Objective: To use the technique of magnetic resonance imaging (MRI) T2* mapping to diagnose and follow-up of patients with iron overload.
Methods: 107 patients who were suspected to have iron overload between 2011.7-2014.3 in Peking Union Medical Colleague Hospital were analyzed retrospectively. Patients had the document of MRI T2* value of liver, heart and pancreas, serum ferritin (SF), transferrin saturation (TS), transfusion amount and other related laboratory tests. T2* values were compared with SF and transfusion amount. T2* values in different organs and their relationship with SF were also evaluated. 10 patients who had been adequately chelated for more than half a year were followed up for their SF and T2* values.
Results: There were 65 males and 42 females with the median age of 51(8-77)-year-old. They were 50 myelodysplastic syndromes (MDS), 36 aplastic anemia, 10 myelofibrosis, 7 hemachromatosis and 4 thalassemia carriers. Liver T2* value was significantly related to SF (r=0.120, P=0.001), but not related to transfusion amount (r=0.019, P=0.175), whereas cardiac MRI T2* was not related either to SF or to transfusion amount. No correlation of the T2* value was found between liver and heart (r=0.015, P=0.235). 70 patients was detected for liver, heart and pancreas T2* simultaneously. Pancreas T2* was compatible to SF (r=0.061，P=0.039) and cardiac T2* (r=0.110, P=0.005), but not correlated to heptic T2* (r=0.047, P= 0.071) or transfusion amount (r=0.000, P=0.960). For the 10 well-chelated patients, during the half year follow-up period, SF changed significantly from (2 566.5±1 152.2) μg/L before chelation to (1 473.4±803.0) μg/L after chelation(P=0.001), while liver T2* remained the same [(6.0±5.1) ms, (6.3±6.0) ms respectively, P=0.629].
Conclusion: MRI, although related to SF to some extent, was a valuable additional methods for quantifying iron overload. Iron deposition in different organs might be not related to each other and needed to be evaluated separately. Well-chelation therapy could change SF in half-year follow-up, but T2* change needed longer time to follow-up.
目的: 探索磁共振成像技术（MRI）在铁过载患者诊断和随访中的应用。
方法: 回顾性分析北京协和医院2011年7月至2014年3月临床上怀疑有铁过载的患者107例，通过MRI技术测定其肝脏、心脏及胰腺T2*值，同时检测了血清铁蛋白（SF)、转铁蛋白饱和度、输血量及其他实验室指标，比较脏器T2*值与SF、输血量的关系；对其中10例经过祛铁治疗的患者进行随访，探索治疗后SF及T2*值的改变。
结果: ①男65例，女42例，中位年龄51(8~77)岁。诊断为骨髓增生异常综合征50例，再生障碍性贫血36例，骨髓纤维化10例，血色病7例，β地中海贫血携带者4例。②肝脏T2*值和SF之间呈低度相关(r=0.120，P=0.001)，心脏T2*值与SF无相关性(r=0.012，P=0.289)；肝脏和心脏T2*值均与输血量无相关性（分别为r=0.019，P=0.175；r=0.000，P=0.845）；肝脏T2*值与心脏T2*值之间无相关性(r=0.015,P=0.235)。③70例患者同时接受肝脏、心脏和胰腺T2*值检测，胰腺T2*值与SF呈低度相关(r=0.061,P=0.039)，与输血量无相关性(r=0.000，P=0.960)；胰腺T2*值与肝脏T2*值无相关性(r=0.047，P=0.071)，而与心脏T2*值呈低度相关(r=0.110，P=0.005)。④其中10例患者进行了规律足量祛铁治疗，治疗前、后SF水平明显下降，分别为（2 566.5±1 152.2)µg/L、(1 473.4±803.0)µg/L(P=0.001)；治疗前、后肝脏T2*值变化不大，分别为（6.0±5.1) ms、(6.3±6.0)ms(P=0.629)。
结论: 各脏器铁过载的程度明显不同，MRI定量检测较SF更好地反映脏器间铁过载程度的差异；规律的祛铁治疗在半年内对SF的变化有显著影响，但对肝脏T2*值影响不大，可能需要更长时间的祛铁治疗才能观察到脏器铁沉积的改善。