Signal intensity changes on MRI during the healing process of spinal Langerhans cell granulomatosis: report of two cases.

Two patients with spinal Langerhans cell granulomatosis were followed by magnetic resonance imaging, and the observed signal changes were detailed. Both patients had no neurologic abnormalities but back pain. They were treated by immobilization with a brace and bed rest. Their back pain disappeared after about a month. At the first visit, the tumorous lesions involving vertebrae showed mainly low signal intensity on T1-weighted imaging (T1WI) and high intensity on T2-weighted imaging (T2WI). They were clearly enhanced by gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA). Their original intensities changed to iso-intensities on both T1WI and T2WI without enhancement by Gd-DTPA after a year. These signal changes might indicate the healing stage of the involved vertebrae and recommend the removal of the spinal brace.