An animal model for ultrasound lung imaging.

In the past decade, a number of clinical investigators have used ultrasound (US) to image the lung during video-assisted thoracoscopic surgery (VATS). In contrast, animal studies have shown prohibitively high attenuation levels in the lung, incompatible with the ability to image the lung. We hypothesized that the use of anesthesia during VATS augments lung collapse upon exposure to atmospheric pressure; thus, making US lung imaging possible. To test this hypothesis, we compared the effect of two commonly used anesthetic protocols on our ability to image 200 microL of US gel injected in rabbit lungs using a pulse echo transducer at 13 MHz. The anesthetic protocol, using acepromazine, ketamine and isoflurane, allowed US lung imaging in rabbits. It is concluded that US at 13 MHz can detect 200 microL of US gel injected into the lung parenchyma in a rabbit model.