Introduction/Objectives. Osteosarcoma (OS) is the most common primary
malignant bone tumor in adolescents and young adults, with a tendency to
produce variable amounts of osteoid, cartilage, and fibrous matrices. The
objective of this study is to differentiate between osteosarcoma subtypes
osteoblastic and chondroblastic according to their magnetic resonance (MR)
signal intensities and X-ray findings. Methods. We performed a
retrospective analysis for 21 pathologically proven osteosarcoma subtypes:
osteoblastic (n = 14) and chondroblastic (n = 7). Conventional images of the
bone of origin, periosteal reactions, lytic and sclerotic features, the
presence of calcification, and pathological fractures were investigated with
X-rays. We measured the mean ROI values for each lesion with MRI sequences.
Results. Among the osteosarcoma lesions, 57% were localized at the knee.
X-ray evaluations of the osteoblastic osteosarcomas revealed pure lytic
lesions in 35.7% and pure sclerotic lesions in 35.7%. Chondroblastic
osteosarcomas revealed pure lytic lesions in 14.3% and pure sclerotic
lesions in 42.9%. Due to variable osteoblastic, chondroblastic, and
fibroblastic areas and proportions of the ossified matrix, osteosarcoma
lesions have a heterogeneous MR signal. However, no statistically
significant value was detected. Conclusion. According to our results, MRI
signal characteristics and X-ray findings may not be able to distinguish
osteosarcoma subtypes, so prospective studies with larger patient cohorts
are needed.