Previous CT a wk before the current presentation
On a recent CT scan, that was performed just a week before the patient current presentation (also for evaluation of head trauma), there was no abnormality in the left subdural space, lowering the possibility of chronic subdural hematoma. Mild subcutaneous hematoma in the left parieto-occipital area.
Based on this comparison with the previous study, a confident diagnosis of left subdural hygroma was done.