Joe Bonnie N, Suh Jongdae, Hildebolt Charles F, Hovsepian David M, Johnston Brian, Bae Kyongtae T
Department of Radiology, University of California San Francisco, Box 0628, L325B, 505 Parnassus Avenue, San Francisco, CA 94143-0628, USA.
Acad Radiol. 2007 Apr;14(4):455-62. doi: 10.1016/j.acra.2007.01.004.
Stereology is a simple, fast method for object segmentation that involves counting the number of intersections of a randomly positioned grid over an object. The objectives of this study were to determine observer reliability in making stereologic- and ellipsoid-based measurements of uterine and leiomyoma volumes and to test the agreement between these two methods of measurement.
Two observers made uterine and dominant leiomyoma volume measurements on MR images in 30 patients using stereology and the popular ellipsoid-based technique. Stereologic volume measurements were made from high-resolution T2 images in two perpendicular planes (axial and sagittal). Ellipsoid volume was calculated by multiplying the maximal sagittal, anteroposterior, and transverse dimensions by pi/6. For these measurements, interobserver reliability was tested with paired t-tests and percent differences were determined. A mean stereologic volume and a mean ellipsoid volume were determined and tested for agreement with a paired t-test. Percent differences were also calculated.
Stereologic measurements demonstrated excellent interobserver reliability with 0.3% difference in mean uterine volumes (P = .69) and 0.3% difference (P = .81) in mean leiomyoma volumes. The ellipsoid method resulted in poorer interobserver reliability with 7% difference (P = .01) in mean uterine volumes and 4% difference (p = .24) in mean leiomyoma volumes. The ellipsoid method also significantly overestimated uterine volumes by 14% (P < .01) compared with stereology.
Stereology provided high interobserver reliability for leiomyoma and overall uterine volume measurements and was more reliable than the ellipsoid method, which uses linear measurements. Stereology appears well suited when precise volume measurements are desired for assessing response to uterine arterial embolization treatments.
体视学是一种简单、快速的对象分割方法，涉及计算随机放置在对象上的网格的交点数量。本研究的目的是确定观察者在基于体视学和椭球体测量子宫及平滑肌瘤体积时的可靠性，并测试这两种测量方法之间的一致性。
两名观察者使用体视学和常用的基于椭球体的技术，对30例患者的磁共振图像进行子宫及主要平滑肌瘤体积测量。体视学体积测量是在两个垂直平面（轴位和矢状位）的高分辨率T2图像上进行的。椭球体体积通过将最大矢状径、前后径和横径乘以π/6来计算。对于这些测量，通过配对t检验测试观察者间的可靠性，并确定百分比差异。确定平均体视学体积和平均椭球体体积，并通过配对t检验测试其一致性。还计算了百分比差异。
体视学测量显示观察者间可靠性极佳，平均子宫体积差异为0.3%（P = 0.69），平均平滑肌瘤体积差异为0.3%（P = 0.81）。椭球体方法导致观察者间可靠性较差，平均子宫体积差异为7%（P = 0.01），平均平滑肌瘤体积差异为4%（P = 0.24）。与体视学相比，椭球体方法还显著高估子宫体积14%（P < 0.01）。
体视学在平滑肌瘤和总体子宫体积测量中提供了较高的观察者间可靠性，并且比使用线性测量的椭球体方法更可靠。当需要精确体积测量以评估子宫动脉栓塞治疗的反应时，体视学似乎非常适用。
Zotero 插件