再生障碍性贫血腰椎骨髓的MRI研究

MRI study of bone marrow in aplastic anemia

目的 探讨再生障碍性贫血 (简称再障 )的MRI诊断和在疗效评价上的应用价值。方法 选择骨髓穿刺镜检证实的再生障碍性贫血 16例及正常组 30例 ,常规行腰椎MRI检查 ,扫描序列包括T1WI、T2 WI和脂肪抑制短时反转恢复 (STIR)脉冲序列 ,层厚 5mm ,层距 1mm ,矩阵 180× 2 5 6。对 2组腰椎骨髓MRI表现分别总结、测量其T1值 ,对再生障碍性贫血组 ,计算椎体异常信号 (低信号 )区所占面积的百分比。结果 本组病例根据腰椎MRI表现分为 3种类型 :1型 2例 ,表现为T1WI呈均匀高信号 ,T2 WI呈均匀等信号 ,STIR呈均匀低信号 ,2例均为急性再障 ;2型 7例 ,表现为 3个序列中出现少许灶状不均匀信号 ,5例为急性再生障碍性贫血 ;3型 7例 ,表现为明显高低混杂不均匀信号 ,7例均为慢性再生障碍性贫血。急性再生障碍性贫血患者的腰椎T1WI低信号的面积占椎体的比例明显小于慢性再生障碍性贫血患者 (t=30 0 0 ,P <0 0 1)。再生障碍性贫血组的T1值明显低于正常组(q =7.0 2 ,P <0 0 1)。治疗好转后 ,骨髓又恢复接近正常信号和T1值。结论 MRI可作为再生障碍性贫血的一种非创伤性的骨髓检查 ,对观察病变程度、范围以及治疗后疗效评价有着重要的临床意义。

Objective To evaluate the MRI in the diagnosis of aplastic anemia (AA) and MRI changes after therapy. Methods MR imaging of lumber spine in 16 patients with AA proved pathologically were performed on 0.5 T superconductive MR unit with T 1WI, T 2WI, and STIR, slice thick 5 mm, slice gap 1 mm, matrix 180×256. Thirty cases of normal volunteers were examined as control group. Lumber spines of the two groups were studied by observation of MRI findings, measurement of the T 1 relaxation value. In AA group, the percentage of the hypointense signal areas in the centrum was calculated. Results Three patterns were classified by MR appearance in lumber spine of our cases. MR findings of pattern 1 (2 cases) were hyperintense on T 1WI, isointense on T 2WI, and hypointense on STIR, and all two cases were acute aplastic anemia (AAA). In pattern 2 (7 cases), a few irregular hypointense signals appeared in the background of hyperintense signal on all 3 sequences, and 5 of them were AAA. Pattern 3 (7 cases) demonstrated mixed irregular shape of hyperintense and hypointense signals, all 7 cases were chronic aplastic anemia (CAA). The percentage of the area of hypointense signal in AAA was significantly smaller than that in CAA (t=30 00, P<0.01). T 1 value in the group of aplastic anemia was significantly lower than that in the control group (q=7.02, P<0.01). The signal intensity and T 1 value in bone marrow in aplastic anemia recovered to the level near the normal group after successful therapy. Conclusion MRI can serve as a non-invasive method in checking bone marrow of aplastic anemia. MRI was of great value in diagnosing aplastic anemia, observing its extent and degree, and evaluating the therapeutic effect.