The "kissing spine" revisited.

A 46-year-old woman presented to our department with persistent low back pain, which increased by back flexion and was released by flexion. On clinical examination, localized midline lumbar tenderness was noted. MRI showed a soft tissue lesion between the adjacent spinous processes of L3 and L4. The lesion was of low signal intensity on T1-weighted images (WI) (Fig. A, arrow), and hyperintense on the T2-WI (Fig. B, arrow) and fatsuppressed (FS) T2images (Fig. C). FS T2-WI revealed also bone marrow edemaat the opposing faces of the spinous processes (Fig. C, asterisk). Based on these imaging findings, the diagnosis of Baastrup’s disease was made. The patient was treated with nonsteroidal analgetics.