E2109. Multimodality Imaging Features and Pitfalls of Hydroxyapatite Deposition Disease in Typical and Atypical Locations
  1. Mark Hess; University of Cincinnati
  2. Artemis Petrides; University of Cincinnati
  3. Ergent Zhiva; University of Cincinnati
Hydroxyapatite Deposition Disease (HADD) is a commonly encountered pathology in clinical practice and radiologic imaging. While most cases of HADD are asymptomatic, the inflammatory response to the calcium hydroxyapatite (CHA) crystals is debilitating and may mimic various other pathologic conditions, including infection or acute musculoskeletal injuries. It is a dynamic entity that can be imaged at various stages of the disease and present in uncommon places in the body. The imaging findings of acute HADD can also be variable depending on the severity of periarthritis, locoregional anatomic involvement, and atypical locations.

Educational Goals / Teaching Points
The goals of this educational exhibit are to review the pathophysiology, stages, common and uncommon locations and multimodality imaging findings of HADD, particularly during the inflammatory stage. Present cases of unexpected acute HADD and point out potential pitfalls. We will also identify differentiating and overlapping imaging features of HADD compared to other pathologic conditions that can involve similar locations.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The cases provided will encompass multimodality examples of common and uncommon locations of HADD, as well as where it can mimic other pathologies. Imaging modalities will include radiographs, MR, CT, and ultrasound. Different HADD stages with respective imaging findings. HADD presenting in uncommon locations. HADD causing atypical periarticular tissue changes.

HADD is a common disease with a complex and variable clinical presentation, which is often asymptomatic. It can mimic acute injury, infection, neoplastic processes, or present in unexpected locations. The material in this educational exhibit will provide a comprehensive case-based review of HADD in typical and atypical presentations.