Assessing Vascularity of Osseous Spinal Metastases with Dual-Energy CT-DSA: A Pilot Study Compared with Catheter Angiography

A 68-year-old male patient with hepatocellular carcinoma with a hypervascular bony metastasis in the T10 vertebral body. A, Coronal 40-keV monoenergetic image of the late arterial phase shows a T10 vertebral body osteolytic lesion with a pathologic compression fracture. B, Coronal 40-keV subtracted CTA after registration shows that the T10 vertebral body had been replaced by a metastatic tumor with avid enhancement stronger than that of the marrow in the adjacent vertebral body. An earlier segmental draining vein (white arrow) parallel to the segmental artery is shown for comparison with a single enhancing segmental artery at the adjacent normal level. C, Color-coded display of the subtracted images demonstrates the degree of enhancement more clearly. The color map is set to a 10-stepped scale with 10% increments for each step to assist in visual grading. D, Frontal view of DSA at the same level shows a typical hypervascular bone metastasis. Early venous drainage to a hemizygous vein is noted (arrowheads), indicating arteriovenous shunting within the metastatic lesion. A smaller part of the vertebral body supplied by the left segmental artery is not opacified in this DSA image. E, Iodine map derived from the material decomposition algorithm shows falsely high iodine content in normal bone marrow. The map failed to demonstrate the expected enhancement difference between the tumor and normal bone marrow because of limitations of the dual-energy CT iodine-based material decomposition in bony tissue.