Receiver operating characteristic curve evaluation on computed radiography: an experimental study
- VernacularTitle:计算机X线摄影的观察者操作特性曲线测试探讨
- Author:
Zixi YU
;
Changyuan WANG
;
Yue XU
;
Jindong XIE
;
Menglong ZHANG
;
Jian WANG
- Publication Type:Journal Article
- Keywords:
Radiography;
Receiver operating characteristic curve;
Image processing, computer-assisted;
Evaluation studies
- From:
Chinese Journal of Radiology
2001;0(05):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To get the maximum information from computed radiography (CR) output images by changing post-processing parameters. Methods Six experimental photos of polypropylene balls of 2.0 mm in diameter were taken by means of one time X-ray exposing on an imaging plate (IP) with different post-processing parameters including rotation amount (GA), gray gradation type (GT), rotation center (GC), shifting amount (GS), frequency rank (RN), frequency type (RT), and degree of enhancement (RE). 6 photos were viewed by three students and one radiologist on a 6 000 lx illuminance viewbox. Receiver operating characteristic (ROC) curves were made by means of 5-value-differentiation method. Results The largest mean area value (Az) below ROC curves of a low contrast experimental photo with post-processing parameters GA=1.0,GT=A, GC=1.6, GS=0.3, RN=4.0, RT=R and RE=3.0 was 0.96, and the maximum information was obtained. The smallest mean area value (Az) was 0.78 with changed post-processing parameters GA=0.8, GS=-0.2 and RE=0.5 while other parameters were not changed. The minimum information was obtained from this photo. Conclusion In order to get the maximum information from a CR output image, the post-processing parameters should be suitably selected.
