Objective: To investigate the feasibility and accuracy of quantifying liver iron concentration (LIC) in patients with thalassemia (TM) using 1.5T and 3T T₂^* MRI.Methods: 1.5T MRI T₂^* values were measured in 391 TM patients from three medical centers: the T₂^* 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 T₂^* data of 55 TM patients were measured as the 3T group: the curve equation of 3T T₂^* 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 T₂^* value, the equation was LIC_F = 37.393T2*∧(−1.22) (R² = 0.971; P < 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 < 0.001) and high correlation (r_s = 0.983, 0.971, 0.960; all P < 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 (χ² = 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 < 0.001). There was no statistical correlation between the LIC_F (≥14 mg/g dw) and the 3T T₂^* 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 T₂^* value (r_s = −0.940; P < 0.001). The curve equation constructed from LIC_F and corresponding 3T T₂^* values in this range is LIC_F = 18.463T₂^*∧^(−1.142) (R² = 0.889; P < 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 < 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 T₂^* value of the liver and the specific LIC-T₂^* curve equation. 3T T₂^* technology can accurately quantify mild-to-moderate LIC, but it is not recommended to use 3T T₂^* technology to quantify higher iron concentrations.

Objective: To summarize the research progress of magnetic resonance imaging (MRI) in quantifying liver iron load.Methods: To summarize the current status and progress of MRI technology in the quantitative study of liver iron load through reviewing the relevant literature at home and abroad.Results: Different MRI sequence examination techniques have formed a series of non-invasive methods for the examination of liver iron load. These techniques have important clinical significance in the imaging diagnosis of liver iron load. So far, the main MRI methods used to assess liver iron load are: signal intensity measurement method (signal intensity, SI) [signal intensity ratio (SIR) and difference in in-phase and out-of-phase signal intensity], T₂/R₂ measurement (such as FerriScan technique), ultra-short echo time (UTE) imaging technique, and susceptibility weighted imaging (including conventional susceptibility weighted imaging) (SWI), quantitative susceptibility mapping (QSM), T₂^*/R₂^* measurement, Dixon and its derivative techniques.Conclusion: MRI has become the first choice for the non-invasive examination of liver iron overload, and it is helpful to improve the early detection of liver injury, liver fibrosis, liver cirrhosis and liver cancer caused by liver iron overload.

To investigate the value of T₂^* technique on 3.0 T magnetic resonance imaging (MRI) in evaluating the changes of cardiac and hepatic iron load before and after hematopoietic stem cell transplantation (HSCT) in patients with thalassemia (TM), the 141 TM patients were divided into 6 group for subgroup analysis: 6, 12, 18, 24 and > 24 months group, according to the postoperative interval. The T₂^* values of heart and liver (H-T₂^*, L-T₂^*) were quantified in TM patients before and after HSCT using 3.0 T MRI T₂^* technology, and the corresponding serum ferritin (SF) was collected at the same time, and the changes of the three before and after HSCT were compared. The overall H-T₂^* (P = 0.001) and L-T₂^* (P = 0.041) of patients after HSCT were higher than those before HSCT (mean relative changes = 19.63%, 7.19%). The H-T₂^* (P < 0.001) and L-T₂^* (P < 0.001) > 24 months after HSCT were significantly higher than those before HSCT (mean relative changes = 69.19%, 93.73%). The SF of 6 months (P < 0.001), 12 months (P = 0.008), 18 months (P = 0.002) and > 24 months (P = 0.001) were significantly higher than those before HSCT (mean relative changes = 57.93%, 73.84%, 128.51%, 85.47%). There was no significant improvement in cardiac and liver iron content in TM patients within 24 months after HSCT, while the reduction of cardiac and liver iron content in patients is obvious when > 24 months after HSCT.

Objective: To explore the relationship between the liver T2* values of thalassemia patients measured by Circle Cardiovascular Imaging CVI42 (CVI42), CMRtools / Thalassemia Tools (CMRtools) and Excel spreadsheet (Excel), and the three software's accuracy in clinical grading of liver iron concentration (LIC). Methods: The liver T2* images thalassemia patients were imported into CVI42 and CMRtools to measure the T2* value. And the signal intensity (SI) of the T2* image, measured in the MR scanning equipment, was input into Excel to calculate T2* value. The relationship of the T2* values measured by the above three software were compared. And LIC clinical grading was performed on the three measured T2* value results, and the LIC (LICF) provided by FerriScan was used as the reference standard to compare the accuracy of the three grading results. Results: There was no statistical difference between the T2* values measured by CVI42, CMRtools and Excel (P>0.05), but there was a high degree of consistency between them (P<0.05), and there was a high linear positive correlation between the them (P0.05). There is a significant difference between the LIC grading results of Excel and the LICF grading results (P<0.05). Conclusion: The liver T2* values measured by CVI42, CMRtools and Excel are equivalent. However, CVI42 and CMRtools have better diagnostic accuracy for LIC clinical grade, while Excel has worse diagnostic accuracy. Keywords: THALASSEMIA; lIVER T2 VALUE;