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Development and utility evaluation of new Multi-Leaf Collimator for Diagnostic X-ray Equipment

  • Ji, Hoon (Division of medical radiation equipment, Korea Institute of Radiological and Medical Sciences) ;
  • Han, Su Chul (Division of medical radiation equipment, Korea Institute of Radiological and Medical Sciences) ;
  • Baek, Jong Hyeun (Dept. of Biomedical Engineering, Tongmyong University) ;
  • Lee, Dong Hoon (Dept. of Biomedical Engineering, Tongmyong University) ;
  • Park, Seungwoo (Division of medical radiation equipment, Korea Institute of Radiological and Medical Sciences)
  • Received : 2017.04.10
  • Accepted : 2017.12.06
  • Published : 2018.03.01

Abstract

The diagnostic multi-leaf collimator preventing unnecessary dose from entering into patients during the diagnostic examination was made in this study. The movement of the entire 50 leaves was embodied with the group of 25 ones thereof configured in a pair facing each other on the left and right of the median line. Dimensions of the length, width, and height of each shielding leaf were $5{\times}0.5{\times}0.5cm^3$ resulting in the maximum boost field of $10{\times}10cm^2$. The material of multi-leaf collimator had the excellence on the machinability with the use of the SKD-11 alloy tool steel having the high wear resistance against frequent movement, and it was devised to control both-side's shielding leaves by moving 2 motors unlike existing remedial multi-leaf collimator that use as many motors as the number of 50 shielding leaves. Thereafter, the transmission dose of leaves, cross-leaf leakage dose, and inter-leaf leakage dose were measured by the developed multi-leaf collimator attached to X-ray equipment. An ionization chamber was used to detect doses there from, and the comparative analysis was carried out by means of the radiographic film that was easy to detect the dose leakage in between each leaf. Results obtained from the test conducted in comparative analysis yielded approximately 98%, 96%, and 94% of shielding efficiency realized at each level of energy of 80kV, 100kV, and 120kV it was confirmed there was no dose leakage resulted from the varied level of irradiation energy. Thus the multi-leaf collimator to be developed based on this study is thought that it could fully reduce the unnecessary dose to patients in the diagnostic test and the shielding efficiency thereof is expected to be increasing if it is made in a miniaturized form with a way of increasing the thickness of each leaf later for an extended application to general diagnostic purposes.

Acknowledgement

Supported by : Korea Health Industry Development Institute (KHIDI)

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