| 1. |
- Danad, Ibrahim, et al.
(författare)
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Coronary risk factors and myocardial blood flow in patients evaluated for coronary artery disease : a quantitative [15O]H2O PET/CT study
- 2012
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:1, s. 102-112
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThere has been increasing interest in quantitative myocardial blood flow (MBF) imaging over the last years and it is expected to become a routinely used technique in clinical practice. Positron emission tomography (PET) using [15O]H2O is the established gold standard for quantification of MBF in vivo. A fundamental issue when performing quantitative MBF imaging is to define the limits of MBF in a clinically suitable population. The aims of the present study were to determine the limits of MBF and to determine the relationship among coronary artery disease (CAD) risk factors, gender and MBF in a predominantly symptomatic patient cohort without significant CAD.MethodsA total of 128 patients (mean age 54 ± 10 years, 50 men) with a low to intermediate pretest likelihood of CAD were referred for noninvasive evaluation of CAD using a hybrid PET/computed tomography (PET/CT) scanner. MBF was quantified with [15O]H2O at rest and during adenosine-induced hyperaemia. Obstructive CAD was excluded in these patients by means of invasive or CT-based coronary angiography.ResultsGlobal average baseline MBF values were 0.91 ± 0.34 and 1.09 ± 0.30 ml·min−1·g−1 (range 0.54–2.35 and 0.59–2.75 ml·min−1·g−1) in men and women, respectively (p < 0.01). However, no gender-dependent difference in baseline MBF was seen following correction for rate–pressure product (0.98 ± 0.45 and 1.09 ± 0.30 ml·min−1·g−1 in men and women, respectively; p = 0.08). Global average hyperaemic MBF values were 3.44 ± 1.20 ml·min−1·g−1 in the whole study population, and 2.90 ± 0.85 and 3.78 ± 1.27 ml·min−1·g−1 (range 1.52–5.22 and 1.72–8.15 ml·min−1·g−1) in men and women, respectively (p < 0.001). Multivariate analysis identified male gender, age and body mass index as having an independently negative impact on hyperaemic MBF.ConclusionGender, age and body mass index substantially influence reference values and should be corrected for when interpreting hyperaemic MBF values.
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| 2. |
- de Haan, Stefan, et al.
(författare)
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Parametric imaging of myocardial viability using ¹⁵O-labelled water and PET/CT : comparison with late gadolinium-enhanced CMR
- 2012
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 39:8, s. 1240-1245
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe perfusable tissue index (PTI) is a marker of myocardial viability. Recent technological advances have made it possible to generate parametric PTI images from a single [15O]H2O PET/CT scan. The purpose of this study was to validate these parametric PTI images.MethodsThe study population comprised 46 patients with documented or suspected coronary artery disease who were studied with [15O]H2O PET and late gadolinium-enhanced (LGE) cardiac magnetic resonance imaging (CMR).ResultsOf the 736 myocardial segments included, 364 showed some degree of LGE. PTI and perfusable tissue fraction (PTF) diminished with increasing LGE. The areas under the curve of the PTI and PTF, used to predict (near) transmural LGE on CMR, were 0.86 and 0.87, respectively. Optimal sensitivity and specificity were 91 % and 73 % for PTI and 69 % and 87 % for PTF, respectively.ConclusionPTI and PTF assessed with a single [15O]H2O scan can be utilized as markers of myocardial viability in patients with coronary artery disease.
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| 3. |
- Harms, Hendrik J, et al.
(författare)
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Parametric Images of Myocardial Viability Using a Single 15O-H2O PET/CT Scan
- 2011
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 52:5, s. 745-749
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Tidskriftsartikel (refereegranskat)abstract
- Perfusable tissue index (PTI) is a marker of myocardial viability and requires acquisition of transmission, 15O-CO, and 15O-H2O scans. The aim of this study was to generate parametric PTI images from a 15O-H2O PET/CT scan without an additional 15O-CO scan.Methods:Data from 20 patients undergoing both 15O-H2O and 15O-CO scans were used, assessing correlation between PTI based on 15O-CO (PTICO) and on fitted blood volume fractions (PTIVb). In addition, parametric PTIVb images of 10 patients undergoing 15O-H2O PET/CT scans were generated using basis-function methods and compared with PTIVb obtained using nonlinear regression. Simulations were performed to study the effects of noise on PTIVb.Results:Correlation between PTICO and PTIVb was high (r2 = 0.73). Parametric PTIVb correlated well with PTIVb obtained using nonlinear regression (r2 = 0.91). Simulations showed low sensitivity to noise (coefficient of variation < 10% at 20% noise).Conclusion:Parametric PTI images can be generated from a single 15O-H2O PET/CT scan.
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| 4. |
- Harms, Hendrik J, et al.
(författare)
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Quantification of [(11)C]-meta-hydroxyephedrine uptake in human myocardium
- 2014
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Ingår i: EJNMMI Research. - : Springer Science and Business Media LLC. - 2191-219X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aims of this study were to determine the optimal tracer kinetic model for [(11)C]-meta-hydroxyephedrine ([(11)C]HED) and to evaluate the performance of several simplified methods.METHODS: Thirty patients underwent dynamic 60-min [(11)C]HED scans with online arterial blood sampling. Single-tissue and both reversible and irreversible two-tissue models were fitted to the data using the metabolite-corrected arterial input function. For each model, reliable fits were defined as those yielding outcome parameters with a coefficient of variation (CoV) <25%. The optimal model was determined using Akaike and Schwarz criteria and the F-test, together with the number of reliable fits. Simulations were performed to study accuracy and precision of each model. Finally, quantitative results obtained using a population-averaged metabolite correction were evaluated, and simplified retention index (RI) and standardized uptake value (SUV) results were compared with quantitative volume of distribution (V T) data.RESULTS: The reversible two-tissue model was preferred in 75.8% of all segments, based on the Akaike information criterion. However, V T derived using the single-tissue model correlated highly with that of the two-tissue model (r (2) = 0.94, intraclass correlation coefficient (ICC) = 0.96) and showed higher precision (CoV of 24.6% and 89.2% for single- and two-tissue models, respectively, at 20% noise). In addition, the single-tissue model yielded reliable fits in 94.6% of all segments as compared with 77.1% for the reversible two-tissue model. A population-averaged metabolite correction could not be used in approximately 20% of the patients because of large biases in V T. RI and SUV can provide misleading results because of non-linear relationships with V T.CONCLUSIONS: Although the reversible two-tissue model provided the best fits, the single-tissue model was more robust and results obtained were similar. Therefore, the single-tissue model was preferred. RI showed a non-linear correlation with V T, and therefore, care has to be taken when using RI as a quantitative measure.
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| 5. |
- Harms, Hendrik J, et al.
(författare)
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Use of a Single 11C-Meta-Hydroxyephedrine Scan for Assessing Flow-Innervation Mismatches in Patients with Ischemic Cardiomyopathy
- 2015
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 56:11, s. 1706-1711
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Tidskriftsartikel (refereegranskat)abstract
- UNLABELLED: Mismatch between areas of reduced myocardial blood flow (MBF) and reduced myocardial innervation (defect areas) may be used to estimate the risk for ventricular arrhythmias. The presence of a mismatch zone can be derived using a combined protocol consisting of both an MBF scan and an (11)C-meta-hydroxyephedrine ((11)C-HED) scan. The rate of influx from blood to myocardium (K1) of (11)C-HED is proportional to MBF and can potentially be used as an index for defining MBF defects. The aim of this study was to assess whether K1 derived from an (11)C-HED scan can be used as an index of MBF, potentially allowing for an assessment of MBF-innervation mismatch areas from a single (11)C-HED scan.METHODS: Seventeen patients with known ischemic cardiomyopathy underwent dynamic (15)O-water and (11)C-HED scans. Discrete arterial blood samples were taken during (11)C-HED scans for metabolite correction of the image-derived input function. (11)C-HED influx rate was obtained using a single-tissue-compartment model and compared with transmural MBF (MBFT), defined as MBF as measured with (15)O-water multiplied by perfusable tissue fraction. Defect sizes were obtained from parametric K1 and MBFT images, using 50% of a remote control segment as the cutoff value.RESULTS: There was a significant correlation between MBFT and K1 (y = 0.40x + 0.05 mL·g(-1)·min(-1), r = 0.80, P < 0.001), although K1 was significantly lower than MBFT (slope of the regression line significantly different from 1, P < 0.001). Correlation between MBFT and K1 defect sizes was high (y = 0.89x + 1.38%, r = 0.95, P < 0.001), with no significant difference in mean defect size based on K1 or MBFT (20.9% ± 11.3% and 20.1% ± 10.7% for MBFT and K1, respectively, P = 0.41).CONCLUSION: (11)C-HED influx rate K1 can be used as an alternative to a separate MBF scan for assessing mismatch areas between MBF and myocardial innervation.
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