Hemivertebral "disappearance" on bone scan

Area of Science:

• Radiology
• Nuclear Medicine
• Skeletal Imaging

Background:

• Bone scintigraphy using Technetium-99m methylene diphosphonate (Tc-99m MDP) is a common imaging modality.
• Vertebral hemihypertrophy can be identified through various imaging techniques.

Observation:

• Two cases presented with absent Tc-99m MDP uptake in a hemivertebra.
• One patient had a normal bone scan 56 days prior to the scan showing absent uptake.
• Radiographs of the vertebrae were unremarkable in both cases.

Findings:

• The observed absence of hemivertebra uptake on bone scintigraphy is likely due to compromised blood supply.
• Each vertebral half typically receives a distinct arterial supply, making it vulnerable to vascular compromise.

Implications:

• This finding suggests that vascular compromise should be considered in the differential diagnosis of absent hemivertebra uptake.
• Further investigation may be warranted in cases of unexpected absent uptake on bone scans to evaluate for vascular etiologies.