Hair-on-End Sign on Skull CT: A Classic Imaging Manifestation of Sickle Cell Disease Every Radiologist Should Recognize
Hair-on-End Sign on Skull CT: When the Skull Reveals Chronic Hemolytic Anemia A Rare Radiologic Clue That Should Never Be Missed Most radiologic signs are subtle. Some, however, are unforgettable. One of the most striking examples is the Hair-on-End Sign , a skull imaging appearance in which vertical bony trabeculae project outward from the calvarium, creating the impression of hair standing upright. Although uncommon in modern clinical practice, this imaging finding remains a classic indicator of long-standing bone marrow hyperplasia , particularly in patients with chronic hemolytic anemia. Recognizing this pattern is far more than identifying an interesting radiologic curiosity. It can provide a critical diagnostic clue that immediately directs clinicians toward underlying hematologic disorders such as sickle cell disease or thalassemia major , sometimes before laboratory confirmation is complete. Clinical Case A 35-year-old man with a known history of sickle cell disease pres...