Retrograde urethrography and voiding cystourethrography -
modalities of choice for imaging the urethra.
RGU-Primary imaging modality for evaluating traumatic
injuries, inflammatory and stricture diseases of male urethra.
VCUG frequently used to evaluate urethral diverticula in women
USG, MRI and CT-useful for evaluating periurethral structures.
MR imaging is also accurate in the local staging of urethral
Length-17.5 to 20 cm.
Each portion is
subdivided in two parts.
Anterior urethra - from external urethral
meatus to inferior edge of the urogenital
diaphragm, coursing through the corpus
The anterior urethra is conventionally divided
- Penile (or pendulous)
- Bulbous parts(at the penoscrotal junction)
The penile portion terminates in the glans
penis to form the fossa navicularis, which is
1–1.5 cm long.
The proximal portion of the bulbous
urethra is dilated called “sump” .
Just proximal to the sump, the bulbous
urethra assumes a conical shape at the
bulbomembranous junction called “cone.”
Approx. 3.5 cm long.
Passes through the prostate slightly anterior to the
Urethral crest-longitudinal ridge of smooth muscle
that extends from bladder neck to membranous urethra
on posterior wall .
Prostatic utricle- small saccular depression which is
remnant of mullerian duct opens over urethral crest at
the centre of Verumontanum.
Just distal & lateral to utricle are the orifices of the
paired ejaculatory ducts.
1-1.5 cm long
perforate UG diaphragm
Surrounded by muscles fibers (sphincter urethrae) of
UG diaphragm( ext. sphincter)
GLANDS & DUCTS
Periurethral Littre´ glands –in ant. Urethra & are more
numerous at the dorsal aspect.
Cowper glands - lie within the urogenital diaphragm
on either side of the membranous urethra. The ducts of
the Cowper gland empty into the bulbous urethral sump.
Ejaculatory duct-on either side of orifice of prostatic
Prostatic glands-opens directly in prostatic urethra via
multiple small openings aound the verumontanum.
Radiologic anatomy of the urethra prostatic urethra (p), membranous urethra (m),
bulbous urethra (b), penile urethra (pe)
Length- 4 cm
Extends from the bladder neck at the urethrovesical
junction to the vestibule which runs downwards and
forwards embedded in the ant.wall of vagina, traverse
UG diaphragm and ends at external urethral orifice of
Many small periurethral glands open into the urethra.
Distally, these glands group together on either side of
the urethra(Skene glands) and empty through two
small ducts to either side of the external meatus.
Retrograde urethrography -Best initial study for
urethral and periurethral imaging in men and is
indicated in the evaluation of urethral injuries,
strictures and fistulas.
Straight forward, readily available, cost-effective
HOCM or LOCM 200-300, 2w0 ml
Pre-warming the contrast media will help
reduce the incidence of spasm of the external
Tilting radiography table with flouroscopy
unit & spot film device.
Foley’s catheter 8F.
Empty urinary bladder
Allergic to x-ray contrast material
Coned supine PA view of bladder base &
The pt. lies supine on x-ray table.
Using aseptic technique the tip of the catheter is
inserted so that the balloon lies in the fossa
navicularis. Lubrication is not recommended.
The patient should be reassured about the
discomfort that is experienced during balloon
Balloon is inflated with 1-2 ml of saline.
The patient is placed in a supine oblique position.
The penis should be placed laterally over the
proximal thigh with moderate traction.
Then, 20–30 ml of contrast material is injected
under fluoroscopic guidance to fill ant urethra.
Commonly spasm of the external urethral
sphincter will be encountered, which prevents
filling of the deep bulbar, membranous, and
Slow, gentle pressure is usually needed to
overcome this resistance.
Retrograde urethrogram : resistance to passage of cm at the region of ext.sphincter
resulting in dilatation of the anterior urethra d/t pressure of injection
1) 30 degrees LAO, with right leg abducted &
2) Supine PA
3) 30 degrees RAO, with left leg abducted &
Retrograde urethrography should be followed
by micturating cystourethrography to
demonstrate the proximal urethra .
Reflux of contrast medium into dilated prostatic ducts is
also better seen during micturition.
The verumontanum is seen as an ovoid filling defect in
the posterior part of the prostatic urethra.
The distal end of the verumontanum marks the
proximal boundary of the membranous urethra. This is
also the region of the external sphincter of the urethra.
The distal boundary of the membranous urethra is the
cone of the bulbar urethra.
Identification of bulbomembranous jn.
The identification of bulbomembranous junction on RGU is very
important for assessing patients with urethral disease and for
planning urologic procedures.
When the posterior urethra is optimally opacified and the
verumontanum visible, the bulbomembranous junction can be
identified 1–1.5 cm distal to the inferior margin of the
When the posterior urethra is suboptimally opacified, the
bulbomembranous junction can be arbitrarily localized where an
imaginary line connecting the inferior margins of the obturator
foramina intersects the urethra.
The anterior urethra extends from its origin at the end of the
membranous urethra to the urethral meatus.
There is usually mild angulation of the urethra where the
pedulous & bulbar segments join at the penoscrotal junction.
Contraction or spasm of the constrictor nudae muscle, a deep
musculotendinous sling of the bulbocavernous muscle, may cause
circumferential indentation of the proximal bulbous urethra. It
should not be confused with urethral stricture
The membranous urethra should not be confused with stricture.
Narrowing elsewhere in the urethra will be clearly defined as
separate from the membranous urethra and, therefore,
representative of a pathologic stricture.
If the patient is not positioned sufficiently oblique,
the bulbous urethra will appear foreshortened and
will therefore not be adequately evaluated .
Filling of the Cowper ducts should not be
misinterpreted as extravasation .
Opacification of the prostatic ducts, Cowper
ducts, and periurethral Littre´glands is often, but
not necessarily, associated with urethral
inflammatory and stricture disease.
If the integrity of the urethral mucosal lining is
disrupted by increased pressure during contrast
material injection, intravasation of contrast
material with opacification of the corpora and
draining veins may occur.
Due to contrast medium
Due to technique
Intravasation of contrast medium,esp. if excessive
presure is used to overcome stricture.
Definition: Filling the bladder with contrast
media through urethral catheter or by
percutaneous needling of bladder
suprapubically for examination of bladder and
the urethra( during voiding)- Voiding
cystourethrography (VCUG) or micturating
Excretory micturition cystourethrography
(EMCU): variation of antegrade method,
the urethra is studied after opacification of
bladder by I.V urography.
Often inadequate for study of the urethra
because of insufficient radiodensity of
bladder urine after IVU; however result can
be improved by having the patient void
against resistance e.g compress penis
between fingers during voiding.
Study of urethra during micturition
Abnormalities of bladder
Hypersensitivity to contrast media
Fever within the past 24 hours
HOCM or LOCM
Water soluble contrast media (150 mg/ml iodine) are
used, which are diluted with normal saline in 1: 3 ratio.
Flouroscopy unit with spot film device & tilting table.
In infants 5-7 F feeding tube is adequate.
Pt. micturates prior to the examination.
Coned view of the bladder.
To demonstrate vesico-ureteric reflux
Indicated almost exclusively in children
Pt. lies supine on x-ray table.
Using aseptic technique ,a catheter lubricated with
sterile gel containing LA & antiseptic is
introduced in bladder.
Residual urine is drained.
Contrast material is slowly dripped in & bladder
filling is observed by intermittent flouroscopy
Initial filling should be monitered by flouroscopy
as catheter may be in ureter(mimick vesico-
ureteric reflux) or vagina.
Any reflux is recorded on spot films.
The catheter should not be removed until the
radiologist is convinced that the patient will
micturate or until no more contrast media will
drip into the bladder.
Older children & adults are given urine
receiver while small children are allowed to
micturate onto absorbent pads on which
Children can lie on table but adults will find
it easier to micturate while standing erect.
In pt. of neuropathic bladder ,micturition can be
accomplished by surapubic pressure.
Spot films are taken during micturition & any reflux
Lower ureter is best seen in anterior oblique position of
Finally a full length view of the abdomen is taken to
demonstrate any reflux of contrast medium that might
have occurred unnoticed into the kidneys & to record
post micturition volume.
To demonstrate vesico-vaginal or
Same procedure but films are taken in lateral
To demonstrate stress incontinence
Same procedure but catheter is left in situ until the
pt. is in erect position
It should include sacrum & symphysis pubis b’coz
bony landmarks are used to assess bladder neck
1. Lateral bladder
2. Lateral bladder,straining
The catheter is then removed.
3. Lateral bladder during micturition.
Normal antegrade urethrogram . The mild areas of narrowing and dilation are
normal. On an antegrade study, unlike a retrograde examination, the proximal
urethral is distended and readily assessed. No evidence of stricture or
extravasation is seen.
Normal female VCUG. Note the smooth contour
of the urinary bladder and the short, conical
Pt. & parents of children should be warned that
dysuria, possibly leading to retention of urine
may rarely occur. In such cases analgesic should
be given & children may be helped by allowing
them to micturite in warm bath.
If reflux is present, antibiotics should be
Due to contrast medium
Contrast medium induced cystitis.
Due to the technique
Catheter trauma-dysuria, increased frequency of
micturation, hematuria & urinary retention.
Complication of bladder filling-perforation from
overdistention, prevented by using non-retaining catheter
Retention of a foley cathter.
Best investigation for Vesico ureteric reflux ?
c. retrograde pyelogram
Posterior urethra is best diagnosed by ?
a. CT cystogram
b. voiding cystogram
c. retrograde urethrogram
d. static cystogram
Identify the defect in MCUG study, marked
Narrowest and least distensible part of the
urethra is ?
a. prostratic urethra
b. membranous urethra
c. bulbous urethra
d. pendulous urethra
which of the following are incorrect regarding ducts
that open into urethra;
A. Glands of littre: penile urethra
B. Ejaculatory duct: prostatic urethra
C. Skene glands: female urethra
D. Cowper’s duct: membranous urethra