Myocardial tissue characterization by segmental T₂ mapping in thalassaemia major: detecting inflammation beyond iron

We measured myocardial T₂ values by a segmental approach in thalassaemia major (TM) patients, comparing such values against T₂* values for the detection of myocardial iron overload (MIO), evaluating their potential in detecting subclinical inflammation, and correlating with clinical status.

One-hundred and sixty-six patients (102 females, 38.29 ± 11.49years) enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network underwent magnetic resonance imaging for the assessment of hepatic, pancreatic, and cardiac iron overload (T₂* technique), of biventricular function (cine images), and of replacement myocardial fibrosis [late gadolinium enhancement (LGE)]. T₂ and T₂* values were quantified in all 16 myocardial segments, and the global value was the mean of all segments. Global heart T₂ values were significantly higher in TM than in a cohort of 80 healthy subjects. T₂ and T₂* values were significantly correlated. Out of the 25 patients with a decreased global heart T₂* value, 11 (44.0%) had reduced T₂ values. No patient with a normal T₂* value had a decreased T₂ value.

Eleven (6.6%) patients had a decreased global heart T₂ value, 74 (44.6%) a normal global heart T₂ value, and 81 (48.8%) an increased global heart T₂ value. Biventricular function was comparable amongst the three groups, whilst LGE was significantly more frequent in patients with reduced vs. increased global heart T₂ value. Compared with the other two groups, patients with reduced T₂ values had significantly higher hepatic and pancreatic iron deposition.

In TM, T₂ mapping does not offer any advantage in terms of sensitivity for MIO assessment but detects subclinical myocardial inflammation.