Visualization of the inferoposterior thoracic wall (VIP) and boomerang signs-novel sonographic signs of right pleural effusion

Objectives

This study is to present the diagnostic values of the novel sonographic visualization of the inferoposterior thoracic wall (VIP) and boomerang signs in detecting right pleural effusion by sonologists with little to no experience in ultrasound.

Methods

A prospective analysis of a convenience sample of patients who were assessed by junior intensive care physicians was performed. The patients all underwent computed tomography (CT) of the chest or abdomen with lung bases as part of their care regardless of indication; the results were interpreted by radiologists and were considered the gold standard. Sonography was performed to assess for the presence of the VIP and boomerang signs. Sonographic and chest radiographic findings were compared against CT results.

Results

73 patients were enrolled. The sensitivity and specificity for the VIP sign were 0.85 (95% confidence interval CI], 0.67–0.94) and 0.86 (95% CI, 0.70–0.95). The sensitivity and specificity for the boomerang sign were 0.78 (95% CI, 0.60–0.90) and 0.87 (95% CI, 0.71–0.95). However, the sensitivity and specificity for the traditional approach of detecting an anechoic collection above the diaphragm to indicate pleural effusion were only 0.54 (95% CI, 0.37–0.71) and 0.86 (95% CI, 0.80–0.99).

Conclusions

Despite inexperience in sonography, the novel VIP and boomerang signs show high diagnostic values in detecting right pleural effusion compared to the traditional methods.