Computer-aided radiation therapy simulation: image intensifier spatial distortion correction for large field of view digital fluoroscopy

被引:19
作者
Cosby, NS [1 ]
Leszczynski, KW [1 ]
机构
[1] NE Ontario Reg Canc Ctr, Dept Phys Med, Sudbury, ON P3E 5J1, Canada
关键词
D O I
10.1088/0031-9155/43/8/019
中图分类号
R318 [生物医学工程];
学科分类号
0831 ;
摘要
An accurate method of correcting spatial distortion in digital fluoroscopy images has been developed for generating fluoroscopy-based large field of view images for computer-aided radiation therapy simulation. This method is applicable to arbitrary gantry rotations and arbitrary shifts of the image intensifier relative to the central axis of the x-ray beam. It is therefore suitable for conventional radiation therapy simulation techniques that involve the arbitrary positioning of the image intensifier by the operator. Spatial distortion is modelled as two image intensifier orientation-dependent components, the first resulting from the projection of the x-ray image onto the curved surface of the image intensifier front end, and the second produced by the image intensifier electron optics, interactions with external magnetic fields and the video system. A geometrical model approximates the first component. The second component is modelled by a third-order polynomial transformation. A weighted mean approach is employed to achieve accurate distortion correction when the image intensifier is oriented differently from the calibration orientations. Mean and maximum residual errors (measured in the plane of the isocentre) of 0.4 mm and 1.0 mm respectively have been achieved with just 48 calibration orientations in four dimensions (gantry rotation and lateral, longitudinal and vertical shifts of the image intensifier).
引用
收藏
页码:2265 / 2278
页数:14
相关论文
共 8 条
[1]   IMAGE INTENSIFIER DISTORTION CORRECTION [J].
CHAKRABORTY, DP .
MEDICAL PHYSICS, 1987, 14 (02) :249-252
[2]  
DOI K, 1985, MED PHYSICS MONOGRAP, V12, P100
[3]   AN AID TO RADIATION-THERAPY SIMULATION [J].
DUNSCOMBE, P ;
LESZCZYNSKI, K ;
COSBY, S ;
KRISPEL, F .
BRITISH JOURNAL OF RADIOLOGY, 1994, 67 (799) :649-650
[4]   Three-dimensional computed tomographic reconstruction using a C-arm mounted XRII: Correction of image intensifier distortion [J].
Fahrig, R ;
Moreau, M ;
Holdsworth, DW .
MEDICAL PHYSICS, 1997, 24 (07) :1097-1106
[5]   COMPREHENSIVE QA FOR RADIATION ONCOLOGY - REPORT OF AAPM RADIATION-THERAPY COMMITTEE TASK-GROUP-40 [J].
KUTCHER, GJ ;
COIA, L ;
GILLIN, M ;
HANSON, WF ;
LEIBEL, S ;
MORTON, RJ ;
PALTA, JR ;
PURDY, JA ;
REINSTEIN, LE ;
SVENSSON, GK ;
WELLER, M ;
WINGFIELD, L .
MEDICAL PHYSICS, 1994, 21 (04) :581-618
[6]   DEVELOPMENT OF VIDEO FRAME STORE AND DISTORTION CORRECTION FACILITIES FOR AN EXTERNAL-BEAM RADIOTHERAPY TREATMENT SIMULATOR [J].
MORTON, EJ ;
EVANS, PM ;
FERRARO, M ;
YOUNG, EF ;
SWINDELL, W .
BRITISH JOURNAL OF RADIOLOGY, 1991, 64 (764) :747-750
[7]  
PRATT WK, 1991, DIGITAL IMAGE PROCES, P430
[8]   ACCURATE CHARACTERIZATION OF IMAGE INTENSIFIER DISTORTION [J].
RUDIN, S ;
BEDNAREK, DR ;
WONG, R .
MEDICAL PHYSICS, 1991, 18 (06) :1145-1151