Abstract 310: MRI Characterization Of Thrombus For Differentiating Acute And Chronic Dvt

Abstract

Background: Optimal patient selection for the endovascular treatment of iliofemoral DVTs remains a significant clinical challenge. 2 Symptom onset is used as a gross surrogate for determining the composition of the clot to determine if it is amenable to endovascular treatment. As thrombus ages, collagen deposition increases, and the bulk of fibrin within the thrombus becomes crosslinked and resistant to lysis 3 . Symptom onset has poor correlation with collagen content 4 and is not a predictor of endovascular success. The goal of this study is to relate MRI characteristics to clot composition to guide patient selection for endovascular treatment of iliofemoral DVT in the future. 5 Methods: 2 patients with popliteal deep venous thrombus that presented within a week of symptom onset underwent Inari thrombectomy. Patient 1 was imaged in the 7T MRI and patient 2 was imaged with 3T Both patients had T2-weighted (T2W) and UTE sequences. Results: Patient 1 had a thrombus with high collagen content indicated by low signal intensity on T2W imaging and high signal intensity on UTE MRI. The extracted clot had gross chronic characteristics and was extremely challenging to extract despite multiple passes. Patient 2 had a thrombus with low collagen content indicated by low signal intensity on T2W imaging and isointense on ultrashort echo time imaging. The clot had acute gross characteristics and was easy to extract. Conclusion: Symptom onset is not always reflective of the composition of deep venous thrombus. MRI characterization of thrombus can aid patient selection for endovascular treatment by differentiating patients with high and low collagen content.