Development and assessment of a carrageenan- based diagnostic ultrasound phantom

Quality assurance (QA) ultrasound phantoms are essential in conducting equipment routine quality control and regular preventive maintenance, procedures that are important in ensuring the optimal performance of diagnostic ultrasound device. Using commercially-available ultrasound quality assurance phantoms in radiology departments, however, are primarily limited due to cost and resources constraints. In this study, a carrageen-based gelatin was investigated as an alternative ultrasound QA phantom. Carageenan or carageenins are derived from seaweeds that are commonly found in the Philippines. A rectangular container with dimensions of 5×5 inches was prepared and ninety grams (90g) of carrageenan- based gelatin (Lady’s Choice Alsa Gulaman) were mixed to 250 mL of near boiling water (approximately 950C). The liquid mixture was transferred to a container, and the air bubbles were removed during the transfer. The targets were placed on the following positions: 1 inch, 2 inches, 3 inches, 4 inches, and 5 inches from the surface of the phantom. The target size used was 13.0 mm for button and 7.0 mm for pellets. The result of Mann-Whitney test at 95% confidence interval. The image quality scores for both button and pellet targets are not statistically different with a p value of .143. The developed phantom was evaluated in terms of its ability to produce diagnostically acceptable sonograms, determine sound penetration depth accuracy, horizontal and vertical measurement accuracy, and target size accuracy. Results of this study show that the carrageenan-based gelatine has a good potential as a base material in the development and construction of an ultrasound QA phantom.

Keywords – Gelatin-based phantom, phantom gel, quality assurance, quality control, ultrasound