心脏MRI-T2*评价重型β-地中海贫血铁过载

目的 探讨心脏MRI-T2*评估重型β-地中海贫血铁过载的临床意义。方法 收集2010年8月—2015年9月中山大学孙逸仙纪念医院重型β-地中海贫血患者91例分别行心脏、肝脏MRI-T2*及血清铁蛋白（SF）、左室射血分数（LVEF）测定及肝组织活检,统计分析心脏MRI-T2*与肝脏MRI-T2*、SF、LVEF、肝铁沉积程度及肝纤维化水平的相关性。结果 91例重型β-地中海贫血患儿中28例(30.8%)发生心肌铁超负荷,其中重度13例（14.3%）,中度6例（6.6%）,轻度9例（9.9%）;肝脏铁过载81例(89.0%),其中重度23例（25.3%）,中度37例（40.7%）,轻度21例（23.1%）;SF>1 000 μg/L的84例（92.3%）,LVEF≤60%的30例（33.0%）。心脏和肝脏两脏器铁过载发生率对比差异有统计学意义（χ²=64.25,P<0.01）,但重度铁过载发生率对比差异无统计学意义（χ²=3.059,P>0.05）;28例心脏铁过载患者中发生重度心脏铁过载13例（46.4%）,81例肝铁过载患者中发生重度心铁过载的患者为11例（13.6%）,重度心脏铁过载发生率对比差异有统计学意义（χ²=13.076,P<0.01）。心脏MRI-T2*与SF呈低度负相关（r=-0.307,P=0.003）,与肝脏MRI-T2*呈低度正相关（r=0.367,P<0.001）,与LVEF呈正相关（r=0.429,P<0.001）,心脏MRI-T2*、LVEF与肝活检铁沉积程度、肝纤维化水平均无相关性（P>0.05）。结论 心脏MRI-T2*在重型β-地中海贫血患者铁过载检测中具有重要意义,可作为心脏等重要脏器铁过载的主要诊断指标。

Cardiac MRI-T2* in assessing iron overload in patients with β-thalassaemia major

Objective To investigate the clinical value of cardiac MRI-T2* in assessing iron overload in patients with β-thalassaemia major. Methods Totally 91 patients with β-thalassaemia major in Sun Yat-sen Memorial Hospital of Sun Yat-sen University August 2010-September 2015, underwent cardiac MRI-T2* , liver MRI-T2*, serum ferritin（SF）, left ventricular ejection fraction（LVEF）and liver biopsy, and then correlation analysis of cardiac MRI-T2* with liver MRI-T2* , SF level, LVEF, hepatic iron deposition and the level of hepatic fibrosis. Results Totally 28 out of the 91 cases ( 30.8%) of cardiac iron overload were found, including 13 severe cases (14.3%) , 6 moderate cases (6.6%) and 9 mild cases (9.9%); 81 out of the 91 cases ( 89.0%) of liver iron overload were found, including 23 severe cases (25.3%) , 37 moderate cases (40.7%) and 21 mild cases (23.1%). There were 84 cases (92.3%) of SF > 1 000 μg/L, 30 cases (33.0%) of LVEF≤60%. The difference in the incidence of iron overload between heart and liver was significantly (χ²= 64.25, P< 0.01), but not significantly different in the incidence of severe iron overload（χ²=3.059,P>0.05）; 13 of 28 cases (46.4%) with cardiac iron overload were severe iron overload, 11 out of the 81 cases(13.6%) who with liver iron overload were severe iron overload. The incidence of severe iron overload was significantly different (χ²=13.076,P<0.01). The cardiac MRI-T2* was negatively correlated with SF(r=-0.307, P=0.003), and was positively correlated with both liver MRI-T2* (r=0.367, P< 0.001) and LVEF (r=0.429, P< 0.001), but both cardiac MRI-T2* and LVEF were not significantly correlated with the level of hepatic fibrosis and the degree of hepatic iron deposition (P> 0.05). Conclusion Cardiac MRI-T2* plays an important role in the detection of iron overload in patients with β-thalassaemia major and can be used as a major diagnostic marker for iron overload in important organs such as the heart.