目的:探讨3.0 T MRI DTI及扩散张量示踪成像(DTT)在评估慢性肾脏病(CKD)患者肾脏早期功能变化中的价值。方法:选择50例CKD患者及19例健康志愿者行DTI扫描(b=0、400、600 s/mm^2),检查前测量血肌酐值。采用Pearson相关分析检验DTI参数与...目的:探讨3.0 T MRI DTI及扩散张量示踪成像(DTT)在评估慢性肾脏病(CKD)患者肾脏早期功能变化中的价值。方法:选择50例CKD患者及19例健康志愿者行DTI扫描(b=0、400、600 s/mm^2),检查前测量血肌酐值。采用Pearson相关分析检验DTI参数与肾小球滤过率(eGFR)的相关性;单因素方差分析检验部分各向异性(FA)值评价CKD患者临床分期的价值;ROC曲线分析FA值评价CKDⅠ期患者的意义。结果:CKD患者肾脏皮、髓质的FA及ADC值与eGFR均呈正相关关系(FA:皮质r=0.708,髓质r=0.684;ADC:皮质r=0.355,髓质r=0.380)。不同CKD分期FA值差异均有统计学意义(皮质F=26.038,髓质F=26.611,均P<0.001)。CKDⅠ期FA值低于对照组(P<0.05)。DTT能直观显示CKD患者肾脏微结构变化;CKD患者肾功能损害,髓质管状结构数量减少、过早中断;CKD越严重,DTT图像变化越显著。结论:DTI能评价CKD患者肾功能变化,尤其能反映Ⅰ期患者的肾脏损伤;DTT能显示肾脏微结构变化。展开更多
The nature of brain interstitial fluid （ISF） has long been a subject of controversy. Most of the previous studies on brain ISF were carded out in vitro. In the present study, a novel method was developed to characte...The nature of brain interstitial fluid （ISF） has long been a subject of controversy. Most of the previous studies on brain ISF were carded out in vitro. In the present study, a novel method was developed to characterize ISF in the living rat brain by magnetic resonance （MR） imaging using gadolinium-diethylenetriaminepentaacetic acid （Gd-DTPA） as a tracer. Sprague Dawley rats （n=8） were subjected to MR scanning before and after the introduction of Gd-DTPA into the caudate nucleus. A one-way drainage of brain ISF was demonstrated on the dynamic MR images. According to the traditional diffusion model, the diffusion and clearance rate constants of the tracer within brain extracellular space （ECS） were derived as （3.38±1.07）×10^-4 mm2 s^-1 and （7.60±4.18）×10^-5 s^-1. Both diffusion and bulk flow contributed to the drainage of ISF from the caudate nucleus, which demonstrated an ISF-cerebrospinal fluid confluence in the subarachnoid space at the lateral and ventral surface of the brain cortex at 3 h after the injection. By using this newly developed method, the brain ECS and ISF can be quantitatively measured simultaneously in the living brain, which will enhance the understanding of ISF and improve the efficiency of drug therapy via the brain interstitium.展开更多
文摘目的:探讨3.0 T MRI DTI及扩散张量示踪成像(DTT)在评估慢性肾脏病(CKD)患者肾脏早期功能变化中的价值。方法:选择50例CKD患者及19例健康志愿者行DTI扫描(b=0、400、600 s/mm^2),检查前测量血肌酐值。采用Pearson相关分析检验DTI参数与肾小球滤过率(eGFR)的相关性;单因素方差分析检验部分各向异性(FA)值评价CKD患者临床分期的价值;ROC曲线分析FA值评价CKDⅠ期患者的意义。结果:CKD患者肾脏皮、髓质的FA及ADC值与eGFR均呈正相关关系(FA:皮质r=0.708,髓质r=0.684;ADC:皮质r=0.355,髓质r=0.380)。不同CKD分期FA值差异均有统计学意义(皮质F=26.038,髓质F=26.611,均P<0.001)。CKDⅠ期FA值低于对照组(P<0.05)。DTT能直观显示CKD患者肾脏微结构变化;CKD患者肾功能损害,髓质管状结构数量减少、过早中断;CKD越严重,DTT图像变化越显著。结论:DTI能评价CKD患者肾功能变化,尤其能反映Ⅰ期患者的肾脏损伤;DTT能显示肾脏微结构变化。
基金supported by the National Natural Science Foundation of China (Grant Nos. 30972811, 81171080 and 81071148)the Twelfth Five-year Plan for National Science and Technology of China (Grant No.2012BAI15B009)
文摘The nature of brain interstitial fluid （ISF） has long been a subject of controversy. Most of the previous studies on brain ISF were carded out in vitro. In the present study, a novel method was developed to characterize ISF in the living rat brain by magnetic resonance （MR） imaging using gadolinium-diethylenetriaminepentaacetic acid （Gd-DTPA） as a tracer. Sprague Dawley rats （n=8） were subjected to MR scanning before and after the introduction of Gd-DTPA into the caudate nucleus. A one-way drainage of brain ISF was demonstrated on the dynamic MR images. According to the traditional diffusion model, the diffusion and clearance rate constants of the tracer within brain extracellular space （ECS） were derived as （3.38±1.07）×10^-4 mm2 s^-1 and （7.60±4.18）×10^-5 s^-1. Both diffusion and bulk flow contributed to the drainage of ISF from the caudate nucleus, which demonstrated an ISF-cerebrospinal fluid confluence in the subarachnoid space at the lateral and ventral surface of the brain cortex at 3 h after the injection. By using this newly developed method, the brain ECS and ISF can be quantitatively measured simultaneously in the living brain, which will enhance the understanding of ISF and improve the efficiency of drug therapy via the brain interstitium.
