High-frequency transducers for point-of-care ultrasound applications: what is the optimal frequency range?

Abstract

To compare images obtained using two linear transducers with a different range of frequencies, and to determine if there is a significant difference in the quality of images between the two transducers for medical decision-making. This was a single-blinded, cross-sectional study at an academic medical center. Twenty-five emergency medicine clinical scenarios with ultrasound images (using both 10-5 and 14-5MHz transducers) covering a variety of point-of-care ultrasound applications were presented to four emergency physician sonographers. They were blinded to the study hypothesis and type of the transducer used to obtain the images. On a scale of 1-10, the mean image quality rating for 10-5MHz transducer was 7.09 (95% CI 6.73-7.45) and 6.49 (95% CI 5.99-6.99) for 14-5MHz transducer. In the majority of cases (84%, 95% CI 75.7-92.3%), sonographers indicated that images obtained with a 10-5MHz transducer were satisfactory for medical decision-making. They preferred images obtained with a 10-5MHz transducer over 14-5MHz transducer in 39% (95% CI 30-50%) of cases. The images obtained with a 14-5MHz transducer were preferred over 10-5MHz transducer in only 16% (95% CI 7.7-24.3%) of the cases. The 14-5MHz transducer has a slight advantage over 10-5MHz transducer for ocular, upper airway, and musculoskeletal (tendon) ultrasound applications. A 10-5MHz linear transducer is adequate to obtain images that can be used for medical decision-making for a variety of point-of-care ultrasound applications.