磁共振在儿童椎体骨髓转化及病变中信号类型的初步研究

The MR patterns of vertebral body changes in conversion of spinal bone marrow in children

目的通过分析椎体骨髓磁共振信号类型分布与年龄、性别的关系,探讨正常儿童椎体骨髓转换中磁共振信号的变化规律及其在椎体病变中的应用。方法选择分析105例正常儿童的脊柱椎体磁共振T1加权序列图像,其中男性63例,女性42例,年龄3个月～17岁(平均年龄6.56岁);同时选择血液系统疾病患儿共32例作为病变组对照研究,其中男性18例,女性14例,年龄3～14岁(平均年龄8.09岁)。病种包括各种原因所致贫血(19例)和白血病(13例)。采用GE 0.2 TProfile Gold永磁型开放式磁共振扫描仪进行脊柱矢状位SE T1WI扫描。采用四级六分法对椎体T1WI表现进行分型观察,并对所获得的数据与年龄、性别的关系进行统计学处理。结果不同年龄组间脊柱椎体信号类型分布差异具有显著统计学意义(P<0.01);0～5岁儿童脊柱椎体信号类型主要为Ⅱa、Ⅲ和Ⅳa型,6～17岁儿童脊柱椎体信号类型主要为Ⅳa和Ⅳb型;脊柱椎体信号类型在不同性别间分布差异均具有显著统计学意义(P<0.01);病变组脊柱椎体表现为Ⅰ型弥漫性T1低信号者最常见(75.6%),其他常见类型还包括Ⅱa型和Ⅳa型。结论椎体磁共振T1信号表现类型的分布与年龄及性别密切相关,不同年龄、不同性别间椎体磁共振成像表现具有显著差异。同时,病变组不同年龄段患儿椎体均主要表现为弥漫性T1信号减低。因此,椎体磁共振表现分型研究有助于直观显示骨髓正常发育过程及弥漫性骨髓病变或翻转的发生。

Objective To elucidate the spectrum of MRI appearance of spinal bone marrow associated with age and sex on T1-weighted images in children.Methods Sagittal T1-weighted MR images of the spinal vertebrae for the distribution of hematopoietic and fatty marrow were retrospectively reviewed.One hundred and five children aged from 3 months to 17 years without evidence of marrow abnormality and 32 children with hematopoietic disorders（19 anemia and 13 leukemia） were measured with the 0.2 T MR unit.Marrow conversion was assessed in cervical vertebrae,thoracic vertebrae and lumbar vertebrae by MRI patterns.Results The distribution of MRI patterns in spinal vertebrae was associated with age and sex before 17 years old（P 〈 0.01）.The most common pattern of MRI appearance in children with hematopoietic disease was reduced T1 signal diffusely（75.6 %）.Conclusion It is demonstrated that the MRI patterns change with age and sex before 17 years old.To assess the patterns of vertebral body in children may be necessary in observing the vertebral bone marrow pathologic status directly.