Mallinckrodt Institute of Radiology, Washington University School of Medicine, Campus Box 8131, 510 S. Kingshighway Blvd, St. Louis, MO 63110, USA.
Neuroradiology. 2012 Feb;54(2):133-8. doi: 10.1007/s00234-011-0861-3. Epub 2011 Apr 7.
Assessment of the motion of the cerebellar tonsils is of interest in diseases affecting the CSF flow at the foramen magnum. Cardiac-gated balanced steady-state free-precession technique, which has recently been shown to demonstrate the pulsatile motion of neural structures, appears well suited to allow direct measurement of craniocaudal translation of cerebellar tonsils during the cardiac cycle. Our aim was to assess the intra-observer and inter-observer variability in the assessment of tonsillar motion utilizing this technique.
We retrospectively identified 44 patients who had undergone MR imaging with cine TrueFISP sequence, as a part of CSF flow study. Two neuroradiologists independently assessed the images. The tonsillar pulsatility was subjectively characterized into none, minimal, and marked categories after review of the images on a cine loop. For patients with identifiable tonsillar motion, the maximal extent of translation of the inferior edge of the cerebellar tonsil was directly measured. Both readers repeated the measurements after a minimum interval of 2 weeks. Intra- and inter-observer variability was characterized by calculating the kappa statistics.
The intra-observer agreement for subjective assessment of tonsillar pulsatility was near perfect while the inter-observer agreement was substantial. A good intra- and inter-observer correlation was also seen for the objective measurements of the tonsillar motion. A good correlation was found between the subjective categorization of the tonsillar pulsatility and the objective measurements.
Steady-state balanced free-precession MR imaging technique allows for a reproducible subjective and objective assessment of tonsillar pulsatility.
评估小脑扁桃体的运动在影响颅颈交界区脑脊液流动的疾病中很有意义。心脏门控平衡稳态自由进动技术（cardiac-gated balanced steady-state free-precession technique）最近已被证明可显示神经结构的脉动运动，似乎非常适合在心脏周期内直接测量小脑扁桃体的颅颈向移动。我们的目的是使用该技术评估评估扁桃体运动的观察者内和观察者间变异性。
我们回顾性地确定了 44 名患者，他们在进行脑脊液流动研究的过程中接受了 cine TrueFISP 序列的磁共振成像。两名神经放射科医生独立评估图像。在对电影循环中的图像进行回顾后，将扁桃体搏动主观特征分为无、轻微和明显三个类别。对于可识别扁桃体运动的患者，直接测量小脑扁桃体下缘的最大移动距离。两位读者在至少 2 周的间隔后重复测量。通过计算kappa 统计量来描述观察者内和观察者间的变异性。
主观评估扁桃体搏动的观察者内一致性近乎完美，而观察者间一致性为中等。扁桃体运动的客观测量也具有良好的观察者内和观察者间相关性。扁桃体搏动的主观分类与客观测量之间存在良好的相关性。
稳态平衡自由进动磁共振成像技术可实现扁桃体搏动的可重复性主观和客观评估。
