Evaluation of myocardial viability by MRI

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Assessing myocardial viability is clinically significant for patient management.
• Various magnetic resonance (MR) techniques exist, but often face limitations in spatial and temporal resolution due to small signal magnitudes.
• Metabolic information can be obtained from phosphorus-31 and hydrogen-1 spectroscopy, and sodium-23 and potassium-39 imaging.

Purpose of the Study:

• To review and compare different magnetic resonance imaging (MRI) techniques for assessing myocardial viability.
• To highlight the clinical utility and evidence supporting specific MRI approaches.

Main Methods:

• Review of proton imaging techniques including MR relaxation times (T1, T2), wall thickness, cine MRI with low-dose dobutamine, and contrast enhancement patterns (first-pass and delayed).
• Evaluation of spectroscopic techniques (phosphorus-31, hydrogen-1) and elemental imaging (sodium-23, potassium-39).

Main Results:

• Cine MRI combined with low-dose dobutamine has substantial clinical evidence supporting its efficacy in assessing myocardial viability.
• Delayed contrast enhancement MRI effectively evaluates the transmural extent of viable myocardium, independent of contractile function.

Conclusions:

• Cine MRI with low-dose dobutamine is a well-supported method for evaluating myocardial viability.
• Delayed contrast enhancement MRI is a valuable technique for clinical assessment of myocardial viability and should be considered.
• Proton imaging techniques offer distinct advantages in assessing myocardial viability compared to metabolic spectroscopic methods due to signal magnitude limitations.