This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
[{'content': 'The intensity of colour in Doppler is \nSelect and explain. \nA. Direction flow, B. Velocity of flow, C. Strength of returning echo, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Velocity of flow Colour doppler Colours are used to represent direction of flowQ towards & away from the transducer; usually red is towards & blue is away from transducer. Mn "BA or AB= Blue - Away; Red - Towards" Shades (intensity of colour) represent velocity of flowQ; the paler shades representing higher velocity. Power doppler - Is good for showing areas of flowing blood, paicularly when it is moving slowly or in small vessels; but at the expense of losing directional & velocity information.', 'role': 'assistant'}]