There is a predominantly hyperdense left cerebral convexity subdural hematoma. Near the vertex, there is a layering hematocrit level, typically seen in the setting of either active bleeding or coagulopathy. The hematoma results in mass effect as evidenced by effacement of the left lateral ventricle compared to the right and midline shift.
The hematoma has components along the left tentorium (red arrow) and the falx (green arrow). These are nicely seen on the coronal reformations from the thin section data but can also be seen on the axial images.