Journal of Ultrasound in Medicine, Vol 14, Issue 10 767-769, Copyright © 1995 by American Institute of Ultrasound in Medicine
"Fluid color" sign: a useful indicator for discrimination between pleural thickening and pleural effusion
R. G. Wu, P. C. Yang, S. H. Kuo and K. T. Luh
Department of Internal Medicine, Lotung Poh-Ai Hospital, Taipei, Taiwan, Republic of China.
Color Doppler imaging has been applied traditionally in the evaluation of
cardiovascular diseases. Recently it was observed that color signal may
appear within the fluid collection in the pleural space during respiratory
and cardiac cycles ("fluid color sign"). We performed this applicability of
fluid color sign to the detection of pleural fluid capable of being removed
to assess needle aspiration. From July 1992 to February 1994, we
prospectively analyzed 76 patients who were suspected of having minimal
pleural effusion on the basis of their chest radiographs. All patients were
examined by color Doppler ultrasonography for the presence of fluid color
sign, which was followed by needle aspiration to verify the presence of
pleural effusion. Among the 65 patients with aspiratable fluid, 58
demonstrated positive fluid color sign (sensitivity 89.2%). None of the
patients with solid pleural thickening showed fluid color sign (specificity
100%). With its relatively high sensitivity and specificity, the fluid
color sign may be a useful diagnostic aid to real-time, gray scale
ultrasonography for minimal or loculated effusion.
