MRI骨髓成像的临床意义及发展

Magnetic Resonance Imaging (MRI) of Bone Marrow and Its Clinical Significance and Recent Development

骨髓磁共振成像(magnetic resonanceimaging,MRI)是当今骨髓疾病评价方法中一项最令人瞩目的发展。其临床意义已逐渐为越来越多的影像及临床医师所认识和重视。 众所周知,MRI具有无电离辐射,多参数多层次成像,任意方向扫描及无骨性伪影等特点。骨髓弛豫时间的变化,能提供机体内部生化及病理学等信息。化学位移及波谱分析等新技术在MRI的应用,除可进一步提供上述信息外,甚至可以在分子水平上反映组织内部的变化。九十年代以来,随着MRI设备及计算机软件的更新升级,骨髓MRI已成为当今医学影像研究的热点之一。 在评价骨髓方面,MRI优于X线平片、CT及核素扫描。 根据近十年来的研究成果,MRI主要可以评价以下几方面骨髓病理改变:第一,骨髓浸润或置换,如各种白血病及转移瘤等;第二,骨髓缺失,如骨髓纤维化、放疗或化疗后骨髓改变等;第三,骨髓缺血或骨梗塞,如股骨头无菌性坏死等;第四,骨髓水肿,如骨髓炎症或创伤等所致骨髓水肿;第五,骨髓逆转换,如慢性贫血、慢性心衰、骨转移瘤、骨髓瘤及白血病等,均可并发骨髓逆转换。 此外,MRI还可以显示骨髓分布形式,鉴别正常与异常骨髓,监测骨髓疾病的病程,指导骨髓穿刺的部位及评价骨髓疾病的放疗或化疗疗效。 总之,骨髓MRI是当今医学影像学中一个新领域。

Magnetic resonance imaging (MRI) ofbone marrow is the most significant step forward inthe evaluation of bone marrow disorders. Its clinicalsignificance has been gradually recognized by more andmore imageologic and clinical doctors. It is commonknowledge that MRI has no ironic irradiation, multiparam- eter and multisection imaging, random direction scan,no bone scanning artifacts and other features. Thechanges in bone marrow relaxation times (T1 andT2) can provide biochemical and pathological infor-mation of human body. Chemical shift imaging, spec-troscopic analysis and other new MRI techniques canprovide more above information, even the changes inmolecular level. In evaluation of bone marrow, MRI is preferableto X - ray plain radiography, X - ray computed to-mography (CT), and nuclide imaging. According to studies of the past decade, MRIcan evaluate following bone marrow pathologicalchanges: 1. bone marrow infiltration or replacementsuch as leukemia and metastasis, etc.; 2. bonemarrow depletion, such as bone marrow fibrosis,post - chemotherapy or post - irradiation therapychanges, etc.; 3. bone marrow ischemia or infarction,such as vascular necrosis of femoral head, etc.; 4. bonemarrow edema. It is a non - specific response to trauma,ischemia, neoplasm, inflammation and others; 5. bonemarrow reconversion, many disorders can cause bone mar-row reconversion such as chronic anemia, chronic heartfailure, metastasis, multiple myeloma, leukemia, lym-phoma, etc. In addition, MRI can demonstrate normal bonemarrow patterns, differentiate normal and abnormal bonemarrow, monitor the extent of bone marrow disease, sug-gest the location of bone marrow aspiration and evaluatethe results of chemotherapy and irradiation treatment. In summary, bone marrow MRI is a new field ofmodern medical imageology and represents the direction inimageologic evaluation of bone marrow diseases. Its clini-cal importance will be more and more eminent.