18F-Sodium Fluoride PET/CT Findings in Osteitis Condensans Ilii.

Osteitis condensans ilii (OCI) is a benign cause of low back pain for which no clear etiology has been identified. We report cases of 2 women with breast cancer referred for 18F-NaF PET/CT for skeletal staging. Both cases show characteristic findings of OCI on CT images, with 18F-NaF PET uptake in symptomatic patient and no uptake in asymptomatic. 18F-NaF PET CT can be useful in evaluating back pain and may be used as an adjunctive biological maker for assessing OCI as a potential cause of pain.