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- Achenbach, Stephan, et al.
(författare)
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CV Imaging : What Was New in 2012?
- 2013
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Ingår i: JACC Cardiovascular Imaging. - : Elsevier BV. - 1936-878X .- 1876-7591. ; 6:6, s. 714-734
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Tidskriftsartikel (refereegranskat)abstract
- Echocardiography, single-photon emission computed tomography (SPECT), positron emission tomography (PET), cardiac magnetic resonance, and cardiac computed tomography can be used for anatomic and functional imaging of the heart. All 4 methods are subject to continuous improvement. Echocardiography benefits from the more widespread availability of 3-dimensional imaging, strain and strain rate analysis, and contrast applications. SPECT imaging continues to provide very valuable prognostic data, and PET imaging, on the one hand, permits quantification of coronary flow reserve, a strong prognostic predictor, and, on the other hand, can be used for molecular imaging, allowing the analysis of extremely small-scale functional alterations in the heart. Magnetic resonance is gaining increasing importance as a stress test, mainly through perfusion imaging, and continues to provide very valuable prognostic information based on late gadolinium enhancement. Magnetic resonance coronary angiography does not substantially contribute to clinical cardiology at this point in time. Computed tomography imaging of the heart mainly concentrates on the imaging of coronary artery lumen and plaque and has made substantial progress regarding outcome data. In this review, the current status of the 5 imaging techniques is illustrated by reviewing pertinent publications of the year 2012.
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| 4. |
- Elliott, Perry, et al.
(författare)
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Development, validation and implementation of biomarker testing in cardiovascular medicine state-of-the-art : Proceedings of the European Society of Cardiology - Cardiovascular Round Table
- 2021
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Ingår i: Cardiovascular Research. - : Oxford University Press. - 0008-6363 .- 1755-3245. ; 117:5, s. 1248-1256
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Tidskriftsartikel (refereegranskat)abstract
- Many biomarkers that could be used to assess ejection fraction, heart failure, or myocardial infarction fail to translate into clinical practice because they lack essential performance characteristics or fail to meet regulatory standards for approval. Despite their potential, new technologies have added to the complexities of successful translation into clinical practice. Biomarker discovery and implementation requires a standardised approach that includes: identification of a clinical need; identification of a valid surrogate biomarker; stepwise assay refinement, demonstration of superiority over current standard-of-care; development and understanding of a clinical pathway; and demonstration of real-world performance. Successful biomarkers should improve efficacy or safety of treatment, while being practical at a realistic cost. Everyone involved in cardiovascular healthcare, including researchers, clinicians, and industry partners, are important stakeholders in facilitating the development and implementation of biomarkers. This paper provides suggestions for a development pathway for new biomarkers, discusses regulatory issues and challenges, and suggestions for accelerating the pathway to improve patient outcomes. Real life examples of successful biomarkers-high sensitivity cardiac troponin (hs-cTn), T2* cardiovascular magnetic resonance (CMR) imaging, and echocardiography-are used to illustrate the value of a standardised development pathway in the translation of concepts into routine clinical practice.
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| 6. |
- Hedström, Erik, et al.
(författare)
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A fully automatic algorithm for assessing T2* and its certainty value for accurate cardiac and liver iron load determination
- 2013
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Ingår i: Journal of Cardiovascular Magnetic Resonance. - 1097-6647. ; 15:Suppl 1
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Tidskriftsartikel (refereegranskat)abstract
- Quantification of myocardial and liver iron load has become a mainstay of guiding therapy in thalassaemia patients. However, current quantification methods are user dependent for data-point exclusion before curve fitting, and do not report the T2* certainty. Recently, an automatic inline maximum likelihood estimate (MLE) method with k-space Rician noise correction was validated against the reference standard manual truncation method. We now present a vendor-independent offline tool for fully automatic post processing and T2* quantification with certainty estimates, tested in computer simulations and patients with iron overload.
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| 7. |
- Hedström, Erik, et al.
(författare)
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The effect of initial teaching on evaluation of left ventricular volumes by cardiovascular magnetic resonance imaging : Comparison between complete and intermediate beginners and experienced observers
- 2017
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Ingår i: BMC Medical Imaging. - : Springer Science and Business Media LLC. - 1471-2342. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: High reproducibility and low intra- and interobserver variability are important strengths of cardiac magnetic resonance (CMR). In clinical practice a significant learning curve may however be observed. Basic CMR courses offer an average of 1.4 h dedicated to lecturing and demonstrating left ventricular (LV) function analysis. The purpose of this study was to evaluate the effect of initial teaching on complete and intermediate beginners' quantitative measurements of LV volumes and function by CMR. Methods: Standard clinical cine CMR sequences were acquired in 15 patients. Five observers (two complete beginners, one intermediate, two experienced) measured LV volumes. Before initial evaluation beginners read the SCMR guidelines on CMR analysis. After initial evaluation, beginners participated in a two-hour teaching session including cases and hands-on training, representative for most basic CMR courses, after which it is uncertain to what extent different centres provide continued teaching and feedback in-house. Dice Similarity Coefficient (DSC) assessed delineations. Agreement, accuracy, precision, repeatability and reliability were assessed by Bland-Altman, coefficient of variation, and intraclass correlation coefficient methods. Results: Endocardial DSC improved after teaching (+0.14 ± 0.17;p < 0.001) for complete beginners. Low intraobserver variability was found before and after teaching, however with wide limits of agreement. Beginners underestimated volumes by up to 44 ml (EDV), 27 ml (ESV) and overestimated LVM by up to 53 g before teaching, improving to an underestimation of up to 9 ml (EDV), 7 ml (ESV) and an overestimation of up to 30 g (LVM) after teaching. For the intermediate beginner, however, accuracy was quite high already before teaching. Conclusions: Initial teaching to complete beginners increases accuracy for assessment of LV volumes, however with high bias and low precision even after standardised teaching as offered in most basic CMR courses. Even though the intermediate beginner showed quite high accuracy already before teaching, precision did generally not improve after standardised teaching. To maintain CMR as a technique known for high accuracy and reproducibility and low intra- and inter-observer variability for quantitative measurements, internationally standardised training should be encouraged including high-quality feedback mechanisms. Objective measurements of training methods, training duration and, above all, quality of assessments are required.
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| 8. |
- Myhre, Peder L., et al.
(författare)
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Cardiac troponin T and NT-proBNP for detecting myocardial ischemia in suspected chronic coronary syndrome
- 2022
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Ingår i: International Journal of Cardiology. - : Elsevier Ireland Ltd. - 0167-5273 .- 1874-1754. ; 361, s. 14-17
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Tidskriftsartikel (refereegranskat)abstract
- Background: Elevated N-terminal pro-B-type natriuretic peptides (NT-proBNP) and cardiac troponin T (cTnT) are associated with poor outcome in patients with chronic coronary syndrome (CCS). The performance of these biomarkers in diagnosing ischemia, and their association with myocardial hypoperfusion and hypokinesis is unclear. Methods: Patients with suspected CCS (history of angina, estimated cardiovascular risk >15% or a positive stress test) were included in the prospective, multi-center DOPPLER-CIP study. Patients underwent Single Positron Emission Computed Tomography for assessment of ischemia and NT-proBNP and cTnT were measured in venous blood samples. Results: We included 430 patients (25% female) aged 64 +/- 8 years. Reversible hypoperfusion and hypokinesis were present in 139 (32%) and 89 (21%), respectively. Concentrations of NT-proBNP and cTnT correlated moderately (rho = 0.50, p < 0.001). NT-proBNP and cTnT concentrations (median [IQR]) were higher in patients with versus without reversible ischemia: 150 (73-294) versus 87 (44-192) ng/L and 10 (6-13) versus 7 (4-11) ng/L, respectively (p < 0.001 for both), and the associations persisted after adjusting for possible confounders. The C-statistics to discriminate ischemia ranged from 63%-73%, were comparable for cTnT and NT-proBNP, and higher for hypokinesis than hypoperfusion, and both were superior to exercise electrocardiography and stress echocardiography. Very low concentrations (<= 5 ng/L cTnT and <= 60 ng/L NT-proBNP) ruled out reversible hypokinesis with negative predictive value >90%. Conclusion: cTnT and NT-proBNP are associated with irreversible and reversible ischemia in patients with suspected CCS, particularly hypokinesis. The diagnostic performance was comparable between the biomarkers, and very low concentrations may reliably rule out ischemia.
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| 9. |
- Myhre, Peder L., et al.
(författare)
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Cardiac Troponin T Concentrations, Reversible Myocardial Ischemia, and Indices of Left Ventricular Remodeling in Patients with Suspected Stable Angina Pectoris: a DOPPLER-CIP Substudy
- 2018
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Ingår i: Clinical Chemistry. - : AMER ASSOC CLINICAL CHEMISTRY. - 0009-9147 .- 1530-8561. ; 64:9, s. 1370-1379
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cardiac troponin T concentrations measured with high-sensitivity assays (hs-cTnT) provide important prognostic information for patients with stable coronary artery disease (CAD). However, whether hsc-TnT concentrations mainly reflect left ventricular (LV) remodeling or recurrent myocardial ischemia in this population is not known. METHODS: We measured hs-cTnT concentrations in 619 subjects with suspected stable CAD in a prospectively designed multicenter study. We identified associations with indices of LV remodeling, as assessed by cardiac MRI and echocardiography, and evidence of myocardial ischemia diagnosed by single positron emission computed tomography. RESULTS: Median hs-cTnT concentration was 7.8 ng/L (interquartile range, 4.8 -11.6 ng/L), and 111 patients (18%) had hs-cTnT concentrations above the upper reference limit (amp;gt; 14 ng/L). Patients with hs-cTnT amp;gt; 14 ng/L had increased LV mass (144 +/- 40 g vs 116 +/- 34 g; P amp;lt; 0.001) and volume (179 +/- 80 mL vs 158 +/- 44 mL; P = 0.006), lower LV ejection fraction (LVEF) (59 +/- 14 vs 62 +/- 11; P = 0.006) and global longitudinal strain (14.1 +/- 3.4% vs 16.9 +/- 3.2%; P amp;lt; 0.001), and more reversible perfusion defects (P amp;lt; 0.001) and reversible wall motion abnormalities (P = 0.008). Age (P = 0.009), estimated glomerular filtration rate (P = 0.01), LV mass (P = 0.003), LVEF (P = 0.03), and evidence of reversible myocardial ischemia (P = 0.004 for perfusion defects and P = 0.02 for LV wall motion) were all associated with increasing hs-cTnT concentrations in multivariate analysis. We found analogous results when using the revised US upper reference limit of 19 ng/L. CONCLUSIONS: hs-cTnT concentrations reflect both LV mass and reversible myocardial ischemia in patients with suspected stable CAD. (c) 2018 American Association for Clinical Chemistry
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| 10. |
- Pedrosa, Joao, et al.
(författare)
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Fast and Fully Automatic Left Ventricular Segmentation and Tracking in Echocardiography Using Shape-Based B-Spline Explicit Active Surfaces
- 2017
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Ingår i: IEEE Transactions on Medical Imaging. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0278-0062 .- 1558-254X. ; 36:11, s. 2287-2296
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Tidskriftsartikel (refereegranskat)abstract
- Cardiac volume/function assessment remains a critical step in daily cardiology, and 3-D ultrasound plays an increasingly important role. Fully automatic left ventricular segmentation is, however, a challenging task due to the artifacts and low contrast-to-noise ratio of ultrasound imaging. In this paper, a fast and fully automatic framework for the full-cycle endocardial left ventricle segmentation is proposed. This approach couples the advantages of the B-spline explicit active surfaces framework, a purely image information approach, to those of statistical shape models to give prior information about the expected shape for an accurate segmentation. The segmentation is propagated throughout the heart cycle using a localized anatomical affine optical flow. It is shown that this approach not only outperforms other state-of-the-art methods in terms of distance metrics with a mean average distances of 1.81 +/- 0.59 and 1.98 +/- 0.66 mm at end-diastole and end-systole, respectively, but is computationally efficient (in average 11 s per 4-D image) and fully automatic.
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