The imaging features of surrounding changes caused by bone tumors and tumor-like lesions

Objective: To explore the imaging features of bone marrow edema (BME) and soft tissue edema (STE) caused by bone tumors and tumor-like lesions. Methods: Ninety nine patients with bone tumors and tumor-like lesions which were proved by surgical pathology were reviewed. The patients were divided into benign and malignant groups. Evaluation parameters included the size and signal intensity of BME and STE, the features of enhancement, the bone sclerosis and its relation with BME, and joint effusion, et al. The data of two groups were analyzed by χ2 test. Results: There were 40 patients in benign group and 59 patients belonged to malignant group. BME and STE demonstrated low signal on T1-weighted images and high signal on fat-suppressed T2-weighted images. Some BMEs demonstrated low signal on T2- weighted images, which corresponded to sclerosis on X-ray film and (or) CT. Both BME and STE demonstrated uniform enhancement. There were statistically significant differences between benign and malignant groups including the frequency of BME, sclerosis, the median of the size of the BME and STE (P<0.05), which were 57.5% (23/40), 25.0% (10/40), 2.7 cm, 1.3 cm, and 32.2% (19/59), 3.4% (2/59), 1.6 cm, 1.7 cm respectively. No significant differences between the frequency of STE, joint effusion in 2 groups (P>0.05). Conclusions: Both benign bone tumors and tumor-like lesions and malignant bone tumors can be accompanied by BME and STE. The size of BME in the benign bone tumors and tumor-like lesions is bigger than those in malignant ones, and the size of STE in malignant bone tumors is bigger than benign ones. (authors)