Cystography 

Updated: Aug 27, 2020
Author: Wellman W Cheung, MD, FACS; Chief Editor: Edward David Kim, MD, FACS 

Overview

Background

Cystourethrography is a radiographic examination of the bladder and the urethra, whereas cystography refers to radiographic evaluation of the bladder alone. The technique depends on contrast media being introduced into the bladder via a urethral catheter, allowing visualization of anatomic defects and workup of functional abnormalities.

Urodynamic evaluation is the standard of care for any type of voiding abnormality in order to illuminate the pathophysiology of the patient’s condition. The study guides decision-making about surgical intervention and treatment, and it indicates to physicians which patients will require closer follow-up. Videourodynamics refers to a urodynamic study with radiographic imaging and is recommended in the following settings: renal transplant, neurogenic bladder, urinary diversion, and previous irradiation or pelvic surgery.

In the setting of more advanced radiographic techniques (such as voiding urosonography), cystography may be phased out as the gold standard for imaging examination. These practice changes often depend on the setting in which they are performed. For example, retrograde computed tomography (CT) is favored in trauma workup. Despite these advances, cystography supplements urodynamic evaluation and remains prevalent as a voiding cystourethrography (VCUG) study in children.

Relevant anatomy

The bladder is a muscular organ that sits behind the pubic symphysis in the pelvis. Its function (and lack thereof) depends on a careful balance of musculoskeletal, neurologic (both autonomic and somatic), and psychological inputs that control filling and voiding. There must be coordination between detrusor muscle relaxation and contraction of the bladder neck and pelvic floor muscles, which both maintain the contents of the bladder. By the same token, detrusor contraction and sphincter relaxation facilitate the passage of urine from the bladder. Dysfunction of any part of this yin and yang results in incontinence. See the image below.

Gross anatomy of the bladder. Gross anatomy of the bladder.

For more information about the relevant anatomy, see Bladder Anatomy.

Indications

Cystography provides additional information about and elucidates a number of bladder abnormalities, such as diverticula or fistulas, in addition to leakage and traumatic rupture. In the trauma setting, cystography is indicated in cases of gross hematuria or nonacetabular pelvic fracture in the presence of microscopic hematuria of more than 25-30 red blood cells (RBCs) per high-power field. A study of bladder injuries in 157 blunt trauma patients revealed that one third of injuries would not have been detected on the basis of gross hematuria and pelvic fracture alone. Four of 12 patients studied who ultimately suffered bladder injury presented with microscopic hematuria, compared with 8 of those 12 patients with gross hematuria.[1]

Indications for VCUG include the following:

  • Follow-up evaluation of vesicoureteral reflux (VUR)

  • Hydronephrosis

  • Enuresis

  • Voiding dysfunction

  • Incontinence

  • Congenital genitourinary malformations and congenital conditions known to be associated with such malformations

VCUG has traditionally been used in patients with urinary tract infection (UTI), although the practice has come under fire with regard to pediatric patients. The American Academy of Pediatrics recommends that febrile children between 2 months and 2 years of age who do not respond to antimicrobial therapy should be evaluated with ultrasonography (US) promptly and VCUG at the next earliest convenience, whereas children of the same age group who do respond should undergo US and VCUG at the earliest convenience.[2]

A patient may undergo VCUG as soon as his or her voiding pattern has returned to baseline (pre-UTI), although clinical practice has favored waiting 3-6 weeks, with antibiotic prophylaxis given in the meantime. VCUG performed in association with a UTI is valuable in its ability to detect VUR. A retrospective study revealed there was no difference in waiting 1 week versus beyond 1 week in the VUR detection rate.[3] Of note, more than half the patients slated for the later VCUG did not undergo the study.

Routine VCUG has been recommended for patients who meet any of the following criteria[4] :

  • Children younger than 5 years with a febrile UTI

  • Males of any age with a first UTI

  • Females younger than 2 years with a febrile UTI

  • Children with recurrent UTIs

A study conducted by Dalirani et al that looked at the utility of a direct radionuclide cystography (DRNC) in children with UTI and normal VCUG results demonstrated that DRNC could uncover VUR despite the normal result in children with hydronephrosis and/or UTI with fever.[5]

 

Periprocedural Care

Equipment

It is important to have all of the following for cystography: 

  • Sterile gloves
  • Lead aprons and thyroid shields for all personnel
  • Sterile catheterization kit with all necessary tubing and tape to secure it in place 
  • Intravenous (IV) pole
  • Urethral catheter – In children, a 5- or 8-French pediatric feeding tube may be used
  • Fluoroscope 
  • 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
  • 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.

 

Technique

Contrast Examination of Bladder

Procedure

The steps in contrast examination of the bladder are as follows:

  1. Obtain an image of the abdomen and pelvis (kidneys-ureters-bladder [KUB]).
  2. Catheterize and drain the patient’s bladder using aseptic technique. Secure the catheter. A urine sample may collected at this point. 
  3. Introduce the contrast agent. An intravenous (IV) pole to suspend the contrast from above may be useful at this point to allow gravity to pull the contrast through the catheter into the bladder.
  4. Instill the contrast according to the bladder capacity of the patient. For adults: 300-400 mL. For children: (age + 2) x 30 in mL. 
  5. Obtain images in several views. Once the patient is prepared and positioned, scout films (KUB) will confirm that the patient is in position for the fluoroscope. Pulsing during fluoroscopy may skew the results by reducing exposure to radiation.

The first view is an early filling (anteroposterior [AP]) view of the bladder. In this view, an ureterocele or bladder tumor may be visualized, which may later become obscured by additional contrast material entering the bladder (see the image below).[7]

Ureterocele. Early anteroposterior voiding cystour 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.

Next, obtain full bladder (oblique) views, centered on the ureterovesical junction (UVJ). Vesicoureteral reflux (VUR) and bladder diverticula at the posterolateral UVJ can be visualized, as well as the appearance of the bladder wall at capacity (see the image below).[7]

Oblique voiding cystourethrogram obtained at left 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.

For a voiding urethra view (see the images below), turn males to the left or right anterior oblique position; females remain in the supine position (see images below). Voiding around the catheter is encouraged and will not obscure detection of posterior urethral valves.[8, 7]

Posterior urethral valves. Oblique voiding cystour 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.
Voiding cystourethrogram (VCUG) in patient with bu 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.
Voiding cystourethrogram in patient with detrusor Voiding cystourethrogram in patient with detrusor sphincter dyssynergia shows trabeculated bladder wall and lack of cone-shaped bladder neck during voiding.

Next, obtain a postvoiding (AP) bilateral renal view, centered on each renal fossa, to determine whether any contrast has reached the upper urinary tract. If a high degree of reflux is present, obtaining delayed images 15 minutes after voiding can help differentiate between simple reflux and reflux associated with an ureteropelvic or UVJ obstruction.

Finally, obtain a postvoiding (AP) bladder view to assess the degree of emptying (see the image below).[9]

Postvoiding film shows no residual contrast materi Postvoiding film shows no residual contrast material. Image courtesy of Radswiki.net.

The final images can be obtained multiple times in repeated voiding studies. Results from multiple voiding studies may be advisable to increase the likelihood of detecting VUR and having a more accurate picture of the grade of the VUR. Joaquim et al reported that of 362 cystographic examinations, VUR was detected correctly in 21% of patients in the first voiding cycle, with 5.5% and 2.5% in the second and third cycles, respectively, pointing to the utility of tracking multiple voiding cycles.[10]

At completion, the bladder is drained and the catheter is removed. For videourodynamics, the bladder is drained before insertion of the urodynamics catheter. Contrast material is infused via catheter and controlled by a pump, with the rate of contrast infusion calculated at the discretion of the radiologist.

Contraindications and Considerations

Cystography is contraindicated in the following conditions: 

  • Active clinical urinary tract infection (UTI)
  • Pregnancy
  • Allergy or sensitivity to contrast medium
  • Labial adhesions – Voiding cystourethrography (VCUG) should be performed after the adhesions have been released.
  • Severe dementia or psychosis – A worthwhile videourodynamic examination depends on the patient and the examiner being able to communicate. 

The American Urological Association’s Best Practice Policy Statement on Antimicrobial Prophylaxis recommends prophylaxis only for patients with risk factors,[11] whereas the American Heart Association no longer recommends prophylaxis for the prevention of infective endocarditis in such procedures.[12]

Special consideration must be taken when performing this procedure in spinal cord injury patients who are affected above the splanchnic sympathetic outflow tract (T5-T6). It is necessary to fill the bladder with contrast during cystourethrography and urodynamics, which can induce autonomic dysreflexia (changes include sudden, severe hypertension with diaphoresis and flushing, and compensatory bradycardia). For these patients, it is important to have a urinary catheterization kit prepared in case the bladder needs to be drained emergently. In patients with a history of autonomic dysreflexia, consider prophylactic nifedipine or an alpha-blocker, in addition to careful blood pressure monitoring.

Complications

Patients commonly experience dysuria and perineal irritation following cystography, both of which are short-lived complications and likely caused by catheterization, although hypersensitivity to the contrast as it enters the bloodstream via bladder mucosa occurs rarely. UTI is another post-procedural complication; however, the risk can be mitigated by close adherence to aseptic technique and antibiotic prophylaxis when indicated. Bladder perforation rarely occurs during cystography. Perforation risk can be minimized by paying close attention not to advance the catheter more than 1-2 cm farther after obtaining the return of urine.

On urodynamic evaluation, bladder filling may trigger a vasovagal response, which can be managed by temporarily stopping contrast instillation and having the patient lie down. Autonomic dysreflexia (discussed above) is a dangerous complication that may also ensue following bladder filling. Immediate bladder drainage is recommended, and the study must be stopped. It is helpful to have a catheterization kit and antihypertensive drugs (for persistent hypertension) in anticipation of this complication, especially in patients with known spinal cord injury.

 

Medication

Medication Summary

The goals of pharmacotherapy are to reduce anxiety, morbidity, and prevent complications.

Anxiolytics, Benzodiazepines

Class Summary

This drug class alleviates anxiety by prolonging the inhibitory effects of gamma-aminobutyrate (GABA), as well as other inhibitory neurotransmitters.

Midazolam

Midazolam is a short-acting benzodiazepine used for short-term sedation. It has been shown to be effective in reducing distress before voiding cystourethrography (VCUG) and does not interfere with the urodynamics being studied.

Antihypertensives, Other

Class Summary

Given that autonomic dysreflexia is a rare but life-threatening complication, a fast-acting antihypertensive is useful, especially if arterial pressure remains elevated after stopping the procedure.

Esmolol (Brevibloc)

Esmolol is an ultra–short-acting beta2-blocker. It is particularly useful in patients with labile arterial pressure, especially if surgery is planned, because it can be discontinued abruptly if necessary. This agent is normally used in conjunction with nitroprusside. It may be useful as a means to test beta-blocker safety and tolerance in patients with a history of obstructive pulmonary disease who are at possible risk of bronchospasm from beta-blockade. The elimination half-life of esmolol is 9 minutes.

Labetalol (Trandate)

Labetalol blocks alpha-, beta1-, and beta2-adrenergic receptor sites, decreasing blood pressure.

Propranolol (Inderal LA, InnoPran XL)

Propranolol is a class II antiarrhythmic nonselective beta-adrenergic receptor blocker. It has membrane-stabilizing activity and decreases the automaticity of contractions. Propranolol is not suitable for emergency treatment of hypertension. Do not administer propranolol intravenously in hypertensive emergencies.

Metoprolol (Lopressor, Toprol XL)

Metoprolol is a selective beta1-adrenergic receptor blocker that decreases the automaticity of contractions. During IV administration, carefully monitor the blood pressure, heart rate, and electrocardiogram (ECG). When considering conversion from intravenous to oral dosage forms, use the ratio of 1 mg IV to 2.5 mg PO metoprolol.

Nitroprusside (Nitropress)

Nitroprusside causes peripheral vasodilation by direct action on venous and arteriolar smooth muscle, thus reducing peripheral resistance. It is commonly given intravenously because of its rapid onset and short duration of action. It is easily titratable to reach the desired effect.

Nitroprusside is light sensitive; both bottle and tubing should be wrapped in aluminum foil. Before initiating nitroprusside, administer a beta-blocker to counteract the physiologic response of reflex tachycardia that occurs when nitroprusside is used alone. This physiologic response increases shear forces against the aortic wall, thus increasing arterial pressure. The objective is to keep the heart rate at 60-80 bpm.

Nifedipine (Procardia)

Nifedipine is a calcium channel blocker that can be considered in cases in which beta-blockers are contraindicated, such as in patients with chronic obstructive pulmonary disease who have known bronchospasm or those with second- or third-degree atrioventricular block.