Hemorrhagic necrosis and vascular injury in carbon monoxide poisoning: MR demonstration.

MR imaging of a patient 3-years status post-carbon monoxide (CO) poisoning revealed areas of abnormal signal bilaterally in the region of the globus pallidus that had shorter T1 characteristics and longer T2 characteristics than cerebrospinal fluid, probably representing methemoglobin, and that is surrounded by a rim of decreased signal on T2-weighted images, felt to represent hemosiderin. This case demonstrates characteristic findings on MR imaging of CO poisoning, as well as observations that suggest prior focal hemorrhage. Typical findings, neuropathology, and the role of vascular injury and prognosis are discussed.