Real-time MR imaging of myocardial regional function using strain-encoding (SENC) with tissue through-plane motion...

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Biomedical Engineering

Background:

• Real-time cardiac imaging is crucial for assessing heart function.
• Myocardial strain-encoding (SENC) imaging measures heart muscle deformation.
• Accurate strain measurement requires accounting for tissue motion in all directions.

Purpose of the Study:

• To integrate real-time SENC with through-plane motion tracking.
• To enhance the accuracy of cardiac strain measurements.
• To validate the novel technique in humans and animal models.

Main Methods:

• Combined SENC with a slice-following technique using 3D selective excitation.
• Optimized imaging for a one-heartbeat scan time.
• Acquired orthogonal Spatial Modulation of Magnetization (SPAMM) tagged images for comparison.
• Induced myocardial infarction (MI) in pigs for validation against delayed-enhancement (DE) MRI.

Main Results:

• Slice-following significantly improved strain values compared to standard SENC, particularly during systole (P < 0.01).
• Strain curves correlated well with orthogonal SPAMM-tagged images.
• SENC imaging accurately identified myocardial infarction in pigs, showing good agreement with DE images.

Conclusions:

• Slice-following effectively corrects for through-plane motion in real-time cardiac imaging.
• The enhanced SENC method provides more accurate strain measurements than conventional SENC.
• The technique is validated in both human and animal subjects against established MRI tagging methods.