Equipment
It is important to have all of the following for cystography:
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Sterile gloves
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Lead aprons and thyroid shields for all personnel
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Sterile catheterization kit with all necessary tubing and tape to secure it in place
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Intravenous (IV) pole
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Urethral catheter – In children, a 5- or 8-French pediatric feeding tube may be used
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Fluoroscope
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Contrast medium – For children, this should be at body temperature to avoid stimulating temperature-sensitive receptors in the mucosa that can alter detrusor muscle tone
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Urodynamics equipment – Specialized urethral catheters and pressure transducers
Patient Preparation
Anesthesia
Voiding cystourethrography (VCUG) can cause considerable anxiety, especially in children; the procedure can be done with sedation on a case-by-case basis. According to a systematic review, midazolam was safe and effective, with no interaction with voiding dynamics (0.5-0.6 mg/kg orally 30-45 minutes prior to the procedure or 0.2 mg/kg intranasally prior to the start of the procedure). [6]
Positioning
Urodynamic examinations are done with the patient in the usual position assumed for voiding. The VCUG position depends on the stage of the procedure and on the patient. For catheterization, the patient is supine with the legs in the “frog-leg” position. The voiding phase can be executed in the patient’s normal position for voiding, with the radiologist opting to have the patient in lateral or oblique views depending on his or her preference.
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Ureterocele. Early anteroposterior voiding cystourethrography (VCUG) demonstrates small ureterocele (left). Ureterocele had been seen at prior ultrasonography of bladder. On VCUG obtained after bladder filling (right), ureterocele is obscured by contrast material. Image courtesy of Fernbach SK, Feinstein KA, Schmidt MB. Pediatric voiding cystourethrography: a pictorial guide. Radiographics. 2000;20:155-16.
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Oblique voiding cystourethrogram obtained at left ureterovesical junction demonstrates primary vesicoureteral reflux (ie, reflux without underlying abnormality such as bladder diverticulum, neurogenic bladder, or bladder outlet obstruction). Image courtesy of Fernbach SK, Feinstein KA, Schmidt MB. Pediatric voiding cystourethrography: a pictorial guide. Radiographics. 2000;20:155-16.
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Posterior urethral valves. Oblique voiding cystourethrogram shows filling defect in the urethra with marked change in urethral caliber at level of defect, which indicates obstruction. Although catheter has remained in place during voiding, secondary changes crucial to diagnosis—trabeculated bladder, abnormally prominent bladder neck, and dilated and elongated posterior urethra—are clearly depicted. Image courtesy of Fernbach SK, Feinstein KA, Schmidt MB. Pediatric voiding cystourethrography: a pictorial guide. Radiographics. 2000;20:155-16.
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Voiding cystourethrogram (VCUG) in patient with bulbar urethral stricture. Graphics are superimposed on VCUG to show locations of prostate and external sphincter muscle (posterior urethra). Image courtesy of Joel Gelman, MD.
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Voiding cystourethrogram in patient with detrusor sphincter dyssynergia shows trabeculated bladder wall and lack of cone-shaped bladder neck during voiding.
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Postvoiding film shows no residual contrast material. Image courtesy of Radswiki.net.
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Gross anatomy of the bladder.
