Assessment of diastolic function using 16-frame 201Tl-gated myocardial perfusion SPECT

金沢大学附属病院核医学診療

Standardization of metaiodobenzylguanidine heartto mediastinum ratio using a calibration phantom: Effects of correction on normal databases and a multicentre study

Purpose: This study was performed to demonstrate that the results obtained with a calibration phantom could be used as a tool for standardizing measurement of heart to mediastinum (H/M) ratio in cardiac metaiodobenzylguanidine (MIBG) imaging. Methods: Images of the phantom containing 123I-MIBG were acquired on the cameras in 10 hospitals (11 camera types) to determine the relationship between H/M ratios using different collimators: low-energy (LE) and mediumenergy (ME)/low-medium-energy (LME) collimators. The effect of standardization on the ME-comparable H/M ratio was examined in two settings: a Japanese standard MIBG database (n=62) and multicentre studies (n=49). In a multicentre study, probable Alzheimer\u27s disease (AD, n=18) and probable dementia with Lewy bodies (DLB, n=31) were studied and standardized by the calibration phantom method. Results: Linear regression equations between LE and ME collimators were obtained for the phantom study in all institutions. When the H/M ratio with an LE collimator wascorrected based upon the calibration phantom, the corrected values were comparable to those obtained using ME collimators. The standard database also exhibited a normal distribution after standardization as determined by skewness and goodness-of-fit test. A mixture of the populations by LE and ME collimators showed significant separation of AD and DLB groups (F ratio=24.9 for the late H/M), but the corrected values resulted in higher F ratios for both early and late H/M (F ratio=34.9 for the late H/M). Conclusion: Standardization of H/M ratios by the heartchest calibration phantom method is feasible among different collimator types. This method could be practically used for multicentre comparison of H/M ratios. © Springer-Verlag 2011

Identification of Myocardial Damage in Systemic Sclerosis: A Nuclear Cardiology Approach

Myocardial involvement is an important prognostic factor in patients with systemic sclerosis, and early diagnosis and staging of the disease have been sought after. Since myocardial damage is characterized by connective tissue disease, including fibrosis and diffuse vascular lesions or microcirculation, nuclear myocardial perfusion imaging has been a promising option for evaluating myocardial damages in early stages. In addition to the conventional stress-rest perfusion imaging, the current use of quantitative electrocardiographic gated imaging has contributed to more precise evaluation of cardiac perfusion, ventricular wall motion, and diastolic function, all of which have enhanced diagnostic ability of evaluating myocardial dysfunction. Abnormal sympathetic imaging with Iodine-123 metaiodobenzylguanidine might be another option for identifying myocardial damage. This paper deals with approaches from nuclear cardiology to detect perfusion and functional abnormality as an early sign of myocardial involvement as well as possible prognostic values in patients with abnormal imaging results. The role of nuclear cardiology in the era of multiple imaging modalities is discussed

The time has come to standardize 123I-MIBG heart-to-mediastinum ratios including planar and SPECT methods

Embargo Period 12 month

Diagnostic utility of 123I-BMIPP imaging in patients with Takotsubo cardiomyopathy

Objective: Takotsubo cardiomyopathy is a cardiac syndrome with an acute onset defined by chest symptoms and ST segment elevation on electrocardiograms. Takotsubo cardiomyopathy is sometimes misdiagnosed as acute myocardial infarction (AMI). Therefore a non-invasive diagnostic method is needed to be established for setting up appropriate strategies. The purpose of this study was to detect myocardial metabolic abnormalities and to determine the diagnostic usefulness of 123I-beta-methy-iodophenyl pentadecanoic acid (123I-BMIPP) imaging in patients with takotsubo cardiomyopathy. Methods and results: We examined 16 patients with takotsubo cardiomyopathy and 12 with AMI in the left anterior descending artery. All patients were studied with resting 123I-BMIPP imaging. Total defect score (TDS) of 123I-BMIPP and perfusion were semi-quantitatively determined with single-photon emission computed tomography (SPECT) imaging using a 17-segment 5-point model. TDS of 123I-BMIPP were 4.8 ± 2.7 in patients with Takotsubo cardiomyopathy and 22.4 ± 10.7 in AMI. The ratio of summed BMIPP defect score of non-apical to apical segments in Takotsubo cardiomyopathy was smaller than that of the patients with AMI (0.1 ± 0.1 vs. 1.1 ± 0.7, p < 0.0001), indicating that 123I-BMIPP abnormalities were exclusively observed the in apical area. The ratio of summed perfusion defect scores of non-apical to apical segments in takotsubo cardiomyopathy did not differ significantly from that of AMI (0.52 ± 0.6 vs. 0.57 ± 0.3, p = NS). Summed BMIPP defect score in the apical area of takotsubo cardiomyopathy was larger than that of perfusion defect score (3.9 ± 2.7 vs. 1.8 ± 1.8, p = 0.04). Conclusion: Impaired metabolic metabolism exclusively in the apical region was observed by 123I-BMIPP SPECT images in takotsubo cardiomyopathy. These typical metabolic SPECT features of the disease can be utilized on differential diagnosis of takotsubo cardiomyopathy. © 2013.This is the author\u27s version of a work accepted for publication by Japanese College of Cardiology. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. The definitive version has been published in Journal of Cardiology, 64 (1), pp. 49-56,2014 July, 10.1016/j.jjcc.2013.10.01

The relationship between stress-induced myocardial ischemia and coronary artery atherosclerosis measured by hybrid SPECT/CT camera

Objective: The coronary artery calcium (CAC) score and myocardial perfusion imaging can now be detected simultaneously using a hybrid SPECT/CT camera. However, there has been little evaluation on the relationship between stress-induced ischemia and coronary artery calcification in a Japanese population. The aim of this study was to investigate the relationship between these parameters and to elucidate the diagnostic value of the CAC score as an adjunct to myocardial perfusion imaging (MPI) for the assessment of coronary artery disease (CAD) in an intermediate-risk population. Methods: We retrospectively analyzed 105 patients (63% men, mean age 71 years) with CAD or suspected CAD who underwent MPI using SPECT/CT. CAC scanning was performed using a SPECT/CT camera. Results: There was a significant difference in the CAC score between patients with ischemia (n = 42) and those without ischemia (n = 63) (1353 ± 1524 vs. 332 ± 554, p 1000; 3.0 ± 2.0). Higher age is related roughly with higher CAC score with no statistical significance (r 2 = 0.1) (80 years old; 1258 ± 1546, ns). The location of calcification was not related to the ischemic area. In a population with a predominately intermediate likelihood of CAD, a calcium score of zero has a possibility of excluding inducible ischemia on MPI. In part, ischemic MPI is associated with a high likelihood of subclinical atherosclerosis as detected by CAC. Conclusion: Hybrid SPECT/CT might be useful for diagnostic assessment and coronary artery with known or suspected CAD. © 2011 The Japanese Society of Nuclear Medicine

Plasma level of oxidized low-density lipoprotein is an independent determinant of coronary macrovasomotor and microvasomotor responses induced by bradykinin

AbstractObjectivesWe examined the relationship between coronary endothelium-dependent vasodilation in response to bradykinin (BK) and plasma levels of oxidized low-density lipoprotein (oxLDL) in subjects with normal coronary arteries.BackgroundIt is unclear whether the plasma oxLDL level is a determinant of coronary endothelial function. Bradykinin plays an important role in regulating resting coronary tone and flow-mediated coronary vasomotion.MethodsCoronary blood flow (CBF) in the left anterior descending (LAD) coronary artery was assessed by quantitative angiography and a Doppler flow wire in 94 consecutive subjects with normal coronary arteries. The plasma oxLDL level was measured by enzyme-linked immunosorbent assay using DLH3R, a specific antibody against oxLDL.ResultsPlasma levels of oxLDL in diabetic subjects (n = 13) were higher than those in non-diabetic subjects (n = 81). Plasma levels of oxLDL correlated with body mass index (BMI). Bradykinin at doses of 0.2, 0.6, and 2.0 μg/min caused dose-dependent increases in diameter and CBF in the LAD coronary artery. By a univariate analysis, oxLDL levels significantly correlated with epicardial (r = −0.30, p < 0.0001) and resistant (r = −0.36, p = 0.003) coronary vasodilator responses to BK at 2.0 μg/min, whereas total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides were not associated with these coronary responses. In a stepwise multivariate analysis, oxLDL levels were significantly correlated with epicardial and resistant coronary vasomotor responses to BK, independent of age, gender, smoking status, other lipid levels, BMI, hypertension, and diabetes.ConclusionsThe plasma level of oxLDL is an appropriate surrogate for assessing coronary endothelial-dependent vasomotor function as estimated by responses to BK compared with conventional risk factors for atherosclerosis

Metabolic syndrome is not a predictor for cardiovascular events in Japanese patients with diabetes mellitus asymptomatic for coronary artery disease: A retrospective analysis of the J-ACCESS-2 study

Purpose: Patients with metabolic syndrome (MetS) have potentially higher risk for cardiovascular events. The aim of this study was to evaluate the effect of MetS on cardiac events in type-2 diabetic patients asymptomatic for coronary artery disease (CAD) in a Japanese population. Methods: A total of 485 patients from a J-ACCESS-2 investigation with stress-gated myocardial perfusion imaging (MPI) and quantitative-gated MPI analysis were examined. Cardiovascular hard events (cardiac death and acute coronary syndrome) and total events during a 3-year follow-up were analyzed. Results: The MetS group (n = 229) had higher incidence of hypertension, dyslipidemia, and ventricular dilatation than the non-MetS group (n = 256). The hard events were 8 and 12 for the MetS and non-MetS groups (P = n.s.), and total events were 31 and 31 for each of these groups, respectively (P = n.s.). Significant variables related to total cardiovascular events included age, current smoking, insulin use, total cholesterol, ejection fraction, summed stress score ≥ 9, and summed difference score ≥ 2. Cox proportional hazard analysis and Kaplan-Meier survival analysis showed that only the summed stress score was related to total events (P = .01), and the presence and the number of items for MetS criteria were not. Conclusion: In patients with type 2 diabetes asymptomatic for CAD, cardiovascular events and ischemia are as common in diabetic patients without MetS as in those with MetS. A high MPI defect score is related to total events including cardiac and cerebrovascular events. © 2012 American Society of Nuclear Cardiology