Abstract
OBJECTIVE: To determine the relation between erythrocyte sedimentation rate and blood echogenicity and whether measurement of erythrocyte sedimentation rate could be replaced by measurement of blood echogenicity in monitoring acute phase reactions. DESIGN: Simultaneous measurement of echogenicity of flowing blood and erythrocyte sedimentation rate in blood samples and comparison of results. SETTING: A radiological department in a university hospital. SUBJECTS: 83 patients with a suspected venous thrombosis and 36 healthy volunteers. MAIN OUTCOME MEASURES: Correlations between the erythrocyte sedimentation rate, packed cell volume, and echogenicity of flowing blood. RESULTS: Blood echogenicity correlated poorly with the packed cell volume, but strongly correlated with the erythrocyte sedimentation rate (when the packed cell volume was within reference limits) (correlation coefficient = 0.73). Blood samples with a greatly raised erythrocyte sedimentation rate were highly echogenic. Only one of the 30 samples with an erythrocyte sedimentation rate below 10 mm in first hour had a higher echogenicity than the least echogenic sample of the 19 with a sedimentation rate above 30 mm in first hour. CONCLUSIONS: Echogenicity of flowing blood correlates with the erythrocyte sedimentation rate and its measurement may compete with conventional methods for evaluating the long term changes in acute phase reactions. Also, it has the added advantage that non-invasive in vivo measurements of blood echogenicity may become possible.