Objective:To analyze the influence of different factors on the entropy and grayscale values extracted from the ultrasonic original radio-frequency signals of normal human gastrocnemius.Methods:The ultrasonic original radio-frequency signals of 10 healthy men and 10 healthy women admitted to the Department of Ultrasound of First Affiliated Hospital of Nanjing Medical University from October to December 2019 in natural ankle joint position, maximum plantar flflexion and maximum dorsiflflexion position were collected, and the entropy and grayscale values were obtained by processing these signals with MATLAB software to analyze the differences of parameters in different positions and sections, and to discuss the influence of age, gender and BMI on them.Results:Comparison of the values between different sections: the differences between longitudinal extraction entropy values and transverse extraction entropy values at the maximum dorsiflexion position were statistically significant ( P<0.05), the differences between longitudinal extraction grayscale values and transverse extraction grayscale values at the natural position were statistically significant ( P<0.05) and both of values extracted in the longitudinal plane were higher than those extracted in the transverse plane. Comparison of the values among different positions of the ankle joints: the values of the maximal metatarsal flexion were statistically different from those of the natural position and the maximal dorsiflexion ( P<0.05), and the values of the maximal metatarsal flexion were the lowest, while the entropy and gray values of the natural position and the maximal dorsiflexion were not statistically different ( P>0.05). There was no significant difference in ultrasonic characteristic parameters between different genders and different age groups ( P>0.05). There was no correlation between BMI and characteristic parameters ( P>0.05). Conclusions:The entropy and grayscale values extracted from the original radio-frequency ultrasonic signals of healthy persons′ gastrocnemius can quantitatively reflect the difference in muscle structure from different positions and setions. As a result, this method can be considered in the quantitative evaluation of neuromuscular diseases.

Objective To observe the correlation between degrees ofextracranial cerebral artery stenosis and pressure ratio across stenosis.Methods The patients with ≥ 50％ stenosis,admitted to our hospital and conformed by DSA from September 2015 to February 2017,were collected in this study.Collateral circulation compensation was assessed by DSA.The distal stenosis pressure (Pd) and stenosis pressure (Pa) were measured by pressure wire system;the pressure ratio across stenosis was recorded.Correlations of pressure ratio with stenosis rate and collateral circulation compensation were analyzed by Spearman correlation.Results Thirty one stenotic extracranial cerebral arteries (9 of carotid stenosis,12 of vertebral artery stenosis and 10 of subclavian artery stenosis) in 28 patients were collected.There were no perioperative complications or adverse events.The vascular stenosis rate showed negative correlation with pressure ratio (r=-0.615,P=0.000).In the subgroups,pressure gradient was negatively correlated with carotid artery stenosis rate (r=-0.948,P=-0.000),vertebral artery stenosis rate (r=-0.757,P=0.004) and subclavian artery stenosis (r=-0.759,P=0.011).Pressure ratio and collateral circulation compensation showed negative correlated relation (r=-0.475,P=0.007).Conclusion The pressure ratio across stenosis gets worse impairment with increase of severity of stenosis,and the collateral circulation influences the pressure ratio.

Objective To study the effect of stenting on intravascular pressure difference at both ends of stenosis in patients with symptomatic internal carotid artery stenosis (CAS).Methods Eleven patients with moderate-severe internal CAS were included in this study.Their distal mean arterial pressure was measured by pushing the pressure guide wire into the distal end of stenosis and the proximal mean arterial pressure was measured by placing the pressure receptor connecting pipe into the proximal end of stenosis.The intravascular pressure difference at both ends of stenosis was calculated.Correlation between the stenosis rate and intravascular pressure difference at both ends of stenosis was analyzed by Spearman correlation analysis.The intravascular pressure difference before and after stenting was analyzed according to the Wicoxon test.Results Complete intravascular pressure difference value was detected in 11 CAS patients before and after operation.No complications and adverse events occurred during the perioperative period.The stenosis rate was 64％-95％ (74.18％±8.70％) and 0％30％ (12.64％±11.07％) respectively before and after operation.The intravascular pressure was 5-72 (15.64±19.64) mm Hg before operation and was 0-9 (2.64±2.69) mm Hg after operation (P=0.035,P=0.000).Spearman correlation analysis showed that the stenosis rate was positively related with the intravascular pressure difference (r=0.767,P＜0.01).Conclusion Carotid artery stenting can reduce both the stenosis rate and intravascular pressure difference at both ends of stenosis.

Objective:To investigate the characteristics of neointimal hyperplasia (NIH) in patients with in-stent restenosis (ISR) over 5 years post-drug-eluting stent (DES) implantation based on optical coherence tomography (OCT).Methods:In this cross-sectional study, patients with DES-ISR who underwent OCT examination at PLA General Hospital between March 2010 and March 2022 were retrospectively included. All patients were divided into≤5 years DES-ISR group and>5 years DES-ISR group according to the time interval after DES implantation. Quantitative and qualitative analyses were conducted on OCT images to compare the clinical data and lesion characteristics of two patient groups. Furthermore, the independent clinical predictive factors of in-stent neoatherosclerosis (ISNA) were analyzed by multivariable logistic regression.Results:A total of 230 DES-ISR patients with 249 lesions were included, with an age of (63.1±10.4) years and 188 males (81.7%). The median interval after DES implantation was 6 (2, 9) years. There were 117 patients (122 ISR lesions) in the≤5 years DES-ISR group, and 113 patients (127 ISR lesions) in the>5 years DES-ISR group. Compared with≤5 years DES-ISR,>5 years DES-ISR showed more heterogeneous patterns (65.4% (83/127) vs. 48.4% (59/122), P=0.007), diffuse patterns (46.5% (59/127) vs. 31.2% (38/122), P=0.013), macrophage accumulations (44.1% (56/127) vs. 31.2% (38/122), P=0.035) in NIH and higher prevalence of ISNA (83.5% (106/127) vs. 72.1% (88/122), P=0.031). According to multivariable logistic regression, the independent predictive factor for ISNA was female ( OR=0.44, 95% CI 0.21-0.90, P=0.026). Female ( OR=0.48, 95% CI 0.23-0.99, P=0.046) and low-density lipoprotein cholesterol level ( OR=1.62, 95% CI 1.01-2.59, P=0.046) were independent predictive factors, respectively, for lipid ISNA. Calcified ISNA was independently associated with time interval of post-DES implantation ( OR=1.18, 95% CI 1.07-1.29, P=0.001). Conclusion:DES-ISR patients with a time interval of>5 years after stent implantation have a higher prevalence of ISNA and more complex lesions. Gender, the level of low-density lipoprotein cholesterol, and the time interval post-DES implantation are independently correlated with ISNA, lipid ISNA, and calcified ISNA.