What are the MRI characteristics of intracranial hemorrhage in the hyperacute phase (0-2 days) with respect to deoxyhemoglobin, red blood cells, and T1/T2 signal intensities?

In the hyperacute phase (0-2 days) of intracranial hemorrhage, red blood cells are intact, and deoxyhemoglobin is present. On MRI, this phase typically shows T1 isointensity to hypointensity and T2 hypointensity. Key diagnostic features include the presence of a hypointense rim on T2-weighted images. A common pitfall is confusing this with calcifications or other causes of T2 hypointensity, such as iron deposition.