What is the diagnosis?
In addition to the blood overlying the surface of the right cerebral hemisphere, where else is blood visible?
Along the right side of the falx and on the superior surface of the tentorium.
What effects is this collection having?
There is significant mass effect with substantial midline shift. This in turn distorts and occludes the left foramen of Munro and results in impaired outflow of the right lateral ventricle which is dilated.
Non-contrast CT of the brain demonstrates an extra-axial collection overlying the right cerebral hemisphere and layering on the right side of the falx and tentorium. There is a prominent haematocrit level. Extensive midline shift is present with dilatation of the left lateral ventricle in keeping with outflow obstruction.