Jørgensen Bettina, Keller Anna Krarup, Radvanska Eva, Rittig Søren, Taagehøj-Jensen Finn, Frøkiaer Jørgen, Jørgensen Troels Munch, Pedersen Michael
Institute of Clinical Medicine, Aarhus University Hospital, Skejby Sygehus, Brendstrupgaardsvej, 8200 Aarhus, Denmark.
J Urol. 2006 Sep;176(3):1171-6. doi: 10.1016/j.juro.2006.04.051.
We sought to determine the reproducibility of magnetic resonance imaging renography using 3 different mathematical models and 2 different approaches to convert the relative signal intensity into quantitative indices. Furthermore, we wanted to examine the influence of fluid intake on the obtained renal parameters.
A total of 10 healthy volunteers 13 to 16 years old were subjected to magnetic resonance imaging 3 times within 10 weeks, including an examination where fluid intake was increased. At each examination 0.1 mmol/kg gadolinium diethylenetriamine pentaacetic acid was administrated intravenously as a rapid bolus during a fast magnetic resonance renography sequence. Images were acquired in the coronal plan, and 1,200 images were recorded during approximately 7 minutes. Cortical data were analyzed to estimate absolute and differential function of renal parameters by converting signal intensities into quantitative units.
Using the simple approach that a change in magnetic resonance imaging signal is linearly related to the change in gadolinium diethylenetriamine pentaacetic acid concentration, we found reproducibility in the range of 1% to 5% of all estimations of the differential renal function. The relative glomerular ultrafiltration (ml per minute per cm(3) kidney cortex) was calculated and a reproducibility of 7% was observed for relative glomerular ultrafiltration (using the model based on deconvolution). Increased hydration caused a significant change in most parameters.
Contrast enhanced magnetic resonance renography is reproducible in the normal human kidney but excessive water intake has a significant influence on these parameters. Further studies are required to elucidate whether similar measurements can be applied to a kidney with impaired function.
我们试图确定使用3种不同数学模型和2种不同方法将相对信号强度转换为定量指标的磁共振成像肾图的可重复性。此外，我们想研究液体摄入对所获得的肾脏参数的影响。
10名年龄在13至16岁的健康志愿者在10周内接受了3次磁共振成像检查，其中包括一次液体摄入量增加的检查。每次检查时，在快速磁共振肾图序列期间，以快速推注的方式静脉注射0.1 mmol/kg钆喷酸葡胺。在冠状面采集图像，在大约7分钟内记录1200张图像。通过将信号强度转换为定量单位，分析皮质数据以估计肾脏参数的绝对和差异功能。
使用磁共振成像信号变化与钆喷酸葡胺浓度变化呈线性相关的简单方法，我们发现所有差异肾功能估计值的可重复性在1%至5%范围内。计算了相对肾小球超滤率（每分钟每立方厘米肾皮质的毫升数），观察到相对肾小球超滤率的可重复性为7%（使用基于去卷积的模型）。增加水合作用导致大多数参数发生显著变化。
对比增强磁共振肾图在正常人体肾脏中具有可重复性，但过量饮水对这些参数有显著影响。需要进一步研究以阐明类似测量是否可应用于功能受损的肾脏。
