On the Development and Comparative Evaluation of an Ultrasound B-Mode Probe Calibration Method

Abstract

Objective: Precise transducer calibration is an essential prerequisite for reliable surface registration based on ultrasound B-mode imaging devices. The clinical usage of a novel B-mode transducer calibration technique was evaluated and its attainable calibration precision assessed.

Materials and Methods: The Three Wire Method and the Cambridge Calibration Method were used as reference techniques to compare the efficiency, calibration precision and spatial requirements of the different techniques. A total of 20 calibration trials were performed using each technique and were statistically evaluated for accuracy and speed.

Results: The mean error characterizing the calibration precision of the Three Wire Method was 3.2 mm, obtained in a phantom with a volume of 14 × 10⁶ mm³ in 18.48 min. The Cambridge method resulted in a mean calibration error of 2.2 mm, but required a larger phantom with a volume of 35 × 10⁶ mm³ to be used for a duration of 9.30 min. The proposed method yielded an average calibration error of 1.9 mm and was performed, on average, in 2 min using a phantom with a size smaller than 1 × 10⁶ mm³.

Conclusions: The suggested calibration method offers decreased time and space while retaining an equivalent calibration precision when compared to established reference methods.

Key Words:

• ultrasound
• transducer calibration
• surface registration