Systematic analysis of factors related to display of the twinkling artifact by a phantom: an optimized investigation.

OBJECTIVES: The purpose of this study was to analyze factors related to display of the twinkling artifact by a phantom.

METHODS: An in vitro phantom made of sandpaper was designed to mimic rough physiologic surfaces prone to generating the twinkling artifact. Sandpaper strips embedded in a plastic box were scanned through a water path under different machine settings with only 1 parameter varied each time. After choosing the best settings for displaying the twinkling artifact, 4 types of sandpaper with different roughness were scanned. The resulting images were recorded at random, and the number of color pixels in the color box of each image was calculated by a custom-designed program developed using commercially available software. All data were then evaluated by regression analysis, a paired 2-tailed Student t test, and single-factor analysis of variance.

RESULTS: The highest color write priority and color gain, which were just below the threshold for color noise, a focus depth setting below the sandpaper, a maximum wall filter under a higher pulse repetition frequency, and a color box adjusted properly in the fundamental imaging mode (P < .001) were found to most readily improve the twinkling artifact intensity. The roughness of the sandpaper was shown to be highly correlated with the twinkling artifact intensity (R(2) = 0.832; P < .001).

CONCLUSIONS: The twinkling artifact was influenced by some machine parameters and the roughness of the sandpaper. By adjusting some ultrasound machine parameters, a better image reflecting the twinkling artifact can be shown in clinical practice and research.