急性白血病儿童髂骨骨髓的扩散加权成像与扩散张量成像研究

Diffusion-Weighted Imaging and Diffusion Tensor Imaging of Iliac Bone Marrow in Acute Leukemic Children

目的探讨扩散加权成像(DWI)及扩散张量成像(DTI)在儿童初发急性白血病髂骨骨髓浸润中的诊断价值。方法搜集36名健康儿童志愿者(对照组)及27例本院临床确诊初发急性白血病儿童(病例组)为研究对象,对照组按年龄划分为三组:A组(≤5岁),B组(5~10岁),C组(10~14岁),其中A组10例,B组15例,C组11例;病例组用同样的方法分组:A’组(≤5岁),B’组(5~10岁),C’组(10~14岁),其中A’组10例,B’组8例,C’组9例。采用GE Singna 1.5 T超导型磁共振扫描仪对所有受试者进行骨盆轴位扫描,扫描序列包括单次激发自旋回波-平面回波DWI(SS-SE-EPI-DWI)扫描序列(b=0,800 s/mm;)及单次激发自旋回波-平面回波DTI(SS-SE-EPI-DTI)扫描序列。原始图据传送到AW 4.6工作站,应用Functool软件对图像数据进行后处理,在髂骨最大层面设置6个感兴趣区(ROI),分别测量表观扩散系数(ADC)值及各向异性分数(FA)值。对照组与病例组组间的ADC值及FA值的比较采用两独立样本t检验;绘制ADC值及FA值的受试者工作特征(ROC)曲线、并计算曲线下面积(AUC)。结果对照组A组与病例组A’组间ADC值及FA值比较,差异均有统计学意义(t=2.653,P<0.05;t=4.495,P<0.001);对照组B组与病例组B’组间ADC值及FA值比较,差异均有统计学意义(t=4.604,P<0.001;t=8.709,P<0.001);对照组C组与病例组C’组间ADC值及FA值比较,其中ADC值差异无统计学意义(t=-1.958,P>0.05),FA值差异有统计学意义(t=7.125,P<0.001);ADC值的AUC为0.653(P=0.038);FA值的AUC为0.962(P=0.000)。结论 FA值比ADC值敏感性更高,FA值与ADC值相比具有更高的诊断价值。可作为判断急性白血病骨髓浸润及严重程度的一项指标。

Objective To investigate the diagnostic value of diffusion weighted imaging(DWI) and diffusion tensor imaging(DTI) in iliac bone marrow infiltration in children with primary acute leukemia. Methods 36 healthy children(control group) and 27 cases of newly diagnosed acute primary leukemia children(case group) were included.The control group was divided into three groups according to their age: Group A( ≤5 years old),group B(5-10 years old),group C(10-14 years old),including 10 cases in group A,15 cases in group B and 11 cases in group C.The case group were grouped by the same method: group A’,group B’,group C’;including 10 cases in group A’,8 cases in group B’ and 9 cases in group C’.The pelvic transversal scan was performed on all subjects using GE Singna 1.5 T super conducting magnetic resonance scanner, The scanning sequence consists of a singleshotspin echo planar DWI(SS-SE-EPI-DWI)sequence(b=0,800 s/mm;) and a single shot spin echo planar DTI(SS-SE-EPI-DTI) sequence.The original images are transmitted to the AW 4.6 workstation and the image data are processed by Functool software, Six regions of interest(ROI) were set at the maximum level of iliac bone, the ADC values and FA values were measured on this plane separately.The ADC values and FA values between the control and the case group were compared using independent samples ttest;drew ROC curves of ADC values and FA values, and calculated the area under the curve(AUC). Results The ADC values and FA values of group A of control group and group A’ of case group were statistically significant(t=2.653,P<0.05;t=4.495,P<0.0019).The ADC values and FA values of group B of control group and group B’ of case group were statistically significant(t=4.604,P<0.001;t=8.709,P<0.001). The ADC values of group C of control group and group C’ of case group were not statistically significant(t=-1.958,P>0.05).The FA values of group C of control group and group C’ of case group were statistically significant(t=7.125,P<0.001). The AUC of ADC value was 0.653(P=0.038). The AUC of FA value is 0.962(P=0.000). Conclusion The ADC values can only identify the difference of iliac bone marrow between some normal children and children with acute leukemia. FA values are more sensitive than ADC values.Thepatients in the case group had lower FA values than the control group, which could be used as an index to judge the severity of bone marrow infiltration of acute leukemia.