Magnetic resonance imaging of acute intracerebral hematomas: in vivo and in vitro studies.

The mechanisms causing unclear differentiation of ICH in the acute phase by MRI are discussed. The increase of the hemoglobin concentration in the hematoma, caused by loss of the plasma component directly after onset, is one of the reasons for the shortening of relaxation times. The clotting system is also responsible for this shortening. Thus, the hematoma reaches the same intensity as the brain in the acute stage. Although knowledge from our animal experiments, in vivo as well as in vitro, cannot be directly transferred to the human, such experiments are useful for the understanding of the pathomechanism influencing MR imaging.