Horsfield Mark A, Rocca Maria A, Pagani Elisabetta, Storelli Loredana, Preziosa Paolo, Messina Roberta, Camesasca Fabiano, Copetti Massimiliano, Filippi Massimo
Xinapse Systems Ltd, Colchester, Essex, UK.
Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
J Neuroimaging. 2016 Jul;26(4):395-402. doi: 10.1111/jon.12344. Epub 2016 Mar 28.
Change in lesion volume over time, measured on brain magnetic resonance imaging (MRI) scans, is an important outcome measure for natural history studies and clinical trials in multiple sclerosis (MS).
To develop and test image analysis methods for quantification of lesion volume change in order to improve reliability.
The technique is based on registration and subtraction, and was evaluated in a cohort of 20 MS patients with dual-echo images acquired annually over a period of four years. The study protocol was approved by the local ethics review boards of participating centers, and all subjects gave written informed consent. The repeatability was compared to that obtained by the standard method for obtaining lesion volume change by evaluating the total volume at each time point, and then subtracting the volumes to obtain the difference.
Compared to the standard method, the subtraction method had improved intrarater correlation (0.95 and 0.72 for the subtraction method and the standard method, respectively) and interrater correlation (0.51 and 0.28, respectively). Furthermore, the mean time required to analyze the scans from one patient was 41 minutes for the subtraction method compared to 125 minutes for the standard method.
Use of the subtraction algorithm leads to improved reliability and lower operator fatigue in clinical trials and studies of the natural history of MS.
通过脑部磁共振成像（MRI）扫描测量病变体积随时间的变化，是多发性硬化症（MS）自然史研究和临床试验的一项重要结果指标。
开发并测试用于量化病变体积变化的图像分析方法，以提高可靠性。
该技术基于配准和减法运算，并在一组20名MS患者中进行了评估，这些患者在四年时间里每年获取双回波图像。研究方案经参与中心的当地伦理审查委员会批准，所有受试者均签署了书面知情同意书。通过评估每个时间点的总体积，然后相减得到差值，将该减法方法的可重复性与通过标准方法获得病变体积变化的可重复性进行比较。
与标准方法相比，减法方法具有更高的同一观察者内相关性（减法方法和标准方法分别为0.95和0.72）和不同观察者间相关性（分别为0.51和0.28）。此外，分析一名患者扫描图像，减法方法平均需要41分钟，而标准方法需要125分钟。
在MS自然史的临床试验和研究中，使用减法算法可提高可靠性并降低操作者疲劳。
