Abstract 14043: A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis
Background: Compression ultrasound (CUS) is used to diagnose acute deep venous thrombosis (DVT). However, CUS cannot assess pelvic veins or quantify thrombus volume. In a study of edoxaban monotherapy for acute, symptomatic DVT treatment (eTRIS), we are utilizing magnetic resonance venography (MRV) to quantify total thrombus volume changes as an assessment of treatment efficacy.
Purpose: We utilized MRV with long circulating contrast agent gadofoveset (Ablavar®) to establish and validate a quantitative assessment of DVT thrombus volume in a multicenter clinical trial setting.
Methods: From 20 eTRIS subjects (evaluating the efficacy of the oral, direct factor Xa inhibitor edoxaban) total thrombus volume in the entire deep venous system was quantified (external iliac, common/superficial/deep femoral, popliteal, anterior/posterior tibial, gastrocnemius, and peroneal veins) bilaterally. Subjects were imaged supine in three sections (pelvis/thighs/calves) using a T1W 3D gradient echo sequence before and 5 minutes after injection of 0.03mmol/kg of Ablavar. DVT was visualized as lower signal intensity compared with surroundings on coronal post contrast images (Figure). A curved path following centerline of each vein was calculated, the vessel straightened and corresponding cross sectional images segmented by 2 observers by placing regions of interest on each reformatted imaging slice to obtain volumetric measurements of DVT. Intra-class correlation (ICC) and Bland Altman analysis were performed to compare results obtained by the two readers.
Results: The average total thrombus volume measured by MRV with Ablavar was 3.13 ± 6.23cm3. ICC between the readers was excellent (0.98, p< 0.001) and Bland Altman analysis revealed little bias between readers.
Conclusion: MR venography with Ablavar® provides a robust and reproducible method to quantify DVT volumes in a multi-center setting and can potentially be used as a tool for quantifying DVT treatment efficacy.
- © 2013 by American Heart Association, Inc.