Phantoms and automated system for testing the resolution of ultrasound scanners

Abstract

Abstract-Tissue-mimicking phantoms and an automated system have been developed for testing the resolution performance of ultrasound scanners by determining detectability of low to higher contrast spherical lesions over the entire depth of field. Axial, lateral and elevational resolutions are accounted for simuRaneously and equally. Tissue-mimicking spherical simulated lesions are either 3 or 4 mm in diameter and have one of four different intrinsic material contrasts. For each diameter and contrast, there is a set of 109 lesions in a regular array with coplanar centers extending from 0.5-15.5 cm in depth. With the scan slice superimposed on the spheres, the image is frame-grabbed for automated analysis. A diameter-dependent lesion signal-to-noise ratio is computed for each pixel position in the image, exchrdhtg a 5-mm boundary. Two universal thresholds, resulting from maximization of agreement between the automated system and human observers, give rise to a depth range, or "resolution zone", over which detection exists for each type lesion. 0 1997 World Federation for Ultrasound in Medicine & Biology.

Real‐time B‐mode ultrasound quality control test procedures. Report of AAPM Ultrasound Task Group No. 1

“…Recently, Rownd et al described a method for computerized assessment of ultrasound system performance: 8 In brief, they developed a very sophisticated technique for computing lesion signal to noise ratios in images of phantoms containing tissue-mimicking spherical lesions. A computer program they wrote automatically analyzes the ultrasound images to determine the depth ranges over which lesions of specific diameters and material contrasts are detected.…”

“…One difference for laser printers is instead of creating a test film with a sensitometer, one creates the test film by recording a digitized image of a known grayscale pattern such as the SMPTE pattern. 8 The pattern should be stored internally in the ultrasound unit.…”

Quality control of ultrasound transducers: analysis of evaluation parameters and results of a survey of 116 transducers in a single hospital

“…Lateral resolution proved to be worse than axial resolution, especially in 3.5-MHz transducers, thus indicating the possible presence of various defects, most of all with regard to ultrasound beam focusing [8,11,[13][14][15][16]. This should be emphasised because it is precisely the lateral resolution more than the axial resolution that has an important impact on image quality.…”

Mechanical and clinical performance of pulse-inversion tissue harmonic imaging in the superficial region

“…It was Rownd et al [19] who first developed a test object and automated system to test axial, lateral, and transverse resolution. Kofler et al [20] thereafter showed there was agreement between automated analysis and radiologists on clinical image quality.…”