The Usability Assessment of the Self-Produced Table for the Quality Control of Mobile CT

Abstract

Since there are no tables customized for mobile CT examinations, it is difficult to place the AAPM phantom to the isocenter during the quality control. This produced a phantom table for the quality control of Mobile CT, assessing its utility through conducting a quantitative evaluation through CNR value comparison between with and without the use of the table on low contrast resolution images among 20 phantom images evaluation, along with a qualitative assessment conducted on the scale of 1 to 5 by 5 quality control operators. The obtained average CNR values from low contrast resolution images in the order of the table being used and not used are -0.01069 ± 0.00149 vs -0.01485 ± 0.00208, -0.01277 ± 0.00131 vs -0.01526 ± 0.00215, -0.01419 ± 0.00144 vs -0.01671 ± 0.00277, -0.01651 ± 0.00140 vs -0.01836 ± 0.00199, -0.01542 ± 0.0188 vs -0.01836 ± 0.00199 from A-row, -0.01132 ± 0.00134 vs -0.01300 ± 0.00222, -0.1202 ± 0.00129 vs -0.01369 ± 0.00145, -0.001391 ± 0.00163 vs -0.01460 ± 0.00139, -0.01607 ± 0.00185 vs -0.01683 ± 0.00182, -0.01502 ± 0.00170 vs -0.01656 ± 0.00125 from B-row, indicating higher absolute values of CNR when the table is being used than not being used, which corresponds to more suitable images. Furthermore, the average score of all items in qualitative assessment has increased from 3.64 to 4.24, suggesting statistically significant margin of increase especially on the items of efficiency and the quality of images. In conclusion, placing the phantom on a more accurate isocenter through the exploitation of the table produced through this research provides phantom images with higher quality along with the decrease of unnecessary efforts from the operators.