Heterogeneous signal intensity in magnetic resonance images of hypertrophied left ventricular myocardium

Background: Proton beam therapy offers radiophysical properties that are appealing for noninvasive arrhythmia elimination. This study was conducted to use scanned proton beams for ablation of cardiac tissue, investigate electrophysiological outcomes, and characterize the process of lesion formation in a porcine model using particle therapy. Methods: Twenty-five animals received scanned proton beam irradiation. ECG-gated computed tomography scans were acquired at end-expiration breath hold. Structures (atrioventricular junction or left ventricular myocardium) and organs at risk were contoured. Doses of 30, 40, and 55 Gy were delivered during expiration to the atrioventricular junction (n=5) and left ventricular myocardium (n=20) of intact animals. Results: In this study, procedural success was tracked by pacemaker interrogation in the atrioventricular junction group, time-course magnetic resonance imaging in the left ventricular group, and correlation of lesion outcomes displayed in gross and microscopic pathology. Protein extraction (active caspase-3) was performed to investigate tissue apoptosis. Doses of 40 and 55 Gy caused slowing and interruption of cardiac impulse propagation at the atrioventricular junction. In 40 left ventricular irradiated targets, all lesions were identified on magnetic resonance after 12 weeks, being consistent with outcomes from gross pathology. In the majority of cases, lesion size plateaued between 12 and 16 weeks. Active caspase-3 was seen in lesions 12 and 16 weeks after irradiation but not after 20 weeks. Conclusions: Scanned proton beams can be used as a tool for catheter-free ablation, and time-course of tissue apoptosis was consistent with lesion maturation.

Download Full-text

Changes of Cardiac Magnetic Resonance T1 and ECV Values in Healthy Adults of Different Gender and Age

10.21203/rs.3.rs-863090/v1 ◽

2021 ◽

Author(s):

Shumei Huang ◽

Meng Zhang ◽

Kanghui Yu ◽

Xiaofen Ma ◽

Chunlong Li ◽

...

Keyword(s):

Cardiac Magnetic Resonance ◽

Magnetic Resonance ◽

T1 Mapping ◽

Healthy Adult ◽

Extracellular Volume ◽

Ventricular Myocardium ◽

Left Ventricular ◽

Healthy Adults ◽

Left Ventricular Myocardium ◽

3T Mri

Abstract BackgroundThe correlation between T1 and ECV value and myocardial fibrosis has been confirmed. In healthy adult, many disease may change T1 and ECV value. The purpose of this reseach is to clarify the T1 mapping and extracellular volume (ECV) value of healthy adults in 3 Tesla (T) magnetic resonance imaging (MRI), and to study the relationship between the values with age and gender.MethodsWe recruited 87 healthy adult subjects (mean age 38 ± 11 years; 61% were females) for cardiac magnetic resonance examination at 3T MRI. The left ventricular function parameters were obtained from functional imaging. T1 mapping was performed using an improved Look-Locker reversal recovery sequence after motion correction. ResultsUnder 3T field strength, T1 value of the myocardium of healthy adults was 1,261 ± 52, and the ECV value was 28.3% ± 2.9%. T1 value and ECV values of female myocardium were higher than those of males (1,274 ± 56 vs. 1,241 ± 40, P = 0.003; 29.6% ± 2.6% vs. 26.2% ± 2.1%, P < 0.001). Only gender (Beta = 0.311, P = 0.003) was independently related to the native T1 mapping of left ventricular myocardium, while gender (Beta = 0.572, P < 0.001) and age (Beta = 0.501, P = 0.003) were related to the ECV value of left ventricular myocardium. T1 value (P = 0.002) and ECV value (P = 0.013) increased significantly from the base to the apex. There were significant differences in the T1 and ECV value between each segment (P < 0.001) in the base of the left ventricle. Significant differences were observed between the middle segments of T1 value (P = 0.001) but not between the middle of the ECV value of each segment (P = 0.068). Lastly, there was no statistical difference between each segment in the apical of the T1 (P = 0.756) and ECV value (P = 0.344).ConclusionsUnder 3T MRI, the T1 value of the myocardium of healthy adults was 1,261 ± 52, and the ECV value was 28.3% ± 2.9%. T1 and ECV values of females were significantly higher than those of males. The ECV values of males increased with age, while T1 value in males and T1 and ECV values in females had no significant relationship with age.

Download Full-text

Magnetic resonance imaging of targeted catheter-based implantation of myogenic precursor cells into infarcted left ventricular myocardium

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(03)00414-5 ◽

2003 ◽

Vol 41 (10) ◽

pp. 1841-1846 ◽

Cited By ~ 63

Author(s):

J.érôme Garot ◽

Thierry Unterseeh ◽

Emmanuel Teiger ◽

S.téphane Champagne ◽

B.énédicte Chazaud ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Ventricular Myocardium ◽

Left Ventricular ◽

Precursor Cells ◽

Left Ventricular Myocardium ◽

Resonance Imaging ◽

Myogenic Precursor

Download Full-text

Changes of Cardiac Magnetic Resonance T1 and ECV Values in Healthy Adults of Different Gender and Age

10.21203/rs.3.rs-863090/v2 ◽

2021 ◽

Author(s):

Shumei Huang ◽

Meng Zhang ◽

Kanghui Yu ◽

Chunlong Li ◽

Zhihong Lan ◽

...

Keyword(s):

Cardiac Magnetic Resonance ◽

Magnetic Resonance ◽

T1 Mapping ◽

Healthy Adult ◽

Extracellular Volume ◽

Ventricular Myocardium ◽

Left Ventricular ◽

Healthy Adults ◽

Left Ventricular Myocardium ◽

3T Mri

Abstract purposeThe correlation between T1 and ECV value and myocardial fibrosis has been confirmed. In healthy adult, many disease may change T1 and ECV value. The purpose of this reseach is to clarify the T1 mapping and extracellular volume (ECV) value of healthy adults in 3 Tesla (T) magnetic resonance imaging (MRI), and to study the relationship between the values with age and gender.Methods We recruited 87 healthy adult subjects (mean age 38 ± 11 years; 61% were females) for cardiac magnetic resonance examination at 3T MRI. The left ventricular function parameters were obtained from functional imaging. T1 mapping was performed using an improved Look-Locker reversal recovery sequence after motion correction. resultsUnder 3T field strength, T1 value of the myocardium of healthy adults was 1,261 ± 52, and the ECV value was 28.3% ± 2.9%. T1 value and ECV values of female myocardium were higher than those of males (1,274 ± 56 vs. 1,241 ± 40, P = 0.003; 29.6% ± 2.6% vs. 26.2% ± 2.1%, P < 0.001). Only gender (Beta = 0.311, P = 0.003) was independently related to the native T1 mapping of left ventricular myocardium, while gender (Beta = 0.572, P < 0.001) and age (Beta = 0.501, P = 0.003) were related to the ECV value of left ventricular myocardium. T1 value (P = 0.002) and ECV value (P = 0.013) increased significantly from the base to the apex. There were significant differences in the T1 and ECV value between each segment (P < 0.001) in the base of the left ventricle. Significant differences were observed between the middle segments of T1 value (P = 0.001) but not between the middle of the ECV value of each segment (P = 0.068). Lastly, there was no statistical difference between each segment in the apical of the T1 (P = 0.756) and ECV value (P = 0.344).ConclusionsUnder 3T MRI, the T1 value of the myocardium of healthy adults was 1,261 ± 52, and the ECV value was 28.3% ± 2.9%. T1 and ECV values of females were significantly higher than those of males. The ECV values of males increased with age, while T1 value in males and T1 and ECV values in females had no significant relationship with age.

Download Full-text