The relationship between heart and liver iron in thalassemia: a quantitative analysis using MRI
10.3760/cma.j.issn.1005-1201.2012.03.010
- VernacularTitle:地中海贫血患者心脏、肝脏铁沉积的MRI定量研究
- Author:
Peng PENG
;
Zhongkui HUANG
;
Liling LONG
;
Mei LONG
;
Fanyu ZHAO
;
Chunyan LI
;
Wenmei LI
- Publication Type:Journal Article
- Keywords:
Thalassemia;
Magnetic resonance imaging;
Comparative study
- From:
Chinese Journal of Radiology
2012;46(3):244-247
- CountryChina
- Language:Chinese
-
Abstract:
Objective To quantify the heart and liver iron overload in thalassemia patients and discuss the relationship of iron deposition between them,and to evaluate the accuracy of using hepatic iron concentration ＞ 15 mg/g dry tissue as an index to predict heart iron deposition as used in clinical practice.Methods One hundred and three transfusion-dependent patients with thalassemia,who were older than 5 years,underwent MRI heart and liver measurement to obtain T2 * values.The Spearman rank correlation was employed to analyze the relationship between cardiac T2 * and liver T2 * values.By using liver T2 * =0.96 ms as standard setting,patients were divided into two groups,and the differences of cardiac T2 * values between the two groups were compared by Wilcoxon rank sum test.Then by using cardiac T2 * =10,20 ms as standard setting,patients were divided into 3 groups,and the differences of liver T2 * values among the 3 groups were compared by Wilcoxon rank sum test.The ROC curves were drawn to predict the possibility of using hepatic iron concentration ＞ 15 mg/g dry tissue as an index of cardiac iron deposition.Results The cardiac and liver T2 * values of the 103 thalassemia patients showed low correlation(r =0.453,P =0.000).With the liver T2 * value reduced,the cardiac T2* value did not decline proportionally.The cardiac T2 * value range and median of 25 patients' group whose liver T2 * ＜ 0.96 ms were 4.70 to 41.70 ms and 12.10 ms,respectively.The cardiac T2 * value range and the median of 78 patients' group whose liver T2 * ＞ 0.96 ms were 4.80 to 51.10 ms and 26.10 ms,respectively.There was statistically significant difference between those of the two groups(Z =-3.566,P =0.000).The liver T2 * value range and the median of 20 patients'group whose cardiac T2 * ＜ 10 ms was 0.68 to 3.83 ms and 1.06 ms,respectively.The liver T2 * value range and the median of 58 patients' group whose cardiac T2 * ≥20 ms were 0.74 to 14.80 ms and 1.76 ms,respectively.There was statistical difference between those of the two groups(Z =-3.553,P =0.000).The liver T2 * value range and the median of 25 patients' group with cardiac 10 ms≤T2 * ＜20 ms were 0.69 to 13.59 ms and 0.99 ms,respectively.The values were significantly different from that of T2* ≥20 ms group(Z =-3.951,P =0.000).The liver T2 * values of cardiac T2* ＜ 10 ms group was not statistically different from that of 10 ms≤T2* ＜20 ms group(Z =-0.046,P =0.964).To predict cardiac iron deposition with the index of hepatic iron concentration ＞ 15 mg/g dry tissue,the area under the ROC curve was 0.771.The sensibility was 42.2％,the specificity was 89.7％.Conclusions There is low correlation between heart and liver iron level in thalassemia patients with long-term transfusions.Patients with hepatic iron concentration ＞ 15 mg/g dry tissue have a higher incidence of heart iron deposition,but the accuracy of using hepatic iron concentration as an index to predict myocardial iron deposition is low to moderate.
