Multimodality imaging considerations for genicular artery embolization in knee osteoarthritis

Table 4 Expected post-genicular artery embolization imaging findings by follow-up interval (0-12 months)

Modality	0-1 month (early)	1-3 months (intermediate)	6-12 months (long-term)
Radiography (X-ray)	No structural response expected. Primary role is safety to exclude fracture or rapid collapse	OA hallmarks (osteophytes, joint space narrowing) remain unchanged; not considered a response biomarker	Useful mainly for longitudinal progression tracking in research cohorts
MRI	May show decreased synovial enhancement transient subchondral marrow signal abnormalities may be seen early and warrant interval reassessment	Most consistent imaging response window: Decreased synovial enhancement/thickness; Effusion-synovitis often trends downward	Reduced synovitis generally persists; cartilage loss and osteophytes remain stable and non-reversible

MRI: Magnetic resonance imaging; OA: Osteoarthritis.