AUTOMATIC VERIFICATION OF RADIATION-FIELD SHAPE USING DIGITAL PORTAL IMAGES

被引:23
作者
BIJHOLD, J
GILHUIJS, KGA
VANHERK, M
机构
[1] Netherlands Cancer Institute, Antoni van Leeuwenhoek huis, Radiotherapy Department, 1066 CX, Amsterdam
关键词
PATIENT SETUP VERIFICATION; PORTAL IMAGING; AUTOMATED INSPECTION;
D O I
10.1118/1.596818
中图分类号
R8 [特种医学]; R445 [影像诊断学];
学科分类号
1002 ; 100207 ; 1009 ;
摘要
Two computer methods for matching digital line drawings have been tested for automatic on-line verification of the radiation field shape during radiotherapy. This work is part of a research program aiming at automated inspection of on-line acquired digital portal images. Both methods, moment normalization and point distance minimization, compare the field edge detected in the portal image with the intended field edge and the beam shaping devices marked in the simulator image. Tests showed that the methods should be used together. First, shape deviations in the detected field edge are classified quickly, in less than a second (25 MHz 386 + 387 PC), as large (e.g., missing blocks) or small (e.g., shifts of a few mm) by moment normalization. Then the portal image is mapped to the simulator image by field edge alignment with a translation and magnification obtained from moment normalization and a rotation from point distance minimization. The mapped portal image and the simulator image are juxtaposed on a monitor screen for visual inspection. Finally, the small field shape deviations are detected by an analysis of the relationship between the radiation field shape and the positioning of field shaping devices using point distance minimization.
引用
收藏
页码:1007 / 1014
页数:8
相关论文
共 23 条
[1]  
ALTHOF VGM, 1990, 10TH P INT C US COMP, P107
[2]   RADIATION-FIELD EDGE-DETECTION IN PORTAL IMAGES [J].
BIJHOLD, J ;
GILHUIJS, KGA ;
VANHERK, M ;
MEERTENS, H .
PHYSICS IN MEDICINE AND BIOLOGY, 1991, 36 (12) :1705-1710
[3]   FAST EVALUATION OF PATIENT SET-UP DURING RADIOTHERAPY BY ALIGNING FEATURES IN PORTAL AND SIMULATOR IMAGES [J].
BIJHOLD, J ;
VANHERK, M ;
VIJLBRIEF, R ;
LEBESQUE, JV .
PHYSICS IN MEDICINE AND BIOLOGY, 1991, 36 (12) :1665-1679
[4]  
BURR D, 1980, 5TH P INT C PATT REC, P223
[5]  
Duda R.O., 1972, PATTERN CLASSIFICATI
[6]  
EVANS PM, 1990, 10TH P INT C US COMP, P99
[7]   A METHOD TO ANALYZE 2-DIMENSIONAL DAILY RADIOTHERAPY PORTAL IMAGES FROM AN ONLINE FIBEROPTIC IMAGING-SYSTEM [J].
GRAHAM, ML ;
CHENG, AY ;
GEER, LY ;
BINNS, WR ;
VANNIER, MW ;
WONG, JW .
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 1991, 20 (03) :613-619
[8]  
HEARN D, 1986, COMPUT GRAPH, P58
[9]   VISUAL-PATTERN RECOGNITION BY MOMENT INVARIANTS [J].
HU, M .
IRE TRANSACTIONS ON INFORMATION THEORY, 1962, 8 (02) :179-&
[10]   AN ONLINE ELECTRONIC PORTAL IMAGING-SYSTEM FOR EXTERNAL BEAM RADIOTHERAPY [J].
LAM, KS ;
PARTOWMAH, M ;
LAM, WC .
BRITISH JOURNAL OF RADIOLOGY, 1986, 59 (706) :1007-1013