SPECT images were made with Technetium labeled red blood cells. On the MR, several angiomas are seen, e.g., in the left pons and right cerebellum, as regions of mixed MR signal, suggesting that the lesions are a complex mix of tissue elements such as blood clot and scarred brain, surrounded by a halo of a crystallized old blood product, hemosiderin. These lesions fail to fill with labeled red cells, indicating that they are not open to circulating blood. Note the cerebral vessels filling with Tc-labeled red cells. In slice 9, look for the internal carotid arteries and the sigmoid and straight sinuses, comparing the MR flow voids to the Tc-labeled red cells.