Abstract: To compare the diagnostic efficacy of X-ray, CT and MRI in diagnosing primary bone tumors of extremities, 92 patients with primary bone tumors of the extremities who were admitted to our hospital were retrospectively collected. The results showed that in the 92 patients, primary bone tumors on humeral was 9.78% (9/92), on the ulna and radius were 7.61% (7/92), on the hand bone was 5.43% (5/92), on the scapula and clavicle were 2.17% (2/92), on the femur was 38.04% (35/92), on the tibia and fibula were 17.39% (16/92), on the foot bone was 5.43% (5/92), and on the hip bone was 14.13% (13/92). X-ray imaging with bone hyperplasia, sclerosis and periosteal reaction was better, counting for 85.87% and 57.61% respectively; CT imaging with bone hyperplasia, sclerosis, soft tissue mass and periosteal reaction was better, counting for 92.39%、66.30%、85.87%, respectively. MRI was better for soft tissue mass, bone hyperplasia, sclerosis, periosteal reaction, and bone marrow edema, counting for 94.57%, 82.61%, 64.13% and 22.83% respectively. Among the 92 cases of primary bone tumors of extremities, the X-ray diagnosis with malignant tumors sensitivity was 94.57%, which was lower than the CT(95.65%) and MRI (97.83%). The X-ray specificity was 82.14%, which was lower than the 89.29% of CT and MRI. The area under the ROC curve of X-ray and CT were 0.767 and 0.855, respectively, which were lower than the area under the ROC curve of MRI(0.942). This paper showed that X-ray films, CT and MRI have advantages in the diagnosis for primary bone tumors of the extremities. Although the sensitivity, specificity and accuracy of MRI are high, the three methods can be effectively combined to locate the qualitative diagnosis better, and avoid misdiagnosis and missed diagnosis.

Key words: primary bone tumor, X-ray film, CT, MRI