This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Venous Disorders, Subject name: Surgery
DVT, investigation of choice is: 
Select and explain. 
A. Duplex scan, B. Plethysmography, C. Venography, D. X-ray
A: Duplex scan
Answer: A: Duplex scan 
Explanation: * USG- Anatomical delineation* Doppler- To assess vascular flow* Duplex scan - Combination of anatomical delineation and vascular flow assessment.* Duplex scan is the IOC for diagnosis of DVT and varicose veins.