This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genitourinary radiology, Subject name: Radiology
Keyhole Appearence on ultrasound is seen in 
Select and explain. 
A. Polycystic kidney, B. Hydronephrosis, C. Intracapsular Breast implant rupture., D. Posterior urethral valve
D: Posterior urethral valve
Answer: D: Posterior urethral valve 
Explanation: *Key hole appearance on antenatal scan is a feature of posterior urethral valve *Key hole appearance/linguine sign on breast MRI is a feature of intracapsular Breast implant rupture.