A multicenter study on the quantification of liver iron concentration in thalassemia patients by means of the MRI T2* technique

Abstract

Objective To investigate the feasibility and accuracy of quantifying liver iron concentration (LIC) in patients with thalassemia (TM) using 1.5T and 3T T 2 * MRI. Methods 1.5T MRI T 2 * values were measured in 391 TM patients from three medical centers: the T 2 * values of the test group were combined with the LIC (LIC F ) provided by FerriScan to construct the curve equation. In addition, the liver 3T MRI liver T 2 * data of 55 TM patients were measured as the 3T group: the curve equation of 3T T 2 * value and LIC F was constructed. Results Based on the test group LIC F (0.6–43 mg/g dw) and the corresponding 1.5T T 2 * value, the equation was LIC F = 37.393 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:msub><mml:mtext>T</mml:mtext><mml:mn>2</mml:mn></mml:msub><mml:msup><mml:mrow/><mml:mrow><mml:mo>*</mml:mo><mml:mo>∧</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math> (−1.22) (R 2 = 0.971; P &amp;lt; 0.001). There was no significant difference between LIC e − 1.5T and LIC F in each validation group ( Z = −1.269, −0.977, −1.197; P = 0.204, 0.328, 0.231). There was significant consistency (Kendall's W = 0.991, 0.985, 0.980; all P &amp;lt; 0.001) and high correlation (r s = 0.983, 0.971, 0.960; all P &amp;lt; 0.001) between the two methods. There was no significant difference between the clinical grading results of LIC e − 1.5T and LIC F in each validation group (χ 2 = 3.0, 4.0, 2.0; P = 0.083, 0.135, 0.157), and there was significant consistency between the clinical grading results (Kappa's K = 0.943, 0.891, 0.953; P &amp;lt; 0.001). There was no statistical correlation between the LIC F (≥14 mg/g dw) and the 3T T 2 * value of severe iron overload ( P = 0.085). The LIC F (2–14 mg/g dw) in mild and moderate iron overload was significantly correlated with the corresponding T 2 * value (r s = −0.940; P &amp;lt; 0.001). The curve equation constructed from LIC F and corresponding 3T T 2 * values in this range is LIC F = 18.463T 2 * ∧ (−1.142) (R 2 = 0.889; P &amp;lt; 0.001). There was no significant difference between LIC F and LIC e − 3T in the mild to moderate range (Z = −0.523; P = 0.601), and there was a significant correlation (r s = 0.940; P &amp;lt; 0.001) and significant consistency (Kendall's W = 0.970; P = 0.008) between them. LIC e − 3T had high diagnostic efficiency in the diagnosis of severe, moderate, and mild liver iron overload (specificity = 1.000, 0.909; sensitivity = 0.972, 1.000). Conclusion The liver iron concentration can be accurately quantified based on the 1.5T T 2 * value of the liver and the specific LIC-T 2 * curve equation. 3T T 2 * technology can accurately quantify mild-to-moderate LIC, but it is not recommended to use 3T T 2 * technology to quantify higher iron concentrations.

Topics & Concepts