Objective:To investigate the clinical value of left ventricular shape index (SI) and eccentricity index (EI) in evaluating left ventricular remodeling.Methods:A retrospective analysis was performed on 324 patients (264 males, 60 females, age (62.5±11.8) years) diagnosed with myocardial infarction (MI) and 113 healthy controls (HC; 47 males, 66 females, age (57.8±10.7) years) who received gated myocardial perfusion imaging (GMPI) in First Hospital of Shanxi Medical University from January 2016 to September 2020. SI (end-diastolic SI (EDSI), end-systolic SI (ESSI)), EI and left ventricular function parameters (end-diastolic volume (EDV), end-systolic volume (ESV), left ventricular ejection fraction (LVEF), summed motion score (SMS), summed thickening score (STS), peak ejection rate (PER) and peak filling rate (PFR)) were obtained by quantitative gated SPECT (QGS) software. Propensity score (PS) inverse probability of treatment weighting (IPTW) was used to balance the intergroup covariates. The differences and correlations of EDSI, ESSI, EI and left ventricular function parameters between patients in MI group and HC group were analyzed. ROC curve analysis was used to evaluate the values of EDV, EDSI, ESSI and EI alone and in combination in the assessment of left ventricular systolic function impairment. Data were analyzed by independent-sample t test, Pearson correlation and Spearman rank correlation analyses, and Delong test. Results:After IPTW, EDSI and ESSI in MI group ( n=319) were higher than those in HC group ( n=133; EDSI: 0.66±0.09 vs 0.60±0.06; ESSI: 0.59±0.11 vs 0.47±0.07; t values: 8.05, 14.67, both P<0.001), and EI was lower than that in HC group (0.81±0.06 vs 0.85±0.03; t=-8.93, P<0.001). In both groups, there were significant correlations between EDSI and ESSI ( r values: 0.928, 0.873), between EDSI, ESSI and EI ( r values: from -0.831 to -0.641), between EDSI, ESSI and LVEF ( r values: from -0.627 to -0.201), between ESSI and EDV, ESV and SMS ( rs values: 0.336-0.584), between ESSI and -PER, PFR ( rs values: from -0.406 to -0.402, r values: from -0.352 to -0.325) (all P<0.01). ROC curve analysis showed that EDV (AUC: 0.895) and ESSI (AUC: 0.839) had the highest efficacy in evaluating left ventricular systolic function impairment in MI group and HC group, respectively. EDV-EDSI-ESSI-(1-EI) had higher efficacy in the assessment of impaired left ventricular systolic function in MI group (AUC: 0.956), which was higher than that of EDV or EDV-EDSI or EDV-ESSI or EDV-(1-EI) ( z values: from -2.64 to -2.18, P values: 0.008-0.029); EDV-EDSI-ESSI-(1-EI) also had high efficacy in HC group (AUC: 0.911), which was higher than that of EDV or EDV-EDSI or EDV-(1-EI) ( z values: from -2.60 to -2.43, P values: 0.009-0.015). Conclusions:In MI patients, the increase of SI and the decrease of EI indicate the increase of left ventricular sphericity and the aggravation of left ventricular remodeling. SI and EI have certain clinical application values in evaluating left ventricular morphology, predicting left ventricular remodeling and left ventricular systolic function impairment.

Objective:To investigate whether patients with pulmonary hypertension (PH) develop abnormal fibroblast activation protein (FAP) inhibitor (FAPI) uptake in the left ventricular free wall and to analyze its characteristics and significance.Methods:Al 18F-1, 4, 7-triazacyclononane-1, 4, 7-triacetic acid (NOTA)-FAPI-04 PET/CT images of 51 patients diagnosed with PH (24 males, 27 females; age: (48±21) years) and 10 healthy volunteers (4 males, 6 females; age: (59±12) years) from Beijing Chaoyang Hospital of Capital Medical University between February 2021 and January 2024 were retrospectively analyzed. Higher FAPI uptake in the left ventricular free wall than that in blood pool was defined as abnormal and SUV max, SUV mean, and total lesion FAP activity were quantitatively measured. Associated factors with FAPI uptake in the left ventricle were analyzed, and differences of clinical parameters between patients with and without abnormal left ventricular uptake were compared. Independent-sample t test and Mann-Whitney U test were used to compare differences between groups. Spearman rank correlation analysis was used for correlation analysis. Results:Abnormal FAPI uptake that was diffusely distributed in the left ventricular free wall was observed in 19 patients with PH. Total lesion FAP activity was positively correlated with peak mitral late-diastolic inflow velocity ( A) ( rs=0.696, P=0.001) and negatively correlated with peak mitral early-diastolic inflow velocity ( E)/ A and pulmonary vascular resistance (PVR) ( rs values: -0.629, -0.540, P values: 0.004, 0.017). Significant differences in E/ A (0.8(0.6, 1.1) vs 0.9(0.8, 1.4); z=-2.33, P=0.020), left ventricular end-systolic internal diameter ((25.7±2.6) vs (27.8±4.2) mm; t=-2.22, P=0.031), and left ventricular end-systolic volume ((26.7±7.3) vs (32.5±9.9) ml; t=-2.26, P=0.028) were found between patients with and without abnormal FAPI uptake in the left ventricle. Conclusion:In patients with PH, the left ventricular free wall develops diffuse abnormal uptake of FAPI, the extent of which is related to impaired left ventricular diastolic function.

Objective:To evaluate the efficacy of balloon pulmonary angioplasty (BPA) in chronic thromboembolic pulmonary hypertension (CTEPH) using 99Tc m-macroaggregated albumin (MAA) pulmonary perfusion tomography imaging. Methods:Twenty-five patients (4 males, 21 females; age (56.5±12.3) years) with CTEPH who underwent BPA from January 2017 to April 2020 in Beijing Chaoyang Hospital, Capital Medical University were enrolled retrospectively. Effect of BPA on the improvement of pulmonary lobe/pulmonary segment perfusion was analyzed, and the proportions of improved and unimproved pulmonary lobe/pulmonary segment perfusion by BPA were calculated. The percentages of perfusion defect scores (PPDs%) of lung perfusion tomography imaging before BPA and after 4-6 times BPA were compared and analyzed (paired t test). The correlations between PPDs% and mean pulmonary artery pressure (mPAP) before BPA and after BPA were analyzed respectively, and the correlation between decreased percentage of PPDs% and decreased percentage of mPAP after BPA were also analyzed (Pearson correlation analysis). Results:Among 150 lobes of 25 patients, 96.00%(144/150) lobes showed perfusion abnormalities before BPA. After BPA, 11.11%(16/144) showed complete improvement, 57.64%(83/144) showed partial improvement, and 31.25%(45/144) showed no improvement. Among 450 pulmonary segments of 25 patients, 62.44%(281/450) showed perfusion abnormalities before BPA. After BPA, 30.60%(86/281), 37.37%(105/281), 32.03%(90/281) showed complete, partial and no improvement, respectively. The post-BPA PPDs% was significantly lower than that of pre-BPA ((39.08±10.88)% vs (57.88±10.46)%; t=10.40, P<0.001). The post-BPA mPAP was significantly lower than that of pre-BPA ((32.36±10.57) vs (49.08±10.23) mmHg; 1 mmHg=0.133 kPa; t=10.25, P<0.001). There was no significant correlation between PPDs% and mPAP either before BPA ( r=0.01, P=0.953) or after BPA ( r=0.27, P=0.199), but there was a positive correlation between the changes of PPDs% and mPAP ( r=0.40, P=0.045). Conclusions:BPA can significantly improve the pulmonary perfusion and reduce mPAP in CTEPH patients. Pulmonary perfusion tomography imaging can be used to evaluate the efficacy of BPA in CTEPH.

Objective:To explore suitable strategies for atrial 18F-FDG PET/CT imaging and analyze the characteristics of abnormal atrial uptake in patients with atrial fibrillation(AF). Methods:From August 2017 to August 2018, 69 AF patients (43 males, 26 females, age (64±11) years) in Beijing Chaoyang Hospital were prospectively enrolled and underwent dual-phase 18F-FDG PET/CT imaging (60 and 120 min postinjection). Additionally, 10 healthy controls (3 males, 7 females, age (66±4) years) were prospectively enrolled and underwent 18F-FDG PET/CT imaging (60 min postinjection). A comprehensive strategy recommended by the Society of Nuclear Medicine and Molecular Imaging/American Society of Nuclear Cardiology/Society of Cardiovascular Computed Tomography (SNMMI/ASNC/SCCT) guideline was followed to suppress myocardial uptake. Image analysis: (1) 18F-FDG uptake of left ventricle was qualitatively analyzed and classified into 3 levels: grade 0, the activity of blood pool exceeded or was equal to myocardial activity; grade 1, myocardial activity was mildly higher than blood pool activity; grade 2, myocardial activity was obviously higher than blood pool activity. 18F-FDG uptake in the left atrium(LA), left atrial appendage (LAA) and right atrium (RA) higher than that in blood pool were defined as abnormal. Paired χ2 test was used to compare the rates of abnormal uptake in atrial structures between two phases. (2) Quantitative analysis: 18F-FDG uptake in all atrial structures were quantitatively analyzed by measuring SUV max, and left atrial cavity and right atrial cavity were quantitatively analyzed by measuring SUV mean. The target to background ratio (TBR) was calculated. Differences of TBR between two phases were analyzed by Wilcoxon signed rank test. Differences of 18F-FDG uptake in atrial structures between patients with AF and healthy controls were analyzed by Mann-Whitney U test and χ2 test. Results:Most subjects (84.8%, 67/79) achieved sufficient myocardial suppression. In one patient, the interpretation of LAA was affected by left ventricle uptake. The incidence of abnormal uptake of LA, LAA and RA in delayed phase were higher than those in early phase, but only the difference of LAA was significantly different (27.9%(19/68) vs 42.6%(29/68); χ2=8.10, P=0.020). TBR of LA, LAA and RA in delayed phase were all significantly higher than those in early phase (LA: 1.1 (1.0, 1.3) vs 1.1 (1.0, 1.2); LAA: 1.2 (1.0, 1.5) vs 1.0 (0.9, 1.2); RA: 1.4 (1.1, 1.9) vs 1.3 (1.0, 1.5); z values: from -6.81 to -3.42, all P<0.05). There were 87.0%(60/69) of AF patients with abnormal atrial FDG accumulation, which was significantly higher than that of the control group (0/10; χ2=31.50, P<0.001). In LAA and RA, the incidences of abnormal accumulation were significantly higher in AF than those in the control group (LAA: 30.4%(21/69) vs 0 (0/10); χ2=4.10, P=0.042; RA: 53.6%(37/69) and 0 (0/10); χ2=8.00, P=0.001). Conclusions:Using the method recommended by the SNMMI/ASNC/SCCT guideline to suppress the physiological uptake of the left ventricle and appropriately extending the interval is conducive to observing the abnormal 18F-FDG uptake in the atrium. The uptake of 18F-FDG in the atrium of patients with AF is increased.

Objective:To investigate the accuracy of free-breathing CT in evaluating the volume and shape of epicardial adipose tissue (EAT), and further explore the characteristics of EAT volume and activity in patients with atrial fibrillation using 18F-FDG PET/CT " one-stop" imaging. Methods:(1) Retrospective analysis was performed on 20 patients (16 males, 4 females, age: 33-86 (61.1±14.2) years) who underwent 18F-FDG PET/CT imaging and without obvious diseases affecting the images of the heart and surrounding lungs between March 2020 and May 2020 in Beijing Chaoyang Hospital. Free-breathing CT and breath-hold high resolution CT (HRCT) images were reviewed. Spearman rank correlation analysis, Bland-Altman consistency analysis and intraclass correlation coefficient (ICC) were used to evaluate the correlation and consistency of the EAT volume and shape, as well as the repeatability of the two operators′ measurements. (2) Prospective analysis was conducted to compare the differences in EAT volume and 18F-FDG uptake values between 20 patients (6 males, 14 females, age: 52-76 (66.0±6.4) years) with atrial fibrillation and 10 healthy controls (3 males, 7 females, age: 59-69 (66.0±3.6) years) collected between August 2017 and August 2018 in Beijing Chaoyang Hospital. Mann-Whitney U test was used to compare the differences in EAT volume and 18F-FDG SUV max between patients with atrial fibrillation and healthy controls. EAT volume measurement was conducted by the combination of Mimics Research 21.0 software and manual analysis. The shape of EAT was automatically calculated by the same software to obtain the maximum length of the projection of the three-dimensional (3D) model on the reference axes ( x, y, z). SUV max of EAT was manually measured. Results:The measurements of EAT volume had good repeatability (intra-operator ICC=0.999; inter-operator ICC=0.997). There was a good correlation and a good consistency between EAT volumes measured by free-breathing CT and breath-hold HRCT (96.6 (79.9, 136.4) vs 96.2 (80.9, 135.8) ml; rs=0.929, P<0.001); data of 19 cases were within 95% limits of agreement (95% LoA). The maximum projection length of EAT 3D model on the reference coordinate axis also showed good correlation and consistency ( x axis: rs=0.869, P<0.001, data of 19 cases were within 95% LoA; y axis: rs=0.854, P<0.001, data of 18 cases were within 95% LoA; z axis: rs=0.586, P=0.007, data of 20 cases were within 95% LoA). EAT volume of atrial fibrillation group was higher than those of healthy control group (137.2 (113.9, 202.9) vs 94.4 (76.6, 134.4) ml; z=-2.11, P=0.035) and SUV max of EAT in the atrial fibrillation group was higher than that in healthy control group (1.2 (1.1, 1.5) vs 1.1 (1.0, 1.2); z=-2.14, P=0.035). Conclusions:Free-breathing CT and breath-hold HRCT have good correlation, consistency and repeatability in measurement of EAT volume and shape. 18F-FDG PET/CT can be a " one-stop" imaging strategy for the evaluation of EAT volume and activity.

Objective:To investigate the value of 18F-FDG PET/CT myocardial inflammation imaging in evaluating the functional prognosis of left ventricle (LV) in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). Methods:Thirty-one patients (26 males, 5 females, age: (55.4±10.1) years) with acute ST-elevation myocardial infarction (STEMI) referred for PCI in Beijing Chaoyang Hospital between January 2016 and December 2016 were prospectively included. All patients underwent 18F-FDG PET/CT following 99Tc m-methoxyisobutylisonitrile (MIBI) rest myocardial perfusion imaging (MPI) on the fifth day after PCI. A comprehensive strategy recommended by guideline was followed to suppress myocardial uptake. 18F-FDG uptake in infarcted and remote myocardium were quantitatively analyzed by measuring SUV max, and that in superior vena cava was quantitatively analyzed by measuring SUV mean. Target-to-background ratios (TBRs) in infarcted and remote area were calculated. In addition, the following parameters were obtained: 18F-FDG uptake volume of LV (Vol-FDG), percentage of 18F-FDG uptake size of LV (F/LV%) , percentage of myocardial perfusion defect size of LV (def/LV%). According to the left ventricular ejection fraction (EF) at baseline and 6 months after AMI, the changing rate of EF (ΔEF) was calculated, and data of patients in improvement group (ΔEF≥10%) and no improvement group (ΔEF<10%) were compared. Independent-sample t test or Mann-Whitney U test, and Pearson correlation analysis or Spearman rank correlation analysis were used for data analysis. Results:TBR was significantly higher in infarcted myocardium than that in remote area (2.8±1.0 vs 1.1±0.3; t=11.03, P<0.001). F/LV% was greater than def/LV% (33.7%(25.8%, 43.3%) vs 8.8%(2.3%, 20.7%); z=-4.72, P<0.001). TBR in both infarcted and remote areas showed positive correlations with peripheral blood monocyte counts ( r=0.44, P=0.014; r=0.37, P=0.042). Vol-FDG had positive correlations with the myocardial injury markers (creatine kinase (CK), CK isoenzyme (CK-MB), cardiac troponin I (cTnI); r values: 0.46, 0.41, 0.68, all P<0.05). Of the 31 patients, 26(83.9%) completed the 6-month follow-up. Vol-FDG in no improvement group ( n=11) was significantly greater than that in improvement group ( n=15; (104.5±47.2) vs (70.1±26.3) cm 3;t=2.38, P=0.026). There was a negative correlation between Vol-FDG and ΔEF ( rs=-0.41, P=0.038). Conclusion:18F-FDG PET/CT imaging can evaluate the intensity and size of myocardial inflammation, and estimate the functional prognosis of LV in patients with AMI undergoing PCI.

Objective:To compare the incidence of coronary microvascular disease (CMVD) between patients with non-obstructive and obstructive coronary arteries.Methods:We retrospectively analyzed 97 patients with angina pectoris, who underwent the absolute quantitative PET examination of myocardial perfusion and coronary anatomy examination within 90 days. All patients were divided into two groups: non-obstructive group (72 cases, no stenosis ≥50% in all three coronary arteries) and obstructive group (25 cases, at least one coronary stenosis ≥50%; and at least one coronary stenosis<50%). Quantitative parameters derived from PET including rest myocardial blood flow (RMBF), stress myocardial blood flow (SMBF), coronary flow reserve (CFR) and cardiovascular risk factors were compared between the two groups. CMVD was defined as CFR<2.90 and SMBF <2.17 ml·min -1·g -1. Results:Incidence of CMVD was significant higher in the non-obstructive coronary arteries of the obstructive group than in the non-obstructive coronary arteries of non-obstructive group (47.1% (16/34) vs. 25.5% (55/216), χ 2=6.738, P=0.009) while incidence of CMVD was similar between non-obstructive and obstructive patients ((44% (11/25) vs. 33.3% (24/72), χ 2=0.915, P=0.339). RMBF ((0.83±0.14) ml·min -1·g -1 vs. (0.82±0.17) ml·min -1·g -1), SMBF ((2.13±0.60) ml·min -1·g -1 vs. (1.91±0.50) ml·min -1·g -1) and CFR (2.59±0.66 vs. 2.36±0.47) were similar between the two groups (all P>0.05). Conclusions:CMVD can occur in non-obstructive coronary arteries in both patients with non-occlusive coronary arteries and patients with obstructive coronary arteries. Prevalence of CMVD is significantly higher in patients with obstructive coronary arteries than in patients with non-obstructive coronary arteries. The CMVD severity is similar between the two groups.

Objective To evaluate the efficacy of pulmonary thromboendarterectomy (PTE) in treatment of chronic thromboembolic pulmonary hypertension (CTEPH) using 99Tcm-macroaggregated albumin (99 Tcm-MAA) pulmonary perfusion tomography.Methods Sixteen patients with CTEPH underwent 99Tcm-MAA pulmonary perfusion tomography before and 6-12 months after PTE.The perfusion defects and improvement both in pulmonary lobe and segment were observed pre-and post-PTE.Percentage of perfusion defect scores (PPDs％) were calculated and the change of systolic pulmonary artery pressure (SPAP) measured by echocardiography was also recorded.Results The postoperative SPAP was significantly lower than that before surgery ([36.56±8.47] mmHg vs [90.52±14.55] mmHg,t=14.14,P＜0.001).Before PTE,perfusion abnormalities were identified in 86 (86/96,89.58％) pulmonary lobes of 16 patients.In all of the 86 abnormal lobes,21 (21/86,24.42％) became normal,and the remaining 65 (65/86,75.58％) were improved after PTE.Perfusion defects were confirmed in 230 (230/304,75.66％) pulmonary segments of 16 patients before surgery.In all of the 230 abnormal segments,73 (73/230,31.74％) became normal,74 (74/230,32.17％) were improved and 83 (83/230,36.09％) remained unchanged after PTE.The mean PPDs％ decreased from (56.79±14.54)％ pre PTE to (28.20±15.24)％ at 6 12 months after PTE.The PPDs％ was positively correlated with homochronous SPAP (r=0.68,P＜0.001).Conclusion PTE can significantly reduce SPAP and improve the pulmonary perfusion in CTEPH patients.Pulmonary perfusion imaging can evaluate the curative effect of PTE.

Objective To explore the imaging characteristics and the complementarity of contrast?enhanced cardiac magnetic resonance CMR and nuclear myocardial perfusion/metabolic imaging in the evaluation of myocardial viability in patients with ischemic cardiomyopathy. Methods A total of 111 patients with diagnosed coronary artery disease and left ventricular dysfunction were retrospectively enrolled in this study. All patients underwent CMR and nuclear myocardial imaging within 1 month. Cine CMR was employed to evaluate cardiac function and wall motion. Contrast?enhanced CMR and myocardial perfusion/metabolic images were quantitatively assessed using a standard 17-segment and 5-score system. Dysfunctional segments were classified as viable or non?viable based on contrast?enhanced CMR and myocardial perfusion/metabolic imaging, respectively. No enhancement or sub?endocardial enhancement was defined as viable, while transmural enhancement was defined as non?viable. Severely matched perfusion/metabolism defects on nuclear imaging were assigned as non?viable while other patterns were considered as viable. Kappa index was calculated to evaluate the diagnostic concordance in assessing myocardial viability between contrast?enhanced CMR and myocardial perfusion/metabolic imaging. Results Among 1 887 segments in 111 patients, 80.3%(1 516/1 887) were dysfunctional. Of them, 63.3%(959/1 516) were viable and 36.7%(557/1 516) were non?viable on contrast?enhanced CMR, while 79.7%(1 208/1 516) were viable and 20.3%(308/1 516) were non?viable on nuclear myocardial imaging. The two modalities had a moderate concordance (Kappa=0.46,P<0.01). In segments with normal perfusion and metabolism, 73.9% (431/583) had various extent of enhancement but most of them(84.2%, 363/431) were subendocardial. On the other hand, 21.0%(117/557) segments with transmural enhancement had hibernating myocardium on nuclear imaging. Conclusions Contrast?enhanced CMR and nuclear myocardial imaging have a moderate concordance in the evaluation of myocardial viability in ischemic cardiomyopathy. Combination of the two modalities is expected to improve the diagnostic accuracy in assessing myocardial viability.

Objective To investigate the myocardial perfusion abnormalities in patients with isolated left ventricular noncompaction (ILVNC) and analyze the correlation between MPI and MRI.Methods Nineteen patients (14 males,5 females,age range:15-76 years) with ILVNC diagnosed by cardiac MRI were recruited.All patients underwent 99Tcm-MIBI MPI.Both MPI and cardiac MRI were analyzed using a 17-segment model.The thickness ratio of the non-compacted to compacted layers of myocardium (NC/C) was calculated,and segments with NC/C＞2.3 were considered as noncompaction.The incidences of delayed enhancement (DE) and myocardial perfusion abnormalities in non-compacted segments and compacted segments were calculated.x2 test was used for categorical data.The Pearson and Spearman correlation coefficient were used to assess the relationship between the numbers of myocardial segments with myocardial perfusion abnormalities/noncompaction/DE and lgLVEF.Results Of 19 patients,myocardial perfusion abnormality was found in 16 (84.2％) patients.The incidences of perfusion abnormality were 33.6％ (36/107) in non-compacted segments and 31.9％ (69/216) in compacted segments,respectively (x2=0.09,P＞0.05).There were 31 segments with DE.The incidences of DE were 5.6％ (6/107) in non-compacted segments and 11.6％ (25/216) in compacted segments,respectively (x2 =2.94,P＞0.05).The incidence of reduced perfusion was higher in segments with DE than those in segments without DE (54.8％ (17/31) vs 30.1％ (88/292) ; x2 =7.80,P＜0.01).The lgLVEF and the numbers of myocardial segments with noncompaction/DE/myocardial perfusion abnormalities were not correlated(r=-0.35,0.15,-0.34,all P＞0.05).Conclusion Most patients with ILVNC have myocardial perfusion abnormality,which can be observed both in non-compacted and compacted myocardium.Further research is required to elucidate the role of myocardial perfusion abnormality in ILVNC.