The lumbar spine x-rays show a sclerotic L3 vertebra, i.e. the ‘ivory vertebra’. The frontal imaging of the lumbar spine show small linear radio dense seeds – brachytherapy seeds.

This patient had a history of prostatic carcinoma that was treated with brachytherapy. The cause of the ivory vertebra is due to metastasis from the ca prostate; this was confirmed upon further investigation.

Apart from vertebral metastasis, usually from prostatic or breast carcinoma, the other causes of ivory vertebra include Paget’s disease and lymphoma.

Reference: Signs in Imaging, The Ivory Vertebra Sign. RSNA Radiology, May 2005,  Volume 235, Issue 2.