Lung Ultrasound for Imaging of B-Lines in Dogs and Cats—A Prospective Study Investigating Agreement between Three Types of Transducers and the Accuracy in Diagnosing Cardiogenic Pulmonary Edema, Pneumonia and Lung Neoplasia

Transthoracic heart and lung ultrasound (LUS) was performed in 200 dogs and cats with dyspnea to evaluate the agreement between the results obtained using three types of transducers (microconvex, linear, and phased array) and to determine the accuracy of LUS in discriminating between three conditions commonly causing dyspnea in companion animals: cardiogenic pulmonary edema (CPE), pneumonia, and lung neoplasm. The agreement beyond chance was assessed using the weighted Cohen’s kappa coefficient (κw). The highest values of κw (>0.9) were observed for the pair of microconvex and linear transducers. To quantify B-lines the lung ultrasound score (LUSscore) was developed as a sum of points describing the occurrence of B-lines for each of 8 standardized thoracic locations. The accuracy of LUSscore was determined using the area under ROC curve (AUROC). In dogs AUROC of LUSscore was 75.9% (CI 95%: 65.0% to 86.8%) for distinguishing between lung neoplasms and the two other causes of dyspnea. In cats AUROC of LUSscore was 83.6% (CI 95%: 75.2% to 92.0%) for distinguishing between CPE and the two other causes of dyspnea. The study shows that results obtained with microconvex and linear transducers are highly consistent and these two transducers can be used interchangeably. Moreover, the LUSscore may help identify dogs with lung neoplasms and cats with CPE, however its diagnostic accuracy is only fair to moderate.

Pulmonary Edema I: Cardiogenic Pulmonary Edema

There are two categories of pulmonary edema: edema caused by increased capillary pressure (hydrostatic or cardiogenic edema) and edema caused by increased capillary permeability (noncardiogenic pulmonary edema, or acute respiratory distress syndrome). This review focuses on cardiogenic pulmonary edema and describes the general approach to patients with suspected cardiogenic pulmonary edema. The pathogenesis, diagnosis, treatment, and outcome of cardiogenic pulmonary edema are reviewed. Figures include chest scans showing pulmonary edema and noncardiogenic pulmonary edema, an illustration of the differences between cardiogenic and noncardiogenic edema, and a chart comparing lung mechanics and other variables in experimental models of cardiogenic pulmonary edema and noncardiogenic edema. Tables show clinical characteristics of patients with cardiogenic pulmonary edema and treatment options. This review contains 3 figures, 4 tables, and 29 references Keywords: cardiogenic pulmonary edema, congestive heart failure, pulmonary edema, Starling’s law