High body mass index is strongly correlated with decreased image quality in focused bedside echocardiography

Background There is a well-established relationship between obesity, as measured by body mass index (BMI), and overall health risk. The presence of body fat is a known limitation to ultrasound, but it is unknown whether any decrease in quality due to obesity limits the interpretability of focused bedside echocardiography (FBE). Objectives To correlate obesity, as measured by BMI, with image quality and interpretability of (FBE) performed by an emergency physician. Methods We conducted a prospective observational study in a convenience sample of adults presenting to two academic emergency departments (EDs) and a bariatric surgery outpatient clinic. Twenty patients were enrolled in each of three BMI categories, <30, 30-39, and ≥40 kg/m². FBE was performed in multiple views in two positions. Images were rated for ability to discern the pericardial myocardial interface (PMI) and the endocardial border of the left ventricle (ELV). Results There were 23 males and 37 females enrolled. The median age was 49 years and the median BMI was 35.6 kg/m². There was a significant difference in the percentage of technically limited examinations between BMI categories for both PMI and ELV. There was an overall negative linear correlation between BMI and image quality for both PMI and ELV. Conclusion There is an overall decrease in the quality of focused bedside echocardiographic images as BMI increases. This relationship exists for visualization of both the PMI and the ELV. Emergency physicians should be aware of the potential limitations of focused bedside echocardiography in this patient population.