Which area is normally showing increased radiotracer uptake on bone scans and is not considered pathological?

Which area is normally showing increased radiotracer uptake on bone scans and is not considered pathological?

• A. Kidneys
• B. Injection site
• C. Sacroiliac joints
• D. Liver

Answer: (B)

Radiotracer distribution on bone scans includes normal soft-tissue uptake where the tracer is injected. The injection site often shows increased activity simply because the tracer resides briefly in the soft tissue before it distributes systemically. This local uptake is expected and nonpathological, reflecting recent injection and local perfusion rather than a bone or disease process. As a result, the injection site is the area you’d expect to be active without implying pathology, whereas true pathologic uptake would occur in bones or known abnormal sites.

Radiotracer distribution on bone scans includes normal soft-tissue uptake where the tracer is injected. The injection site often shows increased activity simply because the tracer resides briefly in the soft tissue before it distributes systemically. This local uptake is expected and nonpathological, reflecting recent injection and local perfusion rather than a bone or disease process. As a result, the injection site is the area you’d expect to be active without implying pathology, whereas true pathologic uptake would occur in bones or known abnormal sites.