This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genito Urinary System, Subject name: Radiology
Investigation of choice for torsion testis is 
Select and explain. 
A. Colour Doppler, B. MRI, C. CT, D. Routine USG
A: Colour Doppler
Answer: A: Colour Doppler 
Explanation: Ans: a) Colour Doppler [ Ref:- Sutton - 7th edition Page No:-Doppler ultrasound is the imaging of choice for torsion testis. It helps in the diagnosis of torsion by virtue of reduced vascularity ( absence or poor colour flow, reduced peak systolic velocities) compared with the unaffected side.