Purpose: The aim of this study was to establish reference values for segmental myocardial strain measured by magnetic resonance (MR) cardiac tagging in order to characterize the regional function of the heart.
Material And Methods: We characterized the left ventricular (LV) systolic deformation in 39 subjects (26 women and 13 men, age 58.8 ± 11.6 years) whose cardiological study had not revealed any significant abnormality. The deformation was measured from MR-tagged (Siemens 1.5T MR) images using an algorithm based on sine wave modeling. Circumferential and radial peak systolic strain values along with the torsion angle and circumferential-longitudinal (CL) shear were determined in 16 LV segments in order to settle the reference values for these parameters.
Results: Circumferential strain was highest at the anterior and lateral walls (-20.2 ± 4.0% and -21.8 ± 4.3%, respectively; P < 0.05) and was lowest at the base level (-17.2 ± 3.1% vs. -20.1 ± 3.1% "mid level," P < 0.05; -17.2 ± 3.1% vs. -20.3 ± 3.0% "apical level," P < 0.05). Radial strain highest values were from inferior and lateral walls (13.7 ± 7.4% and 12.8 ± 7.8%, respectively; P < 0.05) and it was lowest medially (9.4 ± 4.1% vs. 13.1 ± 4.1% "base level," P < 0.05; 9.4 ± 4.1% vs. 12.1 ± 4.4% "apical level," P < 0.05). Torsion angle (counterclockwise when viewed from the apex) increased with the distance from the base (7.9 ± 2.4° vs. 16.8 ± 4.4°, P < 0.05), and the highest and lowest values were found at lateral (medial lateral: 12.0 ± 4.4°, apical lateral: 25.1 ± 6.4°, P < 0.05) and septal wall (medial septal: 3.6 ± 2.1°, apical septal: 8.3 ± 5.3°, P < 0.05), respectively. These differences were found again in CL shear values, around the LV circumference. However, CL shear remained constant with increasing distance from the base (9.1 ± 2.6°, medium and 9.8 ± 2.4°, apex).
Conclusion: In summary, this study provides reference values for the assessment of regional myocardial function by MR cardiac tagging. Comparison of patient deformation parameters with normal deformation patterns may permit early detection of regional systolic dysfunction.
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http://dx.doi.org/10.1002/jmri.24539 | DOI Listing |
mBio
December 2024
Tumour Virology, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
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November 2024
Department of Radiology, Stanford University, Palo Alto, CA 94305, USA.
In boys with Duchenne muscular dystrophy (DMD), cardiomyopathy has become the primary cause of death. Although both positive late gadolinium enhancement (LGE) and reduced left ventricular ejection fraction (LVEF) are late findings in a DMD cohort, LV end-systolic circumferential strain at middle wall (E) serves as a biomarker for detecting early impairment in cardiac function associated with DMD. However, E derived from cine Displacement Encoding with Stimulated Echoes (DENSE) has not been quantified in boys with DMD.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106, United States.
Controlling cellular shape with micropatterning extracellular matrix (ECM) proteins on hydrogels has been shown to improve the reproducibility of the cell structure, enhancing our ability to collect statistics on single-cell behaviors. Patterning methods have advanced efforts in developing human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) as a promising human model for studies of the heart structure, function, and disease. Patterned single hiPSC-CMs have exhibited phenotypes closer to mature, primary CMs across several metrics, including sarcomere alignment and contractility, area and aspect ratio, and force production.
View Article and Find Full Text PDFSci Adv
December 2024
Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan.
Raman microscopy is an emerging molecular imaging technology, yet its signal-to-noise ratio (SNR) in measurements of biological specimens is severely limited because of the small cross section of Raman scattering. Here, we present Raman imaging techniques of cryofixed specimens to overcome SNR limitations by enabling long exposure of specimens under highly stabilized low-temperature conditions. The observation of frozen specimens in a cryostat at a constant low temperature immediately after rapid freezing enabled the improvement of SNR and enhanced the spatial and spectral resolution.
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