# Sonographic Assessment of Hyperechoic Vertical Artifact Characteristics in Lung Ultrasound Using Microconvex, Phased Array, and Linear Transducers

## TL;DR

This study compares how three ultrasound transducers affect the visibility of lung ultrasound artifacts in dogs, finding that some transducers produce clearer images for diagnosis.

## Contribution

The study provides new comparative data on transducer performance in veterinary lung ultrasound, focusing on hyperechoic vertical artifact visualization.

## Key findings

- The phased array transducer produced lower-quality images compared to microconvex and linear transducers.
- Linear transducer allowed better B-line counting despite more artifacts failing to reach the far field.
- Inter-rater agreement on image quality was high, indicating consistent evaluation of transducer performance.

## Abstract

Lung ultrasound is a widely used, non-invasive tool in both human and veterinary medicine. One of its key features is the appearance of bright vertical artifacts, which can provide important information about lung health. However, these artifacts can appear differently depending on the type of ultrasound transducer used, which may make diagnosis more challenging. This study compared three different types of transducers in dogs to see how well each one displayed these vertical artifacts. We found that overall image quality and the ease of evaluating the artifacts varied between transducers. The transducer commonly used in cardiology produced lower-quality images, making it harder to see and count the artifacts clearly. In contrast, the other two transducers generally gave clearer and more reliable images. These results show that the choice of transducer can strongly influence how lung changes are detected in dogs. A better understanding of which transducers provide the clearest images will help clinicians make more accurate diagnoses, which ultimately improves care for animal patients.

Hyperechoic vertical artifacts are an essential feature of lung ultrasound (LUS) arising from various pathological states. Those that meet the criteria for B-lines have the most significant diagnostic value and should be differentiated from other hyperechoic vertical artifacts of unspecified clinical importance. Although numerous studies have assessed the impacts of transducer type on the appearance of B-lines in human medicine, comparative studies in veterinary medicine are limited and conflicting. This study compares three transducer types for the assessment of hyperechoic vertical artifacts in dogs. We hypothesize that there is high-level reviewer agreement in the assessment of HVA image quality and characteristics, and that the image quality/characteristics differ between the three transducers. Dogs (n = 8) with HVAs and sonographic absence of lung consolidations, pleural effusion, and/or pneumothorax were enrolled. Twenty-four cine-loops (5 s) containing HVAs were retrospectively and independently reviewed by two reviewers, who were blinded to the case details but not transducer type. The reviewers assessed the cine-loops for the following: whether HVAs meet the B-line criteria, ease of counting HVAs, and overall image quality. Paired cine-loops from the same patient using different transducers were then presented for HVA quality comparison. Inter-rater concordance was determined using the Kappa coefficient, Kendall’s tau, and Pearson correlation coefficient, while characteristics were compared using chi-square and Kruskal–Wallis tests (level of significance, α = 0.05). The overall concordance of image quality was good (Pearson’s coefficient = 0.82). The PA transducer scored lower in image quality (p < 0.001), HVA blending (p = 0.014), graininess (p < 0.001), and clarity of edges (p < 0.001) when compared with the microconvex and linear transducers, and the identification of B-line criteria differed between transducers (p = 0.024). Furthermore, the PA scored lowest in the comparison of paired cine-loops regarding the image and HVA quality (p < 0.001). Although more HVAs failed to reach the far field with the linear transducer (10/16, 62.5%) compared with the microconvex (8/16, 50%) and PA (3/16, 18.5%) transducers, the linear transducer scored higher than the microconvex and PA transducers regarding its ability to count B-lines (p < 0.001). This study demonstrates that the type of transducer significantly impacts the characteristics of HVAs, with the PA transducer producing lower-quality images compared with the microconvex and linear transducers.