Voiding Cystourethrogram

What it does

Voiding Cystourethrogram reads the fluoroscopy images of a VCUG (micturating cystourethrogram), the standard test for vesicoureteral reflux in children after a urinary tract infection or with hydronephrosis on ultrasound. Upload the images or runs from the filling, voiding and post-void phases.

The run looks at each side separately: whether contrast refluxes from the bladder into the ureter, how far it reaches, and how much the ureter, pelvis and calyces dilate. It returns a reflux grade from I to V for the left and the right side, with the frames that show the highest grade, so that the grade can be checked against the image it came from.

Intended use

Decision support for the reader who grades the reflux. VUR grading has poor agreement between readers, and in many hospitals the films are read by general radiologists rather than paediatric radiologists. A per-side grade, tied to the frames that justify it, gives the report a consistent grade and a baseline for comparison at follow-up.

Who it is for

Paediatric and general radiologists, paediatric urologists, paediatric nephrologists and paediatricians who follow children with recurrent urinary tract infection. Developers can add structured reflux grading to a fluoroscopy archive or a paediatric urology registry.

Accepted input

• DICOM X-Ray Radiofluoroscopic images and runs, including Enhanced XRF multi-frame objects.
• Last-image-hold and spot images, or cine runs, from each phase of the study.
• Upload every phase of one examination together as a single study.

Requirements

Requirement	Why
Images from the filling and voiding phases	Some reflux appears only during voiding
Both renal areas in the field when reflux is present	Grades II to V depend on filling and dilatation of the pelvis and calyces
Image laterality or orientation markers	The grade is reported per side
Post-void image	Shows drainage of refluxed contrast

Oblique projections, transient reflux seen on a single frame and catheter artefacts are noted where they affect a grade.

Optional context

Age, the indication (febrile UTI, antenatal hydronephrosis, follow-up of known reflux) and earlier grades can be given in clinical_context; a prior VCUG in prior_files allows the grade to be compared.

The result

One JSON result whose reflux section carries a per-side classification with the key frames behind it.

Section	Content
Reflux grade	Per-side vesicoureteral reflux present or absent, grade I–V and the frames showing the highest grade
Draft report	Opt-in (options.report): an English narrative that interprets the result for the reader (findings, impression, limitations); every number is checked against the findings

Standards

• Grading: International Reflux Study classification of vesicoureteral reflux, grades I to V.
• DICOM: SR with the per-side classification, GSPS marking the refluxing system on the key frames, Encapsulated PDF.
• Terminology: SNOMED CT for the diagnosis and RadLex for anatomy.

The International Reflux Study grades

Grade	Meaning
I	Reflux into the ureter only
II	Reflux into the ureter, pelvis and calyces without dilatation
III	Mild or moderate dilatation of the ureter and pelvis; no or slight blunting of the fornices
IV	Moderate dilatation and tortuosity of the ureter, pelvis and calyces; sharp fornices obliterated, papillary impressions kept in most calyces
V	Gross dilatation and tortuosity of the ureter, pelvis and calyces; papillary impressions lost in most calyces