An 8-month-old boy is referred for evaluation following a urinary tract infection. Ultrasound examination of the abdomen is normal. The most appropriate investigation to evaluate his lower urinary tract is

Diagnostic imaging studies following UTI * Recommended radiological evaluation includes a combination of ultrasound abdomen, micturating urethrogram (MCU, most appropriate) and radionuclide renal scan. * Detailed radiological investigations are performed on all children: 1. Below 3-year-old with first UTI 2. Those with symptoms of pyelonephritis 3. Recurrent UTI 4. Abnormal voiding 5. Family history of UTI or hypeension. Procedure The estimated age-adjusted bladder capacity can be calculated using : linear equations: <1 year weight x 7 = capacity (mL) 2.5 x age + 38 = capacity (mL) <2 years: (age (years) + 2) x 30 = capacity (mL) 6 >2 years: ((age /2)+6) x 30 = capacity (mL) non-linear equations: (4.5 x age 0.40) x 30 = capacity Reference: GHAI Essential pediatrics, 8th edition