scholarly journals Estimation of Appropriate Dose for Computed Radiography by the Threshold Value of the Image Quality Figure

2009 ◽  
Vol 65 (4) ◽  
pp. 430-437
Author(s):  
Yasuo Mochizuki ◽  
Shinji Abe ◽  
Kojirou Yamaguchi
Author(s):  
Angela Peterzol ◽  
Bruno Bader ◽  
Julien Banchet ◽  
Claire Caperaa ◽  
Vivian Didier

Computed radiography (CR) is a digital radiographic technique, which uses very similar equipment to conventional radiography except that in place of a film to create the latent image, an imaging plate (IP) made of a photostimulable phosphor is used [1]. CR systems are commonly used in medical applications since they have proven reliability over more than two decades. Conversely, the NDT community has discussed the efficacy of film replacement by CR for more than 15 years. Though some standards were introduced in 2005 (ASTM E 2033, CEN EN 14784-2) and others are on the way (PR ISO 17636-2), CR is actually not included within the French RCCM, while the technique is commonly used in US for nuclear applications according to ASME (Section V, article 2). Since 2006, AREVA has been evaluating the performance of CR in comparison to conventional RT in the framework of EN 14784 for the digital part and the RCCM for the conventional part. The objective was to build a technical justification report to eventually support introduction of CR into the RCCM. In 2009 the subject gave rise to collaboration between AREVA NP – NETEC and EDF-CEIDRE, for a joint project to establish performance limits of CR towards EN 14784 specifications and RCCM image quality indicator (IQI) requirements [2]. In this paper, we present performance comparison results of four different CR systems. The measurements were conducted in 2012 and they demonstrate the current state of achievable image quality in CR. The performance has been evaluated for steel with a thickness range of 20÷60 mm using an Iridium 192 gamma source. Image quality has been assessed in terms of EN 462 and ASTM (E 747, E 1742) IQI. The results have been scored considering the PR ISO 17636-2, RCCM 2007, and ASME V-2010. This also permitted comparison among the different standard requirements.


2016 ◽  
Vol 78 (6-7) ◽  
Author(s):  
Varin Chouvatut ◽  
Ekkarat Boonchieng

Radiographic image quality is important in the medical field since it can increase the visibility of anatomical structures and even improve the medical diagnosis. Because the image quality depends on contrast, noise, and spatial resolution, images with low contrast, a lot of noises, or low resolution will decrease image quality, leading to an incorrect diagnosis. Therefore, radiographic images should be enhanced to facilitate medical expertise in making correct diagnosis. In this paper, radiographic images are enhanced by hybrid algorithms based on the idea of combining three image processing techniques: Contrast Limited Adaptive Histogram Equalization for enhancing image contrast, Median Filter for removing noises, and Unsharp Masking for increasing spatial resolution. Two series of medical images consisting of 20 x-ray images and 20 computed radiography images are enhanced with this method. Peak Signal to Noise Ratio (PSNR) and image contrast are computed in order to measure image quality. The results indicate that the enhanced images have better PSNR.


2006 ◽  
Vol 33 (6Part4) ◽  
pp. 2016-2016
Author(s):  
X Kong ◽  
H Liu ◽  
X Rong ◽  
C Sweet ◽  
Z Yang ◽  
...  

2006 ◽  
Vol 19 (2) ◽  
pp. 126-131 ◽  
Author(s):  
John E. Aldrich ◽  
Emerenciana Duran ◽  
Pat Dunlop ◽  
John R. Mayo

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