| 1. |
- Ferreira, Mjv, et al.
(författare)
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Poster Session 3 : Tuesday 5 May 2015, 08
- 2015
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Ingår i: European Heart Journal Cardiovascular Imaging. - : Oxford University Press (OUP). - 2047-2404 .- 2047-2412. ; 16 Suppl 1
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Antoni, Gunnar, et al.
(författare)
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In Vivo Visualization of Amyloid Deposits in the Heart with C-11-PIB and PET
- 2013
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 54:2, s. 213-220
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Tidskriftsartikel (refereegranskat)abstract
- Cardiac amyloidosis is a differential diagnosis in heart failure and is associated with high mortality. There is currently no noninvasive imaging test available for specific diagnosis. N-[methyl-C-11]2-(4'-methylamino-phenyl)-6-hydroxybenzothiazole (C-11-PIB) PET is used in the evaluation of brain amyloidosis. We evaluated the potential use of C-11-PIB PET in systemic amyloidosis affecting the heart. Methods: Patients (n = 10) diagnosed with systemic amyloidosis-including heart involvement of either monoclonal immunoglobulin light-chain (AL) or transthyretin (ATTR) type- and healthy volunteers (n = 5) were investigated with PET/CT using C-11-PIB to study cardiac amyloid deposits and with C-11-acetate to measure myocardial blood flow to study the impact of global and regional perfusion on PIB retention. Results: Myocardial C-11-PIB uptake was visually evident in all patients 15-25 min after injection and was not seen in any volunteer. A significant difference in C-11-PIB retention in the heart between patients and healthy controls was found. The data indicate that myocardial amyloid deposits in patients diagnosed with systemic amyloidosis could be visualized with C-11-PIB. No correlation between C-11-PIB retention index and myocardial blood flow as measured with C-11-acetate was found on the global level, whereas a positive correlation on the segmental level was seen in a single patient. Conclusion: C-11-PIB and PET could be a method to study systemic amyloidosis of type AL and ATTR affecting the heart and should be investigated further both as a diagnostic tool and as a noninvasive method for treatment follow-up.
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| 3. |
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| 4. |
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| 5. |
- Bouyoucef, S E, et al.
(författare)
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Poster Session 2 : Monday 4 May 2015, 08
- 2015
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Ingår i: European Heart Journal Cardiovascular Imaging. - : Oxford University Press (OUP). - 2047-2404 .- 2047-2412. ; 16 Suppl 1
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Bäck, Anna-Karin, 1971-, et al.
(författare)
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Renography with a semiautomated algorithm for diuretic decision 7 min postradiopharmaceutical administration : a feasibility study
- 2020
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Ingår i: Nuclear medicine communications. - : Lippincott Williams & Wilkins. - 0143-3636 .- 1473-5628. ; 41:10, s. 1018-1025
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The F+10 method for diuretic renography (diuretics given 10 min after the radiopharmaceutical) could be a time-conserving method. This method involves a 30-min dynamic acquisition where diuretics are administered only when necessary by the Nuclear Medicine technologist performing the examination. The purpose of this study was to assess the method's performance and to discover the optimal threshold of residual activity for a diuretic administration 7 min into the F+10 renography by reprocessing raw data from prior performed examinations with 20-min acquisitions without diuretics.METHODS: Retrospectively, raw data from 320 original examinations of adult patients performed from 2013 to 2015 were reprocessed into 7-min series and categorized as requiring diuretic or not. The diuretic decisions made by an expert panel were used as a reference. A receiver-operating characteristic curve was drawn to assess the optimal cutoff value for the residual renal activity. Sensitivity, specificity, positive and negative predictive values, as well as the Youden J index were calculated.RESULT: The experts classified 50% (160 examinations) as in need of diuretics. The receiver-operating characteristic curve demonstrated the theoretical optimal cutoff value at 7 min to be 94% of maximum activity (sensitivity 0.93, specificity 0.81, Youden J index 0.73). A clinically acceptable threshold is suggested to be 85% (sensitivity 0.99, specificity 0.59, Youden J index 0.58).CONCLUSION: Tc-mercaptoacetyltriglycine renography with the F+10 method and the threshold 85% for diuretic decision 7 min into the renography is a feasible and acceptable method in clinical practice.
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| 7. |
- Christensen, Nana L, et al.
(författare)
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Detection and correction of patient motion in dynamic 15O-water PET MPI.
- 2023
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Ingår i: Journal of Nuclear Cardiology. - : Elsevier. - 1071-3581 .- 1532-6551. ; 30:6, s. 2736-2749
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Patient motion constitutes a limitation to 15O-water cardiac PET imaging. We examined the ability of image readers to detect and correct patient motion using simulated motion data and clinical patient scans.METHODS: Simulated data consisting of 16 motions applied to 10 motion-free scans were motion corrected using two approaches, pre-analysis and post-analysis for motion identification. Both approaches employed a manual frame-by-frame correction method. In addition, a clinical cohort was analyzed for assessment of prevalence and effect of motion and motion correction.RESULTS: Motion correction was performed on 94% (pre-analysis) and 64% (post-analysis) of the scans. Large motion artifacts were corrected in 91% (pre-analysis) and 74% (post-analysis) of scans. Artifacts in MBF were reduced in 56% (pre-analysis) and 58% (post-analysis) of the scans. The prevalence of motion in the clinical patient cohort (n = 762) was 10%. Motion correction altered exam interpretation in only 10 (1.3%) clinical patient exams.CONCLUSION: Frame-by-frame motion correction after visual inspection is useful in reducing motion artifacts in cardiac 15O-water PET. Reviewing the initial results (parametric images and polar maps) as part of the motion correction process, reduced erroneous corrections in motion-free scans. In a large clinical cohort, the impact of motion correction was limited to few patients.
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| 8. |
- Danad, Ibrahim, et al.
(författare)
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Quantitative Assessment of Myocardial Perfusion in the Detection of Significant Coronary Artery Disease Cutoff Values and Diagnostic Accuracy of Quantitative [O-15]H2O PET Imaging
- 2014
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Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097 .- 1558-3597. ; 64:14, s. 1464-1475
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Recent studies have demonstrated improved diagnostic accuracy for detecting coronary artery disease (CAD) when myocardial blood flow (MBF) is quantified in absolute terms, but there are no uniformly accepted cutoff values for hemodynamically significant CAD. OBJECTIVES The goal of this study was to determine cutoff values for absolute MBF and to evaluate the diagnostic accuracy of quantitative [O-15]H2O positron emission tomography (PET). METHODS A total of 330 patients underwent both quantitative [O-15]H2O PET imaging and invasive coronary angiography in conjunction with fractional flow reserve measurements. A stenosis >90% and/or fractional flow reserve <= 0.80 was considered obstructive; a stenosis <30% and/or fractional flow reserve >0.80 was nonobstructive. RESULTS Hemodynamically significant CAD was diagnosed in 116 (41%) of 281 patients who fulfilled study criteria for CAD. Resting perfusion was 1.00 +/- 0.25 and 0.92 +/- 0.23 ml/min/g in regions supplied by nonstenotic and significantly stenosed vessels, respectively (p < 0.001). During stress, perfusion increased to 3.26 +/- 1.04 ml/min/g and 1.73 +/- 0.67 ml/min/g, respectively (p < 0.001). The optimal cutoff values were 2.3 and 2.5 for hyperemic MBF and myocardial flow reserve, respectively. For MBF, these cutoff values showed a sensitivity, specificity, and accuracy for detecting significant CAD of 89%, 84%, and 86%, respectively, at a per-patient level and 87%, 85%, and 85% at a per-vessel level. The corresponding myocardial flow reserve values were 86%, 72%, and 78% (per patient) and 80%, 82%, and 81% (per vessel). Age and sex significantly affected diagnostic accuracy of quantitative PET. CONCLUSIONS Quantitative MBF measurements with the use of [O-15]H2O PET provided high diagnostic performance, but both sex and age should be taken into account.
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| 9. |
- Ekblom Bak, Elin, 1981-, et al.
(författare)
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Accelerometer derived physical activity and subclinical coronary and carotid atherosclerosis : cross-sectional analyses in 22 703 middle-aged men and women in the SCAPIS study
- 2023
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Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 13:11
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The aim included investigation of the associations between sedentary (SED), low-intensity physical activity (LIPA), moderate-to-vigorous intensity PA (MVPA) and the prevalence of subclinical atherosclerosis in both coronaries and carotids and the estimated difference in prevalence by theoretical reallocation of time in different PA behaviours.DESIGN: Cross-sectional.SETTING: Multisite study at university hospitals.PARTICIPANTS: A total of 22 670 participants without cardiovascular disease (51% women, 57.4 years, SD 4.3) from the population-based Swedish CArdioPulmonary bioImage study were included. SED, LIPA and MVPA were assessed by hip-worn accelerometer.PRIMARY AND SECONDARY OUTCOMES: Any and significant subclinical coronary atherosclerosis (CA), Coronary Artery Calcium Score (CACS) and carotid atherosclerosis (CarA) were derived from imaging data from coronary CT angiography and carotid ultrasound.RESULTS: High daily SED (>70% ≈10.5 hours/day) associated with a higher OR 1.44 (95% CI 1.09 to 1.91), for significant CA, and with lower OR 0.77 (95% CI 0.63 to 0.95), for significant CarA. High LIPA (>55% ≈8 hours/day) associated with lower OR for significant CA 0.70 (95% CI 0.51 to 0.96), and CACS, 0.71 (95% CI 0.51 to 0.97), but with higher OR for CarA 1.41 (95% CI 1.12 to 1.76). MVPA above reference level, >2% ≈20 min/day, associated with lower OR for significant CA (OR range 0.61-0.67), CACS (OR range 0.71-0.75) and CarA (OR range 0.72-0.79). Theoretical replacement of 30 min of SED into an equal amount of MVPA associated with lower OR for significant CA, especially in participants with high SED 0.84 (95% CI 0.76 to 0.96) or low MVPA 0.51 (0.36 to 0.73).CONCLUSIONS: MVPA was associated with a lower risk for significant atherosclerosis in both coronaries and carotids, while the association varied in strength and direction for SED and LIPA, respectively. If causal, clinical implications include avoiding high levels of daily SED and low levels of MVPA to reduce the risk of developing significant subclinical atherosclerosis.
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| 10. |
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| 11. |
- Granstam, Sven-Olof, et al.
(författare)
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Evaluation of patients with cardiac amyloidosis using echocardiography, ECG and right heart catheterization
- 2013
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Ingår i: Amyloid. - : Informa UK Limited. - 1350-6129 .- 1744-2818. ; 20:1, s. 27-33
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Tidskriftsartikel (refereegranskat)abstract
- Aims:To characterize patients with cardiac amyloidosis using echocardiography, electrocardiogram (ECG) and right heart catheterization (RHC).Methods and results:Fourteen patients with biopsy verified light chain or transthyretin cardiac amyloidosis were included. All patients had heart failure with markedly elevated NT-proBNP. Echocardiography demonstrated biventricular hypertrophy, left atrial enlargement and normal to slightly reduced left ventricular ejection fraction. Tissue Doppler septal e´ was low and median E/e´ was high. Within 6 months RHC was performed in eight of the patients. The restrictive filling pattern demonstrated by echocardiography corresponded well to median pulmonary wedge pressure (21 mmHg). Systolic pulmonary artery pressure (SPAP) was increased, whereas cardiac output and stroke volume were seen to be decreased with both methods. ECG demonstrated: low voltage (36%), abnormal R-progression (65%), ST-T abnormalities (71%) and high incidence of fibrillation (36%). In addition, a case report following the treatment of melphalan and dexamethasone is presented with improvement of hypertrophy, SPAP, left ventricular mass and e´.Conclusion: These findings should lead to a suspicion of cardiac amyloidosis and suggest further investigation.
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| 12. |
- Harms, Hendrik J., et al.
(författare)
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Association of right ventricular myocardial blood flow with pulmonary pressures and outcome in cardiac amyloidosis
- 2023
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Ingår i: JACC Cardiovascular Imaging. - : Elsevier. - 1936-878X .- 1876-7591. ; 16:9, s. 1193-1204
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cardiac amyloidosis (CA) is a restrictive and infiltrative cardiomyopathy, characterized by increased biventricular filling pressures and low output. Symptoms are predominantly of right heart origin. The role of right ventricular (RV) myocardial blood flow (MBF) in CA has not been studied.Objectives: This study aimed to first associate RV MBF measured by using positron emission tomography (PET) with reference standards of RV pressures and then to explore its prognostic value in CA.Methods: Cardiac PET was performed at rest in 52 patients with CA and 9 healthy control subjects. MBF was quantified from the right and left ventricles by using 11C-acetate, 15O-water, or both (n = 25). RV pressure was measured invasively or by echocardiography. Associations between biventricular MBF toward symptoms, RV function, and outcome (death or acute heart failure) were studied in patients with CA.Results: MBF of the right ventricle (MBFRV) and the ratio of MBFRV and MBF of the left ventricle (MBFRV/LV) for the 2 tracers were significantly correlated (r > 0.92). MBFRV was directly correlated with RV systolic pressures with both tracers (P ≤ 0.005). MBFLV was inversely correlated with wall thickness (P < 0.0001). MBFRV/LV was significantly associated with N-terminal pro–B-type natriuretic peptide levels, New York Heart Association functional class, RV pressures, and RV systolic function (all; P < 0.001). Twenty-six cardiac events (25 deaths) occurred during follow-up (median 44 months). MBFRV/LV higher than 56% was associated with a diagnosis of pulmonary hypertension (AUC: 0.96 [95% CI: 0.91-1.00]; P < 0.0001); and predicted outcome with hazard ratio 9.0 (95% CI: 4.2-14.5), P < 0.0001).Conclusions: Measurements of MBFRV using PET are feasible, as confirmed with 2 different tracers. Imbalance between RV and LV myocardial perfusion is associated with increased RV load and adverse events in cardiac amyloidosis.
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| 13. |
- Harms, Hendrik J, et al.
(författare)
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Automatic calculation of myocardial external efficiency using a single 11C-acetate PET scan.
- 2018
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 25:6, s. 1937-1944
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Myocardial external efficiency (MEE) is defined as the ratio of kinetic energy associated with cardiac work [forward cardiac output (FCO)*mean systemic pressure] and the chemical energy from oxygen consumed (MVO2) by the left ventricular mass (LVM). We developed a fully automated method for estimating MEE based on a single 11C-acetate PET scan without ECG-gating.METHODS AND RESULTS: Ten healthy controls, 34 patients with aortic valve stenosis (AVS), and 20 patients with mitral valve regurgitation (MVR) were recruited in a dual-center study. MVO2 was calculated using washout of 11C -acetate activity. FCO and LVM were calculated automatically using dynamic PET and parametric image formation. FCO and LVM were also obtained using cardiac magnetic resonance (CMR) in all subjects. The correlation between MEEPET-CMR and MEEPET was high (r = 0.85, P < 0.001) without significant bias. MEEPET was 23.6 ± 4.2% for controls and was lowered in AVS (17.2 ± 4.3%, P < 0.001) and in MVR (18.0 ± 5.2%, P = 0.004). MEEPET was strongly associated with both NYHA class (P < 0.001) and the magnitude of valvular dysfunction (mean aortic gradient: P < 0.001, regurgitant fraction: P = 0.009).CONCLUSION: A single 11C-acetate PET yields accurate and automated MEE results on different scanners. MEE might provide an unbiased measurement of the phenotypic response to valvular disease.
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| 14. |
- Harms, Hendrik Johannes, et al.
(författare)
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Automatic extraction of forward stroke volume using dynamic PET/CT : a dual-tracer and dual-scanner validation in patients with heart valve disease.
- 2015
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Ingår i: EJNMMI Physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to develop and validate an automated method for extracting forward stroke volume (FSV) using indicator dilution theory directly from dynamic positron emission tomography (PET) studies for two different tracers and scanners.METHODS: 35 subjects underwent a dynamic (11)C-acetate PET scan on a Siemens Biograph TruePoint-64 PET/CT (scanner I). In addition, 10 subjects underwent both dynamic (15)O-water PET and (11)C-acetate PET scans on a GE Discovery-ST PET/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase-contrast cardiovascular magnetic resonance (CMR).RESULTS: FSVPET correlated highly with FSVCMR (r = 0.87, slope = 0.90 for scanner I, r = 0.87, slope = 1.65, and r = 0.85, slope = 1.69 for scanner II for (15)O-water and (11)C-acetate, respectively) although a systematic bias was observed for both scanners (p < 0.001 for all). FSV based on (11)C-acetate and (15)O-water correlated highly (r = 0.99, slope = 1.03) with no significant difference between FSV estimates (p = 0.14).CONCLUSIONS: FSV can be obtained automatically using dynamic PET/CT and cluster analysis. Results are almost identical for (11)C-acetate and (15)O-water. A scanner-dependent bias was observed, and a scanner calibration factor is required for multi-scanner studies. Generalization of the method to other tracers and scanners requires further validation.
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| 15. |
- Hoff, Camilla Molich, et al.
(författare)
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Quantitative and qualitative comparison of Rubidium-82 and Oxygen-15 water cardiac PET.
- 2024
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Ingår i: Journal of Nuclear Cardiology. - 1071-3581 .- 1532-6551. ; , s. 101796-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Differences in tracer characteristics may influence the interpretation of positron emission tomography myocardial perfusion imaging (MPI). We compare the reading of MPIs with a low-extraction retention tracer (82Rb) and a high-extraction non-retention tracer (15O-water) in a selected cohort of patients with known coronary artery disease (CAD).METHODS: Thirty-nine patients with known CAD referred to 82Rb MPI due to angina underwent rest and stress imaging with both tracers and experienced MPI readers provided blinded consensus reads of all studies. In addition, a comparison of regional and global quantitative measures of perfusion was performed.RESULTS: The results showed 74 % agreement in the reading of 82Rb and 15O-water MPI for regional reversible ischemia and global disease, and 82 % agreement for regional irreversible ischemia. The 15O-water MPI identified more cases of global disease (n = 12 (15O-water) vs n = 4 (82Rb), p = 0.03), whereas differences in reversible ischemia (n = 22 vs n = 16, p = 0.11) and, irreversible ischemia (n = 8 vs n = 11, p = 0.45) were not significant. The correlation between myocardial blood flow measured using the two tracers was similar to previous studies (R2 = 0.78) with wide limits of agreement (-0.93 to 0.84 ml/g/min).CONCLUSIONS: Agreement between consensus readings of 82Rb and 15O-water MPI was good in patients with known CAD. In this limited size study, no significant differences in the identification of reversible and irreversible ischemia found, whereas 15O-water MPI had a higher positive rate for suspected global disease.
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| 16. |
- Johnston, Nina, et al.
(författare)
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Effect of Gender on Patients With ST-Elevation and Non-ST-Elevation Myocardial Infarction Without Obstructive Coronary Artery Disease
- 2015
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Ingår i: American Journal of Cardiology. - : Elsevier BV. - 0002-9149 .- 1879-1913. ; 115:12, s. 1661-1666
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare the prognoses of patients with ST-segment elevation myocardial infarction (STEMI) and those with non-ST-segment elevation myocardial infarction (NSTEMI) without obstructive coronary artery disease (CAD) and the risk associated with gender for future cardiovascular events. The study population was selected from 95,849 patients who underwent coronary angiography for myocardial infarction from 2005 to 2010 and registered in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). Outcome analyses, including all-cause death, myocardial infarction, congestive heart failure, stroke, and revascularization, were performed in 2,268 patients with STEMI and 10,904 with NSTEMI without obstructive CAD (<50% stenosis). Hazard ratios and 95% confidence intervals comparing women with men were calculated for events, adjusting for cardiovascular risk factors and age. Nonobstructive CAD was found in 7% of patients with STEMI (6% men, 10% women) and in 17% of those with NSTEMI (11% men, 28% women). During a median follow-up of 2.6 years, 8% of patients with STEMI and 5% of those with NSTEMI died. Gender-associated differences in risk were observed in patients with NSTEMI, with adjusted hazard ratios lower in women than men for mortality (hazard ratio 0.90, 95% confidence interval 0.50 to 0.73) and congestive heart failure (hazard ratio 0.61, 95% confidence interval 0.52 to 0.72). In the 2 groups, women underwent less revascularization. In conclusion, nonobstructive CAD was more common in patients with NSTEMI than those with STEMI, as well as in women compared with men. Long-term mortality in patients with nonobstructive CAD was higher after STEMI than NSTEMI. The gender differences in outcomes suggest gender differences in the underlying pathogenesis of myocardial infarction without obstructive CAD.
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| 17. |
- Kero, Tanja, et al.
(författare)
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Accurate analysis and visualization of cardiac (11)C-PIB uptake in amyloidosis with semiautomatic software
- 2016
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 23:4, s. 741-750
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: (11)C-PIB PET is a promising non-invasive diagnostic tool for cardiac amyloidosis. Semiautomatic analysis of PET data is now available but it is not known how accurate these methods are for amyloid imaging. The aim of this study was to evaluate the feasibility of one semiautomatic software tool for analysis and visualization of (11)C-PIB left ventricular retention index (RI) in cardiac amyloidosis.METHODS AND RESULTS: Patients with systemic amyloidosis and cardiac involvement (n = 10) and healthy controls (n = 5) were investigated with dynamic (11)C-PIB PET. Two observers analyzed the PET studies with semiautomatic software to calculate the left ventricular RI of (11)C-PIB and to create parametric images. The mean RI at 15-25 min from the semiautomatic analysis was compared with RI based on manual analysis and showed comparable values (0.056 vs 0.054 min(-1) for amyloidosis patients and 0.024 vs 0.025 min(-1) in healthy controls; P = .78) and the correlation was excellent (r = 0.98). Inter-reader reproducibility also was excellent (intraclass correlation coefficient, ICC > 0.98). Parametric polarmaps and histograms made visual separation of amyloidosis patients and healthy controls fast and simple.CONCLUSION: Accurate semiautomatic analysis of cardiac (11)C-PIB RI in amyloidosis patients is feasible. Parametric polarmaps and histograms make visual interpretation fast and simple.
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| 18. |
- Kero, Tanja, et al.
(författare)
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Evaluation of quantitative CMR perfusion imaging by comparison with simultaneous 15O-water-PET
- 2021
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 28, s. 1252-1266
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundWe assessed the quantitative accuracy of cardiac perfusion measurements using dynamic contrast-enhanced MRI with simultaneous 15O-water PET as reference with a fully integrated PET-MR scanner.Methods15 patients underwent simultaneous DCE MRI and 15O-water PET scans at rest and adenosine-stress on an integrated PET-MR scanner. Correlation and agreement between MRI- and PET-based global and regional MBF values were assessed using correlation and Bland–Altman analysis.ResultsThree subjects were excluded due to technical problems. Global mean (± SD) MBF values at rest and stress were 0.97 ± 0.27 and 3.19 ± 0.70 mL/g/min for MRI and 1.02 ± 0.28 and 3.13 ± 1.16 mL/g/min for PET (P = 0.66 and P = 0.81). The correlations between global and regional MRI- and PET-based MBF values were strong (r = 0.86 and r = 0.75). The biases were negligible for both global and regional MBF comparisons (0.01 and 0.00 mL/min/g for both), but the limits of agreement were wide for both global and regional MBF, with larger variability for high MBF-values.ConclusionThe correlation between simultaneous MBF measurements with DCE MRI and 15O-water PET measured in an integrated PET-MRI was strong but the agreement was only moderate indicating that MRI-based quantitative MBF measurements is not ready for clinical introduction.
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| 19. |
- Kero, Tanja
(författare)
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Methodological aspects of quantitative cardiac molecular imaging
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objective of this research was to facilitate the use of quantitative cardiac molecular imaging by developing and validating methods and applications. More specifically:we determined the optimal tracer kinetic model for analysis of 11C-PIB and evaluated the performance of two simpler measures, retention index (RI) and standardized uptake value (SUV), in the quantification of cardiac 11C-PIB uptake in amyloidosis. An irreversible two-tissue (2Tirr) model best described the 11C-PIB uptake in cardiac amyloidosis. RI and SUV showed high correlation with quantitative results from this kinetic model and also a better discrimination between amyloidosis patients and controls than a 2Tirr model with population averaged metabolite correction. RI and SUV are furthermore more feasible for use in clinical routine and therefore the preferred measure to use in PET diagnosis of cardiac amyloidosis. We also tested the feasibility of a semiautomatic software to analyze RI and visualize cardiac uptake of 11C-PIB in amyloidosis. The RI values were comparable with RI based on manual segmentation, showing significantly higher 11C-PIB RI in amyloidosis patients than in healthy volunteers. A fast and accurate semiautomatic analysis process is thus feasible to use for PET in cardiac amyloidosis instead of the laborious manual analyses that were used so far.Furthermore, we assessed the quantitative accuracy of cardiac perfusion measurements with 15O-water PET in a digital time-of-flight PET-MR scanner. A high correlation and agreement between PET-MR based and PET-CT based MBF was found; cardiac perfusion measurements with 15O-water can therefore be performed accurately with the fully integrated Signa PET-MR scanner. Finally, we assessed the quantitative accuracy of cardiac perfusion measurements using dynamic contrast-enhanced MRI with simultaneous 15O-water PET as reference at rest and during adenosine-induced hyperemia with a fully integrated PET-MR scanner. The correlations between global and regional MRI- and PET-based MBF values were good and the biases were negliable for both global and regional MBF comparisons, but the limits of agreement were wide for both global and regional MBF, with larger variability for high MBF-values indicating that MRI-based quantitative MBF measurement based on widely available acquisition protocols is not yet ready for clinical introduction.
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| 20. |
- Kero, Tanja, et al.
(författare)
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Quantification of (11)C-PIB kinetics in cardiac amyloidosis
- 2020
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 27:3, s. 774-784
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The purpose of this work was to determine the optimal tracer kinetic model of (11)C-PIB and to validate the use of the simplified methods retention index (RI) and standardized uptake value (SUV) for quantification of cardiac (11)C-PIB uptake in amyloidosis. METHODS AND RESULTS: Single-tissue, reversible and irreversible two-tissue models were fitted to data from seven cardiac amyloidosis patients who underwent (11)C-PIB PET scans and arterial blood sampling for measurement of blood radioactivity and metabolites. The irreversible two-tissue model (2Tirr) best described cardiac (11)C-PIB uptake. RI and SUV showed high correlation with the rate of irreversible binding (Ki) from the 2Tirr model (r(2 )=0.95 and r(2 )=0.94). Retrospective data from 10 amyloidosis patients and 5 healthy controls were analyzed using RI, SUV, as well as compartment modelling with a population-average metabolite correction. All measures were higher in amyloidosis patients than in healthy controls (p=.001), but with an overlap between groups for Ki. CONCLUSION: An irreversible two-tissue model best describes the (11)C-PIB uptake in cardiac amyloidosis. RI and SUV correlate well with Ki from the 2Tirr model. RI and SUV discriminate better between amyloidosis patients and controls than Ki based on population-average metabolite correction.
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| 21. |
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| 22. |
- Kero, Tanja, et al.
(författare)
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Quantitative myocardial blood flow imaging with integrated time-of-flight PET-MR
- 2017
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Ingår i: EJNMMI Physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The use of integrated PET-MR offers new opportunities for comprehensive assessment of cardiac morphology and function. However, little is known on the quantitative accuracy of cardiac PET imaging with integrated time-of-flight PET-MR. The aim of the present work was to validate the GE Signa PET-MR scanner for quantitative cardiac PET perfusion imaging. Eleven patients (nine male; mean age 59 years; range 46-74 years) with known or suspected coronary artery disease underwent (15)O-water PET scans at rest and during adenosine-induced hyperaemia on a GE Discovery ST PET-CT and a GE Signa PET-MR scanner. PET-MR images were reconstructed using settings recommended by the manufacturer, including time-of-flight (TOF). Data were analysed semi-automatically using Cardiac VUer software, resulting in both parametric myocardial blood flow (MBF) images and segment-based MBF values. Correlation and agreement between PET-CT-based and PET-MR-based MBF values for all three coronary artery territories were assessed using regression analysis and intra-class correlation coefficients (ICC). In addition to the cardiac PET-MR reconstruction protocol as recommended by the manufacturer, comparisons were made using a PET-CT resolution-matched reconstruction protocol both without and with TOF to assess the effect of time-of-flight and reconstruction parameters on quantitative MBF values.RESULTS: Stress MBF data from one patient was excluded due to movement during the PET-CT scanning. Mean MBF values at rest and stress were (0.92 ± 0.12) and (2.74 ± 1.37) mL/g/min for PET-CT and (0.90 ± 0.23) and (2.65 ± 1.15) mL/g/min for PET-MR (p = 0.33 and p = 0.74). ICC between PET-CT-based and PET-MR-based regional MBF was 0.98. Image quality was improved with PET-MR as compared to PET-CT. ICC between PET-MR-based regional MBF with and without TOF and using different filter and reconstruction settings was 1.00.CONCLUSIONS: PET-MR-based MBF values correlated well with PET-CT-based MBF values and the parametric PET-MR images were excellent. TOF and reconstruction settings had little impact on MBF values.
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- Kero, Tanja, et al.
(författare)
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Quantitative myocardial perfusion response to adenosine and regadenoson in patients with suspected coronary artery disease
- 2022
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 29:1, s. 24-36
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of the present study was to compare the quantitative flow responses of regadenoson against adenosine using cardiac 15O-water PET imaging in patients with suspected or known coronary artery disease (CAD).METHODS: Hyperemic myocardial blood flow (MBF) after adenosine and regadenoson was compared using correlation and Bland-Altman analysis in 21 patients who underwent rest and adenosine 15O-water PET scans followed by rest and regadenoson 15O-water PET scans.RESULTS: Global mean (± SD) MBF values at rest and stress were 0.92 ± 0.27 and 2.68 ± 0.80 mL·g·min for the adenosine study and 0.95 ± 0.29 and 2.76 ± 0.79 mL·g·min for the regadenoson study (P = 0.55 and P = 0.49). The correlations between global and regional adenosine- and regadenoson-based stress MBF were strong (r = 0.80 and r = 0.77). The biases were small for both global and regional MBF comparisons (0.08 and 0.09 mL·min·g), but the limits of agreement were wide for stress MBF.CONCLUSION: The correlation between regadenoson- and adenosine-induced hyperemic MBF was strong but the agreement was only moderate indicating that established cut-off values for 150-water PET should be used cautiously if using regadenoson as vasodilator.
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