You are re-evaluating a 3-year-old girl with cystitis whom you are treating for the second time within 6 months. She has been on amoxicillin for 7 days with complete resolution of her symptoms. Which of the following listed studies would be most likely to demonstrate the most common urinary tract abnormality that is associated with a UTI in this age group?
(A) Radionuclide cystogram
(B) Renal ultrasound
© Cystoscopy
(D) Intravenous pyelogram
(E) Urodynamic study
The answer is A, Radionuclide cystogram. Vesicoureteral reflex is the most likely urinary tract abnormality in this age group and setting. A voiding cystourethrogram is the most common initial diagnostic tool but is not used for follow-up because of the radiation exposure. A radionuclide study for reflux involves less radiation exposure and appears to be more sensitive once the fact of reflux is established. Vesicoureteral reflux is
most often secondary to UTI in women and as such is reversible with therapy. In both sexes, anatomic abnormalities, such as a short intramural ureteral segment, preclude a functional valve effect. With bladder distention the segment fails to shut off retrograde flow of urine with distention, leading to retrograde spread of infection.Females’ incidence and prevalence are significantly greater than males’. However, in males that mechanism accounts for the vast majority of reflux and upper genitourinary tract spread of infection.