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1.
Small ; : e2308171, 2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38095505

ABSTRACT

Isoporous block copolymer membranes are viewed as the next-generation separation membranes for their unique structures and urgent application in precise separation. However, an obvious weakness for such membranes is their poor solvent-resistance which limits their applications to aqueous solution, and isoporous membranes with superior solvent-resistance and tunable pore size have been rarely prepared before. Herein, self-supporting isoporous membranes with excellent solvent resistance are prepared by the facile yet robust hyper-crosslinking approach which is able to create a rigid network in whole membranes. The hyper-crosslinking is found to be a novel and non-destructive approach that does not change pore size and isoporous structure during the reaction, and the resulting hyper-crosslinked isoporous membranes display superior structural and separation stability to a broad range of solvents with varied polarities for months to years. More importantly, hyper-crosslinking has proved to be a universal strategy that is applicable to isoporous membranes with varied pore size and pore chemistry, offering an important opportunity to prepare solvent-resistant isoporous membranes with customizable pore size and pore functionality that are important to realize their accurate separations in organic solvents. This concept is demonstrated finally by precise and on-demand separation of nanoparticles with the prepared membranes.

2.
Comput Intell Neurosci ; 2022: 8148586, 2022.
Article in English | MEDLINE | ID: mdl-36275964

ABSTRACT

Butterfly optimization algorithm (BOA) is a new swarm intelligence algorithm mimicking the behaviors of butterflies. However, there is still much room for improvement. In order to enhance the convergence speed and accuracy of the BOA, we present an improved algorithm SCLBOA based on SIBOA, which incorporates a logical mapping and a Lévy flight mechanism. The logical chaotic map is used for population initialization, and then the Lévy flight mechanism is integrated into the SCLBOA algorithm. To evaluate the performance of the SCLBOA, we conducted many experiments on standard test functions. The simulation results suggest that the SCLBOA is capable of high-precision optimization, fast convergence, and effective global optimization, all of which show that our method outperforms other methods in solving mathematical optimization problems. Finally, the BP network is optimized according to the SCLBOA (SCLBOA-BP) to further verify the availability of the algorithm. Simulation experiments prove the practicability of this method by building a Boston housing price prediction model for training.


Subject(s)
Butterflies , Animals , Algorithms , Computer Simulation , Problem Solving
3.
Sensors (Basel) ; 22(7)2022 Mar 28.
Article in English | MEDLINE | ID: mdl-35408212

ABSTRACT

Industrial control systems (ICS) are applied in many fields. Due to the development of cloud computing, artificial intelligence, and big data analysis inducing more cyberattacks, ICS always suffers from the risks. If the risks occur during system operations, corporate capital is endangered. It is crucial to assess the security of ICS dynamically. This paper proposes a dynamic assessment framework for industrial control system security (DAF-ICSS) based on machine learning and takes an industrial robot system as an example. The framework conducts security assessment from qualitative and quantitative perspectives, combining three assessment phases: static identification, dynamic monitoring, and security assessment. During the evaluation, we propose a weighted Hidden Markov Model (W-HMM) to dynamically establish the system's security model with the algorithm of Baum-Welch. To verify the effectiveness of DAF-ICSS, we have compared it with two assessment methods to assess industrial robot security. The comparison result shows that the proposed DAF-ICSS can provide a more accurate assessment. The assessment reflects the system's security state in a timely and intuitive manner. In addition, it can be used to analyze the security impact caused by the unknown types of ICS attacks since it infers the security state based on the explicit state of the system.


Subject(s)
Artificial Intelligence , Cloud Computing , Algorithms , Big Data , Machine Learning
4.
J Nucl Cardiol ; 29(2): 652-660, 2022 04.
Article in English | MEDLINE | ID: mdl-32909240

ABSTRACT

BACKGROUND: The prognostic value of left ventricular (LV) mechanical dyssynchrony (MD) in patients with LV aneurysm (LVA) is unclear. This study aimed to investigate the long-term prognostic value of LVMD in LVA patients. METHODS: 92 consecutive patients who underwent 99mTc-sestamibi-gated SPECT myocardial perfusion imaging (GSPECT) were retrospectively analyzed and followed-up for a median of 63 months (range, 1-73 months). LV function and histogram bandwidth (BW) were analyzed by QGS software. LVMD was defined by ROC analysis. Cardiac death was defined as the primary endpoint, and the composite of cardiac deaths and severe or acute heart failure (MACE) as the secondary endpoint. RESULTS: The annual cardiac mortality rate of LVA patients with LVMD and treated by surgical therapy was significantly lower than those treated by medical therapy (2.40% vs. 6.40%, P < .05) but not annual MACE rate (6.61% vs. 10.06%, P > .05). In patients without LVMD, no significant difference in survival and MACE-free survival between medical and surgical treatment. In addition, the occurrence of LVMD is related to the worsen cardiac outcome in terms of MACE and cardiac death, independent of the treatment methods. BW was an independent predictor for MACE (HR 1.010, P < .01) and LVEF (HR .928, P < .05) was an independent predictor for cardiac death in all LVA patients. CONCLUSIONS: LVA patients with LVMD might be associated with high risk for cardiac death and surgical treatment might improve cardiac survival compared to medical therapy in these patients.


Subject(s)
Heart Aneurysm , Myocardial Perfusion Imaging , Ventricular Dysfunction, Left , Death , Heart Aneurysm/complications , Heart Aneurysm/diagnostic imaging , Heart Aneurysm/surgery , Humans , Myocardial Perfusion Imaging/methods , Prognosis , Retrospective Studies
5.
Clin Nucl Med ; 46(5): 369-374, 2021 May 01.
Article in English | MEDLINE | ID: mdl-33661201

ABSTRACT

PURPOSE: 18F-FDG PET myocardial metabolic imaging is used to estimate myocardial viability. However, poor image quality can affect the accurate quantification of viable myocardium. We assessed the feasibility of a rescue protocol that reinjected low-dose 18F-FDG with simultaneous 1 to 2 U of insulin injection and oral administration of 10 g of glucose to improve the image quality of 18F-FDG PET myocardial metabolic imaging. PATIENTS AND METHODS: Fifty-one consecutive patients with poor quality to uninterpretable 18F-FDG PET/CT myocardial metabolic images received the rescue protocol immediately after the initial image acquisition. The postrescue image acquisition was performed 1 hour later. The rescue image quality was compared with the initial image. The qualitative visual estimation of the images was graded as follows: grade 0, homogeneous, minimal uptake; grade 1, predominantly minimal or mild uptake; grade 2, moderate uptake; and grade 3, good uptake. The myocardium-to-blood pool activity ratio (M/B) was measured to assess the image quality quantitatively. RESULTS: The grades of 0 to 3 were observed in 24 (47%), 27 (53%), 0 (0%), and 0 (0%) patients, respectively, for the initial imaging, and in 0 (0%), 3 (5.9%), 4 (7.8%), and 44 (86.3%) patients for the rescue imaging (P < 0.001). The rescue M/B was significantly higher than the initial M/B (3.4 ± 1.4 vs 1.6 ± 0.6, respectively; P < 0.001). CONCLUSIONS: The rescue protocol successfully and rapidly improved the quality of myocardial 18F-FDG metabolic imaging.


Subject(s)
Fluorodeoxyglucose F18 , Heart/diagnostic imaging , Myocardium/metabolism , Positron Emission Tomography Computed Tomography/methods , Female , Fluorodeoxyglucose F18/metabolism , Humans , Male , Middle Aged , Quality Control
6.
J Nucl Cardiol ; 28(6): 2812-2822, 2021 12.
Article in English | MEDLINE | ID: mdl-32383080

ABSTRACT

OBJECTIVE: To assess the benefits of coronary collateral circulation on myocardial perfusion, viability and function in patients with total occlusion of a single coronary artery using the 99mTc-sestamibi SPECT and 18F-fluorodeoxyglucose PET. METHODS: 164 Consecutive patients were included who underwent coronary angiography results exhibited total occlusion of a single coronary artery and received 99mTc-MIBI SPECT and 18F-FDG PET within 90 days of angiography. Myocardial perfusion and viability in patients with collateral circulation and those without it were compared. Long-term follow-up was performed through a review of patient clinical records. RESULTS: Collateral circulation was present in 56 patients (34%) and absent in 108 patients (66%). The total perfusion defect size in patients with collateral circulation decreased when compared to those without (30% ± 13% to 35% ± 14%, P < .05). The myocardial viability was 22% ± 12% in patients with collateral circulation, and 12% ± 9% in those without (P < .001). The left ventricular ejection fraction was higher, and the end-diastolic and end-systolic left ventricular volumes were lower in patients with collateral circulation (39% ± 11%, 138 ± 66, 89 ± 57) compared to patients without collateral circulation (31% ± 9%, 177 ± 55, 125 ± 48, all P < .001, respectively). Multi-factor logistic regression identified that concerning the variables of sex, age, viable myocardium, collateral circulation, treatment type and others, only treatment type was significantly associated with therapeutic effects (OR 3.872, 95% CI 1.915-7.830, P < .001). CONCLUSION: Collateral circulation can preserve resting myocardial blood perfusion and myocardial viability, and help maintain the function of the left ventricular myocardium. The appropriate treatment strategy will have a substantial impact on the therapeutic outcome.


Subject(s)
Collateral Circulation , Coronary Circulation , Coronary Occlusion/physiopathology , Fluorodeoxyglucose F18 , Radiopharmaceuticals , Technetium Tc 99m Sestamibi , Tomography, Emission-Computed, Single-Photon/methods , Aged , Female , Heart/physiopathology , Humans , Male , Middle Aged , Retrospective Studies , Tissue Survival
7.
J Nucl Cardiol ; 26(3): 944-953, 2019 06.
Article in English | MEDLINE | ID: mdl-29214612

ABSTRACT

OBJECTIVES: To compare the outcomes among patients treated by complete coronary revascularization (CCR) or incomplete coronary revascularization (ICR) and no coronary revascularization (NCR) by myocardial perfusion imaging (MPI), as well as to evaluate the impact of severity of ischemia on patients with coronary artery disease (CAD) by different therapy strategies. BACKGROUND: Using myocardial ischemia severity determined by MPI guiding treatment strategies for CAD patients still lacks strong clinical evidences. METHODS: Consecutive patients (N = 286) underwent clinical stress-rest SPECT MPI and were retrospectively followed-up. For assessment of outcome of treatment, all patients were classified into three groups (CCR, ICR, and NCR), and further divided into two subgroups as mild ischemia (< 10% ischemic myocardium) and moderate-severe ischemia (≥ 10% ischemic myocardium). All-cause death was defined as the primary endpoint, and the composite of deaths, nonfatal myocardial infarction, and repeat revascularization (MACE) as the secondary endpoint. RESULTS: Two-hundred eighty-six patients were followed-up for 46 ± 21 months. Thirty deaths and 65 MACEs were recorded. Patients treated by revascularization had significantly lower MACE (P < .001) but not mortality (P = .158) than patients treated by NCR. Outcomes of CCR related to mortality rate were greater than ICR and NCR (death: P = .019, MACE: P < .001). In patients with moderate-severe ischemia, CCR showed improved outcomes than ICR and NCR (death: P = .034; and MACE: P < .001). In patients with mild ischemia, the outcomes of CCR, ICR, and NCR had no significant difference (P > .05). Multivariate regression Cox analysis revealed that summed difference score [death: HR 1.09 (1.03, 1.15), P = .004] was an independent risk factor and CCR was an independent negative predictor [death: HR 0.31 (0.12, 0.81), P = .017; MACE: HR 0.30 (0.16, 0.57), P < .001]. CONCLUSIONS: Outcomes of patients treated by CCR were most likely more promising in comparison with treatment of ICR and NCR, especially when patients had over 10% ischemic myocardium.


Subject(s)
Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/therapy , Myocardial Infarction/epidemiology , Myocardial Perfusion Imaging , Myocardial Revascularization , Tomography, Emission-Computed, Single-Photon , Aged , Coronary Artery Disease/complications , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies , Survival Rate , Treatment Outcome
8.
J Nucl Cardiol ; 23(3): 546-55, 2016 06.
Article in English | MEDLINE | ID: mdl-26037599

ABSTRACT

BACKGROUND: Coronary revascularization in patients with coronary artery disease may be guided by coronary angiography (CA) or alternatively by ischemia on stress myocardial perfusion imaging (MPI). Which strategy leads to optimal cardiac outcomes is uncertain. METHODS: We performed a retrospective analysis of 170 patients with MPI ischemia and percutaneous coronary intervention. The primary endpoint was all-cause mortality at a mean follow-up of 47 ± 21 months; the secondary end point was the composite of deaths, nonfatal myocardial infarction, and repeat coronary revascularization (MACE). The coronary revascularization was defined as complete (CCR) or incomplete (ICR) as judged by CA criteria and by MPI ischemia matched with CA criteria. RESULTS: Nighty-two patients (54%) had ICR by CA criteria (ICR-CA) and 84 (49%) had ICR by MPI criteria (ICR-MPI). Mortality and MACE were lower in patients with CCR-MPI than with ICR-MPI (P = .048, and P = .025). Survival of patients with CCR-CA and ICR-CA was not different (P = .081). Patients with both ICR-MPI and ICR-CA had the worst survival, whereas patients with CCR-MPI and CCR-CA had the best survival (P = .047). By multivariate analysis, ICR-MPI + ICR-CA was an independent predictor of death (P = .025). CONCLUSION: Patients with ICR by MPI were at higher risk than those with CCR. Patients with both ICR by MPI and CA were at the highest risk, while patients with CCR by both MPI and CA had the best long-term event-free survival.


Subject(s)
Coronary Angiography/methods , Coronary Artery Disease/mortality , Coronary Artery Disease/surgery , Myocardial Perfusion Imaging/methods , Myocardial Revascularization/mortality , Myocardial Revascularization/statistics & numerical data , China/epidemiology , Coronary Angiography/statistics & numerical data , Coronary Artery Disease/diagnostic imaging , Female , Humans , Longitudinal Studies , Male , Middle Aged , Myocardial Perfusion Imaging/statistics & numerical data , Prevalence , Retrospective Studies , Risk Factors , Survival Rate , Treatment Failure
10.
J Nucl Cardiol ; 21(6): 1230-44, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25189143

ABSTRACT

BACKGROUND: To compare the accuracy of end-diastolic and end-systolic volumes (EDV, ESV) and LV ejection fraction (LVEF) measured by both GSPECT and GPET, using cardiac magnetic resonance imaging (CMR) as a reference. Furthermore, the impacts of severe perfusion defects, akinetic/dyskinetic segments, and residual viable myocardium on the accuracy of LV functional parameters were investigated. METHODS: Ninety-six consecutive patients with LV aneurysm and LV dysfunction (LVEF 32 ± 9%) diagnosed by CMR were studied with GSPECT and GPET. EDV, ESV, and LVEF were calculated using QGS software. RESULTS: Correlations of volumes were excellent (r 0.81-0.86) and correlation of LVEF was moderate (r 0.65-0.76) between GSPECT vs CMR and between GPET vs CMR. Compared with CMR, ESV was overestimated by GSPECT (P < .01) and underestimated by GPET (P < .0001); EDV was underestimated by GPET (P < .001); LVEF was underestimated by GSPECT but overestimated by GPET (both P < .001). Multivariate regression analysis revealed that the number of segments with severe perfusion defects (P < .001) was the only independent factor which was correlated to the EDV difference between GSPECT and CMR, the number of akinetic/dyskinetic segments with absent wall thickening (WT) was the only independent factor which was significantly correlated to the differences of ESV and LVEF measurements between GSPECT vs CMR and between GPET vs CMR (P < .0001), respectively. Neither the mismatch score nor the segments with viable myocardium were correlated to the differences of LV volumes and LVEF measurements between different imaging modalities. CONCLUSIONS: In LV aneurysm patients, LV volumes and LVEF measured by both GSPECT and GPET imaging correlated well with those determined by CMR, but should not be interchangeable in individual patients. The accuracy of LVEF measured by GSPECT and GPET was affected by the akinetic/dyskinetic segments with absent WT.


Subject(s)
Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography/methods , Fluorodeoxyglucose F18 , Heart Aneurysm/diagnostic imaging , Positron-Emission Tomography/methods , Stroke Volume , Technetium Tc 99m Sestamibi , Coronary Artery Disease/complications , Coronary Artery Disease/diagnostic imaging , Female , Heart Aneurysm/etiology , Humans , Magnetic Resonance Imaging, Cine/methods , Magnetic Resonance Imaging, Cine/standards , Male , Middle Aged , Radiopharmaceuticals , Reproducibility of Results , Sensitivity and Specificity , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/etiology
11.
Cardiology ; 125(2): 104-9, 2013.
Article in English | MEDLINE | ID: mdl-23711817

ABSTRACT

OBJECTIVES: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging is useful in assessing left ventricular (LV) myocardial perfusion and function. This study evaluated the LV functional changes after adenosine vasodilator stress, using gated SPECT. METHODS: The study population consisted of 70 patients who underwent adenosine-mediated stress and rest SPECT. All patients underwent coronary angiography. Semi-quantitative assessment of perfusion was analyzed and produced the summed rest score (SRS), the summed stress score (SSS) and the summed difference score (SDS). The global LV function parameters [ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV)] and regional LV function [the summed motion score (SMS) and the summed thickening score (STS)] were quantified by gated SPECT. RESULTS: Patients were divided into 2 groups: group 1 comprised 16 patients with worsening of LVEF (LVEFrest-LVEFado ≥5%), and group 2 comprised the other 54 patients. Compared with group 2, patients in group 1 had a significantly higher SSS and SDS (9.1 ± 6.8 vs. 5.6 ± 4.5 and 6.6 ± 3.8 vs. 3.6 ± 4.0, respectively; p < 0.05) and the severity of coronary artery stenosis was more serious (p < 0.05). CONCLUSION: Worsening of LVEF after adenosine-induced vasodilator stress, as shown by (99m)Tc-MIBI gated SPECT, is a valuable nonperfusion marker of significant CAD.


Subject(s)
Adenosine , Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography , Coronary Artery Disease/physiopathology , Vasodilator Agents , Ventricular Function, Left , Adenosine/pharmacology , Aged , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Exercise Test , Female , Humans , Male , Middle Aged , Myocardial Ischemia/etiology , Stroke Volume , Vasodilator Agents/pharmacology
12.
Ann Nucl Med ; 27(4): 325-34, 2013 May.
Article in English | MEDLINE | ID: mdl-23371445

ABSTRACT

PURPOSE: To investigate the value of gated F-18 FDG PET/CT on left ventricular (LV) dyssynchrony assessment in comparison with gated Tc-99m sestamibi SPECT in patients with coronary artery disease (CAD). METHODS: The data of 100 consecutive CAD patients who underwent both gated myocardial Tc-99m sestamibi SPECT and F-18 FDG PET/CT imaging were analyzed. Phase standard deviation (SD) and histogram bandwidth (BW) were derived from phase analysis using Cedars software package. The correlation and agreement of SD and BW between Tc-99m sestamibi SPECT and F-18 FDG PET/CT were examined. Myocardial viability and the site of latest activation assessed by the two imaging methods were compared as well. RESULTS: A moderate correlation for SD (r = 0.58, p < 0.0001) and BW (r = 0.60, p < 0.0001) was found between gated SPECT and gated F-18 FDG PET/CT. Bland-Altman analysis revealed an overestimation of SD and BW (6.4° ± 14.3° and 22.0° ± 46.8°) by gated F-18 FDG PET/CT. Multivariate logistic regression analysis identified that significant LV remodeling on SPECT imaging, LV functional parameters and F-18 FDG uptake ratio of myocardium to blood pool (SUVM/B) were associated with the overestimation. Myocardial SPECT and F-18 FDG PET/CT had a 67.1 % identity in determining the latest activation site and 5.2 % more viable myocardium was detected by F-18 FDG PET/CT than SPECT. CONCLUSION: Gated F-18 FDG PET/CT moderately correlated with gated Tc-99m sestamibi SPECT in assessing LV dyssynchrony. Gated F-18 FDG PET/CT phase analysis should be cautiously applied in CAD patients with significant LV remodeling on SPECT imaging, severe LV functional impairment or poor myocardial F-18 FDG uptake.


Subject(s)
Cardiac-Gated Imaging Techniques/methods , Coronary Artery Disease/diagnostic imaging , Fluorodeoxyglucose F18 , Multimodal Imaging/methods , Positron-Emission Tomography , Technetium Tc 99m Sestamibi , Tomography, Emission-Computed, Single-Photon/methods , Tomography, X-Ray Computed , Ventricular Dysfunction, Left/diagnostic imaging , Algorithms , Coronary Artery Disease/complications , Humans , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Male , Middle Aged , Radiopharmaceuticals , Reproducibility of Results , Sensitivity and Specificity , Software , Ventricular Dysfunction, Left/etiology
13.
IEEE Trans Neural Syst Rehabil Eng ; 21(2): 254-64, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22801527

ABSTRACT

High-resolution, real-time data obtained by human motion tracking systems can be used for gait analysis, which helps better understanding the cause of many diseases for more effective treatments, such as rehabilitation for outpatients or recovery from lost motor functions after a stroke. In order to achieve real-time ambulatory human motion tracking with low-cost MARG (magnetic, angular rate, and gravity) sensors, a computationally efficient and robust algorithm for orientation estimation is critical. This paper presents an analytically derived method for an adaptive-gain complementary filter based on the convergence rate from the Gauss-Newton optimization algorithm (GNA) and the divergence rate from the gyroscope, which is referred as adaptive-gain orientation filter (AGOF) in this paper. The AGOF has the advantages of one iteration calculation to reduce the computing load and accurate estimation of gyroscope measurement error. Moreover, for handling magnetic distortions especially in indoor environments and movements with excessive acceleration, adaptive measurement vectors and a reference vector for earth's magnetic field selection schemes are introduced to help the GNA find more accurate direction of gyroscope error. The features of this approach include the accurate estimation of the gyroscope bias to correct the instantaneous gyroscope measurements and robust estimation in conditions of fast motions and magnetic distortions. Experimental results are presented to verify the performance of the proposed method, which shows better accuracy of orientation estimation than several well-known methods.


Subject(s)
Acceleration , Actigraphy/instrumentation , Algorithms , Magnetometry/instrumentation , Movement/physiology , Signal Processing, Computer-Assisted/instrumentation , Telemetry/instrumentation , Computer Systems , Equipment Design , Equipment Failure Analysis , Feedback , Humans , Reproducibility of Results , Sensitivity and Specificity
14.
Sensors (Basel) ; 12(9): 12844-69, 2012.
Article in English | MEDLINE | ID: mdl-23112746

ABSTRACT

Long term continuous monitoring of electrocardiogram (ECG) in a free living environment provides valuable information for prevention on the heart attack and other high risk diseases. This paper presents the design of a real-time wearable ECG monitoring system with associated cardiac arrhythmia classification algorithms. One of the striking advantages is that ECG analog front-end and on-node digital processing are designed to remove most of the noise and bias. In addition, the wearable sensor node is able to monitor the patient's ECG and motion signal in an unobstructive way. To realize the real-time medical analysis, the ECG is digitalized and transmitted to a smart phone via Bluetooth. On the smart phone, the ECG waveform is visualized and a novel layered hidden Markov model is seamlessly integrated to classify multiple cardiac arrhythmias in real time. Experimental results demonstrate that the clean and reliable ECG waveform can be captured in multiple stressed conditions and the real-time classification on cardiac arrhythmia is competent to other workbenches.


Subject(s)
Arrhythmias, Cardiac/diagnosis , Computer Systems , Electrocardiography, Ambulatory/methods , Algorithms , Humans , Signal Processing, Computer-Assisted
15.
J Nucl Med ; 53(4): 584-91, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22393224

ABSTRACT

UNLABELLED: This prospective study evaluated the accuracy of electrocardiogram-gated blood-pool SPECT (GBPS) for the assessment of left ventricular (LV) and right ventricular (RV) ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) in patients with dilated cardiomyopathy (DCM), using cardiac magnetic resonance (CMR) imaging as the reference standard. METHODS: Thirty-two patients (24 men and 8 women; mean age, 51 y) with a diagnosis of idiopathic DCM underwent GBPS and CMR. LV and RV parameters including EDV, ESV, and EF from GBPS were calculated using fully automated gradient software and compared with those obtained by CMR. RESULTS: Biventricular volumes were underestimated by GBPS, compared with CMR (P < 0.001). We found no statistical difference between these 2 methods in the assessment of LV EF (P = 0.23), whereas RV EF was overestimated by GBPS (P < 0.001 vs. CMR). Regression analysis yielded significant correlations between GBPS and CMR in the assessments of biventricular parameters (r = 0.83 for LV EDV, 0.88 for LV ESV, 0.89 for LV EF, 0.86 for RV EDV, 0.86 for RV ESV, and 0.62 for RV EF; all P < 0.001). Comparison of the deviations of RV indices between GBPS and CMR with the ratio of RV EDV to LV EDV showed that there was a statistically significant trend for RV volumes to be underestimated and for RV EF to be overestimated as the biventricular volumetric ratio decreased (r = 0.61 for RV EDV, 0.68 for RV ESV, and -0.55 for RV EF; all P < 0.001). CONCLUSION: For patients with DCM, GBPS correlated well with CMR for the assessment of biventricular parameters, but RV indices should be cautiously interpreted.


Subject(s)
Cardiomyopathy, Dilated/diagnostic imaging , Gated Blood-Pool Imaging/methods , Magnetic Resonance Imaging , Stroke Volume , Tomography, Emission-Computed, Single-Photon/methods , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Right/diagnostic imaging , Adolescent , Adult , Aged , Cardiomyopathy, Dilated/physiopathology , Female , Gated Blood-Pool Imaging/standards , Humans , Male , Middle Aged , Reference Standards , Reproducibility of Results , Tomography, Emission-Computed, Single-Photon/standards , Young Adult
16.
Ann Nucl Med ; 25(8): 580-5, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21573869

ABSTRACT

Adenosine is a frequently used pharmacologic stress agent in myocardial perfusion imaging. Its safety profile is well established, and most of its side effects are mild and transient. Coronary vasospasm occurs occasionally during or after adenosine stress test in rare cases, which may lead to seriously adverse outcomes. This study reported 3 such cases after completion of adenosine pharmacologic stress test.


Subject(s)
Adenosine/adverse effects , Coronary Vasospasm/chemically induced , Tomography, Emission-Computed, Single-Photon/methods , Adult , Coronary Vasospasm/diagnostic imaging , Coronary Vessels/pathology , Electrocardiography/methods , Exercise Test , Female , Humans , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Technetium Tc 99m Sestamibi/pharmacology , Time Factors , Treatment Outcome
17.
Zhonghua Xin Xue Guan Bing Za Zhi ; 36(11): 999-1003, 2008 Nov.
Article in Chinese | MEDLINE | ID: mdl-19102913

ABSTRACT

OBJECTIVE: To evaluate the impact of viable myocardium assessed by (99)Tc()m-MIBI SPECT and (18)F-fluorodeoxyglucose (FDG) PET imaging in patients with left ventricular aneurysm (LVA) underwent revascularization (RVS). METHODS: Forty-six consecutive patients with LVA (mean LVEF 36% +/- 7%), underwent (99)Tc(m)-sestamibi SPECT and (18)F-FDG PET examinations and received RVS therapy, were followed-up for a mean period of 80 +/- 27 months. Viable myocardium in aneurysm was defined as perfusion-metabolism mismatch score (MMS) >/= 2.0. Patients were divided into four groups by aneurysm viability and aneurysmectomy. Group A1 (n = 8): viability-; Group A2 (n = 15): viability-, aneurysmectomy; Group B1 (n = 10): viability +; and Group B2 (n = 13): viability +, aneurysmectomy. RESULTS: The cardiac event rates during follow up were similar among groups [A1 (25%, 2/8), B1 (40%, 6/15), A2 (20%, 2/10) and B2 (31%, 4/13; P > 0.05)]. After revascularization, LVEF was improved (> 10%) in groups A2, B1 and B2 (P < 0.05). Multivariate logistic regression analysis showed that LV-MMS (OR = 2.34, 95% CI 1.08 - 5.06, P < 0.05), distal vessel disease (OR = 0.008, 95% CI 0.001 - 0.560, P < 0.05) and nonaneurysm perfusion score (OR = 0.24, 95% CI 0.07 - 0.85, P < 0.05) were significantly associated with the improvement of LVEF after revascularization. CONCLUSIONS: Long term cardiac events rate post revascularization was not affected by viable myocardium or aneurysmectomy in LVA patients. Viable myocardium in LVA patients was associated with better LVEF improvement after revascularization.


Subject(s)
Heart Aneurysm/diagnostic imaging , Positron-Emission Tomography , Tomography, Emission-Computed, Single-Photon , Aged , Fluorodeoxyglucose F18 , Heart Aneurysm/metabolism , Humans , Middle Aged , Myocardium/metabolism , Technetium Tc 99m Sestamibi
18.
J Nucl Med ; 49(8): 1288-98, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18632821

ABSTRACT

UNLABELLED: The prognostic value of myocardial viability assessment on left ventricular (LV) aneurysms remains undetermined. We aimed, first, to evaluate the long-term survival benefit of assessing the viability of the aneurysmal myocardium in patients with ischemic cardiomyopathy and, second, in the revascularization subgroup, to compare the short-term effects on LV function and clinical symptoms in patients treated by revascularization alone or by revascularization plus aneurysmectomy. METHODS: Seventy consecutive patients with an LV aneurysm who underwent 99mTc-sestamibi SPECT and 18F-FDG PET were followed up for a median of 6.8 y (range, 0.1-8.8 y). Only cardiac death during follow-up served as the endpoint. Patients were classified into 4 groups by aneurysmal viability and by treatment strategy (medical or surgical). Further, the effects of aneurysmectomy on LV function at 3 mo were evaluated by an analysis of revascularized patients grouped by aneurysmal viability and by aneurysmectomy. RESULTS: Twenty-four patients were assigned to medical therapy, and 46 patients were assigned to surgery (18 revascularization alone and 28 revascularization plus aneurysmectomy). The annual cardiac mortality rate in patients with a viable aneurysm treated medically (n = 10) was significantly higher than that in patients with a viable aneurysm treated surgically (n = 23) (11.6% vs. 1.5%, chi2 = 12.87, P < 0.0001) and was also significant higher than that in patients with a nonviable aneurysm treated medically (n = 14) (chi2 = 4.13, P < 0.05) or surgically (n = 23) (chi2 = 10.46, P = 0.001). Multivariate analysis showed that the aneurysmal mismatch score (P = 0.003) and surgical therapy (P = 0.001) were independent predictors of cardiac death. Improvement of LV function and symptoms after revascularization (P < 0.05) was observed in patients with revascularization plus aneurysmectomy and in patients with a viable aneurysm and revascularization only. CONCLUSION: Viability in LV aneurysm in patients with ischemic cardiomyopathy was a negative independent predictor of survival. Compared with medical therapy, coronary revascularization was associated with improved long-term survival, symptoms, and LV function in patients with a viable aneurysm. These findings warrant further prospective investigations.


Subject(s)
Fluorodeoxyglucose F18 , Heart Aneurysm/mortality , Radiopharmaceuticals , Technetium Tc 99m Sestamibi , Aged , Cardiomyopathies/diagnostic imaging , Cardiomyopathies/mortality , Cardiomyopathies/surgery , Female , Heart Aneurysm/diagnostic imaging , Heart Aneurysm/surgery , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Myocardial Revascularization , Positron-Emission Tomography , Retrospective Studies , Tomography, Emission-Computed, Single-Photon , Ventricular Function, Left
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