BOLD-MRI与慢性肾脏病血清β2微球蛋白的相关性

Correlation of blood oxygen level⁃dependent functional magnetic resonance imaging with serumβ2 Microglobulin in Patients Chronic Kidney Disease

目的:利用血氧水平依赖磁共振成像(BOLD-MRI)定量参数表观自旋-自旋弛豫率(R2^(*))值探讨慢性肾脏病(CKD)患者血清β2微球蛋白(β2-MG)浓度的变化与肾脏血氧含量的关系及肾脏BOLD-MRI序列最优回波时间(TE)的选择。方法:选取我院45例CKD患者(病例组),根据肾穿刺活检结果又分为CKD 3期组(29例)和CKD 4期组(16例),同时选取42例性别、年龄与之匹配的健康志愿者为对照组,行BOLD-MRI检查,分别测量各组肾皮质、髓质R2^(*)值并进行组间对比,分析病例组肾髓质R2^(*)值与血清β2-MG浓度的相关性。结果:不同病理分期的CKD及对照组肾皮髓质R2^(*)值进行比较,皮质R2^(*)值均大于髓质R2^(*)值,差异有统计学意义(均P<0.01);皮、髓质R2^(*)值均呈现CKD 3期组?对照组?CKD 4期组趋势,但皮质R2^(*)值在3组间差异无统计学意义(P?0.05);而髓质R2^(*)值在3组间差异有统计学意义(P<0.05),且进一步两两比较发现,CKD 3期组和对照组与CKD 4期组之间差异均有统计学意义(P<0.05),CKD 3期组与对照组之间差异则无统计学意义(P?0.05)。病例组髓质R2^(*)值与血清β2-MG浓度呈负相关(r=-0.017,P<0.05)。4期组肾皮值明显变薄,皮髓质界线欠清,BOLD-MRI显示肾皮髓质界线清晰的最优TE值范围为22.9~28.9 ms。结论:BOLD-MRI可无创性评估CKD患者肾功能结构的改变及不同血清β2-MG浓度的肾脏血氧含量,能较敏感地反映并量化肾脏病理改变的严重程度。肾脏BOLD-MRI时的TE过长或过短,肾皮髓质界线越模糊。

Purpose:To investigate the relationship between serumβ2 microglobulin(β2-MG)concentration and kidney oxygen content in patients with chronic kidney disease(CKD)by using the apparent spin-spin relaxation rate(R2^(*))of quantitative parameters of blood oxygenation level dependent-magnetic resonance imaging(BOLD-MRI)and the selection of optimal echo time(TE)in BOLD-MRI sequence.Methods:A total of 45 patients with CKD in our hospital were selected and divided into stage 3(29 cases)and stage 4(16 cases)according to the renal needle biopsy results,and 42 healthy volunteers with matching gender and age were selected as the control group.BOLD-MRI was performed to measure the R2^(*)value of renal cortex and medullary tissue in each group,and the R2^(*)value of renal cortex and medulla among 3 groups(CKD stage 3,CKD stage 4,and control group)were compared.The correlation between R2^(*)value and serumβ2-MG concentration in renal medulla of CKD patients was analyzed.Results:In each of 3 groups,the R2^(*)value of the cortex was higher than that of the medulla,with a statistically significant difference(all P<0.01).The renal cortical and medullary R2^(*)value of stage 3 was higher than that of the control group,and that of control group was higher than that of stage 4.There was no significant difference in cortical R2^(*)value between groups(P˃0.05),and there was no significant difference in the value of medullary R2^(*)between stage 3 and the control group(P˃0.05).There were significant differences in the R2^(*)value of medulla between the stage 3 and the stage 4 and between the stage 4 and control group(P<0.05).The negative correlation was found between medulla R2^(*)value and serumβ2-MG(r=−0.017,P<0.05)in the case group.At stage 4,renal cortex were significantly thinner and the boundary of the medulla was not clear.BOLD-MRI showed that the optimal TE value range with clear boundary of the renal cortex-medulla was from 22.9 ms to 28.9 ms.Conclusions:BOLD-MRI can noninvasively evaluate the changes of renal function and structure,and renal oxygen content at different serumβ2-MG concentrations in patients with CKD,and can respond sensitively and quantify the severity of renal pathological changes.If the TE time of BOLD-MRI of kidney is too long or too short,the boundary of renal cortex and medulla is blurred.