Lung ultrasound: A comparison of image interpretation accuracy between curvilinear and phased array transducers

Abstract

IntroductionBoth curvilinear and phased array transducers are commonly used to perform lung ultrasound (LUS). This study seeks to compare LUS interpretation accuracy of images obtained using a curvilinear transducer with those obtained using a phased array transducer.MethodsWe invited 166 internists and trainees to interpret 16 LUS images/cineloops of eight patients in an online survey: eight curvilinear and eight phased array, performed on the same lung location. Images depicted normal lung, pneumothorax, pleural irregularities, consolidation/hepatisation, pleural effusions and B‐lines. Primary outcome for each participant is the difference in image interpretation accuracy scores between the two transducers.ResultsA total of 112 (67%) participants completed the survey. The mean paired accuracy score difference between the curvilinear and phased array images was 3.0% (95% CI: 0.6 to 5.4%, P = 0.015). For novices, scores were higher on curvilinear images (mean difference: 5.4%, 95% CI: 0.9 to 9.9%, P = 0.020). For non‐novices, there were no differences between the two transducers (mean difference: 1.4%, 95% CI: −1.1 to 3.9%, P = 0.263). For pleural‐based findings, the mean of the paired differences between transducers was higher in the novice group (estimated mean difference‐in‐differences: 9.5%, 95% CI: 0.6 to 18.4%; P = 0.036). No difference in mean accuracies was noted between novices and non‐novices for non‐pleural‐based pathologies (estimated mean difference‐in‐differences: 0.6%, 95% CI to 5.4–6.6%; P = 0.837).ConclusionsLung ultrasound images obtained using the curvilinear transducer are associated with higher interpretation accuracy than the phased array transducer. This is especially true for novices interpreting pleural‐based pathologies.

Evidence‐based innovation in ultrasound practice

“…There are reasons why operators may prefer one over the other, such as rib spaces or frequency, but many regard them as interchangeable. Walsh et al 3 . undertook an experiment where they asked internists and trainees to interpret lung ultrasound performed with both transducers and found that for expert readers, no difference in accuracy was seen, but for novice readers, the curvilinear transducer led to higher accuracy.…”