BACKGROUND:The most common complication of traumatic femoral neck fractures after internal fixation is femoral head necrosis.Currently,many studies have reported on the risk factors that affect the occurrence and development of postoperative femoral head necrosis,but there is still a lack of tools to predict the risk of femoral head necrosis after internal fixation of femoral neck fractures.OBJECTIVE:To develop a predictive model that estimates the risk of femoral head necrosis shortly after patients with femoral neck fractures receive cannulated screw internal fixation.METHODS:A retrospective analysis reviewed clinical records of 172 patients who underwent cannulated screw internal fixation for femoral neck fractures at Department of Orthopedics of Mianyang Central Hospital from January 2013 to June 2023.Patients were categorized into two groups based on the presence or absence of femoral head necrosis within one year post-operation:the necrosis group and the non-necrosis group.Univariate analysis,Lasso regression,and multivariate Logistic regression techniques were employed to identify the determinants of femoral head necrosis.A nomogram prediction model was constructed using R language's"rms"package,version 4.0.The receiver operating characteristic curve was used to evaluate the discriminatory ability of the model.The Hosmer-Lemeshow test was used to evaluate the goodness of fit of the model,and the decision curve analysis was used to determine its clinical application benefits.Internal validation of the study was conducted using the Bootstrap method,involving 1 000 repeated samplings.To delve deeper into the primary factors influencing femoral head necrosis post-internal fixation of the femoral neck,this paper employed the SHAP method for data set analysis.RESULTS AND CONCLUSION:(1)The risk factors leading to femoral head necrosis in the short term after cannulated screw fixation of femoral neck fractures include:smoking,diabetes,Garden classification,fracture line location,reduction quality,age,and operation time.(2)The prediction model demonstrated robust performance,evidenced by an area under the curve of 0.940(95％Confidence Interval:0.903 to 0.977),indicating a high level of prediction accuracy.The model achieved a sensitivity of 90.2％and a specificity of 87.6％,indicating that its diagnostic performance was stable.The Hosmer-Lemeshow goodness-of-fit test yielded a chi-square value of 6.593 with a P-value of 0.581,confirming that the model's predictions closely align with the observed outcomes.(3)The calibration curve of the model also performed well,and its overall trend was very close to the ideal curve,further proving the high accuracy of the model.(4)The internal validation was carried out by the Bootstrap method with 1 000 repeated samplings,and the area under the curve of the model internal validation was still as high as 0.939,proving that the model had good stability.(5)Through the decision curve,it is found that within the probability threshold range of 1％to 92％,the model can obtain the maximum net benefit value.(6)The SHAP analysis results show that among the risk factors analyzed in this study,the location of the fracture line serves as the most significant predictor of femoral head necrosis following internal fixation with cannulated screws in femoral neck fractures,and subcapital fractures are extremely prone to femoral head necrosis after surgery.(7)It is concluded that the validated prediction model demonstrates strong discriminative power and reliability,offering practical clinical utility.It serves as a useful reference tool for short-term risk assessment of femoral head necrosis following internal fixation of femoral neck fractures.

BACKGROUND:The most common complication of traumatic femoral neck fractures after internal fixation is femoral head necrosis.Currently,many studies have reported on the risk factors that affect the occurrence and development of postoperative femoral head necrosis,but there is still a lack of tools to predict the risk of femoral head necrosis after internal fixation of femoral neck fractures.OBJECTIVE:To develop a predictive model that estimates the risk of femoral head necrosis shortly after patients with femoral neck fractures receive cannulated screw internal fixation.METHODS:A retrospective analysis reviewed clinical records of 172 patients who underwent cannulated screw internal fixation for femoral neck fractures at Department of Orthopedics of Mianyang Central Hospital from January 2013 to June 2023.Patients were categorized into two groups based on the presence or absence of femoral head necrosis within one year post-operation:the necrosis group and the non-necrosis group.Univariate analysis,Lasso regression,and multivariate Logistic regression techniques were employed to identify the determinants of femoral head necrosis.A nomogram prediction model was constructed using R language's"rms"package,version 4.0.The receiver operating characteristic curve was used to evaluate the discriminatory ability of the model.The Hosmer-Lemeshow test was used to evaluate the goodness of fit of the model,and the decision curve analysis was used to determine its clinical application benefits.Internal validation of the study was conducted using the Bootstrap method,involving 1 000 repeated samplings.To delve deeper into the primary factors influencing femoral head necrosis post-internal fixation of the femoral neck,this paper employed the SHAP method for data set analysis.RESULTS AND CONCLUSION:(1)The risk factors leading to femoral head necrosis in the short term after cannulated screw fixation of femoral neck fractures include:smoking,diabetes,Garden classification,fracture line location,reduction quality,age,and operation time.(2)The prediction model demonstrated robust performance,evidenced by an area under the curve of 0.940(95％Confidence Interval:0.903 to 0.977),indicating a high level of prediction accuracy.The model achieved a sensitivity of 90.2％and a specificity of 87.6％,indicating that its diagnostic performance was stable.The Hosmer-Lemeshow goodness-of-fit test yielded a chi-square value of 6.593 with a P-value of 0.581,confirming that the model's predictions closely align with the observed outcomes.(3)The calibration curve of the model also performed well,and its overall trend was very close to the ideal curve,further proving the high accuracy of the model.(4)The internal validation was carried out by the Bootstrap method with 1 000 repeated samplings,and the area under the curve of the model internal validation was still as high as 0.939,proving that the model had good stability.(5)Through the decision curve,it is found that within the probability threshold range of 1％to 92％,the model can obtain the maximum net benefit value.(6)The SHAP analysis results show that among the risk factors analyzed in this study,the location of the fracture line serves as the most significant predictor of femoral head necrosis following internal fixation with cannulated screws in femoral neck fractures,and subcapital fractures are extremely prone to femoral head necrosis after surgery.(7)It is concluded that the validated prediction model demonstrates strong discriminative power and reliability,offering practical clinical utility.It serves as a useful reference tool for short-term risk assessment of femoral head necrosis following internal fixation of femoral neck fractures.

Objective:To understand the current status of the actual protective effect of respiratory protective equipment (RPE) for workers exposed to trichloroethylene (TCE), and to explore the factors affecting the actual protective effect.Methods:From July to December 2023, a total of 75 workers occupationally exposed to TCE from 21 hardware and electronics manufacturing facilities in a province were selected as research objects by convenient sampling method. Workplace protection factor (WPF) was used as an index to evaluate the actual protective effect of workers' RPE. The concentration of TCE inside and outside the RPE was detected to calculate WPE, and the temperature, humidity and wind speed near the working place were measured, as well as the forced vital capacity, respiratory rate, heart rate and other indicators of the worker were measured. The log-transformed WPF value (lgWPF) followed a normal distribution. One-sample t-test was used to compare the difference between the mean lgWPF and the log value of the assigned protection factor (APF) of the half mask (lgAPF=1). Multiple linear regression model was used to investigate the influencing factors of lgWPF. Results:The lgWPF of 75 TCE-exposed workers ranged from 0.40 to 1.32 (0.84±0.22). The mean of lgWPF was lower than that of lgAPF, and the difference was statistically significant ( t=-6.37, P<0.001). After adjusting for confounding factors, the results of multiple linear regression showed that humidity, forced vital capacity and respiratory rate were negatively correlated with lgWPF ( β=-0.008, -0.079, -0.021, P<0.05) . Conclusion:The actual protective efficacy of RPE among workers exposed to TCE is suboptimal. High humidity, elevated forced vital capacity, and increased respiratory rate may be contributing factors to the diminished protective performance of RPE.

Objective:To evaluate the image quality and radiation dose in contrast-enhanced thoracic-abdominal-pelvic CT using automatic tube voltage modulation (ATVM) coupled with artificial intelligence iterative reconstruction (AIIR) versus routine tube voltage combined with Karl-3D iterative reconstruction (Karl-3D IR), and to determine the optimal noise level for AIIR in contrast-enhanced thoracic-abdominal-pelvic CT.Methods:A total of 100 patients who underwent contrast-enhanced thoracic-abdominal-pelvic CT examination in the Affiliated Hospital of Hebei University from April to October, 2023 were randomly divided into group A and group B using a random number table, with 50 patients in each group. Group A was scanned using ATVM, and images were reconstructed using AIIR with 1-5 noise levels. Group B was scanned using tube voltage 120 kVp and images were reconstructed with Karl-3D IR and noise level 5. The single-to-noise ratio (SNR), contrast-to-noise ratio (CNR), effective dose (E), and size-specific dose estimate (SSDE) were recorded or calculated for all patients or images. Subjective evaluations of all images were performed. The quality of the reconstructed images using AIIR with 1-5 noise levels were compared and the optimal noise level of AIIR for image reconstruction was determined. Image quality and radiation dose were statistically analyzed for Group A (image reconstruction with optimal AIIR noise level) and Group B.Results:The mean SNR and mean CNR of the reconstructed images using AIIR with noise levels 1, 2, and 3 in group A were higher than those using AIIR with noise levels 4 and 5. The images reconstructed using AIIR with noise levels 3 and 4 scored higher in subjective assessment than those reconstructed using AIIR with noise levels 1, 2, and 5. Therefore, noise level 3 was optimal for AIIR in reconstruction of contrast-enhanced thoracic-abdominal-pelvic CT images. The mean SNR, mean CNR, and subjective evaluation score of group A using AIIR with noise level 3 were higher than those of group B using Karl-3D IR with noise level 5 ( P<0.001). The mean SSDE and the mean E of group A were reduced by 46% and 41%, respectively, compared with those of group B. Conclusions:ATVM technology combined with the AIIR algorithm can improve image quality and reduced patient radiation dose in contrast-enhanced thoracic-abdominal-pelvic CT. Noise level 3 is optimal for AIIR in the reconstruction of arterial-phase and venous-phase contrast-enhanced thoracic-abdominal-pelvic CT images.

Objective:To investigate the efficacy of laparoscopic versus open hepatectomy for intrahepatic bile duct stones based on propensity score matching. Methods:This study used a case-control design to retrospectively analyze 163 patients with intrahepatic bile duct stones who were treated at The Second Hospital of Anhui Medical University between February 2014 and February 2024. Based on the surgical approach, the patients were divided into two groups: the laparoscopic hepatectomy group ( n = 72) and the open hepatectomy group ( n = 91). Using 1:1 PSM, two groups with similar baseline clinical characteristics were created to compare perioperative outcomes, stone residual rates, and recurrence rates. Results:After PSM, a total of 52 matched pairs were successfully obtained. Compared with the laparoscopic hepatectomy group, the open hepatectomy group demonstrated a significantly shorter operative time [233.00 (180.00, 315.00) minutes vs. 313.00 (222.25, 405.75) minutes, Z = 3.41, P = 0.01]. However, no statistically significant differences were observed between the open hepatectomy and laparoscopic hepatectomy groups in terms of pre- to postoperative hemoglobin change [(22.69 ± 14.27) g/L vs. (20.63 ± 14.36) g/L, t = 0.73, P = 0.465], postoperative bile leakage [5.77% (3/52) vs. 11.54% (6/52), χ2 = 1.10, P = 0.25], hypoalbuminemia [82.69% (43/52) vs. 84.62% (44/52), χ2 = 0.07, P = 0.791], pulmonary infection [28.85% (15/52) vs. 40.38% (21/52), χ2 = 1.53, P = 0.216], surgical site infection [5.77% (3/52) vs. 1.92% (1/52), χ2 = 1.04, P = 0.308], intra-abdominal infection [1.92% (1/52) vs. 5.77% (3/52), χ2 = 1.04, P = 0.308], postoperative drainage tube removal time [8.00 (6.00, 11.75) days vs. 8.00 (6.25, 10.00) days, t = 0.05, P = 0.958], postoperative hospital stay [8.00 (9.00, 15.00) days vs. 9.00 (7.00, 12.50) days, t = -1.22, P = 0.222], residual stone rate [11.54% (6/52) vs. 9.62% (5/52), χ2 = 0.10, P = 0.750], and stone recurrence rate [13.46% (7/52) vs. 3.85% (2/52), χ2 = 3.04, P = 0.081]. All differences were statistically significant (all P > 0.05). Conclusions:Laparoscopic hepatectomy and open hepatectomy have comparable efficacy in the treatment of intrahepatic bile duct stones.

Objective:To evaluate the image quality and radiation dose in contrast-enhanced thoracic-abdominal-pelvic CT using automatic tube voltage modulation (ATVM) coupled with artificial intelligence iterative reconstruction (AIIR) versus routine tube voltage combined with Karl-3D iterative reconstruction (Karl-3D IR), and to determine the optimal noise level for AIIR in contrast-enhanced thoracic-abdominal-pelvic CT.Methods:A total of 100 patients who underwent contrast-enhanced thoracic-abdominal-pelvic CT examination in the Affiliated Hospital of Hebei University from April to October, 2023 were randomly divided into group A and group B using a random number table, with 50 patients in each group. Group A was scanned using ATVM, and images were reconstructed using AIIR with 1-5 noise levels. Group B was scanned using tube voltage 120 kVp and images were reconstructed with Karl-3D IR and noise level 5. The single-to-noise ratio (SNR), contrast-to-noise ratio (CNR), effective dose (E), and size-specific dose estimate (SSDE) were recorded or calculated for all patients or images. Subjective evaluations of all images were performed. The quality of the reconstructed images using AIIR with 1-5 noise levels were compared and the optimal noise level of AIIR for image reconstruction was determined. Image quality and radiation dose were statistically analyzed for Group A (image reconstruction with optimal AIIR noise level) and Group B.Results:The mean SNR and mean CNR of the reconstructed images using AIIR with noise levels 1, 2, and 3 in group A were higher than those using AIIR with noise levels 4 and 5. The images reconstructed using AIIR with noise levels 3 and 4 scored higher in subjective assessment than those reconstructed using AIIR with noise levels 1, 2, and 5. Therefore, noise level 3 was optimal for AIIR in reconstruction of contrast-enhanced thoracic-abdominal-pelvic CT images. The mean SNR, mean CNR, and subjective evaluation score of group A using AIIR with noise level 3 were higher than those of group B using Karl-3D IR with noise level 5 ( P<0.001). The mean SSDE and the mean E of group A were reduced by 46% and 41%, respectively, compared with those of group B. Conclusions:ATVM technology combined with the AIIR algorithm can improve image quality and reduced patient radiation dose in contrast-enhanced thoracic-abdominal-pelvic CT. Noise level 3 is optimal for AIIR in the reconstruction of arterial-phase and venous-phase contrast-enhanced thoracic-abdominal-pelvic CT images.

Objective:To investigate the efficacy of laparoscopic versus open hepatectomy for intrahepatic bile duct stones based on propensity score matching. Methods:This study used a case-control design to retrospectively analyze 163 patients with intrahepatic bile duct stones who were treated at The Second Hospital of Anhui Medical University between February 2014 and February 2024. Based on the surgical approach, the patients were divided into two groups: the laparoscopic hepatectomy group ( n = 72) and the open hepatectomy group ( n = 91). Using 1:1 PSM, two groups with similar baseline clinical characteristics were created to compare perioperative outcomes, stone residual rates, and recurrence rates. Results:After PSM, a total of 52 matched pairs were successfully obtained. Compared with the laparoscopic hepatectomy group, the open hepatectomy group demonstrated a significantly shorter operative time [233.00 (180.00, 315.00) minutes vs. 313.00 (222.25, 405.75) minutes, Z = 3.41, P = 0.01]. However, no statistically significant differences were observed between the open hepatectomy and laparoscopic hepatectomy groups in terms of pre- to postoperative hemoglobin change [(22.69 ± 14.27) g/L vs. (20.63 ± 14.36) g/L, t = 0.73, P = 0.465], postoperative bile leakage [5.77% (3/52) vs. 11.54% (6/52), χ2 = 1.10, P = 0.25], hypoalbuminemia [82.69% (43/52) vs. 84.62% (44/52), χ2 = 0.07, P = 0.791], pulmonary infection [28.85% (15/52) vs. 40.38% (21/52), χ2 = 1.53, P = 0.216], surgical site infection [5.77% (3/52) vs. 1.92% (1/52), χ2 = 1.04, P = 0.308], intra-abdominal infection [1.92% (1/52) vs. 5.77% (3/52), χ2 = 1.04, P = 0.308], postoperative drainage tube removal time [8.00 (6.00, 11.75) days vs. 8.00 (6.25, 10.00) days, t = 0.05, P = 0.958], postoperative hospital stay [8.00 (9.00, 15.00) days vs. 9.00 (7.00, 12.50) days, t = -1.22, P = 0.222], residual stone rate [11.54% (6/52) vs. 9.62% (5/52), χ2 = 0.10, P = 0.750], and stone recurrence rate [13.46% (7/52) vs. 3.85% (2/52), χ2 = 3.04, P = 0.081]. All differences were statistically significant (all P > 0.05). Conclusions:Laparoscopic hepatectomy and open hepatectomy have comparable efficacy in the treatment of intrahepatic bile duct stones.

Objective:To understand the current status of the actual protective effect of respiratory protective equipment (RPE) for workers exposed to trichloroethylene (TCE), and to explore the factors affecting the actual protective effect.Methods:From July to December 2023, a total of 75 workers occupationally exposed to TCE from 21 hardware and electronics manufacturing facilities in a province were selected as research objects by convenient sampling method. Workplace protection factor (WPF) was used as an index to evaluate the actual protective effect of workers' RPE. The concentration of TCE inside and outside the RPE was detected to calculate WPE, and the temperature, humidity and wind speed near the working place were measured, as well as the forced vital capacity, respiratory rate, heart rate and other indicators of the worker were measured. The log-transformed WPF value (lgWPF) followed a normal distribution. One-sample t-test was used to compare the difference between the mean lgWPF and the log value of the assigned protection factor (APF) of the half mask (lgAPF=1). Multiple linear regression model was used to investigate the influencing factors of lgWPF. Results:The lgWPF of 75 TCE-exposed workers ranged from 0.40 to 1.32 (0.84±0.22). The mean of lgWPF was lower than that of lgAPF, and the difference was statistically significant ( t=-6.37, P<0.001). After adjusting for confounding factors, the results of multiple linear regression showed that humidity, forced vital capacity and respiratory rate were negatively correlated with lgWPF ( β=-0.008, -0.079, -0.021, P<0.05) . Conclusion:The actual protective efficacy of RPE among workers exposed to TCE is suboptimal. High humidity, elevated forced vital capacity, and increased respiratory rate may be contributing factors to the diminished protective performance of RPE.

Objective:To compare the image quality, radiation dose, and total iodine content of abdominal computed tomography (CT) enhancement scanning of overweight and obese patients with different scanning protocols, and to explore the optimal keV image serial for abdominal CT.Methods:A total of 90 overweight or obese patients [24 kg/m 2 ≤ body mass index (BMI) < 28 kg/m 2 or BMI ≥ 28 kg/m 2] were divied into groups A, B and C, with 30 patients in each group. Group A used Gemstone spectral imaging (GSI) mode and contrast medium with 320 mg I/ml, group B used low tube voltage mode (100 kVp) and contrast medium with 370 mg I/ml, and group C used conventional tube voltage mode (120 kVp) and contrast medium with 370 mg I/ml. Monochromatic energy images at 50-70 keV (5 keV interval) were reconstructed for the arterial and portal vein phases of group A. Radiation dose and total iodine content were recorded and calculated for the 3 groups. The region of interest was placed on the organ, blood vessel, and erector spinae muscle at same level. The CT values and image noise values were measured, and the contrast-to-noise ratio (CNR) was calculated. All images were scored subjectively in double-blinded by two radiologists. One-way analysis of variance or Kruskal-Wallis H test were used to compare The CT values, CNRs, and subjective scores of each subgroup image in group A, group B and group C, and the radiation doses and total iodine contents in 3 groups were compared. The optimal keV value for group A was selected. Results:At 50-60 keV, the CT values and CNRs of arterial and portal vein phases in group A were higher ( P < 0.05) than or similar to those in groups B and C ( P > 0.05), and the subjective scores were lower than those of groups B and C at 50 and 55 keV ( H = 34.47, 41.27, P < 0.05), whereas there was no statistically significant difference at 60 keV ( P > 0.05). At 65 and 70 keV, only the CT value and CNR of the renal cortex in group A at the 65 keV of arterial phase were higher than those in groups B and C ( F = 102.38, 29.47, P < 0.001). The subjective scores were not significantly between groups B and C ( P > 0.05). There were no statistically significant difference between CT values, CNRs, or subjective scores in group B and group C ( P > 0.05). The effective doses in groups A and B were 24.72% and 25.78% lower than those in group C, respectively. Compared to groups B and C, the total iodine content in group A decreased by 12.50% and 13.34%, respectively. Conclusions:GSI model combined with a low-concentration contrast medium in abdominal CT for overweight and obese patients can meet the image quality requirements while reducing patient total iodine content and radiation dose. The optimal keV value of enhanced abdominal CT for double phases was 60 keV.

Objective To investigate the image quality,radiation dose and contrast medium(CM)intake in coronary computed tomography angiography(CCTA)of overweight patients based on wide-detector using different tube voltages and CM of different concentrations.Methods A total of 150 overweight patients[body mass index(BMI)≥ 25 kg/m2]who underwent CCTA were divided into three groups according to scan protocols:group A(120 kVp,370 mg I/mL CM),group B(100 kVp,350 mg I/mL CM),and group C(80 kVp,320 mg I/mL CM),with each group had 50 patients.The mean CT value,mean signal-to-noise ratio(SNR),mean contrast-to-noise ratio(CNR),figure of merit(FOM)of all images were measured and calculated.Images were assessed using a 5-point scale by two radiologists.The volume CT dose index(CTDIvol)and dose length product(DLP)of each patient were recorded and the effective dose(ED)was calculated.The total iodine intake values of patients in three groups were calculated.The above data were statistically analyzed by one-way ANOVA.Results The mean CT value,mean SNR,mean CNR,and mean subjective score of groups B and C were significantly higher than those of group A(P＜0.001),but there was no significant difference between groups B and C(P＞0.05).The FOM value of groups B and C was significantly higher than that of group A(P＜0.001),and the FOM value of group B was significantly lower than that of group C(P＜0.001).The total iodine intake values of groups B and C was significantly lower than that of group A(P＜0.001).The ED and total iodine intake values in groups B and C were 30.34％,68.53％and 10.22％,16.85％lower than those in group A,respectively(P＜0.001).Conclusion Under the premise of ensuring image quality,the lower tube voltage and lower concentration of CM based on wide-detector allows for significant reduction in radiation dose and total iodine intake in CCTA for overweight patients compared to routine scan protocols.