This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ULTRASOUND, Subject name: Radiology
Duplex ultrasound is a combination of 
Select and explain. 
A. A mode and pulse wave doppler, B. B mode and pulse wave doppler, C. M mode and spectral doppler, D. 3D USG and Elastography
B: B mode and pulse wave doppler
Answer: B: B mode and pulse wave doppler 
Explanation: Duplex Scan Combination of B-mode imaging with Pulsed Doppler USG - gives both anatomical & physiological information of vascular system. Colour Duplex Scan Addition of colour frequency mapping - Colour Duplex imaging.