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
Patient with history of tachyarrhythmias is on implantable cardioveer defibrillator. He develops shock. Best method to know the position and integrity of ICD is: 
Select and explain. 
A. CECT, B. MRI, C. USG, D. Plain radiograph
A: CECT
Answer: A: CECT 
Explanation: Ans: A. CECT (Ref Hurst 's The Hea 13/e p1050)Plain radiograph:Best method to know ICD position & integrity.ICD Lead dislodgement:Radiographically visible.Significant increase in pacing threshold /decline in electrogram amplitude.