MR imaging of histiocytosis X in the central nervous system

The magnetic resonance imaging features of two cases of histiocytosis X in the hypothalamus and one in the cerebral hemispheres are described. The lesions were best seen with spin-echo technique using a long repetition time (TR = 1580 msec) and long echo time (TE = 80 msec). Sagittal images provided the best anatomicotopographic evaluation of the lesions. Comparison with computed tomography with and without contrast enhancement showed an advantage with magnetic resonance imaging.