Intra- and inter-observer variability of functional MR urography (fMRU) assessment in children
Intra- and inter-observer variability of functional MR urography (fMRU) assessment in children
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DOI：
10.1007/s00247-015-3532-4
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发表时间：
2016-05-01
影响因子：
2.3
通讯作者：
Darge, Kassa
中科院分区：
文献类型：
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作者：
Khrichenko, Dmitry;Saul, David;Darge, Kassa
功能性磁共振尿路造影（fMRU）提供全面的功能数据，这些数据可能会受到可变性的影响。为了解释fMRU的结果，了解测量参数的观察者内部和观察者之间的可变性是至关重要的。定义fMRU的变异性范围，特别是基于体积（体积差肾功能）和儿童Patlak差肾功能测量的差肾功能。我们纳入了15项fMRU研究，其中10项为非重复肾脏，5项为单侧双肾。我们招募了六名具有fMRU经验的观察员，包括两名核磁共振技术人员，一名住院医生，一名研究员，一名儿科放射科医生和一名儿科泌尿科医生。观察人员接受了使用费城儿童医院(CHOP)-fMRU免费软件进行分析的强化培训。他们对每个病例进行了两次功能性磁共振分析，间隔至少1周。计算每组绝对容积、绝对Patlak、体积差肾功能和Patlak差肾功能的均值和标准差。我们使用学生t检验计算了这些偏差的统计显著性。我们还使用SPSS软件计算了观察者内部和观察者之间体积和Patlak测量一致性的类间相关性。观察者内部和观察者之间的可变性没有显著差异，相对体积测量为6%和4%（容量差肾功能：P > 0.05），相对功能测量为5%和3% （Patlak差肾功能：P > 0.05）。参数的绝对值比相对值表现出更大的变异性。除了双极性上极观察者内部测量（0.80,P < 0.01）外，所有体积测量的观察者内部和观察者之间的一致性远高于0.90 （P < 0.001）。Patlak值的观察者内部和观察者之间的一致性也高于0.90 (P < 0.001)，除了双极性上极测量值分别为0.54 （P = 0.13）和0.81 （P < 0.01）。使用CHOP-fMRU软件进行功能性MRU分析具有可重复性，容量差性肾功能的整体内部和观察者间变异性率为5%，Patlak差性肾功能的总体变异性率为4%。在重复肾的上、下极部分以及总体绝对体积和功能值之间，体积和功能测量有较高的可变性。肾容量差值与帕特拉克差值相对值在45-55%范围内为正常范围。
Functional MR urography (fMRU) provides comprehensive functional data that can be subject to variability. To interpret the results of fMRU, it is essential to know the intra- and inter-observer variability of the measured parameters.To define the range of variability in fMRU, particularly that of the differential renal function based on volume (volumetric differential renal function) and Patlak differential renal function measurements in children.We included 15 fMRU studies, 10 of non-duplicated and 5 of unilateral duplex kidneys. We recruited six observers with a range of fMRU experience, including two MRI technologists, one resident, one fellow, one pediatric radiologist and one pediatric urologist. The observers underwent intensive training in using the Children's Hospital of Philadelphia (CHOP)-fMRU freeware for analysis. They conducted the fMRU analysis on each case twice, at least 1 week apart. Mean and standard deviation were calculated for each set of absolute volume, absolute Patlak, volumetric differential renal function and Patlak differential renal function. We calculated the statistical significance of these deviations using the student's t-test. We also calculated interclass correlations for intra-observer and inter-observer agreement of both volume and Patlak measurements using SPSS software.Intra- and inter-observer variability did not differ significantly, measuring 6% and 4% for relative volume (volumetric differential renal function: P > 0.05) and 5% and 3% for relative function (Patlak differential renal function: P > 0.05). Absolute values of parameters showed more variability than the relative values. Intra- and inter-observer agreement was well above 0.90 (P < 0.001) for all volume measures except for duplex upper pole intra-observer measurements (0.80, P < 0.01). Intra- and inter-observer agreement for Patlak values were also above 0.90 (P < 0.001) except for duplex upper pole measurements, which were 0.54 (P = 0.13) and 0.81 (P < 0.01), respectively.Functional MRU analysis using CHOP-fMRU software is reproducible, with overall intra- and inter-observer variability rates of 5% for volumetric differential renal function and 4% for Patlak differential renal function. There was higher variability in volume and function measurements between upper and lower pole moieties of duplicated kidneys and for absolute volume and function values overall. A range of 45-55% for relative values of volumetric differential renal function and Patlak differential renal function could serve as the normal range.