Inclusion Criteria:  Adults over 19 years old Brain CT acquired Abnormal cohort: A patient diagnosed with intracranial haemorrhage after a brain CT scan Normal cohort: A normal person or a patient not diagnosed with intracranial haemorrhage after a brain CT scan  Exclusion Criteria:  Patients with brain tumor or cerebral toxoplasmosis Patients with brain abscess or brain calcification Poor or incomplete brain CT image quality