This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Liver, Subject name: Surgery
[{'content': 'In high risk population, HCC is best detected by: \nSelect and explain. \nA. USG, B. CT, C. MRI, D. PET scan', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) USGRadiological Investigations for HCC:Imaging Investigation of Choice- Triple Phase CECT abdomenClassical features are:* Arterial Hyper vascularization* Early Wash out in Venous PhaseSmall HCC in Three phases is shown here. See the enhancement in arterial phase and wash out in Venous PhaseHCC Confirmation: (As per NCCN guidelines 2015)* For lesions 1-2cm: 2 Imaging techniques (CECT and MRI)* Focal Lesions >2cm: One imaging technique with Arterial Hyper vascularization and venous wash out is enough.* Screening is based on USG Scanning of High risk population (Like HBV induced Cirrhosis)* Biopsy is not required to prove its an HCC. (INFACT MUST NOT BE TAKEN)', 'role': 'assistant'}]