind manner.The regions of interest（ROI）were delineated on the largest cross-section of the lesion and on two adjacent layers,and their average was taken.Measurements included CT values of the lesions in the arterial and venous phases under 120 k Vp-like conditions;spectral parameters in the arterial and venous phases,including 40 ke V and 70 ke V single-energy CT values,IC,and Zeff;and perfusion parameters including BF,BV,MTT,PS,and Tmax.Clinical data and spectral-perfusion CT data were analyzed using Med Calc and SPSS 26 statistical software.Age was expressed as mean ± standard deviation（（?）±S）and analyzed using independent samples t-tests.Chi-square tests or Fisher’s exact probability tests were used to analyze sex,smoking status,alcohol consumption,and lesion location.Intra-class correlation coefficient（ICC）consistency tests were performed on the three sets of measurements for CT values under 120 k Vp-like conditions and spectral-perfusion CT parameters,including IC,Zeff,s IC,s Zeff,λHU,BF,BV,MTT,PS,and Tmax in the arterial and venous phases.CT values under 120 k Vp-like conditions,spectral parameters,and perfusion parameters were expressed as mean ± standard deviation（（?）±S）and analyzed using independent samples t-tests.ROC curves were plotted for CT values under 120 k Vp-like conditions in the arterial and venous phases,arterial phase spectral parameters,venous phase spectral parameters,and perfusion parameters.AUC values,sensitivity,specificity,Youden index,and Cut-off values were calculated.Correlation analyses were used to assess the relationships among variables,and logistic regression analyses were used to further dimensionally reduce the parameters with moderate correlations,identifying the best independent predictors.The diagnostic model’s ROC curves were plotted,and AUC values,sensitivity,specificity,Youden index,and Cutoff values were calculated.The model with the highest diagnostic efficiency was compared with pathological examination results using the Kappa consistency test to assess the consistency between "one-stop" spectral-perfusion CT and pathological examination results,and the diagnostic model’s concordance rate was calculated.A P <0.05 was considered statistically significant.Results: A total of 102 patients were included,with 88 male and 14 female patients,with an average age of（62.33±8.44）years.There were 81 cases of laryngeal lesions and 21 cases of hypopharyngeal lesions.The high incidence age for benign lesions was（58.35±8.64）years,and for malignant lesions,it was（63.30±8.15）years,indicating a statistically significant difference in the age of onset between benign and malignant space-occupying lesions of the larynx and hypopharynx（P<0.05）.In the 120 k Vp-like CT value parameters,the arterial phase CT values for benign and malignant lesion groups were（63.53±20.43）HU and（88.65±19.33）HU,respectively,and the venous phase CT values were（62.44±17.10）HU and（78.55±13.27）HU,respectively.The CT values of malignant lesions were higher than those of benign lesions in both phases,with statistically significant differences between the two groups（P<0.05）.The AUC values for the arterial and venous phase 120 k Vp-like CT value parameter models were 0.810（0.705-0.915）and 0.778（0.664-0.893）,respectively.Correlation and logistic regression analyses indicated that ACT120 k Vp-like was an independent predictor in differentiating benign and malignant laryngeal and hypopharyngeal lesions.The established 120 k Vp-like CT value parameter model had an AUC value of 0.810（0.705-0.915）.In the arterial phase spectral parameters,the values for AIC,As IC,AZeff,As Zeff,and AλHU in the benign lesion group were（12.32±5.42）100 μg/cm3,（0.09±0.06）,（8.32±0.30）,（0.66±0.06）,and（2.41±1.00）,respectively.In the malignant lesion group,these values were（19.79±7.87）100 μg/cm3,（0.13±0.06）,（8.67±0.47）,（0.73±0.09）,and（3.67±1.60）,respectively.All parameters were significantly higher in the malignant lesion group than in the benign lesion group（P<0.05）.In the venous phase,the values for VIC,Vs IC,VZeff,Vs Zeff,and VλHU in the benign lesion group were（15.17±4.53）100 μg/cm3,（0.42±0.15）,（8.44±0.27）,（0.86±0.07）,and（2.89±1.00）,respectively.In the malignant lesion group,these values were（20.80±5.45）100 μg/cm3,（0.53±0.13）,（8.72±0.29）,（0.90±0.05）,and（3.84±1.02）,respectively.All venous phase spectral parameters were significantly higher in the malignant lesion group than in the benign lesion group（P<0.05）.In the perfusion parameters,BF,BV,and PS values in the benign lesion group were（79.41±63.26）,（5.66±2.10）,and（16.97±15.42）,respectively,and in the malignant lesion group,these values were（138.54±52.28）,（7.91±3.18）,and（32.70±16.24）,respectively.All perfusion parameters（BF,BV,PS）were significantly higher in the malignant lesion group than in the benign lesion group（P<0.05）.The MTT values in the benign and malignant lesion groups were（10.72±5.15）and（6.77±4.54）,respectively,with the malignant lesion group having significantly lower MTT values（P<0.05）.The Tmax parameter showed no significant difference in the differential diagnosis between benign and malignant lesions（P>0.05）.The AUC values for the arterial phase spectral parameters AIC,As IC,AZeff,As Zeff,and AλHU were 0.781（0.675-0.888）,0.687（0.537-0.836）,0.708（0.599-0.817）,0.734（0.615-0.853）,and 0.726（0.618-0.835）,respectively,indicating moderate diagnostic efficiency.For the venous phase spectral parameters VIC,Vs IC,VZeff,Vs Zeff,and VλHU,the AUC values were 0.771（0.668-0.874）,0.690（0.554-0.825）,0.757（0.653-0.861）,0.654（0.515-0.792）,and 0.758（0.640-0.876）,respectively,also indicating moderate diagnostic efficiency.The perfusion parameter AUC values for BF,BV,MTT,and PS were 0.777（0.628-0.926）,0.713（0.594-0.833）,0.717（0.572-0.863）,and 0.766（0.639-0.893）,respectively,demonstrating moderate diagnostic efficiency.Correlation and logistic regression analyses indicated that AIC and BF parameters were independent predictors in differentiating benign and malignant laryngeal and hypopharyngeal lesions.The combined parameter model had an AUC value of 0.855（0.750-0.959）,superior to the traditional 120 k Vp-like CT value parameter model.The Kappa consistency test showed Kappa = 0.612,indicating strong consistency between "one-stop" spectral-perfusion CT imaging and pathological examination results.Compared to pathological results,the diagnostic accuracy for differentiating benign and malignant tumors was 88.235%.Conclusion: In "single-stop" spectral-perfusion CT examination,the joint parameter model of "single-stop" spectral-perfusion demonstrates higher diagnostic efficacy in distinguishing between benign and malignant tumors in the throat and hypopharynx.This promotes the clinical application of spectral-perfusion CT examination in distinguishing throat and hypopharyngeal tumors,while providing more reliable and scientific clinical evidence for the formulation of surgical plans and diagnosis and treatment plans in clinical practice.Section 3 Clinical Study of "One-stop" Dual-energy CT Angiography-Perfusion Imaging in Laryngeal and Hypopharyngeal Cancer: Analysis of Differentiation Degree in Squamous Cell CarcinomaObjective: The aim of this study is to utilize "one-stop" spectral CT imaging combined with perfusion CT scanning techniques for preoperative assessment of squamous cell carcinoma of the larynx and hypopharynx.The goal is to obtain quantitative and qualitative information regarding malignant tumor lesions and investigate whether the spectral parameters during arterial and venous phases,as well as perfusion parameters,have diagnostic value in determining the degree of differentiation and pathological grading of malignant tumors in the larynx and hypopharynx.This aims to assist clinicians in formulating feasible treatment plans and determining the treatment area for patients preoperatively,thereby providing precise and personalized clinical reference for improving patient survival rates and quality of life.Materials and Methods: A prospective study was conducted from March 2023 to February 2024 at the Second Hospital of Jilin University.Patients suspected of having lesions in the neck or larynx underwent "one-stop" spectral-perfusion enhanced CT imaging and clinical laryngoscopy.Following surgery,all patients underwent pathological examination for confirmation,with 16 cases in the well-differentiated group,48 cases in the moderately differentiated group,and 18 cases in the poorly differentiated group.Patients suspected of having lesions in the neck or larynx underwent "one-stop" spectral-perfusion CT scanning using a 256-slice CT scanner.After scanning,single-energy spectral images at 74 ke V in the arterial and venous phases were reconstructed and considered as 120 k Vp-like images obtained under conventional CT conditions.The 120 k Vp-like images,spectral images in the arterial and venous phases,and perfusion images were analyzed using an AW 4.7 postprocessing workstation.A blinded independent review of all imaging data was performed by a head and neck tumor imaging diagnostic physician with five years of experience.Regions of interest（ROIs）were delineated at the largest lesion level and adjacent upper and lower levels,and their average values were recorded.Measurements included lesion CT values in the 120 k Vp-like images,spectral parameters（40 ke V single-energy CT value,70 ke V single-energy CT value,IC,Zeff,λHU,s IC,s Zeff）,and perfusion parameters（BF,BV,MTT,PS,Tmax）.Clinical data and spectral-perfusion CT-derived data were analyzed using Med Calc and SPSS 26 software.Analysis included age represented as（mean ± standard deviation）using variance analysis;gender,smoking status,alcohol consumption,and lesion location were analyzed using chisquare tests or Fisher’s exact probability tests.Intra-group consistency of lesion CT values,spectral parameters,and perfusion parameters was assessed using intraclass correlation coefficient（ICC）.Lesion CT values,spectral parameters,and perfusion parameters were expressed as（mean ± standard deviation）and analyzed using variance analysis.ROC curves were plotted for differentiation diagnosis of well-differentiated from poorly differentiated and moderately differentiated from poorly differentiated lesions,with calculation of AUC values,sensitivity,specificity,Youden index,and Cutoff values.Correlation analysis was performed to evaluate the correlation between variables,and parameters with moderate correlation were included for logistic regression analysis to identify the best independent predictors.Joint prediction models for well-differentiated vs.poorly differentiated and moderately differentiated vs.poorly differentiated were established.ROC curves were plotted for diagnostic models,and diagnostic efficacy was compared.Consistency between spectral-perfusion CT results and pathological examination results was assessed using Kappa consistency test,and diagnostic agreement rate was calculated.Statistical significance was set at P<0.05.Results: A total of 82 patients were enrolled,with a male predominance over females,comprising 72 male patients and 10 female patients,with an average age of（63.30±8.15）years.Among them,there were 61 cases of lesions in the larynx and 21 cases in the hypopharynx.There was no statistically significant difference in the 120 k Vp-like arterial and venous phase CT values among well-differentiated,moderately differentiated,and poorly differentiated squamous cell carcinoma（SCC）groups in the larynx and hypopharynx（P>0.05）.In the differentiation diagnosis of arterial phase spectral parameters among well-differentiated,moderately differentiated,and poorly differentiated SCC groups,the arterial phase spectral parameters including AIC,As IC,AZeff,As Zeff,and AλHU values were（25.69±10.13）100 μg/cm3,（0.18±0.10）,（8.96±0.49）,（0.79±0.10）,and（4.64±1.73）,respectively,in the well-differentiated group,（20.28±6.47）100 μg/cm3,（0.13±0.05）,（8.70±0.45）,（0.73±0.09）,and（3.74±1.50）,respectively,in the moderately differentiated group,and（13.26±3.28）100 μg/cm3,（0.09±0.03）,（8.34±0.29）,（0.67±0.06）,and（2.64±1.14）,respectively,in the poorly differentiated group.The arterial phase spectral parameters in the well-differentiated group were higher than those in the moderately differentiated group and the poorly differentiated group,and the differences among the three groups were statistically significant（P<0.05）.Similarly,in the differentiation diagnosis of venous phase spectral parameters among well-differentiated,moderately differentiated,and poorly differentiated SCC groups,the venous phase spectral parameters including VIC,Vs IC,VZeff,Vs Zeff,and VλHU values were（25.90±5.11）100 μg/cm3,（0.65±0.12）,（8.97±0.33）,（0.93±0.03）,and（4.66±1.15）,respectively,in the well-differentiated group,（20.57±4.87）100 μg/cm3,（0.52±0.12）,（8.72±0.23）,（0.90±0.05）,and（3.80±0.91）,respectively,in the moderately differentiated group,and（16.88±3.50）100 μg/cm3,（0.45±0.10）,（8.51±0.19）,（0.87±0.04）,and（3.22±0.71）,respectively,in the poorly differentiated group.The venous phase spectral parameters in the well-differentiated group were higher than those in the moderately differentiated group and the poorly differentiated group,and the differences among the three groups were statistically significant（P<0.05）.In the perfusion phase,the values of BF,BV,and PS in the welldifferentiated group were（173.06±74.02）,（9.81±3.44）,and（41.81±17.62）,respectively,higher than those in the moderately differentiated and poorly differentiated groups.The differences among the three groups were statistically significant（P<0.05）.The MTT parameter was（4.12±2.26）in the well-differentiated group,（6.74±4.04）in the moderately differentiated group,and（9.19±6.01）in the poorly differentiated group,showing statistically significant differences among the groups（P<0.05）,while Tmax parameter showed no statistically significant differences among the well-differentiated,moderately differentiated,and poorly differentiated groups（P>0.05）.The AUC values of arterial phase spectral parameters AIC,As IC,AZeff,As Zeff,and AλHU in differentiating high from low differentiation were 0.899（0.787-1.000）,0.840（0.700-0.981）,0.884（0.727-0.968）,0.852（0.689-0.950）,and 0.830（0.662-0.936）,respectively.The AUC values of venous phase spectral parameters in differentiating high from low differentiation were 0.924（0.779-0.986）,0.877（0.718-0.964）,0.910（0.761-0.981）,0.908（0.758-0.980）,and 0.851（0.687-0.949）,respectively.The AUC values of perfusion parameters BF,BV,MTT,and PS in differentiating high from low differentiation were 0.795（0.646-0.944）,0.813（0.669-0.956）,0.708（0.522-0.895）,and 0.778（0.624-0.932）,respectively.In the correlation analysis and Logistic regression analysis of the above arterial phase spectral,venous phase spectral,and perfusion parameters,AIC,VIC,Vs Zeff,BV,and MTT parameters were identified as independent predictors for differentiating well-differentiated SCC from poorly differentiated SCC.A joint parameter model was established,with an AUC value of 0.938（0.886-0.991）,and Kappa consistency test showed Kappa=0.766,indicating a strong consistency between "one-stop" spectral-perfusion CT imaging and pathological examination in diagnosis.Compared with pathological results,the consistency rate in differentiating well-differentiated from poorly differentiated lesions was 88.235%.AIC and BV parameters were identified as independent predictors for differentiating moderately differentiated SCC from poorly differentiated SCC.A joint parameter model was established,with an AUC value of 0.915（0.844-0.985）,and Kappa consistency test showed Kappa=0.705,indicating a strong consistency between "one-stop" spectralperfusion CT imaging and pathological examination in diagnosis.Compared with pathological results,the consistency rate in differentiating moderately differentiated from poorly differentiated lesions was 87.879%.Conclusion: "One-stop" spectral-CT imaging technology has broad prospects for the differentiation diagnosis of squamous cell carcinoma of the larynx and hypopharynx,especially when combined with arterial and venous phase spectral parameters and perfusion parameters.This approach enables preoperative prediction and analysis of differentiation grades,assisting clinicians in formulating surgical plans and optimizing treatment strategies,thereby improving patient prognosis and quality of life.Section 4 Synthesis and Application of PMMA-NaBiF₄ Radiation Protection Material: Protection of Radiation-Sensitive Organs in CT Examination without Compromising Image QualityObjective: The aim of this study is to develop a safe and stable nano protective material and analyze its protective performance for the thyroid gland,a radiation-sensitive organ,during CT examinations.Additionally,the study aims to address the issue of metal artifacts produced by Pb-based protective materials during scanning,while obtaining images suitable for diagnostic purposes.Materials and Methods: NaBiF₄ nanoparticles were synthesized using a simple roomtemperature coprecipitation method.Poly（methyl methacrylate）（PMMA）was used as the base material,with NaBiF₄ nanoparticles doped at concentrations of 0 wt%,2.5 wt%,5 wt%,7.5 wt%,and 12.5 wt% as functional fillers.PMMA-NaBiF₄ radiation protective materials with different doping concentrations were prepared using a solvent casting method.The morphology and structure of NaBiF₄ nanoparticles and PMMANaBiF₄ composites were characterized using X-ray diffraction（XRD）,transmission electron microscopy（TEM）,and scanning electron microscopy（SEM）.Radiation protection performance of the prepared PMMA composites with different doping concentrations of NaBiF₄ was analyzed using a 256-slice CT scanner under tube voltages of 100 k Vp,120 k Vp,and 140 k Vp,with a Raysafe X2 X dosimeter.Radiation doses were measured for different groups,with the group without any radiation shielding serving as the control.Radiation protection efficiency was calculated.Additionally,imaging of test tubes containing contrast agents and mice under different concentrations of doped NaBiF₄ PMMA radiation protection materials was performed using a 256-slice CT scanner at tube voltages of 100 k Vp,120 k Vp,and 140 k Vp.CT values,standard deviation（SD）values,signal-to-noise ratio（SNR）,and contrast-tonoise ratio（CNR）were measured with air as the background noise.Results: XRD confirmed the successful synthesis of NaBiF₄ nanoparticles,while TEM and SEM revealed that the nanoparticles were approximately spherical with uniform size distribution,with an average diameter of about 450 nm.SEM analysis of PMMA composites doped with different concentrations of NaBiF₄ nanoparticles showed uniform distribution of NaBiF₄ nanoparticles in the PMMA matrix at concentrations of 0 wt%,2.5 wt%,5 wt%,7.5 wt%,and 10 wt%,without significant aggregation.However,at a doping concentration of 12.5 wt%,non-uniform distribution and noticeable aggregation of NaBiF₄ nanoparticles in PMMA were observed,which could affect the local radiation protection performance of the samples.Radiation protection performance testing of the samples revealed that the X-ray attenuation ability of PMMA-NaBiF₄ radiation protection materials increased with increasing NaBiF₄ loading.Under tube voltages of 100 k Vp,120 k Vp,and 140 k Vp,the radiation protection efficiencies were 17.31% to 46.02%,8.71% to 46.31%,and 1.61% to 29.27%,respectively.Objective image analysis showed no significant artifacts in the CT images of the experimental groups,indicating that the image quality was not affected by the presence of different doping concentrations of NaBiF₄ in PMMA radiation protection materials（P > 0.05）.Conclusion: The synthesized PMMA composite with a doping concentration of 10 wt% NaBiF₄ is a lightweight,eco-friendly,and non-toxic radiation protection material,which holds promise as a leading alternative to Pb-based protective materials.This material addresses the current drawbacks of high weight and potential toxicity associated with lead-based materials,as well as environmental pollution during production and processing.The new radiation protection material effectively protects radiation-sensitive organs during CT examinations while providing images suitable for diagnostic purposes.