T1 mapping: characterisation of myocardial interstitial space

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Myocardial fibrosis is a hallmark of end-stage heart failure and a predictor of poor cardiac outcomes.
• Cardiac magnetic resonance (CMR) is the gold standard for cardiac anatomy and function assessment, including focal fibrosis via late gadolinium enhancement (LGE).
• Diffuse myocardial fibrosis presents a challenge for LGE imaging due to the absence of normal myocardial reference regions.

Purpose of the Study:

• To review current and emerging Cardiac magnetic resonance (CMR) T1 mapping techniques for evaluating diffuse myocardial fibrosis.
• To discuss the potential and limitations of CMR T1 mapping in clinical practice.
• To highlight T1 mapping's ability to quantify myocardial infiltration and fibrosis.

Main Methods:

• Utilizes advanced Cardiac magnetic resonance (CMR) parametric mapping techniques, specifically T1, T2, and T2* relaxation properties.
• Employs T1 mapping with and without contrast agents for comprehensive myocardial assessment.
• Focuses on techniques feasible within a single breath-hold for clinical efficiency.

Main Results:

• T1 mapping techniques allow for the quantification of diffuse myocardial fibrosis and infiltration.
• Native T1 values reflect myocardial disease affecting myocytes and the interstitium.
• Extracellular volume fraction, measured using gadolinium contrast, quantifies interstitial space.

Conclusions:

• Myocardial fibrosis is a common endpoint in cardiac diseases, leading to stiffness, heart failure, and arrhythmias.
• T1-mapping CMR techniques are effective in quantifying diffuse myocardial fibrosis.
• CMR T1 mapping, with and without contrast, provides valuable insights into myocardial interstitial disease and fibrosis.