Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Osteoarthritis Cartilage. 2016 Nov;24(11):1905-1909. doi: 10.1016/j.joca.2016.06.001. Epub 2016 Jun 11.
Magnetic resonance imaging (MRI) is a widely used imaging modality for studies of knee osteoarthritis (OA). Compared to radiography, MRI offers exceptional soft tissue imaging and true three-dimensional (3D) visualization. However, MRI is expensive both due to the cost of acquisition and evaluation of the images. The goal of our study is to develop a new method to address the cost of MRI by combining innovative acquisition methods and automated post-processing software.
Ten healthy volunteers were scanned with three different MRI protocols: A standard 3D dual-echo steady state (DESS) pulse sequence, an accelerated DESS (DESS), acquired at approximately half the time compared to DESS, and a multi-echo time DESS (DESS), which is capable of producing measurements of T2 relaxation time. A software tool was used to measure cartilage volume. Accuracy was quantified by comparing DESS to DESS and DESS and precision was measured using repeat readings and acquisitions. T2 precision was determined using duplicate DESS acquisitions. Intra-class correlation coefficients (ICCs), root-mean square standard deviation (RMSSD), and the coefficient of variation (CoV) were used to quantify accuracy and precision.
The accuracies of DESS and DESS were CoV = 3.7% and CoV = 6.6% respectively, while precision was 3.8%, 3.0%, and 3.1% for DESS, DESS and DESS. T2 repositioning precision was 5.8%.
The results demonstrate that accurate and precise quantification of cartilage volume is possible using a combination of substantially faster MRI acquisition and post-processing software. Precise measurements of cartilage T2 and volume can be made using the same acquisition.
磁共振成像（MRI）是一种广泛用于膝关节骨关节炎（OA）研究的成像方式。与 X 射线相比，MRI 提供了出色的软组织成像和真正的三维（3D）可视化效果。然而，由于采集和评估图像的成本，MRI 非常昂贵。我们的研究目标是通过结合创新的采集方法和自动化后处理软件来解决 MRI 的成本问题。
10 名健康志愿者分别接受了三种不同的 MRI 方案扫描：标准的 3D 双回波稳态（DESS）脉冲序列、加速的 DESS（DESS），与 DESS 相比采集时间缩短了约一半，以及多回波时间 DESS（DESS），可用于测量 T2 弛豫时间。使用软件工具来测量软骨体积。通过比较 DESS 与 DESS 和 DESS 的准确性，并通过重复读数和采集来测量精密度，来量化准确性。使用重复的 DESS 采集来确定 T2 的精密度。使用组内相关系数（ICC）、均方根标准差（RMSSD）和变异系数（CoV）来量化准确性和精密度。
DESS 和 DESS 的准确性分别为 CoV=3.7%和 CoV=6.6%，而 DESS、DESS 和 DESS 的精密度分别为 3.8%、3.0%和 3.1%。T2 重定位的精密度为 5.8%。
结果表明，使用大大加快的 MRI 采集和后处理软件组合，可以实现软骨体积的准确和精确量化。可以使用相同的采集来精确测量软骨 T2 和体积。
