FLUID COLOR SIGN - A USEFUL INDICATOR FOR DISCRIMINATION BETWEEN PLEURAL THICKENING AND PLEURAL EFFUSION

Color Doppler imaging has been applied traditionally in the evaluation of cardiovascular diseases. Recently it was observed that color signa l may appear within the fluid collection in the pleural space during r espirato and cardiac cycles (''fluid color sign''). We performed this applicability of fluid sign to the detection of pleural fluid capable of being removed to assess needle aspiration. From July 1992 to Februa ry 1994, we prospectively analyzed 76 patients who were suspected of h aving minimal pleural effusion on the basis of their chest radiographs . All patients were examined by color Doppler ultrasonography for the presence fluid color sign, which was followed by needle aspiration to verify the presence of pleural effusion. Among the 65 patients with as piratable fluid, 58 demonstrated positive fluid color sign (sensitivit y 89.2%). None of the patients with solid pleural thickening showed fl uid color sign (specificity 100%). With its relatively high sensitivit y and specificity, the fluid color sign may be a useful diagnostic aid to real-time, gray scale ultrasonography for minimal or loculated eff usion.