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• T1 levels are elevated in patients with DMD, compared to healthy individuals.
• "Both native and post-contrast T₁ and ECV estimates are promising diagnostic CMR biomarkers for assessing myocardial remodeling in Duchenne muscular dystrophy."
• "Additionally, from pre- and post-contrast T₁ measurements (and if the patient’s hematocrit is measured), the extracellular volume (ECV) fraction can be calculated and used to quantify diffuse fibrosis."
• "Elevated myocardial ECV in DMD subjects compared to healthy controls has been shown by multiple studies , thus ECV is promising as a quantitative metric for detecting myocardial microstructural remodeling."

The Native T1 mapping or longitudinal (T1) relaxation time is the time constant which determines the rate at which excited protons return to equilibrium. It is a measure of the time taken for spinning protons to realign with the external magnetic field. The T2 mapping or transverse (T2) relaxation time constant determines the rate at which excited protons reach equilibrium or go out of phase with each other. It is a measure of the time taken for spinning protons to lose phase coherence among the nuclei spinning perpendicular to the main field. The term "native" means contrast naive in this context. The T2 measurement is only done prior to contrast.

"T1 mapping stands for registering the course of recovery of longitudinal magnetism", this means the relaxation time after either the preparation step (saturation or inversion prepulse) followed by the acquisition of images at several time points during the T1 recover/relaxation. The T1 value represents the time when recovery of magnetism has reached a percentage of its original state (63%). The recovery rate relates to the myocardial tissue properties that may be altered by pathological tissue presence (ref: https://wwwjcmr-online.ahajournalsbiomedcentral.orgcom/doiarticles/10.1161/circresaha.116.307974). T1 mapping values increase with disease and decrease post contrast.1186/s12968-020-00687-z)

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