Objective To observe the value of semi-quantitative parameters related to gated myocardial perfusion imaging(G-MPI)for predicting occurrence of major adverse cardiovascular events(MACE)in patients with chronic kidney disease(CKD).Methods Totally 148 CKD patients who underwent rest G-MPI(R-GMPI)(R-GMPI group,n=95)or stress/rest G-MPI(S/R-GMPI)(S/R-GMPI group,n=53)were retrospectively included.The patients were categorized into MACE subgroup and non-MACE subgroup according to MACE occurred or not during follow-up.Clinical data and G-MPI parameters were compared between subgroups,and independent predictors of MACE in CKD patients were obtained using multivariate Cox proportional hazards regression analysis.Receiver operating characteristic(ROC)curve was drawn,the area under the curve(AUC)was calculated to assess the efficacy of each independent predictor for predicting MACE.Among patients who underwent only R-GMPI,the optimal cut-off value of each parameter for predicting MACE was obtained by ROC curve analysis,and the risk of MACE was stratified,then Kaplan-Meier curves were drawn and compared with log-rank test.Results Among 95 patients who underwent only R-GMPI,compared with non-MACE subgroup,those in MACE subgroup had smaller body mass index(BMI)and higher proportion of previous myocardial infarction and hemodialysis,as well as higher R-GMPI left ventricle end-diastolic volume(R-LVEDV),left ventricle end-systolic volume(R-LVESV),sum rest score(R-SRS)but lower left ventricle ejection fraction(R-LVEF)(all P＜0.05),while R-SRS(HR=1.068,95％CI[1.027,1.110])and R-LVESV(HR=1.011,95％CI[1.005,1.017])were both independent predictors for MACE(both P＜0.05).Among 53 patients who underwent S/R-GMPI,compared with non-MACE subgroup,those in MACE subgroup had with higher blood creatinine and lower estimated glomerular filtration rate(eGFR),higher S-LVESV,R-LVEDV,sum stress score(SSS),SRS and sum difference score(SDS)(all P＜0.05),and SDS(HR=1.454,95％CI[1.063,1.989])was an independent predictor for MACE(P＜0.05).Among 95 CKD patients who underwent only R-GMPI,AUC of R-SRS and R-LVESV alone for predicting MACE was 0.659 and 0.694,respectively,and higher incidence of MACE was found in those w ith R-SRS ≥8 points,also in those with R-LVESV ≥91 ml(both P＜0.05).Conclusion G-MPI could be used to evaluate myocardial perfusion and function in CKD patients.For CKD patients just underwent only R-GMPI,R-SRS and R-LVESV were independent predictors for MACE,whereas SDS might be utilized to predict MACE in CKD patients who could undergo S/R-GMPI.

Objective:To evaluate the predictive value of stress+ rest gated myocardial perfusion imaging (G-MPI) in assessing all-cause mortality risk in patients with familial hypercholesterolemia (FH).Methods:From June 2010 to March 2022, 72 patients (39 males, 33 females; age (21.1±12.3) years) who diagnosed with FH clinically and genetically and underwent stress+ rest G-MPI in Beijing Anzhen Hospital, Capital Medical University were retrospectively followed up. Image analysis was performed using the 17-segment 5-point method to obtain left ventricular myocardial perfusion and functional parameters. Patients were followed for all-cause mortality events, and predictors associated with the risk of all-cause mortality were analyzed using Cox regression. The efficiencies of predictors were evaluated by ROC curve analysis, and the Kaplan-Meier method and log-rank test were used to compare the differences in the incidence of all-cause mortality in different groups of patients with FH. Independent-sample t test or Mann-Whitney U test was used to analyze the data. Results:The follow-up time of 72 patients was 7(4, 10) years, and all-cause death occurred in 16(22.2%) patients during the follow-up period. There were statistically significant differences in total cholesterol (TC), low density lipoprotein cholesterol (LDLC), summed stress score (SSS), summed rest score (SRS), summed difference score (SDS), stress end-systolic volume (SESV), stress ejection fraction (SEF), rest end-diastolic volume (REDV), rest end-systolic volume (RESV) and rest ejection fraction (REF) between the death group and the survival group ( t values: from -2.65 to 4.47, z values: from -3.43 to -1.98, all P<0.05). Cox regression analysis showed that SDS (hazard ratio ( HR)=1.337, 95% CI: 1.114-1.604, P=0.002), SESV ( HR=1.019, 95% CI: 1.008-1.030, P<0.001) and LDLC ( HR=1.355, 95% CI: 1.049-1.749, P=0.020) were independent predictors associated with the risk of all-cause mortality in patients with FH. The optimal cut-off value of SESV for predicting mortality in patients with FH determined by ROC curve analysis was 35.5 ml, with the AUC of 0.701 (95% CI: 0.517-0.885). The incidence of all-cause mortality in the group with SESV≥35.5 ml was significantly higher than that in the group with SESV<35.5 ml (28.6% vs 6.9%; χ2=5.15, P=0.023). Conclusion:Stress+ rest G-MPI is an important imaging method for all-cause mortality risk assessment in patients with FH, and SDS, SESV and LDLC are important factors in predicting mortality in patients with FH.

Objective:To compare the feasibility and efficacy of translocator protein (TSPO) molecular probes N, N-diethyl-2-(2-(4- 18F-fluorophenyl)-5, 7-dimethylpyrazolo[1, 5-a]pyrimidin-3-yl)acetamide ( 18F-FDPA) and 18F-(R)-( N-sec-butyl)-3-fluoromethyl- N-methyl-4-phenylquinoline-2-carboxamide (LW223) for the detection of abdominal vulnerable atherosclerotic plaques (VAP) in rabbit models. Methods:Nine healthy New Zealand white rabbits were divided into group A (control group, n=3), group B (VAP group, n=3) and group C (VAP treatment group, n=3) using completely randomized design. Animals were injected with 18F-FDPA and 18F-LW223 at the end of 12, 16 and 24 weeks. PET/CT and CT angiography (CTA) was performed 40-50 min post injection. All rabbits were sacrificed at the end of 24 weeks after imaging studies. All abdominal aortas were collected for pathological and immunofluorescence examination. Repeated measures analysis of variance (Bonferroni test) and paired t-test were used to analyze the data. Results:Target-to-background ratio (TBR; abdominal aortic lesion/left ventricular blood pool) values of 18F-FDPA in 3 groups at the end of 12, 16 and 24 weeks were significantly different ( F values: 68.09-144.88, all P<0.001). At the end of 12 weeks, there was no increased uptake of 18F-FDPA in the abdominal aorta region in 3 groups. The local 18F-FDPA uptake of the abdominal aorta in group B was significantly higher than the uptake in group C and that in group A at the end of 16 and 24 weeks( P<0.05 or P<0.001), and there were significant differences between group C and group A, with higher uptake in group C (both P<0.01). In 3 groups, there was no significant 18F-LW223 uptake in the abdominal aorta region at 3 time points of PET/CTA imaging. At the end of 12, 16 and 24 weeks, TBR values of 18F-FDPA and 18F-LW223 in 3 groups exhibited statistical differences ( t values: 2.88-36.79, all P<0.05). HE, immunofluorescent CD68 and TSPO staining showed more macrophage infiltration in group B than group C. Conclusion:18F-FDPA can be used to detect VAP in rabbits′ abdominal arteries at early time compared to 18F-LW223, and to evaluate the changes in the stability of vulnerable plaque after lipid-lowering drug intervention.

Objective:To establish the normal reference value of left ventricular function parameters by cadmium-zinc-tellurium (CZT) SPECT stress gated myocardial perfusion imaging (G-MPI) in low-likelihood of stable coronary artery disease (SCAD).Methods:From March 2022 to August 2022, 348 consecutive SCAD patients (146 males, 202 females, age (58±10) years) who underwent exercise or pharmacological stress G-MPI (CZT SPECT) in Beijing Anzhen Hospital, Capital Medical University were retrospectively recruited. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction (LVEF) were acquired using quantitative gated SPECT (QGS) analysis. EDV and ESV were corrected by body surface area (BSA) to obtain EDV index (EDVI) and ESV index (ESVI), respectively. Independent-sample t test, one-way analysis of variance and Mann-Whitney U test were used for data analysis. The influences of EDV, ESV, EDVI, ESVI and LVEF were analyzed by multiple regressions for linear models. Results:There were 314 patients with low-likelihood of SCAD (128 males, 186 females, age (58±10) years) and 34 normal controls (18 males, 16 females, age (55±10) years). There were no significant differences of basic clinical characteristics and left ventricular function parameters in different genders between 2 groups ( z values: from -1.74 to -0.02, t values: from -1.16 to 1.17, all P>0.05). Using the 95% CI as the cut-off value for left ventricular function parameters in patients with a low-likelihood of SCAD, the upper limits of EDV, ESV, EDVI and ESVI in females and males were 84 and 111 ml, 30 and 44 ml, 47 and 54 ml/m 2, 17 and 21 ml/m 2, respectively, and the lower limit of LVEF in females and males were 58% and 55%, respectively. In the low-likelihood of SCAD group, the EDV ((58±13) vs (77±17) ml) and ESV ((16±7) vs (26±9) ml) of females were smaller than those of males ( t values: 10.65, 10.35, both P<0.001), while LVEF of females was higher than that of males ((72±7)% vs (67±6)%; t=-6.23, P<0.001). However, there were no significant differences in left ventricular function parameters among different age groups with the same gender ( F values: 0.12-2.19, all P>0.05). Based on multiple regression for linear models, the primary predictors of EDV, ESV and LVEF were gender and weight ( β values: from -0.380 to 0.358, all P<0.05). Conclusions:Normal reference values of left ventricular function parameters are established by CZT SPECT stress G-MPI in low-likelihood of SCAD patients. Left ventricular EDV and ESV of females are smaller than those of males, while LVEF of females is higher than that of males. The influence of gender on left ventricular function parameters should be considered in clinical practice.

Objective:To explore the diagnostic value of 18F-deoxyglucose (FDG) PET/CT dual-time-point imaging (DTPI) in the diagnosis of aortic grafts infection (AGI). Methods:Forty-two patients with suspected AGI were prospectively recruited in this DTPI study from October 2014 to October 2021. There were 35(83%) males and 7 females, mean age (54±15) years old, range 22-79 years old. PET/CT image quality was scored as 5 grading scale. Semi-quantitative analysis of DTPI data was performed using maximum standardized uptake value (SUVmax) of suspected AGI lesions. The percentage of SUVmax change between initial and delayed images were recorded as retention index (RI). Management of Aortic Graft Infection Collaboration (MAGIC) criteria were used as the diagnostic reference criteria for AGI.Results:According to the MAGIC criteria, 27 patients (64%) were positive for AGI, and 15 patients (36%) were negative. The mean RI of AGI was higher than that of non-AGI ones[(26.7±18.9)% vs. (6.4 ±18.8)%, P<0.01]. The sensitivity, specificity, and accuracy of initial SUVmax ≥6 with the presence of AGI was 88.9%, 73.3%, and 83.3%, respectively. Delayed SUVmax ≥6 improved the sensitivity (96.3%) and accuracy (88.1%) for diagnosing AGI. DTPI with 15% increment as the optimal cut-off value of RI improved the specificity (93.3%) and accuracy (90.5%) for diagnosing AGI. Fifteen (56%, 15/27) AGI patients had improved image quality grading on the delayed images, leading to more accurately delineating the detailed extent of the infected aortic graft. Conclusion:18F-FDG PET/CT DTPI has better diagnostic performance for AGI than conventional Single-time-point PET/CT imaging by improving image quality as well as enhancing delineation of infected aortic graft extent.

Objective:To serially characterize the myocardial perfusion, myocardial hibernation and left ventricular (LV) function as well as LV remodeling in progressive coronary artery stenosis in Chinese mini-pigs.Methods:In 8 Chinese mini-pigs (5 males, 3 females; age: 10 months), chronic progression of coronary stenosis and finally occlusion was established using Ameroid constrictor implantation at the 1 cm below the bifurcation of the first diagonal branch of the left anterior descending (LAD) artery. Serial gated 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT/CT, gated 18F-FDG PET/CT imaging and coronary angiography (CAG) were performed before surgery and at the 1st, 4th and 8th week after surgery. Longitudinally, total perfusion defect (TPD), LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), summed motion score (SMS), summed thickening score (STS) and hibernating myocardium (HM) were analyzed. Repeated measures analysis of variance, Kruskal-Wallis rank sum test and Bonferroni correction method were used to analyze data. Results:One mini-pig died of infection after the Ameroid constrictor implantation. In the remaining 7 mini-pigs, TPD was progressively increased with time prolonged (0, 12.0%(0, 33.0%), (41.1±23.7)% and (49.3±24.5)%; H=17.03, P=0.001); Compared with HM before the surgery (100%), HM was gradually reduced from the 1st (21.0%(6.0%, 100%)) to the 4th (18.0%(3.0%, 33.0%)) week after surgery, and then increased to the 8th week after surgery ((23.0±15.4)%; H=13.09, P=0.004), but there was no significant difference between the 1st and 4th week, or between the 4th and 8th week after surgery (both P>0.05 (Bonferroni correction method)). Accordingly, LVEF gradually decreased ((73.7±8.4)%, (63.7±19.1)%, (53.7±14.6)% and (49.9±15.4)%; F=6.22, P=0.004). LVEDV (9.0(6.0, 21.0), (31.4±16.3), (32.9±17.4) and (36.4±17.5) ml; H=8.58, P=0.035)and LVESV ((3.8±3.2), (15.9±15.3), 12.0(10.0, 17.0)and (19.3±10.9) ml; H=10.51, P=0.015) gradually increased. SMS and STS continuously increased as well ( H values: 16.49, 13.33, P values: 0.001, 0.004). Conclusions:With the progression of coronary artery stenosis to occlusion, myocardial perfusion is gradually decreased, while the global and regional LV function, LV remodeling are gradually aggravated, and HM is gradually reduced. After the chronic coronary artery occlusion, myocardial perfusion has a trend to be improved and HM is gradually recovered.

Objective:To evaluate the effect of remote ischemic conditioning (RIC) on left ventricular (LV) myocardial perfusion, myocardial viability, LV remodeling, regional and global LV function serially following acute myocardial infarction (AMI) in Chinese mini-pigs.Methods:AMI was established in 12 Chinese mini-pigs (8 males, 4 females; age: 6-8 months) and they were randomly divided into RIC group ( n=6) and non-RIC group ( n=6). RIC was performed in pigs by blood pressure inflation on the lower limbs for 5 min period and 4 cycles immediately after surgery. A series of myocardial perfusion imaging and gated 18F-fluorodeoxyglucose (FDG) myocardial metabolism PET/CT imaging were performed longitudinally at the 1st, 14th, 28th and 56th days after AMI, and parameters including total perfusion defect (TPD), hibernating myocardium (HM), Scar, left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), summed motion score (SMS), summed thickening score (STS) and changes of these parameters were obtained. Independent-samples t test and Mann-Whitney U test were used to analyze data. Results:Nine Chinese mini-pigs survived after surgery and were performed imaging. Compared to non-RIC group ( n=4), HM at the 28th ((6.0±2.4)% vs (17.0±4.6)%; t=-4.158), TPD 14th-1st ((-11.8±5.4)% vs 9.0%(4.5%, 15.0%); z=2.449), TPD 28th-1st ((-15.3±3.9)% vs (12.0±3.0)%; t=-10.071), TPD 56th-1st ((-18.0±6.5)% vs 9.0%(4.5%, 12.0%); z=2.449), HM 28th-1st ((-10.5±6.9)% vs (8.3±2.1)%; t=-4.507), HM 56th-1st (-15.0%(-17.5%, -8.5%) vs 2.0%(0%, 7.0%); z=2.449) and LVEDV 14th-1st (-0.5(-2.5, 0) ml vs (13.0±4.4) ml; z=2.470) were reduced in RIC group ( n=5; all P<0.05). Conclusion:RIC can improve myocardial perfusion, delay LV remodeling in the acute stage and salvage hibernating myocardium in the subacute stage and chronic stage.

Objective To evaluate the features of myocardial perfusion imaging (MPI) in patients with homozygous familial hypercholesterolemia (HoFH) and its influence factors.Methods Forty-two consecutive HoFH patients (21 males,21 females;average age:(14.8±8.4) years) were retrospectively enrolled in this study from June 2010 to November 2016.Diagnosis was proved by clinical and chromosome tests,and all patients underwent ATP stress and rest 99Tcm-methoxyisobutylisonitrile (MIBI) SPECT MPI with a two-day protocol.Summed stress score (SSS) and summed rest score (SRS) were acquired,and summed difference score (SDS;SSS-SRS) was calculated.Relations between SSS,SRS,SDS and age,lipid profile were analyzed.Two-sample t test,x2 test,multiple linear regression analysis and multivariate logistic regression were used to analyze the data.Results There were 24 patients with positive MPI results (SSS≥1),and females (76.2％,16/21) showed more positive MPI results than males (38.1％,8/21;x2=6.22,P＜0.05).Eighteen patients had negative MPI results.There were 6,8,10 patients with MPI positive results in ＜ 10 years group (n =14),10-18 years group (n =14) and ≥ 19 years group,respectively (x2=2.33,P＞0.05).Positive electrocardiograph (ECG) in ATP stress test was observed in 9 females (42.9％,9/21) and 3 males (14.3％,3/21;x2 =4.20,P＜0.05).Sixty-three (8.8％,63/714) abnormal myocardial perfusion segments (SSS≥ 1) were found,which was mainly (60.3％,38/63) distributed in myocardial regions supplied by left anterior descending branch (LAD).SSS was positively correlated with age and high density lipoprotein cholesterol (HDLC).SRS,SDS were positively correlated with HDLC and age respectively.Multivariate logistic regression analysis indicated that the female was the only independent risk factor to predict positive MPI (odds ratio=5.2,95％ CI:1.363-19.774).Conclusions In HoFH patients,abnormal myocardial perfusion had a rising trend with age increasing.Female patients are more likely to have abnormal MPI.Abnormal myocardial perfusion segments are mainly located in myocardial regions supplied by LAD.Age and gender are influence factors of abnormal MPI in HoFH patients.

Objective To evaluate 18F-fluorodeoxyglucose (FDG) PET/CT in the rabbit model of vulnerable plaques by correlation with 99Tcm-Arg-Gly-Asp (RGD) SPECT/CT imaging,lipid levels,pathological and immunohistochemical results.Methods Sixteen male New Zealand white rabbits were randomly divided into normal diet group (group A,n =4),stable plaque group (group B,n =4) and vulnerable plaque group (group C,n =8) using completely random grouping method.The animals were given abdominal aorta sham operation (groups A and B) or balloon injury of the abdominal aorta (group C) 2 weeks after feeding.Animals were injected with 18F-FDG and 99Tcm-RGD respectively at the end of 4,8 and 12 weeks.PET/CT was performed at 1,2 and 3 h post-injection.SPECT/CT was performed at 30 min post-injection.One rabbit was sacrificed at the end of 4 and 8 weeks after imaging studies,respectively.The others were sacrificed at the end of 12 weeks after imaging studies.All abdominal aortas were harvested.Pathology and immunohistochemistry analysis were performed.The data were analyzed by one-way analysis of variance and Pearson correlation analysis.Results There was no uptake in any group at 4th week and no uptake in group A or group B at 8th week.There was mild uptake in group B at 12th week and group C at 8th week.There was intense uptake in group C at 12th week,whereas both mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax) were significantly higher than the other two groups (F values:7.952,14.279,both P＜0.05).In group C,SUVmax(0.43±0.08,0.68±0.06,1.74±0.63) and SUV (0.37±0.03,0.56±0.03,1.26+0.23) had significant difference at 3 h post-injection for imaging at 4th,8th and 12th week (F values:10.939,39.747,both P＜0.05).At 12th week,there was a strong correlation between the uptake of 18 F-FDG and target/non-target (T/NT) ratio of 99Tcm-RGD in all groups(r values:0.748,0.709,both P＜0.05).Histopathology results showed that the plaques had rich macrophages and a small amount of smooth muscle cells in group C,little macrophages in group B,while no macrophages in group A.Conclusion 18F-FDG PET/CT might be an effective noninvasive method for early assessment of aortic vulnerability to atherosclerotic plaque.

Objective To discuss the impact of an iterative reconstruction algorithm (True X) implemented with point spread function (PSF) on image quality and SUV in 18F-FDG PET, and compare with other reconstruction algorithms.Methods A total of 79 hypermetabolic lesions from 37 cancer patients (23 males, 14 females, age (63.38±15.25) years) were retrospectively studied.The PET images were reconstructed using the following six reconstruction algorithms, including FBP, FBP+TOF, iteration, iteration+TOF, True X, True X+TOF.Paired t test was used for statistical analysis.Results All six reconstruction algorithms showed significant difference in lesion SUVmax.The adoption of PSF increased SUVmax by 15%-16%, and decreased the dispersion of SUV in the liver parenchyma remarkably.Conclusions Lesion SUVmax calculated from different reconstruction algorithms has significant differences.Caution should be taken in using PSF, as it can improve image quality but may also increase lesion SUVmax.