Department of Neurosurgery, Seoul National University College of Medicine, Jongno-gu, Seoul 110-744, Republic of Korea.
J Neurosurg Spine. 2012 Feb;16(2):154-62. doi: 10.3171/2011.10.SPINE11367. Epub 2011 Dec 2.
Recent studies have emphasized measuring the sagittal vertical axis (SVA) and pelvic parameters (pelvic incidence, sacral slope, and pelvic tilt) when evaluating spinal disorders. An accurate and reproducible measurement is important for a reliable result. Although computerized measurement is more consistent than manual measurement, computerized measurement requires an expensive software program, the need to transfer images to a workstation, and additional education for users. An inexpensive and convenient computerized measurement program is desirable and necessary. The object of this study was to propose a computerized tool for measuring spinal and pelvic parameters and to evaluate the efficacy of this new tool compared with manual measurement.
The authors devised a tool that provides computerized measurements of the SVA and pelvic parameters in a picture archiving and communication system (PACS) without transferring images to another program. This tool was created by merging functions in the PACS. The resulting tool is easy to implement by merging functions (indicate the center of 2 points, plot a vertical and a horizontal line from a point, and measure the angles between lines) in any image viewer. The tool was made into icons on a toolbar in the PACS. Measurements of distance and angle were computerized by identifying crucial points after selecting the icon. For SVA, 4 points were identified around each corner of the C-7 body and a fifth point at the superior/posterior corner of the S-1 body. For pelvic parameters, 4 points were identified at the centers of each femoral head and at the anterior/superior and posterior/superior corners of S-1. Thirty-three whole-spine lateral radiographs were randomly selected from the radiographic database. To evaluate inter- and intraobserver variability between observers and method, skilled (2 years of experience) and unskilled (1 week of experience) observers measured SVA and pelvic parameters 3 times with a 7-day interval between each time using both computerized and manual measurement methods. The reliability was measured using the intraclass correlation coefficient.
The computerized method showed better congruity than the manual method in both skilled and unskilled observers (p < 0.05), and the intraclass correlation coefficients were > 0.9. The skilled observer showed better agreement than the unskilled observer with both computerized and manual methods, and this difference was prominent in measuring pelvic parameters (p < 0.05). The computerized method required less time than the manual method, especially for the unskilled observer (p < 0.05).
A computerized measurement of pelvic parameters may be a more reliable and efficacious approach than manual measurements. This benefit is more prominent in the unskilled observer, and adding this simple function to an image viewer may be recommended in future studies.
最近的研究强调在评估脊柱疾病时测量矢状垂直轴（SVA）和骨盆参数（骨盆入射角、骶骨倾斜度和骨盆倾斜角）。准确且可重复的测量对于可靠的结果很重要。尽管计算机测量比手动测量更一致，但计算机测量需要昂贵的软件程序、将图像传输到工作站的需求以及用户的额外教育。需要并期望有一种廉价且方便的计算机测量程序。本研究的目的是提出一种用于测量脊柱和骨盆参数的计算机工具，并评估与手动测量相比，该新工具的效果。
作者设计了一种工具，可在不将图像传输到另一个程序的情况下在图片存档和通信系统（PACS）中进行 SVA 和骨盆参数的计算机测量。该工具是通过合并 PACS 中的功能创建的。该工具很容易通过在任何图像查看器中合并功能（指示 2 个点的中心、从一个点绘制垂直线和水平线以及测量线之间的角度）来实现。该工具已在 PACS 的工具栏上制成图标。通过选择图标后识别关键点来实现距离和角度的计算机化测量。对于 SVA，在 C-7 体的每个角和 S-1 体的上/后角周围确定 4 个点，在第五个点。对于骨盆参数，在每个股骨头的中心和 S-1 的前/上和后/上角确定 4 个点。从放射学数据库中随机选择了 33 张全脊柱侧位片。为了评估观察者之间以及方法之间的观察者内和观察者间变异性，熟练（2 年经验）和不熟练（1 周经验）观察者使用计算机化和手动测量方法，在 7 天的间隔内分别测量 SVA 和骨盆参数 3 次。使用组内相关系数测量可靠性。
计算机方法在熟练和不熟练观察者中均比手动方法具有更好的一致性（p <0.05），组内相关系数>0.9。熟练观察者使用计算机化和手动方法的一致性均优于不熟练观察者，这种差异在测量骨盆参数时更为明显（p<0.05）。与手动方法相比，计算机方法所需的时间更少，尤其是对于不熟练观察者（p<0.05）。
与手动测量相比，骨盆参数的计算机化测量可能是一种更可靠和有效的方法。这种优势在不熟练观察者中更为明显，在未来的研究中，建议在图像查看器中添加此简单功能。
