A free-breathing, non-ECG gated cardiac MRI accurately assessed myocardial injury in a canine model, reducing scan time by >50% with excellent agreement to conventional imaging methods.
Does a free-breathing, whole-heart, non-ECG gated cardiac MRI accurately measure myocardial injury compared to conventional MRI in a canine model of reperfused MI?
A novel free-breathing, non-ECG gated cardiac MRI protocol reduces scan time by over 50% while maintaining accurate assessment of myocardial injury in a canine model of reperfused MI.
Absolute Event Rate: 0% vs 0%
Abstract Background Staging irreversible tissue injury in myocardial infarction (MI) enables risk assessment for post-MI major cardiovascular events. While cardiac MRI is the preferred modality for staging the severity of tissue injury, conventional scan protocols require long acquisition times with multiple breath-held and ECG-gated acquisitions, limiting its utilization. Objective To develop a free-breathing, whole-heart, non-ECG gated cardiac MRI for staging irreversible tissue injury in MI that can be completed in 20 minutes. Methods A fast cardiac MRI (Biograph, Siemens Healthcare, 3 T) method based on a low-rank tensor framework was developed (reconstruction performed in MATLAB) and tested against the conventional approach using a pre-clinical canine model of reperfused MI (n = 15) with histological validation. Each subject underwent 2 exams that were randomized two days apart (day 6—8 post MI respectively). Correlation between the proposed and conventional methods and left-ventricular ejection fraction (LVEF), MI size and transmurality, size of microvascular obstruction (MVO), and intramyocardial hemorrhage (IMH) volumes were assessed using linear regression and Bland-Altman analysis. Results Twelve out of 15 subjects survived the initial reperfusion injury. The proposed method reduced acquisition time by 50%. The cardiac MRI evidence of tissue injury was confirmed on histopathology in all cases. The agreements between the proposed and conventional methods for LVEF, MI volume, persistent MVO volume and IMH volume were excellent; limits of agreement (LoA) were -2.1-1.8%, -2.9-3.3%, -2.4-4.1%, and -1.5-1.5% respectively. MI transmurality and early MVO showed good agreement; LoA were -6.8-9.7% and -6.6-8.2% respectively. Conclusion The proposed free-breathing, whole-heart, non-ECG gated cardiac MRI approach permits accurate determination of tissue injury in a canine model with 2-fold reduction in scan time. While the method remains to be tested in patients, it has the potential to facilitate efficient use of cardiac MRI for staging the severity of tissue injury in patients with reperfused MI.
Zhang et al. (Thu,) reported a other. A free-breathing, non-ECG gated cardiac MRI accurately assessed myocardial injury in a canine model, reducing scan time by >50% with excellent agreement to conventional imaging methods.