原发性骨髓纤维化腰椎和骨盆的MRI和X线诊断探讨

MRI findings and X-ray appearance of primary myelofibrosis in marrow of lumbar vertebra and pelvis

目的 探讨原发性骨髓纤维化 (PMF)在下胸椎至骶椎、髂骨和股骨中上段的MRI和X线表现的特点。方法 搜集 1998～ 2 0 0 1年住院并有完整的临床、病理资料的PMF共 11例 ,所有病例均同时行X线和MR检查。分析其腰椎和骨盆X线平片及MRI表现 ,探讨其骨髓影像学表现的特点 ,并比较 2种影像检查方法的优缺点。结果 11例PMFX线平片 ,5例诸骨形态、大小、密度均未见异常 ;3例骨小梁模糊 ,病骨呈磨玻璃样改变 ;3例骨质密度普遍增高 ,骨小梁增粗、致密、融合 ,呈骨硬化 ,长骨不能分辨其骨髓腔。 11例PMF其腰椎、髂骨、股骨中上段骨髓的MRI信号改变均一致 ,即6例T1WI、T2 WI表现为明显均匀弥漫的低信号 (降低的程度略有不同 ) ,5例表现为等信号背景下可见多个斑点、斑片状低信号灶 ,数目不等 ,呈不均匀散在分布。 4例股骨头及大转子信号不变 ,仍保持与皮下脂肪相同的高信号 ,脂肪抑制序列高信号灶变为低信号。结论 PMF的MRI表现具有特征性 ,平片对早期诊断PMF有较大的局限性。

Objective To evaluate MRI findings and X ray appearance in primary myelofibrosis (PMF) in marrow of lumber vertebra and pelvis. Methods Eleven cases of PMF with integrated clinical and pathology data were collected. All cases were examined with X ray and MRI simultaneously. The imaging findings of PMF were studied and compared with that of normal group. The MRI findings and X ray appearance of cases with PMF were evaluated and compared with each other to find their good quality, the shortcoming, and the relationships. Results X ray appearance in the plain film in cases with PMF: There were no abnormal findings in lumbar vertebra, iliac bone, and superior segment of femur in 5 of 11 cases. Blurred bone trabecula and ground glass changes in bone marrow were found in 3 of 11 cases. In another 3 cases, the bone trabeculas were obscured, tightly closed or mixed together, and the density of bone marrow were widespreadly high, and the difference in it couldn′t be distinguished. MRI findings in cases with PMF: MRI findings in different parts of lumbar vertebrae, iliac bone, and femur superior segments in all 11 cases were consistent. Compared with the control group, both images on T 1 and T 2 weighted spin echo displayed diffusely and well distributed lower signal intensity in 6 of 11 cases, but displayed scattered spot and patchy lowersignals in 5 of 11 cases in all parts of bone marrow including lumbar vertebra, iliac bone, and superior segment of femur. The extents of lower marrow signal intensity varied in different cases. The high signal in femoral head and greater trochanters remained unchanged as that of subcutaneous fat in 4 of 11 cases. The positive rate was 54.6%(6/11)in X ray findings, but 100%(11/11)in MRI appearances. Conclusion MRI has greater value than X ray in the early diagnosis of PMF. The early diagnostic value of X ray plain film for PMF is limited.