Combination of extremity computed tomography angiography and abdominal imaging in patients with musculoskeletal tumors

PURPOSE: To introduce a comprehensive computed tomography (CT) protocol for the evaluation of patients with musculoskeletal tumors by combining extremity CT angiography and abdomen CT in a dynamic multidetector CT study. METHODS: Single contrast bolus was used for each study in 4 patients with musculoskeletal tumors involving the lower extremities. Extremity CT angiography and abdominal CT were acquired sequentially by 4-channel multidetector CT. Technical parameters for extremity CT angiography were as follows: detector collimation, 4 mm x 1 mm; pitch, 1.75; slice thickness, 1.25 mm; reconstruction interval, 1 mm; coverage, 42 cm; and table speed, 14 mm/s. Thick and thin maximum intensity projections, volume renderings, and multiplanar reformats with or without bone subtraction were used to display vascular supply of the extremity mass and adjacent vascular structures. RESULTS: Satisfactory images of the extremity arterial system and abdomen were obtained in all patients. The mean delay time for CT angiography was 25 seconds. Extremity CT angiography demonstrated feeding arteries of a fibular giant cell tumor and a large lymphomatous mass. The same protocol was used for the evaluation of a distal tibial osteosarcoma and a fibular chondrosarcoma. In 2 patients, early venous return was noted, indicating vascularity of the tumors. In all patients, the relation of osseus masses to adjacent vascular structures was visualized as well as the bony anatomy. CONCLUSION: Extremity CT angiography and abdominal staging CT can be combined in a single dynamic multidetector CT protocol in patients with musculoskeletal tumors, resulting in a reduction of costs, acquisition time, and contrast dose as well as an improvement in patient management. The same protocol can also be used in trauma patients.