|
KMID : 0384620120230030154
|
|
Korean Journal of Medical Physics
2012 Volume.23 No. 3 p.154 ~ p.161
|
|
|
Evaluation of Image Quality by Using a Tungsten Edge Block in a Megavoltage (MV) X-ray Imaging
|
|
Min Jeong-Hwan
Son Jin-Hyun
Kim Ki-Won
Lee Jeong-Woo
Son Soon-Yong
Back Geum-Mun
Kim Jung-Min
Kim Yon-Lae
Jung Jae-Yong
Kim Sang-Young
Lee Do-Wan
Choe Bo-Young
|
|
|
Abstract
|
|
|
|
Digital Radiography (DR) has rapidly developed in megavoltage X-ray imaging (MVI). Thus, a very simple and general quality assurance (QA) method is required. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS) and the detective quantum efficiency (DQE) for MVI using general QA method and computed radiography (CR) device. We used tungsten edge block with 19×10×1cm3 thickness and 6MV energy. For detector, CR-IP (image plate), CR-IP-lead, the CR-IP-back (lanex TM fast back screen), CR-IP-front (lanex TM fast front screen) were used and pre-sampling MTF was calculated. The MTF of CR-IP-front showed the highest value with 1.10 lp/mm although the CR-IP showed the only 0.70 lp/mm. The best NPS was observed in CR-IP front screen. According to the increase in spatial frequency, our results showed that DQE was approximately 1.0 cycles/mm. The present study demonstrates that the QA method with our home-made edge block can be used to evaluate MTF, NPS and DQE for MVI.
|
|
|
KEYWORD
|
|
|
Modulation transfer function (MTF), Noise power spectrum (NPS), Detective quantum efficiency(DQE), Megavoltage x-ray imaging (MVI)
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|