A semiautomatic method for rapid segmentation of velocity‐encoded myocardial magnetic resonance imaging data

Espe, Emil Knut Stenersen; Skårdal, Kristine; Aronsen, Jan Magnus; Zhang, Lili; Sjaastad, Ivar

doi:10.1002/mrm.26486

Cited by 9 publications

(7 citation statements)

References 23 publications

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“…A further drawback of our study is related to the time-consuming manual segmentation of epi-and endocardium. To overcome this issue, the implementation of automatic segmentation algorithms (56,57) into the workflow should be explored in future studies. Especially in TOF patients with their altered RV anatomy, the standardized short-axis view was often acquired at basal locations that cannot accurately capture both LV and RV myocardium.…”

Section: Discussionmentioning

confidence: 99%

Impact of age and cardiac disease on regional left and right ventricular myocardial motion in healthy controls and patients with repaired tetralogy of fallot

Ruh

Sarnari

Berhane

et al. 2019

Int J Cardiovasc Imaging

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Purpose-The assessment of both left (LV) and right ventricular (RV) motion is important to understand the impact of heart disease on cardiac function. The MRI technique of tissue phase mapping (TPM) allows for the quantification of regional biventricular three-directional myocardial velocities. The goal of this study was to establish normal LV and RV velocity parameters across a wide range of pediatric to adult ages and to investigate the feasibility of TPM for detecting impaired regional biventricular function in patients with repaired tetralogy of Fallot (TOF). Methods-36 healthy controls (age=1-75 years) and 12 TOF patients (age=5-23 years) underwent cardiac MRI including TPM in short-axis locations (base, mid, apex). For ten adults, a second TPM scan was used to assess test-retest reproducibility. Data analysis included the calculation of biventricular radial, circumferential, and long-axis velocity components, quantification of systolic and diastolic peak velocities in an extended 16+10 LV+RV segment model, and assessment of inter-ventricular dyssynchrony.

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Section: Discussionmentioning

confidence: 99%

Impact of age and cardiac disease on regional left and right ventricular myocardial motion in healthy controls and patients with repaired tetralogy of fallot

Ruh

Sarnari

Berhane

et al. 2019

Int J Cardiovasc Imaging

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“…As described in detail in the Supplementary material online, three short-axis slices (basal, mid-ventricular, and apical) were acquired in each animal using phase-contrast MRI 11 . The myocardium was segmented semiautomatically 12 and the viable myocardium divided into three equally sized regions adjacent, medial, and remote to the infarct ( Figure 1A ). In each region, circumferential strain and strain rate were calculated as previously described 13 .…”

Section: Methodsmentioning

confidence: 99%

Regional diastolic dysfunction in post-infarction heart failure: role of local mechanical load and SERCA expression

Røe

Ruud

Espe

et al. 2018

Cardiovascular Research

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AimsRegional heterogeneities in contraction contribute to heart failure with reduced ejection fraction (HFrEF). We aimed to determine whether regional changes in myocardial relaxation similarly contribute to diastolic dysfunction in post-infarction HFrEF, and to elucidate the underlying mechanisms.Methods and resultsUsing the magnetic resonance imaging phase-contrast technique, we examined local diastolic function in a rat model of post-infarction HFrEF. In comparison with sham-operated animals, post-infarction HFrEF rats exhibited reduced diastolic strain rate adjacent to the scar, but not in remote regions of the myocardium. Removal of Ca2+ within cardiomyocytes governs relaxation, and we indeed found that Ca2+ transients declined more slowly in cells isolated from the adjacent region. Resting Ca2+ levels in adjacent zone myocytes were also markedly elevated at high pacing rates. Impaired Ca2+ removal was attributed to a reduced rate of Ca2+ sequestration into the sarcoplasmic reticulum (SR), due to decreased local expression of the SR Ca2+ ATPase (SERCA). Wall stress was elevated in the adjacent region. Using ex vivo experiments with loaded papillary muscles, we demonstrated that high mechanical stress is directly linked to SERCA down-regulation and slowing of relaxation. Finally, we confirmed that regional diastolic dysfunction is also present in human HFrEF patients. Using echocardiographic speckle-tracking of patients enrolled in the LEAF trial, we found that in comparison with controls, post-infarction HFrEF subjects exhibited reduced diastolic train rate adjacent to the scar, but not in remote regions of the myocardium.ConclusionOur data indicate that relaxation varies across the heart in post-infarction HFrEF. Regional diastolic dysfunction in this condition is linked to elevated wall stress adjacent to the infarction, resulting in down-regulation of SERCA, disrupted diastolic Ca2+ handling, and local slowing of relaxation.

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“…The RV free-wall was segmented semiautomatically (17). This required the operator to delineate the endo-and epicardium at end-systole and end-diastole.…”

Section: Mri Post-processingmentioning

confidence: 99%

“…In the long-axis slices, the RV free-wall was divided into nine parallel segments ( Figure 1D). The median number of pixels in the segments was 13 [9,17].…”

Section: Mri Post-processingmentioning

confidence: 99%

Regional right ventricular function in rats: a novel magnetic resonance imaging method for measurement of right ventricular strain

Espe

Aronsen

Nordén

et al. 2020

American Journal of Physiology-Heart and Circulatory Physiology

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The function of the right ventricle (RV) is linked to clinical outcome in many cardiovascular diseases, but its role in experimental heart failure remains largely unexplored due to difficulties in measuring RV function in vivo. We aimed to advance RV imaging by establishing phase-contrast MRI (PC-MRI) as a robust method for measuring RV function in rodents. A total of 46 Wistar-Hannover rats with left ventricular (LV) myocardial infarction and 10 control rats (sham) were examined 6 wk after surgery. Using a 9.4-T preclinical MRI system, we utilized PC-MRI to measure strain/strain rate in the RV free wall under isoflurane anesthesia. Cine MRI was used to measure RV volumes. LV end-diastolic pressure (LVEDP) was measured and used to identify pulmonary congestion. The infarct rats were divided into two groups: those with signs of pulmonary congestion (PC), with LVEDP ≥ 15 mmHg ( n = 26) and those without signs of pulmonary congestion (NPC), with LVEDP < 15 mmHg ( n = 20). The NPC rats exhibited preserved RV strains/strain rates, whereas the PC rats exhibited reduced strains/strain rates (26–48% lower than sham). Of the strain parameters, longitudinal strain and strain rate exhibited the highest correlations to LVEDP and lung weight (rho = 0.65–0.72, P < 0.001). Basal longitudinal strain was most closely associated with signs of pulmonary congestion and indexes of RV remodeling. Longitudinal RV strain had higher area under the curve than ejection fraction for detecting subtle RV dysfunction (area under the curve = 0.85 vs. 0.67). In conclusion, we show for the first time that global and regional RV myocardial strain can be measured robustly in rodents. Reduced RV strain was closely associated with indexes of pulmonary congestion and molecular markers of RV remodeling. NEW & NOTEWORTHY Global and regional right ventricular myocardial strain can be measured with high reproducibility and low interobserver variability in rodents using tissue phase mapping MRI. Reduced right ventricular strain was associated with indexes of pulmonary congestion and molecular markers of right ventricular remodeling. Regional strain in the basal myocardium was considerably higher than in the apical myocardium.

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A semiautomatic method for rapid segmentation of velocity‐encoded myocardial magnetic resonance imaging data

Abstract: The proposed method reduced the segmentation time substantially and exhibited well-preserved data quality and excellent interobserver limits of agreement. Magn Reson Med 78:1199-1207, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Cited by 9 publications

References 23 publications

Impact of age and cardiac disease on regional left and right ventricular myocardial motion in healthy controls and patients with repaired tetralogy of fallot

Impact of age and cardiac disease on regional left and right ventricular myocardial motion in healthy controls and patients with repaired tetralogy of fallot

Regional diastolic dysfunction in post-infarction heart failure: role of local mechanical load and SERCA expression

Regional right ventricular function in rats: a novel magnetic resonance imaging method for measurement of right ventricular strain

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