Ultrasonographic Patterns of Calcium Hydroxyapatite According to Dilution and Mix With Hyaluronic Acid

To assess the ultrasonographic patterns of different calcium hydroxyapatite (CaHA) formulations, including the undiluted, diluted, and mixed with hyaluronic acid (HA) compounds.

To review the ultrasonographic images of patients ≥18 years with confirmed injections of CaHA clinically and ultrasonographically, and without different concomitant types of fillers in the same region or other systemic or localized cutaneous diseases.

Twenty-one patients met the criteria (90% female; 10% male; mean age: 52 years ± 12.8). Of these, 33.3% have been injected with an undiluted formulation, 33.3% with diluted, and 33.3% with a mixed formulation. All cases were studied with devices presenting frequencies that ranged from 18 to 24 MHz. Twelve cases (57%) were also studied with the 70 MHz. The ultrasonographic patterns of CaHA presented differences in the presence and intensity of PAS and the degree of inflammation according to the dilution and mix with HA. Diluted formulations show a milder intensity posterior acoustic shadowing (PAS) artifact than undiluted at 18-24 MHz. In mixed formulations, 57% showed mild PAS, and 43% demonstrated no PAS artifact at 18-24 MHz, besides fewer inflammatory changes in the periphery of the deposits.

The ultrasonographic patterns of CaHA show differences in the presence and intensity of PAS and the degree of inflammation according to the dilution and mix with HA. Awareness of these ultrasonographic variations can support better discrimination of CaHA.