1
|
Sharrack N, Das A, Kelly C, Teh I, Stoeck CT, Kozerke S, Swoboda PP, Greenwood JP, Plein S, Schneider JE, Dall'Armellina E. The relationship between myocardial microstructure and strain in chronic infarction using cardiovascular magnetic resonance diffusion tensor imaging and feature tracking. J Cardiovasc Magn Reson 2022; 24:66. [PMID: 36419059 PMCID: PMC9685947 DOI: 10.1186/s12968-022-00892-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 10/03/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Cardiac diffusion tensor imaging (cDTI) using cardiovascular magnetic resonance (CMR) is a novel technique for the non-invasive assessment of myocardial microstructure. Previous studies have shown myocardial infarction to result in loss of sheetlet angularity, derived by reduced secondary eigenvector (E2A) and reduction in subendocardial cardiomyocytes, evidenced by loss of myocytes with right-handed orientation (RHM) on helix angle (HA) maps. Myocardial strain assessed using feature tracking-CMR (FT-CMR) is a sensitive marker of sub-clinical myocardial dysfunction. We sought to explore the relationship between these two techniques (strain and cDTI) in patients at 3 months following ST-elevation MI (STEMI). METHODS 32 patients (F = 28, 60 ± 10 years) underwent 3T CMR three months after STEMI (mean interval 105 ± 17 days) with second order motion compensated (M2), free-breathing spin echo cDTI, cine gradient echo and late gadolinium enhancement (LGE) imaging. HA maps divided into left-handed HA (LHM, - 90 < HA < - 30), circumferential HA (CM, - 30° < HA < 30°), and right-handed HA (RHM, 30° < HA < 90°) were reported as relative proportions. Global and segmental analysis was undertaken. RESULTS Mean left ventricular ejection fraction (LVEF) was 44 ± 10% with a mean infarct size of 18 ± 12 g and a mean infarct segment LGE enhancement of 66 ± 21%. Mean global radial strain was 19 ± 6, mean global circumferential strain was - 13 ± - 3 and mean global longitudinal strain was - 10 ± - 3. Global and segmental radial strain correlated significantly with E2A in infarcted segments (p = 0.002, p = 0.011). Both global and segmental longitudinal strain correlated with RHM of infarcted segments on HA maps (p < 0.001, p = 0.003). Mean Diffusivity (MD) correlated significantly with the global infarct size (p < 0.008). When patients were categorised according to LVEF (reduced, mid-range and preserved), all cDTI parameters differed significantly between the three groups. CONCLUSION Change in sheetlet orientation assessed using E2A from cDTI correlates with impaired radial strain. Segments with fewer subendocardial cardiomyocytes, evidenced by a lower proportion of myocytes with right-handed orientation on HA maps, show impaired longitudinal strain. Infarct segment enhancement correlates significantly with E2A and RHM. Our data has demonstrated a link between myocardial microstructure and contractility following myocardial infarction, suggesting a potential role for CMR cDTI to clinically relevant functional impact.
Collapse
Affiliation(s)
- N Sharrack
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - A Das
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - C Kelly
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - I Teh
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - C T Stoeck
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Centre for Surgical Research, University of Zurich and University Hospital Zurich, Zurich, Switzerland
| | - S Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - P P Swoboda
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - J P Greenwood
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - S Plein
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - J E Schneider
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - E Dall'Armellina
- Biomedical Imaging Sciences Department, Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK.
| |
Collapse
|
2
|
Gotschy A, Jordan S, Stoeck CT, Von Deuster C, Gastl M, Vishnevskiy V, Wissmann L, Dobrota R, Mihai C, Becker MO, Maurer B, Kozerke S, Ruschitzka F, Distler O, Manka R. Diffuse myocardial fibrosis precedes impairment of myocardial strain in patients with systemic sclerosis. Eur Heart J Cardiovasc Imaging 2021. [DOI: 10.1093/ehjci/jeab090.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background - Myocardial involvement is common in patients with systemic sclerosis (SSc) and causes myocardial fibrosis and subtle ventricular dysfunction. However, the temporal onset of myocardial involvement during the progression of the disease is yet unknown.
Purpose - To investigated the presence of subclinical functional impairment and diffuse myocardial fibrosis in patients with very early diagnosis of SSc (VEDOSS) and to compared the findings to patients with established SSc and healthy controls.
Methods - 110 SSc patients (86 with established SSc and 24 with VEDOSS) and 15 healthy controls were prospectively recruited. The study subjects underwent cardiovascular magnetic resonance on a clinical 1.5T system. Pre- and post-contrast T1 mapping was performed using a MOLLI (Modified Look-Locker Inversion Recovery) sequence. For extracellular volume (ECV) measurements, a single bolus protocol with image acquisition 15-20 min. post-contrast injection was used. For the assessment of subtle functional impairment, global longitudinal (GLS) and circumferential (GCS) myocardial strain were evaluated.
Results - Native T1 values and ECV were elevated in VEDOSS and in patients with established SSc compared to controls (p < 0.001; Figure 1 A & B). GLS was similar in VEDOSS and controls but significantly reduced in patients with established SSc (p < 0.001; Figure 1 C). GCS was similar over all groups (p = 0.88). Patients with clinical evidence of pulmonary or gastrointestinal involvement had higher ECV or T1 values, respectively. Patients with clinical signs of cardiac involvement had lower absolute GLS. SSc subtype, classification or disease duration were not associated with the extent of myocardial fibrosis or impaired strain.
Conclusion - Subclinical myocardial involvement first manifests as diffuse myocardial fibrosis identified by expansion of ECV and increased native T1 in VEDOSS patients while subtle functional impairment as measured by GLS only occurs in established SSc. No single clinical feature of SSc shows a strong association with subtle myocardial involvement.
Collapse
Affiliation(s)
- A Gotschy
- University Hospital Zurich, Department of Cardiology, Zurich, Switzerland
| | - S Jordan
- University Hospital Zurich, Department of Rheumatology, Zurich, Switzerland
| | - CT Stoeck
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - C Von Deuster
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - M Gastl
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - V Vishnevskiy
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - L Wissmann
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - R Dobrota
- University Hospital Zurich, Department of Rheumatology, Zurich, Switzerland
| | - C Mihai
- University Hospital Zurich, Department of Rheumatology, Zurich, Switzerland
| | - MO Becker
- University Hospital Zurich, Department of Rheumatology, Zurich, Switzerland
| | - B Maurer
- University Hospital Zurich, Department of Rheumatology, Zurich, Switzerland
| | - S Kozerke
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - F Ruschitzka
- University Hospital Zurich, Department of Cardiology, Zurich, Switzerland
| | - O Distler
- University Hospital Zurich, Department of Rheumatology, Zurich, Switzerland
| | - R Manka
- University Hospital Zurich, Department of Cardiology, Zurich, Switzerland
| |
Collapse
|
3
|
Das A, Kelly C, Teh I, Stoeck C, Kozerke S, Chowdhary A, Jex N, Thiranavukarasu S, Sharrack N, Ben-Arzi H, Aldred M, Greenwood JP, Plein S, Schneider JE, Dallarmellina E. Microstructural characteristics of chronic infarct segments assessed using diffusion tensor imaging. Eur Heart J Cardiovasc Imaging 2021. [DOI: 10.1093/ehjci/jeab090.090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): British Heart Foundation
Background
The microstructural changes following myocardial infarction (MI) can be characterised in-vivo with cardiac diffusion tensor imaging (cDTI) imaging, using mean diffusivity (MD), fractional anisotropy (FA), secondary eigenvector angle (E2A) and helix angle (HA) maps. In this study, we use cDTI to explore the microstructural differences between subendocardial and transmural chronic infarct segments.
Method
Twenty STEMI patients (15 men, 5 women, mean age 59) underwent 3T CMR scan at 3 months following presentation (mean interval 107 ± 18 days). Scan protocol included: second order motion compensated (M012) free-breathing spin echo DTI (3 slices, 18 diffusion directions at b-values 100s/mm2[3], 200s/mm2[3] and 500s/mm2[12], acquired resolution was 2.20x2.27x8mm3; cine gradient echo and LGE imaging. Average MD, FA, E2A and HA parameters were calculated on a 16-AHA-segmental level. HA maps were described by dividing values into left-handed HA (LHM, -90° < HA < -30°), circumferential HA (CM, -30° < HA < 30°), and right-handed HA (RHM, 30° < HA < 90°) and reported as relative proportions. Infarct segments were identified using LGE; patients were categorised according to the maximal transmurality of their infarct segments, into subendocardial (<50% LGE) or transmural (>50% LGE) MI.
Results
DTI acquisition was successful in all patients (acquisition time 13 ± 5mins). Ten patients had transmural MI. The results are shown in table 1. Transmurally infarcted segments had significantly lower FA (FA subendocardial MI = 0.27 ± 0.04, FA transmural MI = 0.23 ± 0.02, p < 0.01), lower E2A (E2A subendocardial MI = 47 ± 7°, E2A transmural MI = 38 ± 6°, p < 0.01) and lower proportions of right-handed cardiomyocytes (RHM subendocardial MI = 21 ± 5%, RHM transmural MI = 14 ± 5%, p < 0.01) than subendocardial infarct segments.
Conclusion
Compared to subendocardial MI segments, the diffusion of water molecules is more isotropic in transmurally infarcted myocardium as evidenced by lower FA values, signifying increased structural disarray. The significantly lower E2A values suggest that laminar sheetlets of transmural infarct segments remain fixed at shallower angles during systole and are unable to reach their usual contractile configuration. The lower proportions of RHM on HA maps highlight the significantly greater loss of subendocardial cardiomyocytes in transmural infarct segments. Further studies are required to assess if these segmental changes can be predictive of long-term LV remodelling.
Collapse
Affiliation(s)
- A Das
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - C Kelly
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - I Teh
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - C Stoeck
- University of Zurich, Institute of Biomedical Engineering, Zurich, Switzerland
| | - S Kozerke
- University of Zurich, Institute of Biomedical Engineering, Zurich, Switzerland
| | - A Chowdhary
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - N Jex
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - S Thiranavukarasu
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - N Sharrack
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - H Ben-Arzi
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - M Aldred
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - JP Greenwood
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - S Plein
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - JE Schneider
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - E Dallarmellina
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| |
Collapse
|
4
|
Sharrack N, Das A, Kelly C, Aldred M, Teh I, Stoeck CT, Kozerke S, Chowdhury A, Jex N, Ben-Arzi H, Swoboda PP, Greenwood JP, Plein S, Schneider JE, Dall"armellina E. The relationship between myocardial microstructure and strain in chronic infarcts, assessed using diffusion tensor imaging and feature tracking. Eur Heart J Cardiovasc Imaging 2021. [DOI: 10.1093/ehjci/jeab090.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): British Heart Foundation
Background
Cardiac diffusion tensor imaging (cDTI) is a novel technique for the non-invasive assessment of myocardial microstructure. It allows in-vivo characterisation of microstructural changes post myocardial infarction (MI). Previously published evidence shows significant loss of sheetlet orientation as derived by cDTI secondary eigenvector (E2A), and loss of subendocardial cardiomyocytes derived by reductions in the proportions of myocytes with right-handed orientation (RHM) on helix angle (HA) maps. The assessment of myocardial strain by feature tracking (FT) allows the measurement of radial strain (RS), thought to be driven by the dynamic reorientation of laminar sheetlets, and longitudinal strain (LS), which is thought to relate to subendocardial function. We sought to explore the relationship between the strain and cDTI parameters in patients at 3 months following ST-elevation MI (STEMI).
Methods
Twenty five STEMI patients (M:F = 18:7, mean age 58 ± 9) underwent 3T CMR scan (mean interval 106 ± 17 days) with the following protocol: second order motion compensated (M2), free-breathing spin echo DTI (3 slices, 18 diffusion directions at b-values 100s/mm2, 200s/mm2 and 500s/mm2, acquired resolution was 2.20*2.27*8mm3; cine gradient echo and Late Gadolinium Enhancement (LGE) imaging. HA maps were described by dividing values into left-handed HA (LHM, -90< HA < -30), circumferential HA (CM, -30° < HA < 30°), and right-handed HA (RHM, 30° < HA < 90°) and reported as relative proportions. Segmental analysis were undertaken to derive: HA proportions, E2A, longitudinal strain and LGE%. Segments positive for LGE were classed as infarct segments.
Results
cDTI acquisition was successful in all patients (acquisition time 13 ± 5mins). Mean ejection fraction was 47 ± 8% with mean LGE in the infarcted segment of 57 ± 27%. Mean radial strain was 21 (95% confidence interval, 15-26). The mean E2A was 44 (95% confidence interval 41-47). There was a significant correlation between segmental radial strain and segmental E2A in infarcted segments (p < 0.001, figure 1). In addition, segmental longitudinal strain correlated with the proportion of RHM on HA maps (p < 0.02, figure 2).
Conclusion
Through the combined use of cDTI and FT in patients with chronic infarcts, our results show that the loss of sheetlet orientation assessed using E2A, correlates with worsening radial strain. Segments with less subendocardial cardiomyocytes, evidenced by a lower proportion of myocytes with right-handed orientation on HA maps, correlated with worse longitudinal strain. While this could potentially elucidate the complex association between myocardial microstructure and regional function, further studies are needed to define the incremental clinical value of cDTI.
Collapse
Affiliation(s)
- N Sharrack
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - A Das
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - C Kelly
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - M Aldred
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - I Teh
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - CT Stoeck
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Zurich, Switzerland
| | - S Kozerke
- Swiss Federal Institute of Technology Zurich (ETH Zurich), Zurich, Switzerland
| | - A Chowdhury
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - N Jex
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - H Ben-Arzi
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - PP Swoboda
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - JP Greenwood
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - S Plein
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - JE Schneider
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - E Dall"armellina
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| |
Collapse
|
5
|
Das A, Kelly C, Teh I, Stoeck CT, Kozerke S, Brown LAE, Saunderson CED, Craven T, Swoboda PP, Levelt E, Greenwood JP, Plein S, Schneider JE, Dallarmellina E. 542Longitudinal changes in diffusion tensor imaging parameters following acute ST-elevation myocardial infarction. Eur Heart J Cardiovasc Imaging 2019. [DOI: 10.1093/ehjci/jez104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A Das
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - C Kelly
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - I Teh
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - C T Stoeck
- University of Zurich, Institute of Biomedical Engineering, Zurich, Switzerland
| | - S Kozerke
- University of Zurich, Institute of Biomedical Engineering, Zurich, Switzerland
| | - L A E Brown
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - C E D Saunderson
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - T Craven
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - P P Swoboda
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - E Levelt
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - J P Greenwood
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - S Plein
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - J E Schneider
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - E Dallarmellina
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| |
Collapse
|
6
|
Pozzoli A, Taramasso M, Kuwata S, Cesarovich N, Zuber M, Guidotti A, Andreas M, Emmert Y, Alkadhi H, Manka R, Stoeck C, Maisano F, Plass R. Preclinical Multimodality Fusion Imaging Platform to Optimize Catheter-Based Mitral Valve Interventions. Thorac Cardiovasc Surg 2019. [DOI: 10.1055/s-0039-1678999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- A. Pozzoli
- Heart and Vascular Surgery, University Hospital Zürich, Zürich, Switzerland
| | - M. Taramasso
- Heart and Vascular Surgery, University Hospital Zürich, Zürich, Switzerland
| | - S. Kuwata
- Heart and Vascular Surgery, University Hospital Zürich, Zürich, Switzerland
| | - N. Cesarovich
- Experimental Hybrid Surgery Unit, University Hospital Zürich, Zürich, Switzerland
| | - M. Zuber
- Cardiology Unit, University Hospital Zürich, Zürich, Switzerland
| | - A. Guidotti
- Heart and Vascular Surgery, University Hospital Zürich, Zürich, Switzerland
| | - M. Andreas
- Heart and Thoracic Surgery, University Hospital Wien, Wien, Austria
| | - Y. Emmert
- Heart and Vascular Surgery, University Hospital Zürich, Zürich, Switzerland
| | - H. Alkadhi
- Radiology Unit, University Hospital Zürich, Zürich, Switzerland
| | - R. Manka
- Cardiology Unit, University Hospital Zürich, Zürich, Switzerland
| | - C. Stoeck
- ETH Zürich, Institute for Biomedical Engineering, Zürich, Switzerland
| | - F. Maisano
- Heart and Vascular Surgery, University Hospital Zürich, Zürich, Switzerland
| | - R. Plass
- Heart and Vascular Surgery, University Hospital Zürich, Zürich, Switzerland
| |
Collapse
|
7
|
Genet M, Stoeck CT, von Deuster C, Lee LC, Kozerke S. Equilibrated warping: Finite element image registration with finite strain equilibrium gap regularization. Med Image Anal 2018; 50:1-22. [PMID: 30173000 DOI: 10.1016/j.media.2018.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 07/21/2018] [Accepted: 07/24/2018] [Indexed: 01/30/2023]
Abstract
In this paper, we propose a novel continuum finite strain formulation of the equilibrium gap regularization for image registration. The equilibrium gap regularization essentially penalizes any deviation from the solution of a hyperelastic body in equilibrium with arbitrary loads prescribed at the boundary. It thus represents a regularization with strong mechanical basis, especially suited for cardiac image analysis. We describe the consistent linearization and discretization of the regularized image registration problem, in the framework of the finite elements method. The method is implemented using FEniCS & VTK, and distributed as a freely available python library. We show that the equilibrated warping method is effective and robust: regularization strength and image noise have minimal impact on motion tracking, especially when compared to strain-based regularization methods such as hyperelastic warping. We also show that equilibrated warping is able to extract main deformation features on both tagged and untagged cardiac magnetic resonance images.
Collapse
Affiliation(s)
- M Genet
- Laboratoire de Mécanique des Solides, École Polytechnique/C.N.R.S./Université Paris-Saclay, Palaiseau, France; M3DISIM team, Inria / Université Paris-Saclay, Palaiseau, France.
| | - C T Stoeck
- Institute for Biomedical Engineering, University and ETH Zurich, Switzerland
| | - C von Deuster
- Institute for Biomedical Engineering, University and ETH Zurich, Switzerland
| | - L C Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, USA
| | - S Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Switzerland
| |
Collapse
|
8
|
Gotschy A, Von Deuster C, Van Gorkum RJH, Gastl M, Vintschger E, Flammer AJ, Manka R, Stoeck CT, Kozerke S. 4383Characterizing cardiac involvement in amyloidosis using in-vivo cardiac diffusion tensor imaging. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.4383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A Gotschy
- University Hospital Zurich, Department of Cardiology, Zurich, Switzerland
| | - C Von Deuster
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - R J H Van Gorkum
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - M Gastl
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - E Vintschger
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - A J Flammer
- University Hospital Zurich, Department of Cardiology, Zurich, Switzerland
| | - R Manka
- University Hospital Zurich, Department of Cardiology, Zurich, Switzerland
| | - C T Stoeck
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| | - S Kozerke
- University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland
| |
Collapse
|
9
|
Zurbuchen A, Pfenniger A, Stahel A, Stoeck CT, Vandenberghe S, Koch VM, Vogel R. Energy harvesting from the beating heart by a mass imbalance oscillation generator. Ann Biomed Eng 2012; 41:131-41. [PMID: 22805983 DOI: 10.1007/s10439-012-0623-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 07/09/2012] [Indexed: 10/28/2022]
Abstract
Energy-harvesting devices attract wide interest as power supplies of today's medical implants. Their long lifetime will spare patients from repeated surgical interventions. They also offer the opportunity to further miniaturize existing implants such as pacemakers, defibrillators or recorders of bio signals. A mass imbalance oscillation generator, which consists of a clockwork from a commercially available automatic wrist watch, was used as energy harvesting device to convert the kinetic energy from the cardiac wall motion to electrical energy. An MRI-based motion analysis of the left ventricle revealed basal regions to be energetically most favorable for the rotating unbalance of our harvester. A mathematical model was developed as a tool for optimizing the device's configuration. The model was validated by an in vitro experiment where an arm robot accelerated the harvesting device by reproducing the cardiac motion. Furthermore, in an in vivo experiment, the device was affixed onto a sheep heart for 1 h. The generated power in both experiments-in vitro (30 μW) and in vivo (16.7 μW)-is sufficient to power modern pacemakers.
Collapse
Affiliation(s)
- A Zurbuchen
- ARTORG Center for Biomedical Engineering Research, University of Bern, 3010, Bern, Switzerland
| | | | | | | | | | | | | |
Collapse
|