Assessing Cutaneous Psoriasis Activity Using FDG-PET: Nonattenuation Corrected Versus Attenuation Corrected PET Images.

Psoriasis is a chronic inflammatory skin condition characterized by well-circumscribed erythematous plaques with thick silvery scale. Infiltration of inflammatory cells such as lymphocytes, neutrophils, and macrophages and epidermal cell proliferation within psoriatic lesions may result in selective FDG accumulation. We present a 55-year-old patient with a 30-year history of psoriasis. Nonattenuation corrected PET/CT images demonstrated significant cutaneous FDG uptake corresponding to clinically apparent psoriatic lesions. However, in attenuation corrected (AC) FDG-PET images, the signal was substantially diminished and minimally detectable. Nonattenuation corrected FDG-PET images may be useful and preferable to AC images in assessing skin inflammation in psoriasis.