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.

Objective To investigate the value of Cedars-Sinai quantitative gated SPECT (QGS) phase analysis for left ventricular synchrony assessment in healthy subjects.Methods Seventy-four healthy subjects (41 males,33 females,average age:(60±13) years) underwent both rest and exercise 99Tcm-MIBI G-MPI.QGS software was used to analyze the reconstructed rest gated SPECT images automatically,and then the parameters of left ventricular synchrony including phase bandwidth (BW) and phase standard deviation (SD) were obtained.The influences of gender and age (age＜60 years,n =36; age ≥ 60 years,n =38) on left ventricular systolic synchronicity were analyzed.The phase angle for original segmental contraction was measured to determine the onset of the ventricular contraction using 17-segment model.Forty healthy subjects were selected by simple random sampling method to evaluate the intra-observer and interobserver repeatability of QGS phase analysis software.Two-sample t test and linear correlation analysis were used to analyze the data.Results The BW and SD of left ventricular in healthy subjects were (37.22 ±11.71)°,(11.84±5.39)° respectively.Comparisons between male and female for BW and SD yielded no statistical significance (BW:(36.00±9.70)°,(38.73±13.84)°; SD:(11.88±5.56)°,(11.79±5.26)°; t=0.96 and-0.07,both P＞0.05) ; whereas the older subjects (age≥60 years) had larger BW than the others (age＜60 years ; (39.95± 12.65) °,(34.33± 10.00) ° ; t =-2.11,P＜0.05) and no statistical significance was shown for SD between the two age groups ((11.18±4.31) °,(12.54±6.33) ° ; t =1.08,P＞0.05).Of the 74 subjects,the mechanical activation started from the ventricular base to apex in 54 subjects (73％),and from apex to base in only 20 subjects (27％).High repeatability of phase analysis was observed for both intra-observer and inter-observer (r=0.867-0.906,all P＜0.001).Conclusions Good left ventricular segmental synchrony is shown in healthy subjects.No gender difference exists for ventricular synchrony assessment.Age (＜60 years) is important for better synchrony.Cedars-Sinai QGS cardiac phase analysis software is valuable in quantitative assessment of left ventricular synchrony with high repeatability.

Objective To evaluate the relationship of myocardial MR contrast delay-enhancement and nuclear perfusion-metabolism pattern in patients with idiopathic dilated cardiomyopathy (IDCM).Methods Forty-two consecutive patients (29 men and 13 women,age:(53 ±12) years) diagnosed clinically with IDCM were enrolled.All patients underwent 99Tcm-MIBI SPECT,18F-FDG PET imaging and MR contrast delay-enhancement imaging within 3-7 d.The myocardial perfusion-metabolism segment analysis was performed using a 17-segment model.Segmental 99Tcm-MIBI and 18F-FDG uptakes were scored visually using a 4-grade scoring system (0 =normal uptake,1 =mildly reduced uptake,2 =moderately reduced uptake,3 =severely reduced uptake).Patterns of perfusiorn/metabolism were classified as normal,mismatch,mild-to-moderate match and severe match.Myocardial MR contrast delay-enhancement was classified into 3 categories (non,mid-wall and transmural delay-enhancement).x2 test was used to analyze the differences of perfusion/metabolism patterns among non,mid-wall and transmural delay-enhancement groups and the myocardial MR contrast delay-enhancement incidence among four perfusion/metabolism groups.Resuits Among the 42 patients,myocardial delay-enhancement was present in 18 patients,of which 94.4％ (17/18) showed abnormal myocardial perfusion/metabolism patterns and only 33.3 ％ (8/24) patients without abnormal myocardial delay-enhancement had abnormal myocardial perfusion/metabolism patterns (x2 =15.944,P ＜ 0.001).Perfusion/metabolism patterns varied in three different categories of non,mid-wall and transmural delay-enhancement (x2 =14.276,P ＜ 0.001).The normal peffusion/metabolism pattern proportions in the non,mid-wall and transmural delay-enhancement groups were 86.2％ (526/610),71.0％ (44/62) and 28.6％ (12/42),respectively.The incidence of transmural delay-enhancement (44.4％ (12/27)) was significantly higher in segments with severe match than that in the other 3 groups (normal:2.1％ (12/582) ; mismatch:18.1％ (15/83) ; mild-to-moderate match:13.6％ (3/22) ; x2 =112.530,P ＜ 0.001).Conclusions MR contrast delay-enhancement is much more sensitive in detecting moderate fibrosis,while nuclear perfusion-metabolism imaging can detect more impaired but viable myocardium.Combining the two imaging modalities is useful for providing comprehensive evaluations of myocardial injury in patients with IDCM.

Objective To explore the value of stress dual-phase (early and delayed phases)18 FFDG myocardial PET/CT in detection of myocardial ischemia.Methods Ten swine were prepared as ischemic models and underwent 3 imaging procedures:pre-model stress (8 swine),post-model rest (8 swine)and post-model stress dual-phase imaging (10 swine).To perform stress dual-phase imaging,the tested subjects were fasted for more than 12 h and underwent early-phase PET imaging at 50 min after the intravenous injection of 18F-FDG (5 MBq/kg) for 10 mins,and followed by a dobutamine stress test,and then delayed-phase PET imaging at 50 min after the stress test for another 10 mins.The post-model rest dual-phase imaging was performed in almost the same way except that there was no dobutamine-loading.18F-FDG uptake image was qualitatively analyzed and classified into 4 levels:1 =no uptake,2 =diffuse uptake,3 =focal uptake,4=focal on diffuse uptake.Level 1 or 2 was considered as normal.If the focal uptake (level 3 or 4)was found on anterior wall or septum,ischemia was diagnosed.x2 test was used to determine the difference of the rate of ischemic myocardium between the two phases.18F-FDG uptake ratio of the anterior wall to posterior wall (K) of the left ventricle was calculated (K1 for early phase and K2 for delayed phase).Wilcoxon rank sum test was applied to determine the difference between K1 and K2.Results CAG showed LAD stenosis ＞70％ in all swine.In pre-model stress dual-phase imaging,no ischemia was detected at two phases (8/8 for level 1 or 2,0 for level 3 or 4).There was no significant difference between K1 and K2(1.08±0.10,1.11 ±0.10; Z =-1.48,P＞0.05).In post-model rest dual-phase imaging,the rate of ischemic myocardium was not significantly different between early and delayed phases (1/8,3/8 ; x2 =0.50,P＞0.05).There was no significant difference between K1 and K2(1.47±0.28,1.28±0.40; Z=-2.02,P＞0.05).In post-model stress dual-phase imaging,the rate of ischemic myocardium between the two phases was statistically different (4/10,10/10;x2=4.17,P＜0.05),and the difference between K1 and K2 was also significant (1.55±0.32,1.86±0.39; Z=-2.49,P＜0.05).Conclusion Stress dual-phase 18F-FDG myocardial PET/CT might be useful for the diagnosis of ischemia.

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 analyze the severity of coronary artery lesions and the prognosis in patients with low levels of free triiodothyronine (fT3)undergoing coronary angiography (CAG). Methods From August 2011 to August 2012, 600 consecutive suspected patients with coronary heart disease (CHD) who undergone CAG were selected. The patients were divided into two groups based on thyroid function prior to CAG:euthyroidism group (450 patients) and low T3 group (150 patients). All the patients underwent elective coronary angiography, then the severity of coronary artery lesions was assessed by the Gensini scores , and the patients were followed up for cardiovascular events. Results The incidence rate of CHD in low T3 group was significantly higher than that in euthyroidism group (P=0.01). Multiple variables logistic regression analysis showed that fT3 was a protective factor for CHD (OR = 0.351,P < 0.001); The severity of coronary artery lesions was greater in low T3 group than in euthyroidism group (P < 0.001). The mean duration of follow-up was (15.4 ± 3.6) months; the incidence of the composite end-point (death, non-fatal myocardial infarction and target vessel revascularization ) was significantly higher in low T3 group than in euthyroidism group (P=0.023). Conclusions Patients with a decreased T3 level has a higher incidence rate of CHD , an increase in the severity of coronary artery lesions , and a poorer prognosis.

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 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 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 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.