Characterization of the normal pulmonary surface and pneumonectomy space by reflected ultrasound

Abstract

KEYWORDSTransthoracic; Normal pleuropulmonary; Pneumonectomy space; Ultrasound artifacts.Abstract Interest has been increasing in the use of transthoracic ultrasound for the study of the pleuropulmonary disease. US imaging depends mainly on the physical interactions between ultrasound waves and the tissues being examined. In the thoracic region, the prescence of the chest wall and the air-containing pulmonary tissues cause various artifacts that strongly influence the resulting images. At the interface between tissues and air, the ultrasound beam is totally reflected and produces simple reverberation, comet-tail artifacts, and ring-down artifacts. We report the findings of transthoracic ultrasound in normal healthy subjects and in those who had undergone pneumonectomy.This experience shows that, in terms of the ultrasound artifacts mentioned above, the postpneumonectomy cavity is not significantly different from the healthy lung.Sommario SommarioL'interesse nell'utilità dell'ecografia del torace si è di recente accresciuto specialmente nello studio delle malattie pleuro-polmonari. L'immagine ecografica dipende prevalentemente dalle interazioni fisiche tra gli ultrasuoni e i tessuti esaminati; pertanto nello studio del torace la presenza della gabbia toracica e del tessuto polmonare contenente aria influenza fortemente le immagini generando molteplici artefatti. Il fascio ultrasonoro passando attraverso l'interfaccia tessuti/aria è quasi totalmente riflesso, producendo semplici riverberazioni (artefatti orizzontali), "comet-tail" e "ring-down" (artefatti verticali). Riportiamo gli effetti fisici implicati nella formazione di artefatti durante l'ecografia del torace in soggetti normali confrontati con lo spazio residuo post-pneumonectomia. In tutti i soggetti sani esaminati così come nella cavità residua dopo pneumonectomia abbiamo rilevato tutti gli artefatti descritti in accordo con i principi fisici degli ultrasuoni. ª

High-Resolution Transthoracic Ultrasonography for Assessment of Pleural Lines in Patients With Dyspnea With CT Comparison: An Observational Study

“…Because of a distinct difference in acoustic impedance, the interface of the air in the lung and the soft tissues generates a thin hyperechoic line. It is visible as a white band with an average thickness of 2 mm with a 3.5‐ to 5‐MHz convex probe . When an 8‐ to 12.5‐MHz linear probe is used, the visible thickness of the pleural line is 1 mm; however, the thickness of the white line does not correspond anatomically to the pleura.…”

Transthoracic ultrasound for pleural effusion: traps and tricks

“…All these artifacts are usually and commonly present, to a lesser extent, even in normally aerated lung and are not pathological (24). These artifacts are also present even in the pneumonectomy space of patients undergoing pneumonectomy, according with the physical principles of ultrasounds, which are generated by the large difference in acoustic impedance between the superficial soft tissues of the rib cage and the air and fluid in the residual cavity after pneumonectomy (25).…”

Echocardiographic and Lung Ultrasound Characteristics in Ambulatory Patients with Dyspnea or Prior Heart Failure

“…In 2013, in a sample of 20 MDs, with >5 years US practice and expertise (10 operators) or with 6 months of training in clinical US (10 operators), we asked them to assess twice the same movie clips of LUS with B-lines in 5 different clinical conditions; a fair intra-observer internal consistency is observed and the standard deviation is around 33.0% of the averages for each condition, considering the reports of all observers. Nonetheless, ranges of the B-lines individual counts are exceedingly wide for identical cases of each condition: pulmonary edema (3-10), chronic obstructive pulmonary disease exacerbation (4-10), pulmonary fibrosis (3-11), pleural effusion in congestive heart failure (HF) (3-10), pulmonary cancer lymphangitis (4)(5)(6)(7)(8)(9)(10). Which is the range for any measurement that the observers reported in the cases studied by Platz et al?…”

“…2 B-lines are visible and approximately measured in conditions different from pulmonary congestion, and notably in chronic obstructive pulmonary disease 3 and pulmonary fibrosis 4,5 : it is a challenge to "count" them, being not an actual "measurement." 6,7 However, the main concern is related to the methodology. The most relevant reference studies, quoted also by the authors, did not use phased array transducers, 1 but linear or convex probes.…”