This research was aimed to develop an in-house phantom for quality control (QC) of image quality in PET/CT imaging. Wax and rice powder were mixed to produce tissue-equivalent materials characterized by Hounsfield Unit (HU). The in-house phantom was two circular cylinders with 20 cm in diameter and 10 cm in length which consists of six symmetric vessel pairs with varied diameters of 4.20, 6.20, 8.30, 9.80, 16.30, and 19.00 mm. Each measurement was performed using radioactivity concentrations of 18F-FDG with variation from 1 to 17Ci/mL Images were displayed with the pixel size of 4 × 4 mm2. Image quality was evaluated in terms of conversion factor between full-width-half-maximum (FWHM) and actual diameter, and a pixel value for local uniformity of each object. Two types of phantoms have been designed which were liver-equivalent material (LEM) and muscle-equivalent material (MEM). HU and electron densities were (74.17 ± 1.48) HU and 3.396 × 1023 electron/m3 for LEM, while (20.27 ± 0.33) HU and 3.461 × 1023 electron/m3 for MEM, respectively. The conversion factor was initially high at 2.240 ± 0.07 for diameter 4.20 mm, falls to 0.99 ± 0.003 for diameter 9.80 mm, slowly decrease up to 0.82 ± 0.01 at diameter 16.30 mm, and then nearly constant at 0.82 with increasing diameter for both phantoms. The in-house phantom could be used to analyse the image quality performance of PET imaging with a tissue-specific material. The phantom design including the development of tissue-surrogate materials, size, and geometrical considerations of the features will be beneficial for innovating QC tools.
|Journal||Journal of Physics: Conference Series|
|Publication status||Published - 6 Jun 2019|
|Event||18th Asia-Oceania Congress of Medical Physics, AOCMP 2018 and 16th South-East Asia Congress of Medical Physics, SEACOMP 2018 - Bangsar South, Kuala Lumpur, Malaysia|
Duration: 11 Nov 2018 → 14 Nov 2018