常见血液病的骨髓磁共振成像

磁共振成像(MRI)以其无创伤性、直接显示骨髓、检测异常骨髓的能力而成为评价骨髓病变的首选影像学检查方法。随着年龄的增长，正常人红骨髓按照一定规律转换为黄骨髓，MRI表现也发生相应的变化。多种原发血液病可引起骨髓MRI信号异常，甚至骨髓T1的变化。白血病骨髓典型表现为弥漫性的T1WI低信号，T1延长；白血病治疗后缓解，T1缩短接近正常范围。淋巴瘤及多发性骨髓瘤的MRI表现多种多样，取决于病变的恶性程度，但骨髓的T1均延长。再生障碍性贫血具有特征性的T1WI、T2WI高信号。增生性贫血由于红骨髓增生，黄骨髓逆转为红骨髓，贫血严重时甚至骨骺内的黄骨髓逆转为红骨髓。

Magnetic Resonance Imaging of Bone Marrow in Common Hematological Diseases

Magnetic resonance imaging has become preferred over other imaging modalities in evaluation disease in the bone marrow with non - invasively and directly displaying normal bone marrow and detecting abnormal marrow. Red marrow in normal convert to yellow marrow with aging according to certain pattern, then, the MR appearance of the bone marrow varies correspondently with the conversion. The bone marrow of varied primary hematological diseases manifested abnormal signal intensity, evenly changes of T_1 relaxation time on MR imaging. Diffuse low signal intensity on T_1 - weighted imaging and prolonged T_1 relaxation time were established as typically manifestation of bone marrow in leukemia on MR imaging. The prolonged T_1 relaxation time decreased to approach to normal range in patients with leukemia who achieved remission after initiation of treatment. The manifestation of bone marrow in patients with lymphoma and multiple myeloma on MR imaging were divers which accounted for the malignancy of the diseases, but increase of T_1 relaxation time was identical findings in both. Aplastic anemia was characterized as high signal intensity of bone marrow on both T_1 - and T_2 - weighted imaging. In hyperplasia anemia, yellow marrow reconverted to red marrow because of marrow hyperplasia, furthermore, marrow reconversion affected the epiphyses and apohyses when there is a severe anemia.