SU-FF-I-26: Tissue Equivalent Phantoms for the Evaluation of Tube Current Modulated CT Dose and Image Quality

2006 ◽  
Vol 33 (6Part3) ◽  
pp. 2002-2002 ◽  
Author(s):  
R Fisher ◽  
D Hintenlang
2021 ◽  
Vol 11 (5) ◽  
pp. 2047
Author(s):  
Nor Azura Muhammad ◽  
Zunaide Kayun ◽  
Hasyma Abu Hassan ◽  
Jeannie Hsiu Ding Wong ◽  
Kwan Hoong Ng ◽  
...  

The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p > 0.05) observed between the protocols and image metrics.


2020 ◽  
Vol 49 (5) ◽  
pp. 20190336
Author(s):  
Miss Fei Wang ◽  
Xiaoyan Xie ◽  
Gang Li ◽  
Zuyan Zhang

Objectives: The purpose of this study was to investigate the image quality of cone beam CT (CBCT) under different exposure parameters and the relationship between contrast-to-noise and visibility of eight anatomical structures. Methods: CBCT images for the evaluation of subjective image quality were acquired on an anthropopathic phantom containing a human skeleton embedded in soft tissue equivalent materials using 25 exposure protocols. Visibility of eight anatomical structures was evaluated by five independent observers. Using the SEDENTEXCT IQ Image Quality phantom, the contrast-to-noise ratio (CNR) was calculated by ImageJ software. Results: A reduction on the visibility of anatomical structures was seen under lower exposure parameters. However, for 84% of the protocols, visibility of anatomical structures remained acceptable even under some lower parameter settings. As CNR increased, the visibility of anatomical structures also increased correspondingly. A change point could be found in the CNR interval 29.42–36.51 after which the visibility of anatomical structures no longer increases with the increase of CNR. Conclusions: Although CNR decrease under a lower exposure parameter, the image quality often remained acceptable at exposure levels below the manufacture’s recommended settings. It is possible to standardize subjective image quality by physical factors. Currently, it is not possible to predetermine a change point CNR value due to different CBCT machine and variation of diagnostic tasks.


2020 ◽  
Vol 49 (1) ◽  
pp. 29-33
Author(s):  
Thomas R. Mulvey ◽  
Xiangyang Tang ◽  
Elizabeth A. Krupinski ◽  
Pardeep K. Mittal ◽  
Courtney C. Moreno

2015 ◽  
Author(s):  
Yannan Jin ◽  
Zhye Yin ◽  
Yangyang Yao ◽  
Hui Wang ◽  
Mingye Wu ◽  
...  

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