Sonographic Interstitial Syndrome

Abstract

Objective. Ultrasound lung comets (ULCs) now have an acknowledged correlation with extravascular lung water, but they present in different orders and numbers in different pathologic pulmonary entities. How these artifacts are created is not yet known, and the literature gives discordant hypotheses. Understanding their formation is the first step in understanding lung disease. The purpose of this study was to show the morphologic and genetic variability of interstitial lung disease studied with echography and thus to propose a unitary mechanism for the formation of ULCs. Methods. This study included 3 parts: (1) a retrospective analysis of echographic lung images of patients with interstitial syndrome; (2) an analysis of the literature for definitions of the size of the pulmonary lobule; and (3) an experimental model of different air-water interfaces scanned with varying ultrasonic frequencies.Results. The retrospective analysis of echographic lung images included 176 patients with diffuse ULCs: 118 patients had acute pulmonary edema; 18 had acute lung injury/acute respiratory distress syndrome; and 40 were premature neonates with respiratory distress syndrome. Experimental models permitted us to discover that ring-down artifacts are produced only by single and double layers of bubbles in specific structural settings. Conclusions. Reverberation between bubbles with a critical radius seems to be at the origin of ring-down artifacts. Echographic manifestations of interstitial lung disease, whose genesis lies in the partial air loss of lobes and segments, are acoustic phenomena originating from variations in the tissue-fluid relationship of the lung. A correlation between anatomopathologic characteristics and structures of sonographic artifacts could allow more rapid and noninvasive diagnoses.

Bedside US imaging in multiple trauma patients. Part 1: US findings and techniques

“…For years, US imaging of the lungs was thought to be impossible because the US beams are attenuated by the air contained in the lungs. However, in the last two decades, the artifacts arising in the pleuropulmonary complex due to reflection of the US beams in the air-water interface have attracted considerable interest [23]. Today it is believed that the interpretation of these artifacts can provide substantial information about the condition of the underlying pleural space and the lung.…”

“…The interstitial syndrome is defined by the presence of multiple pleural and pulmonary artifacts referred to as ''B-lines''. An interesting hypothesis is that B-lines are generated in a ventilated lung by the air-water interface in the air-filled alveolar spaces, whose geometry is modified because of the thickening or distortion of interstitial septa [23]. B-lines arise from the pleura extending to the bottom of the field of view without dissolving; they move synchronously with the sliding lung.…”

Ultrasound detection of foreign body and gas contamination of a penetrating wound

“…The monodimensional linear distribution [4] and the small size of the microbubbles (<1 mm) did not allow the forming of the typical US artifacts (comet tails), but gas was suspected due to spontaneous and pressure provoked movements like ''sparkling-wine microbubbles''. The clinical picture was uncertain because the trauma was recent, but the patient complained of increasing, localized pain with edema, although there were no general symptoms.…”

Comparison of a basic lung scanning protocol against formally reported chest x‐ray in the diagnosis of pulmonary oedema

“…Patients with combined cardiac and respiratory pathology, with no indicator of primary cause of breathlessness throughout the admission were labelled as indeterminate. This standard is the one used in recent literature 12 – 14 , 16 , 27 as it includes but is not limited by radiologist x‐ray report. Alternative gold standards were not available (immediate echocardiography) or not clinically warranted due to radiation dose (CT chest).…”