Thalassemia
CT of the 6 years old with thalassemia showing extensive hypertrophy of the diploic spaces mostly in the maxillary walls, skull base and frontal bones. Note obliteration of the maxillary, sphenoid and frontal sinuses. Also note increased trabeculation in the diploƫ. This results from bone marrow hypertrophy due to ineffective erythropoiesis.
See also:
The Hair-on-End Sign by Margaret A. Hollar - article from Radiology
See also:
The Hair-on-End Sign by Margaret A. Hollar - article from Radiology