Vascular and Interventional RadiologyE2834. Echogenicity of Acute Versus Residual Venous Thrombosis
Ahmad H, Li Z, Needleman L. Thomas Jefferson University Hospital, Philadelphia, PA
Address correspondence to H. Ahmad (email@example.com)
Objective: Acute deep vein thrombosis (DVT) and chronic venous thrombosis (or residual venous thrombosis [RVT]) require different treatments. An array of characteristics are used to determine the acuity of DVT on gray scale sonography, including vein size, compressibility, clot borders, vessel walls, and echogenicity. However, there are conflicting reports of the relationship between echogenicity and DVT acuity in the literature and radiology texts. Previous studies were limited by the uncertainty of the age of DVTs, small sample size, and inconsistent methods of measurement.
Materials and Methods: A retrospective cohort study was performed at a neuroscience hospital at which patients are screened for DVT at admission. Patients were selected if they had acute thigh DVT and a negative screening ultrasound within the previous 10 days. A subset of these patients developed RVT. Analysis of echogenicity was performed in the transverse plane with noncompressed veins using two methods: ROI measurements and expert observer. ROI data was obtained by comparison to the surrounding muscle to obtain relative echogenicity. The thrombi were also characterized by their most representative echogenicity with the categories including no echoes, minimal echoes, moderate echoes, and bright echoes by an expert observer.
Results: Preliminary data of 55 patients with acute DVT demonstrated a relative echogenicity of 0.82 (± 0.09, 95% CI). Fourteen patients had follow-up imaging with RVT with a relative echogenicity of 0.85 (± 0.17, 95% CI). In patients who developed RVT, when compared with their own acute thrombus, there was an mean change ± SD of 0.14 ± 0.32. Analysis of acute DVT by an expert observer demonstrated the most representative echogenicity as 6.3%, no echoes; 35.4%, minimal echoes; 41.7%, moderate echoes; and 16.6%, bright echoes. In the RVT, the representative echogenicity was characterized as 9.1%, no echoes; 54.5%, minimal echoes; 36.4%, moderate echoes; and 0%, bright echoes.
Conclusion: RVT has been described as having greater echogenicity than acute DVT. By measuring the echogenicity in patients with confirmed acute DVT and follow-up with RVT, the data demonstrate that echogenicity is an inconsistent and unreliable metric to determine the age of a thrombus using both objective and subjective analyses.