Objective: To evaluate the characteristics of renal cortical blood perfusion assessed by contrast-enhanced ultrasound (CEUS) in elderly patients with renal artery stenosis (RAS) and its relationship with renal function. Methods: Ninety-three elderly patients diagnosed with RAS, who were admitted in Beijing Hospital during June 2017 and December 2018, were retrospectively enrolled. According to the degree of RAS, 186 renal arteries were divided into normal renal artery group (n=79), mild RAS group (30% to 49%, n=59), moderate RAS group (50% to 70%, n=33), and severe RAS group (70% to 99%, n=15). Renal cortical blood perfusion and renal glomerular filtration rate (GFR) were measured by CEUS and radionuclide renal dynamic imaging. According to the renal GFR, 186 kidneys were divided into normal renal function group (GFR≥35 ml/min, n=42) and mild renal insufficiency group (35 ml/min>GFR≥25 ml/min, n=51), moderate renal insufficiency group (25 ml/min>GFR≥15 ml/min, n=75) and severe renal insufficiency group (GFR<15 ml/min, n=18). The renal cortical blood perfusion time-intensity curve (TIC) and related parameters were analyzed, including the area under the curve (AUC), the slope of the ascending branch (A), the peak intensity (PI), the peak time (TTP) and the mean transit time (MTT), the kidneys of different RAS groups and patients with different renal function groups were analyzed. Pearson correlation analysis was used to evaluate the correlation between renal cortical blood perfusion parameters and renal GFR. Results: (1) Renal cortical blood perfusion and GFR: CEUS showed that parameter A of TIC was significantly reduced, while TTP was prolonged in the mild renal artery stenosis group compared with the normal renal artery group (both P<0.05), GFP was similar between the two groups. Cortical perfusion parameters, such as AUC, A, PI and GFR were significantly lower, while TTP and MTT were significantly prolonged in the moderate and severe renal artery stenosis group than in the normal and mild stenosis groups (all P<0.05). Compared with the moderate stenosis group, AUC, A, PI and GFR were significantly lower while TTP, MTT were significantly prolonged in the severe renal artery stenosis group (all P<0.05). (2) TIC showed that the renal perfusion parameters, AUC, PI and A were significantly lower, while TTP was significantly longer in the mild renal dysfunction group than in the normal renal function group (all P<0.001). The changes aggravated in proportion with renal dysfunction. (3) Correlation between perfusion parameters and GFR: Pearson correlation analysis showed that the AUC (r=0.774, P<0.05), A (r=0.815, P<0.05) and PI (r=0.772, P<0.05) were positively correlated with GFR; serum creatinine level (r=-0.841, P<0.05), renal function grading (r=-0.731, P<0.05), TTP (r=-0.803, P<0.05) and MTT (r=-0.741, P<0.05) were negative correlated with GFR. The degree of stenosis was negatively correlated with GFR (r=-0.427, P<0.05). Conclusion Cortical perfusion parameters differ significantly among patients with various degree of RAS and renal dysfunction. The renal cortical blood perfusion parameters are correlated with renal GFR.

Objective To investigate the renal cortical perfusion parameters assessed by contrast-enhanced ultrasound(CEUS)in elderly patients with moderate-to severe renal artery stenosis (RAS),and relationship of those with glomerular filtration rate(GFR).Methods A total of 59 elderly patients with unilateral moderate to severe RAS(50％-99％)admitted into Beijing Hospital during June 2017 to December 2018 were consecutively enrolled in the cross sectional and self-control study.Based on the GFR assessed by radionuclide renal dynamic imaging,patients were divided into the mild-(35＞GFR≥25 ml/min,n=18),moderate-(25 ＞ GFR≥ 15 ml/min,n =37) and severe renal dysfunction(GFR＜ 15 ml · min-1,n =4) groups.CEUS evaluated-renal cortical perfusion parameters,including area under curve (AUC),ascending slope (A),derived peak intensity (DPI),time to peak (TTP) and mean transit time(MTT),were compared among different levels of severity of renal dysfunction groups.Pearson correlation analysis was used to evaluate the relationship between CEUS imaging-evaluated renal cortical perfusion parameters and radionuclide renal dynamic imaging-assessed GFR.Results Compared with the mild renal dysfunction group,the moderate renal dysfunction group showed a reduced AUC and A(P＜0.05),and the severe renal dysfunction group showed more markedly reduced AUC,A,DPI,TTP and MTT (P ＜ 0.05).Compared with the moderate renal dysfunction group,the severe renal dysfunction group showed a reduced AUC,A and GFR(P ＜0.05),while no significant differences in TTP and MTT were found.As far as relationship between renal cortical perfusion parameters and GFR were concerned,Pearson correlation analysis demonstrated that AUC(r =0.804),A(r =0.813) and DPI(r =0.733) were significantly and positively correlated with GFR(all P ＜ 0.05).However,renal function (r =-0.721),TTP(r =-0.744) and MTT(r =-0.743)were negatively correlated with GFR(P＜0.05).And the degree of renal artery stenosis was poorly correlated with GFR (r =-0.462).Conclusions For elderly patients with unilateral moderate to severe RAS,contrast-enhanced ultrasonography can display the changes of renal cortical blood perfusion parameters along with the aggravation of renal function impairment.AUC and A are strongly positively correlated with GFR.The degree of renal artery stenosis is poorly correlated with renal function.And more studies are needed to confirm these findings.

Objective:To observe the effect of the cortical blood perfusion parameter of wash-in area under curve (iAUC) with contrast-enhanced ultrasound(CEUS) on the effect of short-term outcomes of stent implantation in patients with severe renal artery stenosis (RAS).Methods:Retrospective analysis was performed on 82 patients with unilateral severe RAS who received stent implantation in Beijing Hospital from October 2017 to December 2019. According to the baseline iAUC before CEUS, all patients were divided into the poorly-perfused group (iAUC<850.0 dB×s) (37 cases) and the well-perfused group (iAUC≥850.0 dB×s) (45 cases). Baseline and perioperative clinical-imaging data were analyzed between the two groups. Followed up for 10-12 (11.5±1.7) months, Kaplan-Meier survival curves and Log-rank test were used to analyze the rate of adverse cardiac and renal vascular events and hypertension control rates.Results:Compared with the well-perfused group, the poorly-perfused group showed a longer course of hypertension, more diabetic patients, higher systolic blood pressure, diastolic blood pressure, 24 h average systolic blood pressure, and 24 h average diastolic blood pressure, lower glomerular filtration rate, and severe renal artery stenosis. Besides, the iAUC, wash-out AUC and the peak intensity were lower, the average transit time was longer, and the hypoglycemic treatment rate was higher (all P<0.05). Kaplan-Meier survival curve and Log-rank test analysis showed that the occurrence of cardio-renal vascular events ( HR=0.361, 95% CI=0.144-0.907, P=0.012) and renal function deterioration rate ( HR=0.286, 95% CI=0.090-0.914, P=0.035) in the well-perfused group were significantly lower than those in the poorly-perfused group. The blood pressure results demonstrated that the effective rate of hypertension treatment in the well-perfused group was significantly higher than that in the poorly-perfused group (93.3% vs 59.5%, P<0.001), but the improvement rate of hypertension (60.0% vs 43.2%) and cure rate (28.9% vs 16.2%) were not statistically significant between the two groups(all P>0.05). Conclusions:Severe RAS patients with decreased baseline iAUC often have diabetes, longer duration of hypertension, significantly reduced glomerular filtration rate and more severe RAS, short-term outcomes are worse with stent implantation.

Objective:To establish and validate a prognostic model of a contrast-enhanced ultrasound scoring(CEUS)system for evaluating renal artery stenosis(RAS)in the elderly.Methods:This was a single-center retrospective study.A total of 324 elderly RAS patients admitted to Beijing Hospital from October 2017 to July 2020 were randomly assigned into the model group(n=174)and the validation group(150)in a 1∶1 ratio.Clinical and imaging data of patients on admission including general conditions, previous medical history, blood pressure, blood creatinine, renal artery stenosis and cortical blood perfusion in the affected kidney and renal function(GFR)at 1-year follow-up were collected.Univariate and multivariate logistic regression was used to establish a model of the CEUS scoring system.The receiver operating characteristic(ROC)curve and area under the ROC curve(AUC)were used to evaluate prediction accuracy.Clinical application value of the CEUS scoring system model was evaluated via decision curve analysis using a nomogram.Results:Baseline clinical and radiomic data had no significant difference between the model group and the validation group( P>0.05). Multivariate logistic regression analysis results showed that age( OR=1.242, 95% CI: 1.081-1.427, P<0.01), diabetes( OR=1.545, 95% CI: 1.107-2.156, P<0.05), blood pressure( OR=1.328, 95% CI: 1.056-1.670, P<0.05), renal function( OR=2.374, 95% CI: 1.216-3.887, P<0.01)and cortical blood perfusion parameter( OR=2.646, 95% CI: 1.553-6.369, P<0.01)were risk factors for the deterioration of renal function during 1 year follow-up.Based on these results, a nomogram for the CEUS scoring system model was drawn, and its consistency index, the C-Index, was 0.725(95% CI: 0.653-0.776). The AUC of the CEUS scoring system was 0.824 and the Youden index was 0.711 in the model group, with a specificity of 0.774 and a sensitivity of 0.837.The AUC of the CEUS scoring system was 0.853 and the Youden index was 0.715 in the validation group, with a specificity of 0.684 and a sensitivity of 0.889.There was no significant difference in ROC curve between the two groups( D=1.387, P>0.05). In addition, calibration charts of the two models showed that the calibration curve of the CEUS scoring system was close to the standard curve, with no statistically significant difference( P>0.05). Conclusions:The CEUS scoring system model can be used to predict the risk of worsening renal function in elderly RAS patients during 1-year follow-up.

Objective:To investigate the imaging characteristics on contrast-enhanced ultrasound(CEUS)of carotid plaque instability and their correlation with histopathological changes in elderly patients.Methods:Twenty-three patients undergone carotid endarterectomy(CEA)at the Department of Neurosurgery of Beijing Hospital from June 2018 to November 2020 were retrospectively enrolled, including 27 males and 5 females, aging from 60 to 87(68.1±6.3)years.They were diagnosed with moderate to severe carotid artery stenosis(50%-99%)based on digital subtraction angiography(DSA).Carotid artery CEUS was conducted before surgery, and HE staining and CD34 immunohistochemical staining were used to record histopathological scores and microvessel density(MVD)counts.Results:The mean pathological score and MVD count were 2.46±0.66 and 37.17±12.88 for 32 cases with hypoechoic patterns, 22.42±0.55 and 38.06±13.66 for 18 cases with mixed echo patterns, and 2.75±0.35 and 23.50±9.192 for 2 cases with strong echo patterns, respectively.CEUS grading was positively correlated with histopathology score and MVD count( r=0.53、0.76, all P<0.01). Conclusions:Low echo and mixed echo plaques are more unstable than strong echo plaques.CEUS can be used to comprehensively assess the vulnerability of atherosclerotic plaques and to decide the optimal surgical time for patients with carotid atherosclerotic plaque stenosis.

Objective:To investigate the characteristics of multimodal ultrasound imaging in elderly hyperlipidemia patients with statin-related myopathy and to provide a reference of new method for non-invasive quantitative evaluation on statin myopathy.Methods:We collected 20 elderly hyperlipidemia patients with statin-related myopathy(the statin-related myopathy group), 20 elderly hyperlipidemia patients without statin-related myopathy after taking statins during the same period(the non-statin-related myopathy group), and 20 healthy volunteers who matched the age and sex of the above two groups during the same period(the healthy control group)in our hospital.Two-dimensional ultrasound, shear wave elastography and superb microvascular imaging were used to obtain thickness, echo, pinnation angle and shear wave velocity(SWV)values as well as vascular index(VI)values of the medial gastrocnemius during relaxation, dorsiflexion, and plantar flexion for each group, which were then analyzed.Results:There were no significant differences among the three groups in general conditions such as age, height, weight, and body mass index(all P>0.05). The mean thickness of the medial gastrocnemius in the statin-related myopathy group was about(1.04 ± 0.20)cm, which was less than(1.34 ± 0.16)cm in the non-statin-related myopathy group and(1.35 ± 0.15)cm in the healthy control group( F=22.03, P<0.001). The pinnation angle in the statin-related myopathy group was about(12.50 ± 1.10), which was less than(18.55 ± 1.28)in the non-statin-related myopathy group and(18.60 ± 1.35)in the healthy control group( F=158.03, P<0.001). Compared with the non-statin-related myopathy group and the healthy control group, SWV during resting, dorsiflexion and plantar flexion in the statin-related myopathy group decreased( F=61.71, 111.96 and 8.69, respectively, P<0.01). The average value of VI in the statin-related myopathy group was about(0.43 ± 0.12)%, which was less than that in the non-statin-related myopathy group(0.75 ± 0.20)% and in the healthy control group(0.93 ± 0.17)%( F=48.93, P<0.001). However, there was no significant difference in values from the parameters between the non-statin-related myopathy group and the healthy control group(all P>0.05). Conclusions:Multimodal ultrasound imaging of statin-related myopathy in elderly hyperlipidemia patients shows distinct characteristics and can be used to evaluate muscle damage of statin-related myopathy.