Bronchoalveolar lavage affects computed tomographic and radiographic characteristics of the lungs in healthy dogs

Abstract

Bronchoalveolar lavage is a common diagnostic test for dogs with suspected pulmonary disease, however there is no published information on whether this procedure could affect the imaging characteristics of the lungs. Aims of this prospective experimental study were to describe computed tomography (CT) and radiographic features of the lungs after bronchoalveolar lavage in a sample of healthy dogs. Thoracic CT and radiographic images of eight healthy Beagles were acquired at the following time points: before bronchoalveolar lavage, immediately following bronchoalveolar lavage, and at 2, 4, 8, 12, and 24 h following bronchoalveolar lavage. Lung consolidation or interstitial patterns were seen in CT and radiographic images immediately after the procedure. Radiographic lung patterns resolved within 2 h and CT patterns resolved within 24 h. Resolution of the CT pulmonary patterns in the ventral areas of the lungs was delayed compared to the dorsal areas. Mean CT imaging scores differed over time (P < 0.001), while mean radiographic imaging scores did not differ over time. This study suggests that thoracic radiography and CT imaging assessments should precede bronchoalveolar lavage procedures if possible, or be performed at least 24 h afterward.

Bronchoalveolar lavage affects thorax computed tomography of healthy and SARS-CoV-2 infected rhesus macaques (Macaca mulatta)

“…The majority of these opacities decreased within four hours after BAL and returned to normal within 24 hours after the procedure. Despite differences in BAL procedure, the changing opacities in time after BAL seen in the macaques are comparable to results obtained in humans (15) and dogs (12). In both studies, a known amount of unrecovered BAL fluid was left in the lung, bilateral in humans and unilateral in dogs.…”

“…Computed tomography (CT) of the thorax and bronchoalveolar lavage (BAL) are diagnostic procedures widely used in clinical pulmonary research and veterinary medicine (9–12). These techniques are also used in COVID-19 research in NHPs to gain more information and to create a bridge between the human and NHP data (6, 13, 14).…”

“…To determine infection and viral load, nasopharyngeal and tracheal swabs are used to sample the upper respiratory tract. With a BAL, samples from the lower respiratory tract can be obtained (12, 15). BAL fluid can be used both as diagnostic tool and for detailed analysis of the infection.…”

“…We investigated the effect of BAL on thorax CTs of rhesus macaques. Additionally, we determined the timeframe of possible interference as during BAL a part of the instilled saline is left unrecovered in the lungs (12). Studies performed in dogs and humans demonstrated that retained saline is correlated with an increase in lung opacity on immediate post-BAL CTs (12, 15).…”

“…Additionally, we determined the timeframe of possible interference as during BAL a part of the instilled saline is left unrecovered in the lungs (12). Studies performed in dogs and humans demonstrated that retained saline is correlated with an increase in lung opacity on immediate post-BAL CTs (12, 15). By this the retained saline can mask COVID-19 associated lesions on CT as one of the main groups of those lesions are ground glass opacities (GGOs) which are also characterized by a slight increase in lung opacity (13, 20).…”