CHEST

Any cause of hypercalcemia, most commonly primary or secondary hyperparathyroidism , can cause metastatic calcifications and abnormal pulmonary uptake. Metastatic osteosarcoma, neuroblastoma , radiation pneumonitis, and rarely bronchogenic carcinoma may demonstrate increased uptake of bone tracers. Accumulation of Tc-99m diphosphonate is also seen in pleural effusions, usually malignant.

CHEST UPTAKE

• Alveolar microlitiasis (ref)
• Artefact
• Aspergillosis
• Berylliosis
• Fibrothorax
• Hyperparathyroidism
  • primary (ref)
  • secondary (ref)
• Hypercalcemia (ref)
• Hypervitaminosis D
• Idiopatic pulmonary ossification
• Infection (ref)
• Liver transplant
• Lung carcinoma (ref)
• Metastases (ref)
  • Osteosarcoma (ref)
  • Seminoma
• Mitral stenosis
• Neuroblastoma (ref)
• Pleural effusion (ref)
• Radiation therapy
• Sarcoidosis
• Tuberculosis

Primary hyperparathyroidism.

The scintigrams (posterior (A) and anterior (B) projections) shows diffuse increased radionuclide uptake in the lungs and stomach, that represents metastatic calcifications, in a patient with parathyroid adenoma.

Osteosarcoma with pulmonary metastases

This bone scintigram in posterior projection demonstrates foci of abnormally increased radiotracer activity in the left hemithorax, in a patient with known osteosarcoma.

Neuroblastoma.

This scintigram shows intense uptake in the mediastinum. Thirty-five to 74% of primary neuroblastomas accumulate bone agents, presumably secondary to dystrophic calcifications in the tumor.

Malignant pleural effusion.

The bone scintigram (A) shows diffuse accumulation of the radiotracer in a malignant pleural effusion within the right hemithorax of this patient with lung carcinoma. A CT scan (B) confirms the presence of a right-sided pleural effusion.

Malignant pleural effusion

Anterior (A) and posterior (B) bone scintigrams show generalized increased radionuclide accumulation in the left hemithorax in this patient with lung carcinoma. A chest X-ray (C) confirms the presence of a left-sided pleural effusion.

Seminoma

(A) The bone scintigram in anterior projection demonstrates abnormally increased radionuclide activity in the mediastinum. There is a bulky soft tissue mass occupying the mediastinum on this axial CT (B) of the chest, that displaces the thoracic aorta posteriorly. The mediatinal mass is biopsy-proven seminoma.

Urine Contamination

(A) Initial bone scintigram in anterior projection shows several ill-defined areas of radiotracer accumulation that subsequently disappears on repeat scan (B) following decontamination.