photopenia
Pronunciation: foh-toh-PEE-nee-ah
A region of decreased radiotracer uptake on nuclear medicine scans, appearing as a cold spot relative to surrounding tissue.
Full Definition
Photopenia refers to areas of reduced or absent radiotracer accumulation on nuclear medicine imaging studies such as bone scans or PET scans. In oncologic contexts, photopenia may indicate osteolytic bone lesions, necrotic tissue, or areas where tumor has destroyed normal metabolically active tissue. The term is essential for editors reviewing nuclear medicine reports, as it contrasts with areas of increased uptake (hot spots) that typically suggest active disease or inflammation.
Usage
Usage note: Often confused with photophobia (light sensitivity). In nuclear medicine contexts, always refers to decreased tracer uptake.
In Context
- "The bone scan revealed photopenia in the left femoral head consistent with an osteolytic metastasis." — Nuclear medicine report
- "Areas of photopenia on the FDG-PET corresponded to necrotic tumor following treatment." — Treatment response assessment