Magnetic resonance imaging assisted with fine needle aspiration biopsy in the diagnosis of fibrosarcomas of the skull in dogs.

Five canine patients were directed to low-field magnetic resonance imaging due to different neurological defects. In each case there were heterogeneous extraaxial masses covering left or right dorsal parietal and occipital lobes that were isointense to the brain on T1-weighted Spin Echo images, isointense to hypointense to the brain on T2-weighted Fast Spin Echo sequences and hypointense to the brain on Flair sequence. After MRI study fine needle aspiration biopsy of the tumors was performed. On the basis of the cytological examination fibrosarcomas with of moderate malignancy were diagnosed.