上面是英文,下面是中文

1、上面是英文，下面是中文History: Twenty-year-old man.Shown below are fat-sat T1W enhanced GRE images.Here now are fat-sat T2W and Dualecho FSPGR images. ( 5-7)Findings: There is markedly decreased T2 signal intensity within the liver. The liver is normal in size and otherwise normal in appearance. The spleen is

2、surgically absent. The pancreas and kidneys are normal in size and show normal signal characteristics.Diagnosis: Secondary hemochromatosis (hemosiderosis).DiscussionThis patient has had hemolytic anemia, thought to be hereditary, since birth. Etiology is uncertain but there is a family history. He h

3、as had multiple hospitalizations and blood transfusions and had splenectomy at age 5. Serum iron studies revealed a hemoglobin level of 10.4 gm/dL, a hematocrit of 34%, a markedly elevated ferritin level of 3055 ng/mL, an elevated iron level of 216 mcg/mL, a decreased TIBC of 216 mcg/mL, and an elev

4、ated iron saturation level of 95%. MRI was ordered to evaluate for iron overload in the liver.On non-enhanced CT, a liver with increased iron content shows diffusely increased attenuation, usually greater than 75 HU. The contrast between parenchyma and vasculature is increased. These findings can al

5、so be present in glycogen storage disease, patients on amiodarone therapy, gold therapy, and in Wilson disease.MR is more sensitive and specific for detection of increased hepatic iron deposition. MR imaging of a liver with increased iron content shows a characteristic T2 signal loss due to the magn

6、etic susceptibility artifact of iron which causes spin dephasing. T2-weighted gradient echo images are the most sensitive.On MR, increased iron accumulation in the liver can be diagnosed if the liver demonstrates signal intensity equal to or lower than that of skeletal muscle, such as the paraspinal

7、 muscles, on either T2-weighted gradient echo, or T2-weighted spin echo images.Primary hemochromatosis is an autosomal recessive disease which results in abnormally increased iron absorption from the gut, and subsequent deposition into organs including the liver, heart, pancreas, pituitary, joints,

8、and skin. This can result in organ dysfunction including liver cirrhosis and its complications including HCC, skin pigmentation, and type 1 diabetes which generally occur late in the disease.Most patients with primary hemochromatosis do not have involvement of the spleen; iron deposition in primary

9、hemochromatosis occurs in the parenchymal cells of the liver (hepatocytes) and not in the reticuloendothelial system (Kupffer cells and spleen). Therefore, splenic signal intensity usually is normal in these patients.Patients who receive multiple blood transfusions also develop iron overload, occasi

10、onally termed hemosiderosis or secondary hemochromatosis. Iron from the transfused erythrocytes is deposited in the reticuloendothelial system in the liver, spleen, and bone marrow. Abnormal iron accumulation in the reticuloendothelial system does not damage the affected organs, thus is of little cl

11、inical significance.In patients who have received more than 40 units of blood, the reticuloendothelial system is typically saturated with iron （10 g）, and additional iron deposits are seen in the parenchymal cells of the liver, pancreas, and heart. The abnormal parenchymal iron deposition can cause

12、organ dysfunction, similar to that seen in primary hemochromatosis. Iron chelation therapy is used in patients who receive large numbers of transfusions to remove excess iron and prevent organ damage.Quantitative measurement of hepatic iron content can be performed with MR. Various methods include m

13、easuring liver-to-tissue signal-intensity ratios, and utilizing gradient echo sequences to correlate the natural logarithm of the ratio of signal intensity of the liver to the standard deviation of the background noise However, to accurately perform quantitative MR, each MR scanner needs to be prope

14、rly calibrated with patients who have undergone liver biopsy to measure iron content.病史： 21 岁男性患者。以下是饱和脂肪抑制 T1W增强梯度回波（GRE图像。这是饱和脂肪抑制 T2W和双回波快速扰相梯度回波（FSPGR图像。（5-7）发现：肝脏 T2 信号强度显著下降。肝脏大小和形态正常。脾已手术切除。胰腺和肾脏大小 和信号均正常。诊断：继发性血色病（含铁血黄素沉着症） 。讨论： 该患者出生后就有溶血性贫血， 认为是遗传性的。 病因虽不清，但有家族史。他曾多次 住院并接受输血治疗，在 5 岁时进行了脾切除

15、。血清铁检测显示血红素浓度为 10.4mg/dl ； 红细胞压积为 34；铁蛋白浓度为 3055 ng/mL ，较正常值明显升高；血清铁浓度为 216 mcg/mL ，较正常值升高；总铁结合力为 216 mcg/mL ，较正常值下降；铁饱和度为 95，较 正常值升高。行 MRI 检查以评估肝脏铁负荷。在CT平扫中，肝脏铁含量增加，表现为弥漫性衰减增强，数值一般高于75HU。肝脏实质和血管对比增强。 这些表现还可见于糖原贮积症， 接受胺碘酮治疗、 金疗法的患者以及 Wilson 病患者。MR 检测肝脏铁沉积增加的敏感性和特异性更高。铁含量升高的肝脏MR 显像表现为特征性 T2 信号缺失，缺失的原

16、因为铁离子的磁敏感性伪影引起的自旋去相。T2 加权梯度回波成像的敏感性最高。在MR上，无论是T2加权梯度回波还是 T2加权自旋回波成像，如果肝脏信号强度和骨 骼肌（如椎旁肌）相同或稍低，则可诊断为铁沉积增加。原发性血色病是一种常染色体隐性遗传病。 此病导致机体从肠道吸收铁异常升高， 继而 多余的铁沉积于肝脏、心脏、胰腺、垂体、关节和皮肤等器官中。这可导致器官功能异常， 如：肝硬化及其并发症（包括原发性肝癌） ，皮肤色素沉着和通常在疾病后期出现的 1 型糖 尿病。大多数原发性血色病患者的脾脏不受累；原发性血色病铁沉积于肝脏实质细胞（肝细 胞），而不是网状内皮系统（ Kupffer 细胞和脾）。因此，这些患者的脾脏信号强度往往正常。曾接受多次输血的患者也可发生铁超负荷，有时称为含铁血黄素沉着症或继发性血色 病。输入的红细胞中的铁通常沉积于肝脏、 脾和骨髓的网状内皮系统。 网状内皮系统的异常 铁沉积不会损伤受累器官，因此无太大临床意义。接受超过40单位血液输入的患者，其