Vertical Artifacts as Lung Ultrasound Signs: Trick or Trap? Part 2‐ An Accademia di Ecografia Toracica Position Paper on B‐Lines and Sonographic Interstitial Syndrome

Abstract

Although during the last few years the lung ultrasound (LUS) technique has progressed substantially, several artifacts, which are currently observed in clinical practice, still need a solid explanation of the physical phenomena involved in their origin. This is particularly true for vertical artifacts, conventionally known as B-lines, and for their use in clinical practice. A wider consensus and a deeper understanding of the nature of these artifactual phenomena will lead to a better classification and a shared nomenclature, and, ultimately, result in a more objective correlation between anatomo-pathological data and clinical scenarios. The objective of this review is to collect and document the different signs and artifacts described in the history of chest ultrasound, with a particular focus on vertical artifacts (B-lines) and sonographic interstitial syndrome (SIS). By reviewing the possible physical and anatomical interpretation of the signs and artifacts proposed in the literature, this work also aims to bring order to the available studies and to present the AdET (Accademia di Ecografia Toracica) viewpoint in terms of nomenclature and clinical approach to the SIS.

Lung Ultrasound Signs

“…A denser pre‐consolidated parenchyma surrounds the peripheral areas of a lung consolidation, which is particularly the case in inflammatory consolidations. The US depicts this subverted parenchymal architecture as a mix of artifacts, including differently shaped vertical artifacts (long, short, confluents, or/and isolated); when they arise from the border of consolidations they are so called C‐lines, when arising from irregular deep borders and deep shape consolidations, they are so called shred signs (Figure 9), 26,77,78 and pleural irregularities/vertical artifacts arising from the pleural ine close to consolidation are defined focal sonographic interstitial syndrome 72,79 . Images are extremely diverse depending on several factors, including the pathological moment of the disease.…”

Acute dyspnea in the emergency department: a clinical review

“…To the contrary, interest in lung ultrasound is more recent, as in the past ultrasonography was not considered an appropriate tool for lung imaging due to the presence of air, impeding proper visualization of pulmonary parenchyma. In the last three decades, however, a number of studies has uncovered several potentialities of this technique, and many ultrasound findings, previously considered artifacts without a precise meaning, are now signs which may help the diagnosis of critically ill patients [ 77 , 78 ]. Since its introduction, lung ultrasound, in addition to echocardiography, proved to be at least as accurate as a standard of care in the assessment of several conditions presenting with acute dyspnea, such as pneumonia, pleural and pericardial effusion, pneumothorax and heart failure [ 79 , 80 ].…”

“…lung fibrosis, interstitial edema, interstitial pneumonia, COVID-19 pneumonia, etc.) [ 77 , 78 , 84 , 85 ]. A graphical overview of the main lung ultrasound findings is summarized in Fig.…”

The Role of Lung Ultrasonography Scoring in Predicting the Need for Surfactant Therapy in Neonates, With Respiratory Distress Syndrome

“…During the last few years, the use of diagnostic lung sonography has progressed substantially. 1 In addition, significant progress has been made in using sonography in pediatrics, especially in assessing the developmental status of the fetus and infant. This diagnostic method has been very popular due to its cost-effectiveness and availability as well as its noninvasive approach.…”