What is T2 shine-through effect on MRI and how can it be differentiated from true restricted diffusion?

T2 shine-through occurs when a lesion appears bright on both T2-weighted and diffusion-weighted (DW) MRI sequences but is not truly restricted, as evidenced by a normal or elevated apparent diffusion coefficient (ADC) map. Key diagnostic features include high signal intensity on T2 and DW images with corresponding high ADC values. Clinical pearls include recognizing that T2 shine-through is common in cystic or edematous lesions. A common pitfall is mistaking T2 shine-through for true restricted diffusion, which would show low ADC values.