Volume 54, Number 2, April–June 2019
|Page(s)||117 - 123|
|Published online||30 April 2019|
Evaluation of CT calibration curves from stoichiometric and tissue substitute methods according to tissue characteristics
Immunology Research Center, Tabriz University of Medical Sciences,
2 Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
3 Students’ Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
* Corresponding author: email@example.com
Accepted: 10 April 2019
In order to optimize and increase the precision of dose determination, it is important to obtain the relationship between CT Hounsfield units and electron densities, as the basic inputs for radiotherapy planning systems. Therefore, the aim of this study was to plot and compare the CT calibration curves resulted from both tissue substitute calibration (based on the tissue equivalent materials) and stoichiometric calibration (based on biological tissues) methods for a specific CT scanner at tube voltage of 120 kVp by applying a precise homemade physical phantom. Hence, the Hounsfield units of all phantom materials were measured experimentally and also calculated by related formulas. Considering the CT numbers and the electron densities of various tissue equivalent materials and real tissues, the calibration curves were plotted. According to the results, the higher accuracy of the stoichiometric method relative to tissue substitute method was confirmed in this study. On the other hand, since estimating Hounsfield unit of each human tissue strongly depends on the physical properties of tissue substitutes of the physical phantom, the high precision of this phantom led to increase the accuracy of the calibration curves obtained based on the stoichiometric method.
Key words: CT calibration curve / electron density / physical phantom / stoichiometric calibration / tissue substitute method
© EDP Sciences 2019
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.