What is noted in these USG images?
A valve is seen in the posterior urethra with upstream dilatation of the posterior urethra and backpressure changes in the bladder in the form of wall thickening and trabeculations with bilateral hydroureteronephrosis.
What will be the next imaging modality of investigation?
VCUG (voiding cystourethrography) to look for posterior urethral dilatation, valve and vesicoureteric reflux.
What is the imaging protocol for urinary tract infections?
Current recommendation is that all infants with urinary tract infection should have a ultrasonography, followed by MCU and DMSA scintigraphy. In older children (1-5 year old) with abnormal scintigraphy or abnormal ultrasound showing reflux or urinary tract anamolies MCU is advised. Older children (more than 5 years) are initially evaluated with ultrasound and then further evaluated if the ultrasound is abnormal. Children with recurrent UTI at any age need to have detailed imaging with ultrasonography, MCU and DMSA scintigraphy. Ultrasound done as early as possible after the diagnosis of UTI. MCU is recommended 2-3 weeks later. DMSA acan is recommended 2-3 months after treatment. (Revised Statement on Management of Urinary Tract Infections, Vijayakumar, Indian Society of Pediatric Nephrology, Indian Pediatr 2011;48: 709-717).
MCU image shows thickened and trabeculated bladder with dilated posterior urethra giving a "spinning top" appearance. On the video recording, posterior urethral valve shows a diaphragm like appearance on the MCU with a thin anterior urinary stream.