Diffusion- and Perfusion-weighted MRI Studies Just Before and After Removal of Hypertensive Putaminal Hematoma: Case Report

It has been suspected that a zone of perihematomal ischemia analogous to an ischemic penumbra exists in patients with subacute putaminal hemorrhage who showed transient neurological improvement with hyperbaric oxygenation therapy (HBO). A 54-year-old woman, who suffered from left putaminal hemorrhage, was examined for regional hemodynamics in the perihematomal region just before and just after the removal of putaminal hematoma in the subacute period by diffusion and perfusion MRI. The pyramidal tract adjacent to the hematoma was intact in three-dimensional anisotropy contrast (3DAC) MRI, the perihematomal region increased apparent diffusion coefficient (ADC) values and decreased cerebral blood flow (CBF) and cerebral blood volume (CBV) was visualized, but mean transit time (MTT) was slightly increased just before the operation. Just after removal of the hematoma, increasing ADC values, CBF and CBV were demonstrated in the peri- hematomal region. The increased MTT suggested the vasodilatation of perihematomal region after hematoma removal. This case revealed that the perihematomal hypoperfusion (penumbra) in the subacute period probably existed as a consequence of reduced metabolic demand and compression of hematoma rather than a sign of ischemia, but after decompression of tissues adjacent to hematoma the hyperperfusion resulted from vasodilatation in the perihematomal region.