What are the HU parameters for brain and subdural windows?
Brain window - centre 40HU; window 76HU. Subdural window - centre 80HU; window 200HU.
Right frontoparietal craniotomy noted. Underlying the the flap is an extra- axial collection measuring up to 6.5mm that is high-density (*95HU) and most likely represents acute blood. At the inferior aspect of the surgical resection cavity is some high-density material measuring 25 x 13mm, which represents parenchymal haemorrhage. Mass effect evidence by right cortical sulcal effacement and right-to-left midline shift of 3mm, which is stable. Ventricular size is unchanged. Right frontoparietal subcutaneous haematoma and gas.