Multimodality imaging considerations for genicular artery embolization in knee osteoarthritis.

Area of Science:

• Interventional Radiology
• Musculoskeletal Imaging
• Osteoarthritis Treatment

Background:

• Genicular artery embolization (GAE) is a minimally invasive therapy for symptomatic knee osteoarthritis (OA), especially for inflammation-predominant disease.
• Accurate patient selection and outcome assessment rely heavily on pre-, intra-, and post-procedure imaging.
• Distinguishing between inflammation-predominant and structure-predominant OA is key for GAE candidacy.

Purpose of the Study:

• To review contemporary evidence on imaging in GAE for knee OA.
• To discuss pre-, intra-, and post-procedure imaging techniques and interpretation.
• To highlight semiquantitative MRI scoring systems and common pitfalls in post-GAE imaging.

Main Methods:

• Review of current literature on imaging for genicular artery embolization in knee osteoarthritis.
• Analysis of magnetic resonance imaging (MRI) findings differentiating inflammatory and structural knee OA phenotypes.
• Discussion of imaging criteria for GAE candidate selection and post-procedure monitoring.

Main Results:

• Moderate-to-large effusion-synovitis (MRI grade 2-3), higher MRI lesion burden (≥4 abnormalities), and full-thickness cartilage loss may help phenotype knee OA for GAE.
• Synovial enhancement and effusion-synovitis on MRI are expected to improve post-GAE.
• Structural OA changes often persist post-GAE and require careful interpretation to avoid misinterpreting treatment failure.

Conclusions:

• Imaging plays a vital role in the entire GAE process for knee OA, from patient selection to follow-up.
• MRI findings like synovial enhancement and effusion-synovitis are key indicators of potential GAE success.
• Radiologists must be aware of post-GAE imaging changes to accurately assess treatment outcomes and avoid misinterpretation.