To establish a normal range for distribution of breath sounds in a healthy Japanese population.
Vibration response imaging (VRIÖ) was used for recording and automatic analysis of lung sound distribution in 104 healthy subjects (52m, 52f). Three reviewers blindly assessed the images. Intensity and location of breath sounds in left and right lungs and were quantified and analyzed. Subgroup analyses assessed the effect of gender and cigarette smoking.
Intensities for left and right lungs as percentages of the total (100%) were analyzed. The left lungs (55 7%, mean SD) had a higher intensity than the right lungs (45 7%, P < 0.05) in 76% of the subjects. Further analysis showed that the intensity in the left lung was greater in females than in males (58 8% versus 52 6%) (P < 0.05). Also, the intensity in the left lung was significantly decreased in cigarette smokers (52 6%) compared to non-smokers (57 7%, P < 0.05). Qualitative analysis showed 83% of images were normal/healthy. Of the 18 abnormals, 72% had disturbed dynamics.
Breath sounds have a characteristic distribution in healthy subjects and are predictably greater in the left lung, affected by gender and by cigarette smoking. These findings validate a previous study in another population (1).
VRI technology provides a non-invasive, complementary tool to function testing for evaluating lung conditions. Dynamic gray-scale images of healthy individuals have typical features that are discerned by trained raters and serve as a reference for interpreting recordings of patients with lung disease in future studies.(1) Yigla M, Gat M, Meyer JJ, Friedman PJ, Maher TM, Madison JM. Vibration response imaging technology in healthy subjects. AJR Am J Roentgenol. 2008 Sep;191(3):845–52.
Taeko Shirakawa, No Financial Disclosure Information; No Product/Research Disclosure Information