| 1. |
- Almeida, Nuno, et al.
(författare)
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Left atrial volumetric assessment using a novel automated framework for 3D echocardiography: a multi-centre analysis
- 2017
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Ingår i: European Heart Journal Cardiovascular Imaging. - : OXFORD UNIV PRESS. - 2047-2404 .- 2047-2412. ; 18:9, s. 1008-1015
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Tidskriftsartikel (refereegranskat)abstract
- Aims This study aims at validating a software tool for automated segmentation and quantification of the left atrium (LA) from 3D echocardiography. Methods and results The LA segmentation tool uses a dual-chamber model of the left side of the heart to automatically detect and track the atrio-ventricular plane and the LA endocardium in transthoracic 3D echocardiography. The tool was tested in a dataset of 121 ultrasound images from patients with several cardiovascular pathologies (in a multi-centre setting), and the resulting volumes were compared with those assessed manually by experts in a blinded analysis using conventional contouring. Bland-Altman analysis showed good agreement between the automated method and the manual references, with differences (mean +/- 1.96 SD) of 0.5 +/- 5.7 mL for LA minimum volume and -1.6 +/- 9.7 mL for LA maximum volume (comparable to the inter-observer variability of manual tracings). The automated tool required no user interaction in 93% of the recordings, while 4% required a single click and only 2% required contour adjustments, reducing considerably the amount of time and effort required for LA volumetric analysis. Conclusion The automated tool was validated in a multi-centre setting, providing quantification of the LA volume over the cardiac cycle with minimal user interaction. The results of the automated analysis were in agreement with those estimated manually by experts. This study shows that such approach has clinical utility for the assessment of the LA morphology and function, automating and facilitating the time-consuming task of analysing 3D echocardiographic recordings.
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| 2. |
- Maret, Eva, et al.
(författare)
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Phase analysis detects heterogeneity of myocardial deformation on cine MRI
- 2015
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa Healthcare. - 1401-7431 .- 1651-2006. ; 49:3, s. 149-158
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Objectives. Myocardial scar will lead to heterogeneous left ventricular deformation. We hypothesized that a myocardial scar will display an elevated standard deviation of phase and that this effect could be compared with mechanical dispersion. Design. Thirty patients (3 women and 27 men) were investigated 4-8 weeks after ST-elevation myocardial infarction treated with percutaneous coronary intervention. Seventeen had a scar area >75% in at least one antero- or inferoseptal segment (scar) and 13 had scar <1% (non-scar). The phase delays of velocity, displacement and strain were measured in the longitudinal direction, tangential to the endocardial outline, and in the radial direction, perpendicular to the tangent. Results. The standard deviation of phase in radial measurements differentiated scar patients from those without scar (p<0.01), while longitudinal measurements did so only for longitudinal strain. Likewise, the standard deviation for radial measurements of time to peak for segmental velocity, displacement and strain performed better than longitudinal measurements and equal to the results of phase. Conclusion. Phase dispersion in deformation imaging may be used for detecting heterogeneous left ventricular contraction.
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| 3. |
- 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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| 4. |
- 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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| 5. |
- Pedrosa, Joao, et al.
(författare)
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Automatic Short Axis Orientation of the Left Ventricle in 3D Ultrasound Recordings
- 2016
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Ingår i: MEDICAL IMAGING 2016: ULTRASONIC IMAGING AND TOMOGRAPHY. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510600256
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Konferensbidrag (refereegranskat)abstract
- The recent advent of three-dimensional echocardiography has led to an increased interest from the scientific community in left ventricle segmentation frameworks for cardiac volume and function assessment. An automatic orientation of the segmented left ventricular mesh is an important step to obtain a point-to-point correspondence between the mesh and the cardiac anatomy. Furthermore, this would allow for an automatic division of the left ventricle into the standard 17 segments and, thus, fully automatic per-segment analysis, e.g. regional strain assessment. In this work, a method for fully automatic short axis orientation of the segmented left ventricle is presented. The proposed framework aims at detecting the inferior right ventricular insertion point. 211 three-dimensional echocardiographic images were used to validate this framework by comparison to manual annotation of the inferior right ventricular insertion point. A mean unsigned error of 8, 05 degrees +/- 18, 50 degrees was found, whereas the mean signed error was 1, 09 degrees. Large deviations between the manual and automatic annotations (amp;gt; 30 degrees) only occurred in 3, 79% of cases. The average computation time was 666ms in a non-optimized MATLAB environment, which potentiates real-time application. In conclusion, a successful automatic real-time method for orientation of the segmented left ventricle is proposed.
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| 6. |
- 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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| 7. |
- Rademakers, Frank, et al.
(författare)
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Determining optimal noninvasive parameters for the prediction of left ventricular remodeling in chronic ischemic patients
- 2013
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa Healthcare. - 1401-7431 .- 1651-2006. ; 47:6, s. 329-334
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. DOPPLER-CIP aims to determine the optimal noninvasive parameters (myocardial function, perfusion, ventricular blood flow, cell integrity) and methodology (ergometry, echocardiography, scintigraphy, MRI) in a given ischemic substrate that best predicts the impact of an intervention (or the lack thereof) on adverse morphological ventricular remodeling and functional recovery. Moreover, the relative predictive value of each of these parameters, in respect to the cost of extracting this information in order to enable optimization of cost-effectiveness for improved health care, will be determined by this project. Design. DOPPLER-CIP is a multi-center registry study. All patients with ischemic heart disease included in this study undergo at least two noninvasive stress imaging examinations at baseline. The presence/or absence of left ventricular (LV) remodeling will be assessed after a follow-up of 2 years, during which all cardiac events will be registered. Results. 676 patients were included. Currently, baseline data analysis is almost finished and the follow-up is ongoing. Conclusions. After completion, DOPPLER-CIP will provide evidence-based guidelines toward the most effective use of cardiac imaging in the chronically ischemic heart disease patient. The study will generate information, knowledge, and insight into the new imaging methodologies and into the pathophysiology of chronic ischemic heart disease.
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| 8. |
- Rosendahl, Lene, 1963-
(författare)
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Infarct size and myocardial function : A methodological study
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The size of a myocardial infarction (MI) and the concurrent effect on left ventricular (LV) function are essential for decisions regarding patient care and treatment. Images produced with the late gadolinium enhancement (LGE) technique visualize the scar with high spatial resolution. The general aim of this thesis was to study methods to assess scar size in chronic MI, primarily with the use of LGE, and to relate area‐at‐risk and LV function to scar size.Myocardial perfusion single photon emission computed tomography (MPS) is a well established technique for the assessment of MI size. Our study showed that there is a fairly good agreement between MPS and LGE in the determination of scar size. Wall motion score index (WMSI) correlated moderately with both infarct size and infarct extent determined with LGE.Manual delineation of myocardium and scar is time consuming and subjective and there is a need for help in objective assessment. We showed that the semi‐automatic computer software, Segment, reduced the evaluation time ≥50% with maintained clinical accuracy.The segmented scar sequence ‐ inversion recovery fast gradient echo, IR_FGRE, is a well documented sequence for scar determination, however, the sequence requires regular heart rhythm and breath holding for good imaging. We showed that a single shot scar sequence ‐ steady state free precession, SS_SSFP ‐ acquired under free breathing in patients with ongoing atrial fibrillation, had significantly better image quality than IR_FGRE. The scar size and the error of determination were equal for both sequences and the examination time was shorter with SS_SSFP.In an acute MI it is essential to know the myocardial area‐at‐risk. WMSI is clinically the most common way of assessing LV function, but is highly subjective. Tissue Doppler imaging with strain measurements is considered objective and quantitative in assessing both global and regional LV function compared to WMSI. Our results showed that WMSI is superior to strain for the detection of scar with transmurality ≥50% in patients with acute MI. Also WMSI correlated better than strain on all levels (global, regional, segmental) with final scar size determined with LGE.LGE images visualize myocardial scar much more distinctly than any other modality. This new technique needs clinical validation but promises intense competition with existing modalities such as myocardial scintigraphy and echocardiography.However, in individual patient care all modalities should be used according to their own advantages and limitation.
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