Objectives The aim of this study was to examine the value of native and post-contrast T1 relaxation in the differentiation between healthy and diffusely diseased myocardium in 2 model conditions, ...hypertrophic cardiomyopathy and nonischemic dilated cardiomyopathy. Background T1 mapping has been proposed as potentially valuable in the quantitative assessment of diffuse myocardial fibrosis, but no studies to date have systematically evaluated its role in the differentiation of healthy myocardium from diffuse disease in a clinical setting. Methods Consecutive subjects undergoing routine clinical cardiac magnetic resonance at King's College London were invited to participate in this study. Groups were based on cardiac magnetic resonance findings and consisted of subjects with known hypertrophic cardiomyopathy (n = 25) and nonischemic dilated cardiomyopathy (n = 27). Thirty normotensive subjects with low pre-test likelihood of cardiomyopathy, not taking any regular medications and with normal cardiac magnetic resonance findings including normal left ventricular mass indexes, served as controls. Single equatorial short-axis slice T1 mapping was performed using a 3-T scanner before and at 10, 20, and 30 minutes after the administration of 0.2 mmol/kg of gadobutrol. T1 values were quantified within the septal myocardium (T1native ), and extracellular volume fractions (ECV) were calculated. Results T1native was significantly longer in patients with cardiomyopathy compared with control subjects (p < 0.01). Conversely, post-contrast T1 values were significantly shorter in patients with cardiomyopathy at all time points (p < 0.01). ECV was significantly higher in patients with cardiomyopathy compared with controls at all time points (p < 0.01). Multivariate binary logistic regression revealed that T1native could differentiate between healthy and diseased myocardium with sensitivity of 100%, specificity of 96%, and diagnostic accuracy of 98% (area under the curve 0.99; 95% confidence interval: 0.96 to 1.00; p < 0.001), whereas post-contrast T1 values and ECV showed lower discriminatory performance. Conclusions This study demonstrates that native and post-contrast T1 values provide indexes with high diagnostic accuracy for the discrimination of normal and diffusely diseased myocardium.
Objectives This study sought to compare the diagnostic performance of a multidetector computed tomography (MDCT) integrated protocol (IP) including coronary angiography (CTA) and stress-rest ...perfusion (CTP) with cardiac magnetic resonance myocardial perfusion imaging (CMR-Perf) for detection of functionally significant coronary artery disease (CAD). Background MDCT stress-rest perfusion methods were recently described as adjunctive tools to improve CTA accuracy for detection of functionally significant CAD. However, only a few studies compared these MDCT-IP with other clinically validated perfusion techniques like CMR-Perf. Furthermore, CTP has never been validated against the invasive reference standard, fractional flow reserve (FFR), in patients with suspected CAD. Methods 101 symptomatic patients with suspected CAD (62 ± 8.0 years, 67% males) and intermediate/high pre-test probability underwent MDCT, CMR and invasive coronary angiography. Functionally significant CAD was defined by the presence of occlusive/subocclusive stenoses or FFR measurements ≤0.80 in vessels >2mm. Results On a patient-based model, the MDCT-IP had a sensitivity, specificity, positive and negative predictive values of 89%, 83%, 80% and 90%, respectively (global accuracy 85%). These results were closely related with those achieved by CMR-Perf: 89%, 88%, 85% and 91%, respectively (global accuracy 88%). When comparing test accuracies using noninferiority analysis, differences greater than 11% in favour of CMR-Perf can be confidently excluded. Conclusions MDCT protocols integrating CTA and stress-rest perfusion detect functionally significant CAD with similar accuracy as CMR-Perf. Both approaches yield a very good accuracy. Integration of CTP and CTA improves MDCT performance for the detection of relevant CAD in intermediate to high pre-test probability populations.
Objectives The aim of this study was to compare fully quantitative cardiovascular magnetic resonance (CMR) and positron emission tomography (PET) myocardial perfusion and myocardial perfusion reserve ...(MPR) measurements in patients with coronary artery disease (CAD). Background Absolute quantification of myocardial perfusion and MPR with PET have proven diagnostic and prognostic roles in patients with CAD. Quantitative CMR perfusion imaging has been established more recently and has been validated against PET in normal hearts. However, there are no studies comparing fully quantitative CMR against PET perfusion imaging in patients with CAD. Methods Forty-one patients with known or suspected CAD prospectively underwent quantitative13 N-ammonia PET and CMR perfusion imaging before coronary angiography. Results The CMR-derived MPR (MPRCMR ) correlated well with PET-derived measurements (MPRPET ) (r = 0.75, p < 0.0001). MPRCMR and MPRPET for the 2 lowest scoring segments in each coronary territory also correlated strongly (r = 0.79, p < 0.0001). Absolute CMR perfusion values correlated significantly, but weakly, with PET values both at rest (r = 0.32; p = 0.002) and during stress (r = 0.37; p < 0.0001). Area under the receiver-operating characteristic curve for MPRPET to detect significant CAD was 0.83 (95% confidence interval: 0.73 to 0.94) and for MPRCMR was 0.83 (95% confidence interval: 0.74 to 0.92). An MPRPET ≤1.44 predicted significant CAD with 82% sensitivity and 87% specificity, and MPRCMR ≤1.45 predicted significant CAD with 82% sensitivity and 81% specificity. Conclusions There is good correlation between MPRCMR and MPRPET. For the detection of significant CAD, MPRPET and MPRCMR seem comparable and very accurate. However, absolute perfusion values from PET and CMR are only weakly correlated; therefore, although quantitative CMR is clinically useful, further refinements are still required.
Objectives The objective of this study was to compare visual and quantitative analysis of high spatial resolution cardiac magnetic resonance (CMR) perfusion at 3.0-T against invasively determined ...fractional flow reserve (FFR). Background High spatial resolution CMR myocardial perfusion imaging for the detection of coronary artery disease (CAD) has recently been proposed but requires further clinical validation. Methods Forty-two patients (33 men, age 57.4 ± 9.6 years) with known or suspected CAD underwent rest and adenosine-stress k -space and time sensitivity encoding accelerated perfusion CMR at 3.0-T achieving in-plane spatial resolution of 1.2 × 1.2 mm2 . The FFR was measured in all vessels with >50% severity stenosis. Fractional flow reserve <0.75 was considered hemodynamically significant. Two blinded observers visually interpreted the CMR data. Separately, myocardial perfusion reserve (MPR) was estimated using Fermi-constrained deconvolution. Results Of 126 coronary vessels, 52 underwent pressure wire assessment. Of these, 27 lesions had an FFR <0.75. Sensitivity and specificity of visual CMR analysis to detect stenoses at a threshold of FFR <0.75 were 0.82 and 0.94 (p < 0.0001), respectively, with an area under the receiver-operator characteristic curve of 0.92 (p < 0.0001). From quantitative analysis, the optimum MPR to detect such lesions was 1.58, with a sensitivity of 0.80, specificity of 0.89 (p < 0.0001), and area under the curve of 0.89 (p < 0.0001). Conclusions High-resolution CMR MPR at 3.0-T can be used to detect flow-limiting CAD as defined by FFR, using both visual and quantitative analyses.
Abstract Cardiovascular magnetic resonance (CMR) has evolved from a pioneering research tool to an established noninvasive imaging method for detecting inducible myocardial perfusion deficits. In ...this consensus document, experts of different imaging techniques summarize the existing body of evidence regarding CMR perfusion as a viable complement to other established noninvasive tools for the assessment of perfusion and discuss the advantages and pitfalls of the technique. A rapid, standardized CMR perfusion protocol is described, which is safe, clinically feasible, and cost-effective for centers with contemporary magnetic resonance equipment. CMR perfusion can be recommended as a routine diagnostic tool to identify inducible myocardial ischemia.
Objectives Our aim was to assess the predictive value of myocardial infarct size assessed with late gadolinium-enhanced (LGE) magnetic resonance imaging (MRI) in medically treated patients with ...chronic myocardial infarction relative to contractile reserve on low-dose dobutamine magnetic resonance (DSMR) for long-term event-free survival. Background Information on the relative merits of scar tissue and contractile reserve to predict long-term prognosis in patients with chronic myocardial infarction is lacking. Methods A total of 177 patients with known coronary artery disease and scar tissue on LGE MRI were enrolled. Left ventricular (LV) functional parameters at rest and during low-dose DSMR were assessed, and the wall motion score index was calculated. Results Eleven patients (6.2%) suffered an event during follow-up (average 20.3 months). Infarct size was a stronger predictor of events than LV ejection fraction and LV volumes at rest and during low-dose DSMR. Myocardial infarct size was used to separate patients at high risk (spatial extent ≥6 segments, n = 98) from those at low risk (spatial extent <6 segments, n = 79) for mortality. In the subgroup of patients at high risk, transmurality of infarct was not a predictor of events. However, the presence of contractile reserve (n = 63) was associated with a significantly higher number of events (12.7%) compared with no change in wall motion score index (6.7%; n = 15; p = 0.008). Conclusions Myocardial infarct size on LGE MRI is a stronger predictor of clinical outcome than contractile reserve in medically treated patients with myocardial infarction. In patients with large myocardial scar, the presence of contractile reserve is more important for the prediction of events than scar tissue.
MR Imaging of Coronary Arteries and Plaques Dweck, Marc R., MD, PhD; Puntmann, Valentina O., MD, PhD; Vesey, Alex T., MD ...
JACC. Cardiovascular imaging,
03/2016, Letnik:
9, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Abstract Cardiac magnetic resonance offers the promise of radiation-free imaging of the coronary arteries, providing information with respect to luminal stenosis, plaque burden, high-risk plaque ...characteristics, and disease activity. In combination, this would provide a comprehensive, individualized assessment of coronary atherosclerosis that could be used to improve patient risk stratification and to guide treatment. However, the technical challenges involved with delivering upon this promise are considerable, requiring sophisticated approaches to both data acquisition and post-processing. In this review, we describe the current status of this technology, its capabilities, its limitations, and what will be required in the future to translate this technology into routine clinical practice.
Objectives The goal of this study was to determine the diagnostic accuracy of dynamic 3-dimensional (3D) whole heart myocardial perfusion cardiovascular magnetic resonance (CMR) against invasively ...determined fractional flow reserve (FFR) and to establish the correlation between myocardium at risk defined by using the invasive Duke Jeopardy Score (DJS) and noninvasive 3D whole heart myocardial perfusion CMR. Background 3D whole heart myocardial perfusion CMR overcomes the limited spatial coverage of conventional two-dimensional perfusion CMR methods and allows estimation of the extent of ischemia. The method has shown good diagnostic accuracy for the detection of coronary artery disease (CAD) as defined by using quantitative coronary angiography. However, quantitative coronary angiography does not provide a functional assessment of CAD as available from pressure wire–derived FFR. In the catheter laboratory, the DJS can complement FFR to estimate the myocardium at risk. Methods Fifty-three patients referred for angiography underwent rest and adenosine stress 3D whole heart myocardial perfusion CMR at 3-T. Perfusion was scored visually on a patient and coronary territory basis, and ischemic burden was calculated by quantitative segmentation of the volume of hypoenhancement. FFR was measured in vessels with ≥50% severity stenosis and an FFR <0.75 considered as hemodynamically significant. The DJS was calculated from the coronary angiograms to quantify the myocardium at risk. Results FFR was measured in 64 of 159 coronary vessels, and 39 had an FFR <0.75. Sensitivity, specificity, and diagnostic accuracy of CMR for the detection of significant CAD were 91%, 90%, and 91%, on a patient basis and 79%, 92%, and 88%, respectively, by coronary territory. There was a strong correlation between the DJS and ischemic burden on CMR (p < 0.0001; Pearson's r = 0.82). Conclusions 3D whole heart myocardial perfusion CMR accurately detects functionally significant CAD as defined by using FFR and provides an assessment of ischemic burden in agreement with the invasive DJS. The accurate detection of significant CAD combined with an estimation of ischemic burden by using 3D myocardial perfusion CMR holds promise for noninvasive guidance of therapy and risk stratification of patients with CAD.
...endomyocardial biopsy results reveal that only 8% of patients in the acute group had histological evidence of acute myocarditis, hinting toward similar patients in both groups presenting in a ...chronic rather than acute stage of disease.
Abstract The evaluation of patients with suspected stable ischemic heart disease is among the most common diagnostic evaluations with nearly 20 million imaging and exercise stress tests performed ...annually in the United States. Over the past decade, there has been an evolution in imaging research with an ever-increasing focus on larger registries and randomized trials comparing the effectiveness of varying diagnostic algorithms. The current review highlights recent randomized trial evidence with a particular focus comparing the effectiveness of cardiac imaging procedures within the stable ischemic heart disease evaluation for coronary artery disease detection, angina, and other quality of life measures, and major clinical outcomes. Also highlighted are secondary analyses from these trials on the economic findings related to comparative cost differences across diagnostic testing strategies.
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