Abstract
Background: Echographic vertical artifacts (B-lines) in chest\r\nultrasonography have often been associated with pathological\r\npatterns. A scientifically sound explanation of these\r\nartifacts has not yet been proposed. Objectives: The\r\n‘spongy’ nature of the lung in its liquid and solid components\r\nand the changes that take place in peripheral airspace\r\n(PAS) geometry might be the key point to understanding\r\nthese phenomena. Methods: Six excised right rabbit lungs\r\nwere obtained. Each lung underwent direct ultrasound\r\nevaluation in two different conditions: at complete tissue\r\nelastic recoil volume and at pulmonary expansion volume\r\nachieved by applying a constant positive pressure of 12 cm\r\nH 2 O. Lung volumes and densities were reported in both\r\nconditions. Histological examination was performed on\r\nthree naturally collapsed lungs and on three lungs under\r\npositive pressure inflation after having been fixed in forma-lin solution. Results: Mean volumes of naturally collapsed\r\nlungs and fixed expanded lungs were 11.2 ± 0.36 and 44.83\r\n± 3.03 ml, respectively. Mean densities were 0.622 ± 0.016\r\nand 0.155 ± 0.007 g/ml, respectively. Ultrasound evaluation\r\nof collapsed lungs showed dense vertical artifacts and a\r\n‘white lung’ pattern, while the evaluation of expanded lungs\r\nshowed hyperechoic line and horizontal artifacts of reflection.\r\nHistological evaluation showed a different PAS geometry\r\nin collapsed lungs caused by alveolar size reduction and\r\nshape changes with unfolded and closed units modifying\r\nthe peripheral porosity of the frothy nature of the lung. Conclusions:\r\nAirspace geometry, frothy nature and porosity are\r\nthe determinants of the different behavior of ultrasound interacting\r\nwith the subpleural lung parenchyma. Chest ultrasound\r\nmay thus be interpreted as an indirect ‘estimator’ of\r\nlung porosity.
Lingua originale | Inglese |
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pagine (da-a) | 458-468 |
Numero di pagine | 11 |
Rivista | Respiration |
Volume | 88 |
Numero di pubblicazione | Dicembre |
DOI | |
Stato di pubblicazione | Pubblicato - 2014 |
Pubblicato esternamente | Sì |
All Science Journal Classification (ASJC) codes
- Medicina Polmonare e Respiratoria
Keywords
- Chest ultrasound
- Lung density