MRI follow-up

• LR-3 ≥2 cm: repeat multiphase imaging in ≤6 months.
• LR-4: multidisciplinary discussion; biopsy or short-interval follow-up.
• LR-5: diagnostic of HCC — refer to hepatology/transplant.

Source: ACR LI-RADS 2018

• <2.5 cm, asymptomatic: MRI in 12 months, then space out if stable.
• Symptomatic, near critical structures, or growth: neurosurgical referral.

Source: Consensus guidance

• Non-functioning <1 cm: MRI at 1 year, then less frequently if stable.
• Functioning or near optic chiasm: endocrine + neurosurgery referral.

Source: Endocrine Society

• Acute marrow edema on STIR → consider DXA + osteoporosis workup.
• Atypical features (posterior involvement, mass): contrast MRI + oncology referral.

Source: ACR Appropriateness Criteria