Compact MR-compatible ergometer and its application in cardiac MR under exercise stress: A preliminary study

Area of Science:

• Cardiovascular Imaging
• Magnetic Resonance Imaging
• Physiology

Background:

• Assessing myocardial function during exercise stress is crucial for diagnosing cardiovascular diseases.
• Existing methods for exercise stress testing within MRI environments are often limited by space and compatibility.
• Developing specialized equipment is necessary to facilitate simultaneous exercise and advanced cardiac MRI.

Purpose of the Study:

• To engineer a compact, Magnetic Resonance (MR)-compatible ergometer for inducing exercise stress.
• To evaluate the reproducibility of myocardial native T1 and myocardial blood flow (MBF) measurements during ergometer-induced exercise stress.

Main Methods:

• A novel compact ergometer was designed with exercise, workload, and data processing components.
• Ten healthy subjects underwent cardiac MRI scans twice, assessing reproducibility.
• Myocardial native T1 and MBF were measured at rest and during moderate exercise (45W, 5 min).

Main Results:

• Exercise significantly increased systolic blood pressure and heart rate, with a two-fold increase in rate pressure product.
• Excellent reproducibility was observed for myocardial native T1 during exercise (CoV = 3.0%).
• Good reproducibility was found for myocardial blood flow (MBF) and myocardial perfusion reserve (CoV = 10.7% and 8.8%, respectively).

Conclusions:

• The developed compact MR-compatible ergometer facilitates reproducible myocardial native T1 and MBF measurements during exercise stress.
• This pilot study confirms the feasibility of using the new ergometer for reliable cardiac MRI assessments in healthy individuals.