Abstract Purpose Balloon pulmonary angioplasty (BPA) has been proven to be an effective alternative treatment for inoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, the segmental lung perfusion (LP) improvement after BPA may be inapparent. Therefore, this study aimed to explore the characteristics of BPA-targeted vessels related to segmental perfusion improvement after BPA. Methods Twenty-seven patients with CTEPH who underwent ≥ 4 BPA sessions and had both pre- and post-BPA LP single-photon emission computed tomography (SPECT) were retrospectively analyzed. The baseline perfusion defect score (PDs), location, and angiographic characteristics of BPA-targeted vessels were collected to evaluate their correlations with the efficacy of BPA assessed by LP-SPECT. Results The percentage of overall PDs improvement correlated with the percentage of mean pulmonary artery pressure (mPAP) improvement after BPA (r values of 0.479, P = 0.012). Lesions in the upper lobe had the lowest perfusion improvement rate (upper lobe vs middle or lingual lobe, P < 0.001; upper lobe vs lower lobe, P < 0.001). Moreover, lesions with baseline PDs ≥ 0.5 had a lower perfusion improvement rate than those with PDs < 0.5 (all P < 0.05). Nevertheless, angiographic characteristics of target vessels had no association with the perfusion improvement rate. Based on these results, a 3-point scale was constructed for predicting segmental perfusion improvement after BPA. The perfusion improvement rates of vessels with scores of 0, 1, and 2 were 76.5%, 62.3%, and 8.3%, respectively (all P < 0.05). Conclusions This study demonstrates that LP-SPECT can effectively evaluate the efficacy of BPA in patients with CTEPH. Lesions located in the upper lobe with mild perfusion injury are unsuitable for BPA.

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.

Background: Delayed contrast-enhanced magnetic resonance imaging (DE-MRI) is a useful technique to identify arterial wall inflammation. The aim of this study was to explore the value of DE-MRI in the evaluation of pulmonary artery (PA) lesions in Takayasu’s arteritis (TAK) compared with 18F-fuorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Methods: Patients with TAK were recruited for this prospective, observational study. Imaging and clinical assessments were performed concurrently. Only thoracic arteries were evaluated, and they were divided into 18 segments per person. All arterial lesions were evaluated using both PET/CT and DE-MRI. Correlations between both methods were assessed in the PA and thoracic aorta. A receiver operating characteristic (ROC) curve was used to analyze the value of imaging features in detecting disease activity based on National Institutes of Health (NIH) criteria. Results: A total of 24 patients contributed 432 arterial segments. Using PET/CT, correlations between arterial wall DE, thickening, and edema in the PA were 84.52%, 67.92%, and 58.33%, respectively, with Cohen’s kappa =0.69, 0.30, and 0.13, respectively; for the thoracic aorta, the values were 86.38%, 80.00%, and 75.92%, respectively, with Cohen’s kappa =0.71, 0.52, and 0.372, respectively. There was a significant difference in the incidence of wall DE between the PA and thoracic aorta in patients with clinically active TAK (χ2=6.85, P=0.009). DE-MRI presented a higher area under the curve [area under the curve (AUC); 0.729, P=0.047] than wall thickening and edema in the detection of TAK activity. The wall DE combined with erythrocyte sedimentation rate (ESR) showed improved efficiency (AUC: 0.858, P=0.003). Conclusions: DE-MRI displays appreciable correlations with PET/CT findings and allows for the detection of PA inflammation in patients with TAK; it shows higher values in the thoracic aorta than in the PA. The combination of wall DE and ESR can improve the efficiency of assessing disease status.

BACKGROUND:Cardiac metabolism alterations may be involved in abnormalities of cancer patients' cardiovascular system. This study aimed to explore whether left ventricular myocardial glucose metabolism is altered and its related factors in newly diagnosed patients with lung adenocarcinoma (LAD) who underwent fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT).METHODS:From our 18F-FDG PET/CT imaging database, 171 patients with newly diagnosed LAD and 43 nononcologic subjects with matched age and sex were retrospectively analyzed. The included patients underwent conventional 18F-FDG PET/CT imaging with a >12-h fasting before 18F-FDG administration. The standardized uptake values (SUVs) of the left ventricular (LV) myocardium, arterial wall, epicardial adipose tissue (EAT), spleen, and bone marrow were separately measured. Laboratory parameters and echocardiographic results were collected as well. LAD patients were divided into 2 groups based on the 95th percentile of LV maximal SUV (SUVmax) obtained from the 43 nononcologic subjects. Univariate analysis and multiple logistic regression analysis were used to identify significant factors.RESULTS:Higher LV SUVmax was found (3.8 [2.4, 7.7] vs. 3.0 [2.0, 5.4], p = 0.052) in LAD than that in nononcologic patients, whereas no significant differences of 18F-FDG uptake were found in the arterial wall, EAT, spleen, or bone marrow between LAD patients and controls. The maximum diameter (Dmax) of the LAD lesion, SUVmax of spleen, and SUVmax of EAT were related to LV SUVmax in LAD.CONCLUSIONS:Myocardial glucose metabolism is increased in patients with newly diagnosed LAD. Dmax of LAD lesion, spleen activity, and EAT activity contribute to the increased LV activity in LAD.

目的 探讨初诊肺腺癌患者治疗前氟-18-脱氧葡萄糖(18F-fluorodeoxyglucose,18F-FDG)正电子发射型计算机断层扫描显像(positron emission tomography/computed tomography,PET/CT)的左心室心肌代谢是否发生改变及其影响因素.方法 分析182例新确诊肺腺癌的患者及与其年龄和性别匹配的45例非肿瘤患者(对照组)的18 F-FDG PET/CT显像.比较两组患者左心室心肌、动脉、心外膜脂肪组织(epicardial adipose tissue,EAT)、脾脏、骨髓的代谢.采用多因素Logistic回归分析肺腺癌患者左心室心肌代谢增高的影响因素.结果 与对照组相比,初诊肺腺癌患者治疗前左心室心肌代谢显著增高(P=0.05),动脉、EAT、脾脏及骨髓的代谢在两组间差异无统计学意义(P>0.05).Logistic回归分析显示,EAT代谢与肺腺癌患者左心室心肌代谢增高具有独立的正相关性(OR=6.8,95％CI=1.1～42.4,P=0.039).结论 肺腺癌患者抗肿瘤治疗前左心室心肌代谢较非肿瘤患者显著增高,EAT代谢是肺腺癌患者左心室心肌代谢增高的独立影响因素.

AIMS This prospective study explored relevant factors and clinical significance of atrial 18F-fluorodeoxyglucose (FDG) uptake in patients with atrial fibrillation (AF). METHODS AND RESULTS One hundred AF patients underwent baseline FDG imaging prior to radiofrequency catheter ablation (RFCA). Of those, 30 subjects underwent additional FDG imaging at 3 months post-RFCA. Voltage mapping of the left atrium was analysed as a voltage score. Patients who received RFCA were followed for 26 months (17-31 months) to assess recurrence. At baseline FDG imaging, 74% of patients with persistent AF (PsAF) and 24% of patients with paroxysmal AF showed increased atrial FDG uptake. The prevalence was higher in the right atrium (49%) than in the left atrium (15%, P < 0.001) or left atrial appendage (21%, P < 0.001). Multivariate analysis demonstrated that PsAF and elevated B-type natriuretic peptide (BNP) were related to enhanced right atrial (RA) activity, and increased epicardial adipose tissue (EAT) activity was predictive of left atrial (LA) activity. LA activity was inversely associated with voltage score, while increased FDG uptake in the right atrium was predictive of successful AF termination by RFCA. Atrial FDG activities decreased significantly post-RFCA, but none of the FDG parameters were predictive of AF recurrence. CONCLUSIONS Enhanced RA activity was associated with elevated BNP level, whereas LA activity was related to the increased activity of EAT and inversely correlated with LA fibrosis. Increased RA activity was predictive of successful AF termination by RFCA in PsAF patients.

Aims To explore the value of F-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the detection of active pulmonary artery (PA) lesions in patients with Takayasu's arteritis (TA). Methods and results Consecutive TA patients with PA involvement were prospectively recruited. Clinical activity was assessed according to the National Institutes of Health (NIH) criteria. CT pulmonary angiography (CTPA) or magnetic resonance pulmonary angiography was performed for evaluation of vascular structural characteristics, and mural thickening was considered as radiologically active. A vascular segment with F-18-FDG uptake >= liver was considered as PET-active. A total of 38 F-18-FDG PET/CT scans were performed in 29 patients. In terms of disease activity, the sensitivity of F-18-FDG PET/CT did not significantly differ from radiological imaging (71.4% vs. 92.9%, P = 0.250), but F-18-FDG PET/CT had higher specificity (91.7% vs. 37.5%, P = 0.001) and accuracy (84.2% vs. 57.9%, P = 0.022). Although the majority of PET-active PA segments (54.9%) showed mural thickening, 14 PA segments with normal structure were also PET-active. F-18-FDG activity did not significantly differ between the PA and aorta in clinically active patients. In addition, F-18-FDG activity of the PA was positively correlated with inflammatory markers. Changes in F-18-FDG activity in PA during follow-up reflected therapeutic effects. Conclusion F-18-FDG PET/CT can effectively evaluate PA activity in TA patients, and its diagnostic performance is superior to radiological imaging. The F-18-FDG activity of PA shows a good correlation with clinical disease status and inflammatory markers and can be used to monitor therapeutic effects.

Objective: To investigate the incidence, location and etiology of abnormal cardiac uptake in patients underwent oncologic 18F-fluorodeoxyglucose positron emission tomography/computed tomography(PET/CT) imaging. Methods: The 18F-FDG PET/CT images of 2000 consecutive patients with suspected or diagnosed malignancy in Beijing Chaoyang Hospital from January 2014 to September 2016 were retrospectively analyzed. Fasting time was more than 12 hours before imaging, and fasting blood glucose level before 18F-FDG injection was less than 6.7 mmol/L. Focal uptake in the non-basal and non-papillary regions of the left ventricle, uptake in the right ventricle exceeding uptake in the left ventricle, and uptake in the atrium higher than that of the blood pool (when uptake of left ventricle was zero or low) were defined as abnormal, and all abnormal uptake was visually determined by experienced nuclear medicine physicians. General clinical data and the results of cardiac examination were collected to explore the incidence, location and etiology of cardiac diseases. Results: There were 138 patients with history of diabetes (6.90%), 228 patients with history of cardiovascular disease (11.40%) out of the 2 000 patients ((60.5±13.2) years, 1 117 male (55.85%)). The number and proportion of patients with malignancy, benign lesions, diseases of unknown etiology were 939 (46.95%), 484 (24.20%), 557 (28.85%), respectively. Abnormal cardiac uptake was detected in 145 patients (7.3%). The proportion of abnormal uptake in left ventricle, right ventricle and atrium was 52.4% (76 cases), 12.4% (18 cases), 35.2% (51 cases), respectively. Of the 76 individuals who had abnormal uptake in left ventricle, 25 cases (32.9%) were caused by coronary artery disease, and other causes included hypertrophic cardiomyopathy and myocardial damage caused by chemotherapy drugs, etc. Of the 18 cases who had abnormal uptake in right ventricle, 14 cases (14/18) were caused by pulmonary hypertension. In addition, 20 out of the 51 cases (39.3%) with abnormal uptake in atrium suffered from atrial fibrillation. Seventy-one patients with abnormal cardiac uptake (49.0%) had no clear manifestation and evidence of heart disease before imaging. Conclusions: The abnormal 18F-FDG uptake on oncologic PET/CT is not rare. The most common site of abnormal uptake is left ventricle, coronary artery disease, pulmonary hypertension and atrial fibrillation are common causes of abnormal 18F-FDG uptake.

To determine the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in differentiating malignancy of pulmonary artery (PA) from pulmonary thromboembolism (PTE) based on a larger number of cases by pooling our cases and those from the literature. Consecutive patients with a PA lesion who had undergone 18F-FDG PET/CT in our hospital were retrospectively reviewed. Moreover, PubMed, Embase, and Medline were searched for literature reporting individual maximum standardised uptake value (SUVmax) of the malignant PA lesion and/or PTE. 18F-FDG activity was compared between PA malignancy and PTE by pooling the data from literature and our patients. Receiver operating characteristic curve analysis was performed to determine the ability of SUVmax to differentiate PA malignancy from PTE. From our database, we identified 11 patients with pulmonary artery sarcoma (PAS), and nine cases of PTE. Fifty patients with a malignant PA lesion (40 cases of PAS and 10 cases of tumor embolism) and 22 subjects with PTE were extracted from the literature. In our cases, the SUVmax of PAS (11.1 ± 4.9, range: 5.5–19.9) was significantly higher than that of PTE (1.9 ± 0.6, range: 1.1–3.2; P < 0.001). There was no significant difference in the SUVmax between the literature data and our cases in malignant lesions or in PTE. Based on the pooled analysis of the literature data and our cases (61 cases of malignant lesions and 31 cases of PTE), the area under the curve for SUVmax to differentiate PA malignancy from PTE was 0.996 (95% CI: 0.989–1.000). At a cutoff value of 3.3, the sensitivity, specificity, and accuracy were 98.4%, 96.8%, and 97.8%, respectively. The 18F-FDG uptake value is an accurate index for determining PA malignancy.

BACKGROUND:This retrospective study was designed to explore the factors relevant to increased atrial 18F-fluorodeoxyglucose (FDG) uptake in patients with atrial fibrillation (AF) who had undergone routine whole-body positron emission tomography/computed tomography (PET/CT) imaging.METHODS AND RESULTS:Forty-eight consecutive AF patients (32 persistent, 16 paroxysmal) were identified from our routine FDG PET/CT database. Twenty-two control subjects were selected to establish the normal range of FDG uptake (maximum standardized uptake value, SUVmax) in target tissues. A target-to-background ratio (TBR) was calculated to determine abnormal uptake in the atrium and atrial appendage (AA). Univariate comparisons and multivariate regression analyses were conducted to explore the factors associated with the increased FDG accumulation in the atrium and AA. Seventeen AF patients, all with persistent AF, had increased atrial FDG uptake. Most of them (14, or 82.4%) had increased uptake in the right atrium. Eleven AF patients, 9 with persistent AF, had increased uptake in the AA, and bilateral AAs were equally involved. Multivariate logistic regression analyses identified that female gender, persistent AF, and activity in epicardial adipose tissue (EAT) were independent factors predicting the increased activity of the atrium; also, SUVmax of the left ventricle was found for the AA. In addition, multivariate linear regression analyses showed that EAT activity was the only independent variable linearly correlated with the activity of the atrium and AA.CONCLUSIONS:Atrial uptake was present in persistent AF and localized mainly in the right atrium, whereas bilateral AAs could be equally involved. Multiple factors contributed to the increased activity in atrium; in particular, the EAT activity was independently correlated with the activity of the atrium and AA.