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Parvati Ramchandani, MD

Genitourinary Fluoroscopic 

examinations

  1.  What are genitourinary fluoroscopic examinations?

Genitourinary fluoroscopic examinations are studies that require “real-time” observation using fluoroscopy so 

that maximal information is obtained about the anatomy of the structure being studied; some studies also provide 

physiologic information about function. Contrast agent is injected into the various portions of the urinary tract for these 

examinations. Examples are retrograde pyelograms for evaluation of the upper urinary tract, cystogram or voiding 

cystourethrogram (VCUG) to evaluate the lower urinary tract, retrograde urethrogram (RUG) to evaluate the urethra, and 

hysterosalpingogram to evaluate the uterus and fallopian tubes.

  2.  How are retrograde pyelograms and intravenous urograms (IVUs) different? Do they 

provide the same information?

For a retrograde pyelogram, cystoscopy is performed (most often by a urologist), and a catheter is placed into the 

renal pelvis. Contrast agent is injected through this catheter under fluoroscopic guidance to evaluate the lumen of the 

pyelocalyceal system and the ureter for mucosal abnormalities, such as transitional cell carcinoma.

As discussed in Chapter 21, IVU requires intravenous administration of contrast agent, and it provides physiologic 

information about the function of the kidney, in addition to depicting the anatomy of the renal parenchyma and the 

collecting systems. A retrograde pyelogram provides only anatomic information about the lumen of the collecting 

system, but the depiction of the anatomy is superior to that seen with IVU.

A retrograde pyelogram is performed if the patient cannot 

receive an intravenous contrast agent because of renal 

insufficiency or a history of severe contrast agent allergy. 

Retrograde examination can also be performed if IVU fails 

to show the entire pyelocalyceal system or ureter or to 

evaluate further an abnormality seen on IVU.

3.   What is the difference between a 

cystogram and VCUG?

A cystogram is tailored to evaluate the urinary 

bladder alone, whereas VCUG includes evaluation 

of the bladder neck and urethra under fluoroscopic 

observation. Both studies require injection of 

radiographic contrast agent into the urinary bladder 

through either an indwelling bladder drainage catheter 

or a catheter placed in the urinary bladder solely for 

the procedure. A cystogram is limited to images of the 

bladder, whereas in VCUG, the catheter is removed 

after the bladder has been distended with contrast 

agent, and the patient voids under fluoroscopic 

observation so that the bladder neck and urethra can 

also be evaluated.

4.   What are the indications for cystogram 

and VCUG?

These studies can be performed to evaluate the 

anatomy of the bladder and urethra in patients with 

voiding dysfunction or recurrent urinary tract infections 

(UTIs) (

Fig. 22-1

), to look for a leak or fistula from the 

bladder after surgery or abdominal trauma (

Fig. 22-2

), 

B

D

Figure 22-1. 

Cystogram in a 70-year-old man with complaints 

of incomplete emptying. There is a large bladder diverticulum (D) 

arising from the left side of the urinary bladder (B) with a wide neck 

(single arrow). When the patient voids, contrast agent (and urine) 

fills the diverticulum and then flows back into the urinary bladder 

when voiding stops, accounting for the patient’s symptoms of 

incomplete emptying. The urine stasis in a bladder diverticulum can 

be associated with the formation of stones or recurrent UTIs. The 

double arrows point to a surgical clip in the pelvis from a previous 

surgery.

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Genitourinary tract

to evaluate vesicoureteral reflux (VUR), or to evaluate 

urinary incontinence.

  5.  Is a cystogram sensitive in excluding 

a leak from the bladder?

Yes, but only if the study is performed in the correct 

manner. It is important to distend the urinary bladder 

with contrast agent until a detrusor contraction 

occurs, which indicates that the bladder capacity 

has been reached. Otherwise, small leaks may not 

be shown. There is a great deal of variation in the 

amount of bladder filling required to produce a 

detrusor contraction, but most patients require 300 

to 600 mL of contrast agent to reach this point. A 

detrusor contraction is recognized by one of the 

following: (1) the patient voids, (2) there is resistance 

to injection of contrast agent through a hand-held 

syringe so that the barrel of the syringe starts to 

move back, or (3) flow through a contrast agent–filled 

bag 35 to 40 cm above the fluoroscopy table stops or 

reverses.

  6.  A patient is brought to the emergency 

department with blunt abdominal 

trauma and pelvic fractures. Does this patient need both an abdominopelvic 

computed tomography (CT) scan and a fluoroscopic cystogram?

No. The bladder can be distended with contrast agent on the CT table (termed CT cystogram) to evaluate for a 

leak. CT cystogram is as sensitive as a fluoroscopic cystogram, if not more so, in excluding a leak from the urinary 

bladder. Before placing a catheter in the urinary bladder in a patient with pelvic fractures, however, the urethra 

should be evaluated with RUG, and a catheter should be advanced through the urethra only if there is no urethral 

injury. Failure to follow this sequence could cause a partial urethral injury to become a complete urethral disruption.

  7.  Why is VUR important? How is it shown?

VUR in children can cause recurrent UTIs and lead to permanent renal scarring, termed reflux nephropathy. This 

condition can cause complications such as hypertension and renal insufficiency; 10% to 30% of all cases of end-stage 

renal disease may be related to reflux nephropathy. In adults, VUR has less clinical significance, although it can be 

associated with recurrent UTI and, rarely, even flank pain. VUR is reliably shown by fluoroscopically monitored VCUG. If 

the bladder is not distended to the point of voiding, VUR may not be shown. In children, radionuclide cystography is an 

alternative study to minimize the radiation exposure to pelvic organs.

  8.  What is RUG?

RUG is a study used primarily to evaluate the anterior urethra in men (

Fig. 22-3

). The male urethra is divided into 

two portions: the posterior urethra, consisting of the prostatic and membranous urethra, and the anterior urethra, 

consisting of the bulbar and pendulous urethra. The external urethral sphincter, located in the urogenital diaphragm, 

demarcates the posterior urethra from the anterior urethra. The posterior urethra has smooth muscle that relaxes when 

the detrusor muscle contracts during voiding and is best seen on VCUG. Although visualized on VCUG, the anterior 

urethra is better evaluated by RUG, which is performed by placing a Foley catheter in the tip of the penis and injecting 

contrast agent under fluoroscopic guidance. The urethra is usually opacified only to the level of the external sphincter 

on RUG because the sphincter is contracted in the nonvoiding state, and contrast agent cannot flow proximal to it.

  9.  How is the female urethra evaluated?

The entire female urethra is well shown on VCUG (

Fig. 22-4

). The short length of the female urethra makes RUG 

a difficult and unnecessary procedure in women.

 10.  What is a loopogram?

In patients who have undergone cystectomy (usually performed for muscle-invasive bladder cancer), the ureters 

are connected to a loop of ileum known as an ileal conduit. The ileal conduit is excluded from the intestinal stream 

and is connected to the anterior abdominal wall through a stoma; a urinary drainage bag is usually applied to the 

stoma site. A loopogram is performed to evaluate the conduit and the upper urinary tracts. A catheter is placed 

in the ileal conduit, and contrast agent is injected under fluoroscopic guidance until it refluxes in a retrograde 

fashion into the ureters and the pyelocalyceal systems.

B

V

Figure 22-2. 

VCUG in a 40-year-old woman with vaginal leakage 

after hysterectomy. There is a fistula (arrow) between the posterior 

aspect of the urinary bladder (B) and the vagina (V). Vesicovaginal 

fistulas can be a complication of hysterectomy; difficult vaginal 

delivery, particularly if forceps are used; cesarean section; and 

gynecologic neoplasms, such as cervical cancer.

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Genitourinary Fluoroscopic examinations

 11.  What is a hysterosalpingogram?

A hysterosalpingogram is a study to evaluate 

the uterine cavity and the fallopian tubes 

(

Fig. 22-5

). After sterile cleansing of the vaginal 

canal and the exocervix, a cannula is placed 

in the external cervical os, and contrast agent 

is injected under fluoroscopic guidance. The 

procedure is performed in women with primary 

or secondary infertility and in women with 

recurrent miscarriages.

 12.  Does magnetic resonance 

imaging (MRI) or ultrasound 

(US) examination of the pelvis 

provide the same information as 

hysterosalpingogram?

MRI and US are excellent at showing the 

uterus, but both studies are poor at showing the 

normal fallopian tubes. Dilated fallopian tubes 

(hydrosalpinx) can be identified on MRI and 

ultrasound, but abnormality in nondilated  

tubes is best seen on a hysterosalpingogram 

(

Fig. 22-6

).

 13.  If I have a female patient with a 

pelvic mass, what study would be 

helpful in further evaluation?

Either MRI or US would be useful to determine 

the organ of origin of the mass (gynecologic vs. 

nongynecologic mass, uterine vs. ovarian origin) 

and to characterize it further. Hysterosalpingogram 

has no role in this situation.

 14.  What about a postmenopausal patient with vaginal bleeding? Would 

hysterosalpingogram be helpful in evaluating the endometrium in this patient?

Endometrial abnormalities, such as endometrial hyperplasia or endometrial cancer, can cause perimenopausal/

postmenopausal bleeding and are best evaluated by transvaginal US or pelvic MRI.

A

B

Figure 22-3. 

RUG in a 30-year-old man with history of gonorrhea. 

A, The balloon of the Foley catheter (arrow) is in the tip of the penis 

and has been distended with contrast agent. The balloon is usually placed in the fossa navicularis, which is an area of natural widening 

in the glans penis. 

B, The anterior urethra is opacified with contrast agent. Multiple strictures (arrows) in the penile urethra are typical 

of inflammatory disease. The bulbar urethra is the urethral segment proximal to the arrows. The wide caliber of the proximal bulbar urethra 

is the normal appearance of this segment of the bulbar urethra.

Figure 22-4. 

VCUG in a 34-year-old woman. A large pocket of contrast 

agent on the posterior aspect of the urethra represents a urethral 

diverticulum (arrows). A urethral diverticulum is usually the result of 

infection in periurethral glands, which decompress into the urethra 

and result in a communicating cavity. Patients present with postvoid 

dribbling, perineal discomfort, or recurrent UTIs.

Genitourinary Fluoroscopic examinations

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B

iBliography

[1]  N.R. Dunnick, C.M. Sandler, J.H. Newhouse, E.S. Amis (Eds.), Textbook of Uroradiology, third ed., Lippincott Williams & Wilkins, Philadelphia, 2001.

[2]  C.M. Sandler, S.M. Goldman, A. Kawashima, Lower urinary tract trauma, World J. Urol. 16 (1998) 69–75.

[3]  J.P. Vaccaro, J.M. Brody, CT cystography in the evaluation of major bladder trauma, Radiographics 20 (2000) 1373–1381.

Figure 22-5. 

Normal hysterosalpingogram in a young woman with 

primary infertility. The metal cannula within the external os is seen at 

the bottom of the figure. The uterine cavity and both fallopian tubes 

appear normal. There is contrast agent spilling from both tubes into 

the pelvic peritoneal cavity, which is a normal finding.

Figure 22-6. 

Hysterosalpingogram in a woman with a history of 

pelvic inflammatory disease. Outpouchings of contrast agent (arrows) 

are seen in the proximal portions of both fallopian tubes, a sequela of 

prior pelvic inflammatory disease. This condition is termed salpingitis 

isthmica nodosa, and it is associated with tubal dysmotility and 

infertility. This diagnosis would be difficult to make with any other 

imaging modality. The patient was advised to consider in vitro 

fertilization.

Key Points: Genitourinary Fluoroscopic Examinations

1.  Diagnosing small leaks from the urinary bladder requires adequate distention until a detrusor contraction occurs, 

regardless of whether the evaluation is performed with CT or fluoroscopy.

2.  The anterior urethra in men is better evaluated on RUG. The posterior urethra in men is better evaluated on VCUG.

3.  In a man with pelvic trauma, the urethra should be evaluated with RUG before placement of a bladder drainage 

catheter.

4.  A retrograde pyelogram is an alternative study to IVU to evaluate the urothelium in patients in whom intravenous 

contrast administration is contraindicated.

5.  A hysterosalpingogram is the most useful imaging study to evaluate the uterus and the fallopian tubes in patients 

with infertility.