A Quantitative Ultrasound Phantom Calibration Study: Effect of Depth on Attenuation and Backscatter Properties

Calibration using a reference phantom is a crucial first step in Quantitative Ultrasound (QUS) parameter estimation. In this paper, we have designed a phantom study to analyze the effect of depth of the corresponding region-of-interest (ROI) and envelope SNR deviation on the QUS estimation bias. Our results indicate that QUS estimation bias is more pronounced when the attenuation of the sample under study is different from the attenuation of the reference phantom. For such cases, the increase in QUS estimation bias follows a power law with the depth of the ROI. Our results also found that we can use Envelope SNR deviation to obtain a usable range of calibration depth, irrespective of the attenuation difference between sample and reference.