This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal Tubular And Obstructive Disorders, Subject name: Pediatrics
Which of the following investigation is not needed during evaluation following 1st episode of urinary tract infection on a 7 month old boy? 
Select and explain. 
A. DMSA scan, B. Ultrasound of kidney and urinary tract, C. DTPA scan, D. Micturating cystourethogram (MCU)
C: DTPA scan
Answer: C: DTPA scan 
Explanation: Evaluation following the first episode of urinary tract infection: Age < 1 yr --> USG, MCU, DMSA scan Age 1-5 yr --> USG, DMSA scan (if USG or DMSA scan is abnormal --> MCU) Age > 5 yr --> USG (if USG abnormal --> MCU & DMSA scan)