Fig. 1
From: Imaging algorithm and multimodality evaluation of spinal osteoblastoma
Osteoblastoma in a 25-year-old male, Enneking stage 3 on both CT and MRI. a and b Axial CT soft tissue and bone windows show a lesion causing extensive osteolytic destruction in L4 (which mainly affects the left pedicle, traverse process and lamina) with an incomplete sclerotic rim, unclear borders, and spotted calcifications. Note the thin flares in the epidural space (arrow). c and d Axial MRI T2WI and contrast-enhanced T1WI demonstrate the flare phenomenon adjacent to the tumor, i.e., abnormal swollen soft tissues in the spinal canal compressing the dural sac (arrow) lateral to the spinous process (arrowheads), showing hyperintensity on T2WI and marked enhancement with contrast