This week's #xrayoftheweek is this single axial slice from a spine MRI study. Two questions:
(1) Can you see an animal in this image? I can see a cat!
(2) What is the actual name of the sign seen here and what is it due to?
This sign is called the "draped curtains" sign. There is an intermediate to high signal intensity lesion growing in the posterior part of the vertebral body, and pushing into the spinal canal and causing cord compression. The lesion has a bilobed appearance, with a low signal central cleft. This is caused by the strong attachment of the posterior longitudinal ligament to the back of the vertebral body - so the lesion grows into the spinal canal around the ligament attachment, giving a bilobed, or "draped curtains" appearance. The lesion is metastatic disease.