An Investigation of the Relationship Between in Vitro and in Vivo Ultrasound Image Quality Parameters

Abstract

The aim of this paper is to investigate the relationship between B-mode and colour Doppler technical test methods with the clinical perception of B-mode and Doppler in vivo test parameters. It was found that technical and clinical comparisons between the B-mode test parameters — lateral resolution versus clinical resolution, anechoic target detection versus clinical noise and penetration depth versus clinically useful penetration depth — demonstrated moderate correlations ( r = –0.69, p < 0.003; r = 0.5, p = 0.14; and r = 0.56, p < 0.03, respectively). However, axial resolution versus tissue texture variation, slice thickness versus overall clinical image quality and contrast resolution versus clinically useful dynamic range demonstrated poor correlations. The majority of the colour Doppler performance parameters were found to demonstrate moderate correlations: sensitivity performance index and clinical Doppler sensitivity ( r = 0.52, p < 0.07); axial/lateral resolution and clinical colour Doppler resolution ( r = –0.64, p = 0.02/–0.55, p = 0.05); and temporal resolution and clinical temporal resolution ( r = –0.59, although not statistically significant p = 0.4). The poor correlations for axial resolution slice thickness and contrast resolution suggest that some revision of the test protocols may be required or that these quantities are not as important as previously thought in image quality. Whereas, the test protocols for anechoic target detection, penetration depth and, in particular, lateral resolution appear promising in their prediction of clinical perception of image quality. The newly developed colour Doppler test protocols and test objects also appear promising in their prediction of clinical perception and merit further investigation.