J Korean Soc Radiol.  2023 Sep;84(5):1110-1122. 10.3348/jksr.2023.0051.

Variability of Transrectal Shear Wave Elastography in a Phantom Model

• Lee J
• Yoon SK
• Cho JH
• Kwon HJ
• Kim DW
• Lee JW

• KMID: 2546650
• DOI: http://doi.org/10.3348/jksr.2023.0051

Abstract

Purpose
This study aimed to assess the variability of transrectal shear wave elastography (SWE) using a designed phantom.
Materials and Methods
In a phantom, the SWE values were examined by two radiologists using agarose and emulsion silicone of different sizes (1, 2, and 3 cm) and shapes (round, cubic) at three depths (1, 2, and 3 cm), two region of interest (ROI) and locations (central, peripheral) using two ultrasound machines (A, B from different vendors). Variability was evaluated using the coefficient of variation (CV).
Results
The CVs decreased with increasing phantom size. Significant changes in SWE values included; agarose phantom at 3 cm depth (p < 0.001; machine A), 1 cm depth (p = 0.01; machine B), emulsion silicone at 2 cm depth (p = 0.047, p = 0.020; both machines). The CVs increased with increasing depth. Significant changes in SWE values included; 1 cm agarose (p = 0.037, p = 0.021; both machines) and 2 cm agarose phantom (p = 0.047; machine A). Significant differences in SWE values were observed between the shapes for emulsion silicone phantom (p = 0.032; machines A) and between ROI locations on machine B (p ≤ 0.001). The SWE values differed significantly between the two machines (p < 0.05). The intra-/inter-operator agreements were excellent (intraclass correlation coefficient > 0.9).
Conclusion
The phantom size, depth, and different machines affected the variability of transrectal SWE.

Keyword

Elastography; Ultrasound; Prostate; Tissue Elasticity Imaging