Lung ultrasound volume sweep imaging for respiratory illness: a new horizon in expanding imaging access

• Published in: BMJ open respiratory research 2021-11, Vol.8 (1), p.e000919
• Main Authors: Marini, Thomas J, Weis, Justin M, Baran, Timothy M, Kan, Jonah, Meng, Steven, Yeo, Alex, Zhao, Yu T, Ambrosini, Robert, Cleary, Sean, Rubens, Deborah, Chess, Mitchell, Castaneda, Benjamin, Dozier, Ann, O'Connor, Timothy, Garra, Brian, Kaproth-Joslin, Katherine
• Format: Article
• Language: English
• Subjects: Accuracy; Adolescent; Adult; Aged; Aged, 80 and over; Asthma; Child; Child, Preschool; Chronic obstructive pulmonary disease; Edema; Humans; Illnesses; Infant; Infant, Newborn; Lung - diagnostic imaging; Lungs; Medical imaging; Medical records; Middle Aged; Pleural effusion; Pneumonia; Pneumonia - diagnostic imaging; Point of care testing; pulmonary edema; Radiography; Respiratory diseases; Respiratory Research; Sensitivity and Specificity; Telemedicine; teleultrasound; Thorax; Ultrasonic imaging; Ultrasonography; ultrasound; X-rays; Young Adult
• ISSN: 2052-4439; 2052-4439
• DOI: 10.1136/bmjresp-2021-000919

BackgroundRespiratory illness is a leading cause of morbidity in adults and the number one cause of mortality in children, yet billions of people lack access to medical imaging to assist in its diagnosis. Although ultrasound is highly sensitive and specific for respiratory illness such as pneumonia, its deployment is limited by a lack of sonographers. As a solution, we tested a standardised lung ultrasound volume sweep imaging (VSI) protocol based solely on external body landmarks performed by individuals without prior ultrasound experience after brief training. Each step in the VSI protocol is saved as a video clip for later interpretation by a specialist.MethodsDyspneic hospitalised patients were scanned by ultrasound naive operators after 2 hours of training using the lung ultrasound VSI protocol. Separate blinded readers interpreted both lung ultrasound VSI examinations and standard of care chest radiographs to ascertain the diagnostic value of lung VSI considering chest X-ray as the reference standard. Comparison to clinical diagnosis as documented in the medical record and CT (when available) were also performed. Readers offered a final interpretation of normal, abnormal, or indeterminate/borderline for each VSI examination, chest X-ray, and CT.ResultsOperators scanned 102 subjects (0–89 years old) for analysis. Lung VSI showed a sensitivity of 93% and a specificity of 91% for an abnormal chest X-ray and a sensitivity of 100% and a specificity of 93% for a clinical diagnosis of pneumonia. When any cases with an indeterminate rating on chest X-ray or ultrasound were excluded (n=38), VSI lung ultrasound showed 92% agreement with chest X-ray (Cohen’s κ 0.83 (0.68 to 0.97, p