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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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PURPOSE: To identify loci concerned with radiosensitivity in a mouse model using single nucleotide polymorphism (SNP) markers. MATERIALS AND METHODS: We subjected 276 second filial generation (F2) mice descended from two inbred mouse strains, radiation-induced apoptosis sensitive C57BL/6JNrs (B6) and radiation-induced apoptosis resistant C3H/HeNrs (C3H), to 2.5 Gy whole-body irradiation. We quantified jejunal crypt apoptosis, performed a genome-wide survey, and identified quantitative trait loci (QTL) associated with radiation sensitivity. We expressed apoptosis levels as an apoptotic score (AS), which was equal to the number of apoptotic bodies divided by the number of crypts. We genotyped the mice for 109 SNP markers. RESULTS: AS values were 97.7+/-32.9 in B6 mice and 49.0+/-24.9 in C3H mice (p < 0.01). Genome-wide analysis revealed 8 markers (2 on chromosome 9, 4 on 15, 1 on 17, and 1 on 18) affecting radiation-induced jejunal apoptosis with log odds (LOD) scores ranging from 2.11+/-3.91. We found a significant locus on chromosome 15, which was previously reported by Weil and colleagues. CONCLUSION: These findings support the view that the radiosensitivity of clinically normal tissue depends on variations in several genes.
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Apoptose/effets des radiations , Polymorphisme de nucléotide simple , Irradiation corporelle totale , Animaux , Apoptose/génétique , Femelle , Génotype , Modes de transmission héréditaire/effets des radiations , Jéjunum , Lod score , Mâle , Souris , Souris de lignée C3H , Locus de caractère quantitatif , Radiotolérance/génétique , Radiotolérance/effets des radiationsRÉSUMÉ
The multifraction regimens commonly used in conventional clinical radiotherapy are largely based on radiobiological experiments. However, no experimental reports on skin reactions focusing on inter-strain differences have displayed clinical relevance to the fractionated dose schedule. In this study, mice of inbred strains A/J, C57BL/6J, and C3H/HeMs were used to reveal inter-strain difference after multifractionated irradiation. Irradiation was performed daily at graded doses of 30-60 Gy total doses, with 10 fractions of 3-6 Gy. Acute skin reactions following irradiation were scored for 50 days after irradiation. Dividing a dose into a number of fractions obviously spared skin damage in the three strains of mice. No mouse exhibited a skin damage score more than 1.5, while single dose irradiation resulted in skin damage scores up to 3. The three different strains, however, showed varying susceptibility to fractionated irradiation within the range under 1.5. C3H/HeMs did not display any skin reaction after irradiation with 40 Gy total dose, while C57BL/6J and A/J demonstrated various skin reactions. Different latent periods of damage were also observed among the strains after irradiation at each dose. Our data suggest that genetic factors cause obvious variations in severity of damage and latent period after fractionated irradiation.