The relationship between myocardial and hepatic T2 and T2* at 1.5T and 3T MRI in normal and iron

Cardiac and liver iron assessment using magnetic resonance imaging (MRI) is non-invasive and used as a preclinical “endpoint” in asymptomatic patients and for serial iron measurements in iron-overloaded patients. To compare iron measurements between hepatic and myocardial T2* and T2 at 1.5T and 3T MRI in normal and iron-overloaded patients. The T2 and T2* values from the regions of interest (ROIs) at mid-left ventricle and mid-hepatic slices were evaluated by 1.5T and 3T MRI scans for healthy and iron-overloaded patients. For iron-overloaded patients, the myocardial T2 (1.5T) and myocardial T2 (3T) values were 60.3？ms (range？=？56.2–64.8？ms) and 55？ms (range？=？51.6–60.1？ms) (ρ？=？0.3679) while the myocardial T2* (3T) 20.5？ms (range？=？18.4–25.9？ms) was shorter than the myocardial T2* (1.5T) 35.9？ms (range？=？31.4–39.5？ms) (ρ？=？0.6454). The hepatic T2 at 1.5T and 3T were 19.1？ms (range？=？14.8–27.9？ms) and 15.5？ms (14.6–20.4？ms) (ρ？=？0.9444) and the hepatic T2* at 1.5T and 3T were 2.7？ms (range？=？1.8–5.6？ms) and 1.8？ms (range？=？1.1–2.9？ms) (ρ？=？0.9826). The line of best fit exhibiting the linearity of the hepatic T2* (1.5T) and hepatic T2* (3T) had a slope of 2 and an intercept of –0.387？ms (R？=？0.984). Our study found myocardial T2 (1.5T) nearly equal to T2 (3T) with myocardial T2* (3T) 1.75 shorter than myocardial T2* (1.5T). The relationship of hepatic T2* (1.5T) and hepatic T2* (3T) was linear with T2* (1.5T) approximately double to T2* (3T) in iron-overloaded patients. This linear relationship between hepatic T2* (1.5T) and hepatic T2 (3T) could be an alternative method for estimating liver iron concentration (LIC) from 3T