Radiological impact of the use of calcium hydroxylapatite dermal fillers

Aim To report a case series in which the radiological features of the subcutaneous use of calcium hydroxylapatite (CaHa) dermal fillers are described for the first time. Materials and methods Five patients with facial hyperattenuating hypermetabolic subcutaneous lesions were identified on 2- [18 F]-fluoro-2-deoxy- d- glucose (FDG) positron-emission tomography/computed tomography (PET/CT), who gave a history of facial injections to augment physical appearance. Correlation with additional imaging studies was performed. Results All cases had subcutaneous high attenuation material on CT (range 280–700 HU), which was FDG avid on PET, with a standardized uptake value (SUV) range of 2.9–13.4. Magnetic resonance imaging (MRI) demonstrated a heterogeneous intermediate signal intensity subcutaneous lesion with enhancement post-gadolinium in one case. Conclusions CaHa dermal filler is hyperattenuating on CT, hypermetabolic on FDG-PET imaging, of intermediate signal intensity on MRI, and is a potential cause of a false-positive imaging study.