Extramedullary paraspinal hematopoiesis in thalassemia: CT and MRI evaluation.

We present a comparative CT and MRI study of the paraspinal extramedullary hematopoiesis in 32 thalassemic patients. The patients were classified into four groups according to the MRI and CT imaging findings. Active recent extramedullary paraspinal hematopoietic masses show soft tissue behavior in both CT and MRI. Older inactive masses reveal iron deposition or fatty replacement. Combined imaging findings of paraspinal extramedullary hematopoiesis revealed the phase of its evolution and the correct diagnosis.