A METHOD OF CORRECTING FOR THE EFFECT OF TEMPERATURE ON LOW-CONTRAST PENETRATION MEASUREMENT IN URETHANE PHANTOMS

Urethane-based test objects are routinely used for ultrasound quality assurance because of their durability and robustness. The acoustic properties of these phantoms including speed of sound and attenuation, however, have a strong dependence on temperature. Reliable measurement of low-contrast penetration, which is widely used for ultrasound system quality assurance testing, with these phantoms is therefore problematic. To alleviate this, a correction method was proposed using speed of sound estimated by measuring filament target separation. The method was developed using a range of 17 transducer geometry and frequency combinations across 5 ultrasound systems and validated using a further 5 systems. This was found to reduce the uncertainty of low-contrast penetration measurement from an average 17.6 mm to 4.9 mm over the temperature range 8 degrees C to 32 degrees C. This represents a greater than threefold improvement in precision of low-contrast penetration measurement. (E-mail: nick.gibson@nuh.nhs.uk) (C) 2019 World Federation for Ultrasound in Medicine & Biology. All rights reserved.