Quantifying Vascular Occlusion in Genicular Artery Embolization (GAE) using Parametric Analysis of Digital Subtraction Angiogram (DSA) images

Monday, March 6, 2023

3:45 PM – 3:54 PM

Location: Phoenix Convention Center, 222C

Presenting Author(s)

Wali Badar, MD

Resident
University of Illinois at Chicago

Disclosure(s): No financial relationships to disclose

Author/Co-author(s)

Osman Ahmed, MD

Associate Prof
University of Chicago

Disclosure(s):

Wali Badar, MD: No financial relationships to disclose

Osman Ahmed, MD: Argon Medical: Advisory Committee or Review Panel Member (Ongoing); Asahi: Consultant (Ongoing); Bard Peripheral Vascular: Speaking and Teaching (Terminated, September 1, 2022); Boston Scientific: Advisory Committee or Review Panel Member (Ongoing), Consultant (Ongoing); Canon Medical Systems: Consultant (Ongoing), Contracted Research (Ongoing); Cook: Speaking and Teaching (Ongoing); Johnson & Johnson: Advisory Committee or Review Panel Member (Ongoing); Penumbra Inc.: Speaking and Teaching (Ongoing); Philips: Contracted Research (Terminated, October 1, 2022)

Purpose: GAE is thought to be effective at reducing pain and disability from knee osteoarthritis1 through vascular occlusion which inhibits angiogenesis and the associated inflammatory cascade2. In this pilot study, we investigate the primary endpoint of GAE, vascular occlusion, using color-coded parametric images derived from DSA images.

Materials and Methods: Ten consecutive patients (8 female & 2 male, Mean Age: 71 yo, SD: 12.6 yo, Range: 52-94 yo) with average BMI 27.9 (SD: 7.2) underwent GAE between 09/2021 to 09/2022. Selected genicular vessels (8 right knee, 2 left knee) were embolized using 200 μm microparticles. Pre-and-post embolization DSA images were collected at identical conditions and region-of-interests (ROI’s) were processed with Parametric ImagingTM (Canon Medical Systems Corporation, Japan) software to extract peak contrast opacification and area under the time-intensity curves.

Results: A total of 30 ROI’s (15 pairs) from the pre-and-post images were included. Paired t-test showed both peak contrast opacification (pre: 0.062, SD: 0.038; post: 0.042, SD: 0.037) and area under the time-intensity curves (pre: 0.136, SD: 0.141; post: 0.067, SD: 0.112) decreased from pre to post embolization (p< 0.01). Specifically, there was 37% and 137% reduction in peak contrast opacification and area under the time-intensity curves, respectively. The decreased peak contrast opacification indicated lower contrast concentration in the ROI after GAE, whereas the decreased area under the curve suggested a decrease in total contrast in the ROI.

Conclusion:
This initial study demonstrates a method to qualitatively and quantitatively evaluate vascular occlusion during selective GAE using parametric analysis of DSA images. Future research will aim to understand how changes in flow dynamics influence the therapeutic effects and clinical outcomes of GAE.