This document discusses micturating cystourethrography (MCU) and retrograde urethrography (RGU). MCU involves introducing contrast into the bladder via catheter and imaging the bladder and urethra during micturition. It is used to assess for abnormalities like vesicoureteral reflux (VUR). The document then reviews normal bladder and urethral anatomy, indications for MCU including recurrent UTI and pre-/post-operative evaluation, the technique for MCU, and findings that can be identified like VUR grade. VUR involves abnormal flow of urine from bladder to kidneys and is a common cause of UTIs in children. MCU

1. Micturating cystourethrography (MCU)
& Retrograde urethrography(RGU)
GROUP DISCUSSION
MODERATOR
Dr. SUNIL KUMAR
MD
PRESENTER
Dr. NABA KUMAR BARMAN
JR 1

2.  Urethrography refers to the radiographic
study of the urethra using iodinated
media and is generally carried out in males.
 When the urethra is studied with instillation
of contrast into the distal/anterior urethra it
has been referred to as
Retrograde urethrography (RUG)
Ascending urethrography (ASU)
 When the posterior urethra is studied
micturation, this has been referred to as
Voiding cystourethrography (VCUG)
Descending urethrography
Micturating urethrography

3. ANATOMY OF URINARY BLADDER
• Hollow, distensible, muscular organ located within the
pelvic cavity, posterior to the symphysis pubis and inferior to
the parietal peritoneum.
Shape is that of a flattened tetrahedron when empty and
round/oval when distended with fluid.
The size of the bladder varies: when filled, the upper border of
the
bladder, should not rise above the level of the lumbosacral
junction in the child and the second or third sacral segment in
the adult.
Normal bladder wall is thickness is 2-3mm in fully distended
bladder.
Apex(superoanterior portion) of the bladder attached to
anterior abdominal wall by
median umbilical ligament(remnant of urachus).
Base(posterioinferior portion) is continuous with the bladder

4. • First urge to void is felt at a bladder volume of 150ml
• Bladder capacity is between 500-600 ml.
• The max capacity of bladder is up to 1200 ml. ( F > M
).
Bladder wall consists of mucosa,
submucosa,lamina propria and smooth
muscle. The mucosa consists of multilayered
transitional epithelium and
the muscle layer consists of longitudinal and
circular muscle bundles.

5. ANATOMY OF URETHRA
In females:
Length of 3–4 cm.
In males:
20 cm in length .
It has four named regions:
 Prostatic urethra:
Is approximately 3 cm in length.
Passes through the prostate gland.
 Membranous urethra:
Is approximately 1 cm in length.
Passes through the urogenital
diaphragm.
 Bulbar urethra
From inferior aspect of urogenital
diaphragm to penoscrotal junction.
 Spongy (penile) urethra:
Passes through the length of the penis.

6. The interior of the prostatic urethra:
On the posterior wall of the prostatic
urethra there are:
• Urethral crest:
A longitudinal ridge.
• Seminal colliculus / Verumontanum:
An enlargement of the urethral crest.
( act as a normal filling defect on RGU )
• Prostatic sinus:
The groove on either side of the
seminal colliculus.
• Prostatic utricle:
A small opening on the midline
of the seminal colliculus.
• Opening of the ejaculatory duct:
One on either side of the prostatic utricle.

7. Female urethra
• This forms the Spinning top
configuration of urethra on
normal MCU.
• Widest at bladder neck.
• 4-5cms in length
• Narrowest & least distensible
at meatus.

8. SPHINCTERS OF URETHRA
• INTERNAL URETHRAL
SPHINCTER –
 involuntary in nature
• Supplied by sympathetic nerves
• It controls the neck of the bladder
& prostatic urethra above the
opening of ejaculatory ducts
• EXTERNAL URETHRAL SPHINCTER-
• voluntary in nature
• Supplied by perineal branch of the
pudendal nerve (s2-s4)
• Controls the membranous urethra & is
responsible for voluntary holding of
urine

9. The division into anterior and posterior urethra is important
in terms of pathology and in imaging the urethra: the
anterior urethra being visualised by performing a
retrograde (ascending) urethrogram and the posterior
urethra with an antegrade (descending or micturating)
urethrogram.
Normal male urethral anatomy demonstrated by (A) voiding
cystourethrography and by (B) retrograde urethrography.

10. MCU
Voiding cystourethrography (VCUG), also known
as a micturating cystourethrography (MCU), is a
fluoroscopic study of the lower urinary tract in
which contrast is introduced into the bladder via a
catheter. The purpose of the examination is to
asses the bladder, urethra, postoperative anatomy
and micturition in order to determine the presence
or absence of bladder and urethral abnormalities,
including vesicoureteral reflux (VUR).

11. Indications
 RECURRENT urinary tract infection
 dysuria
 dysfunctional voiding
 hydronephrosis and/or hydrourete
r
 bladder outlet obstruction
 haematuria
 postoperative evaluation of the
urinary tract
 trauma
 incontinence
 neurogenic dysfunction of
the bladder
 congenital anomalies of
the genitourinary tract
As per American College of Radiology (ACR) and Society for Paediatric
Radiology (SPR) guidelines clinical indications for voiding cystourethrography
include:

12. Contraindications
1) Acute urinary tract infection
2) Hypersensitivity to contrast medium
3) Pregnancy

13. Technique
 Explain the procedure to the patient
 Take written informed consent
 empty the bladder prior to the
procedure
 Sedation may be given to the
children
 Patient lies supine on the X-ray table
 Plain film of bladder region is taken

14.  The bladder is filled with contrast using an
infant feeding tube under aseptic
precautions; a Foley catheter can be used
for older children
 Intermittent screening of the patient on
fluoroscopy, while distending the bladder
with contrast, is necessary to check for a
ureterocoele or VUR
 After the bladder is filled to its capacity
(which will vary as per age of patient) the
patient is now asked to void

15. Formula for bladder capacity
 For children> 2 years
Bladder capacity in ml= ( Age[years] + 2 ) X
30
 For children< 2 years
Bladder capacity in ml= weight[kg] X 7
 Adult: around 500 ml

16.  Bladder is filled until the patient is
seen to start voiding or there is an
umcomfortable urge to micturate
 Spot radiographs of full bladder are
taken in PA & oblique projections
 After withdrawing catheter, patient is
asked to micturate
 Older children & adults are given a
urine receiver but smaller children
should be allowed to micturate onto
absorbent pads/table.

17.  Micturating film is taken
Female: AP/lateral
 Male:RAO/LAO(left anterior oblique
position
with right hip and knee flexed –
entire urethra , lower ureter)
 Finally, a post-void film is taken to
record post-void residual contrast in
bladder
 Post-void film should include whole
KUB region to demonstrate any relfux
of contrast medium that might have
occurred unnoticed into the kidneys

18. Modifications
 For stress incontinence , following additional
films are taken
1) Lateral full bladder,at rest
2) Lateral bladder, straining
3) Lateral bladder, during micturition
 For fistulae , a series of films in AP. lateral
and oblique positions may be required

19.  Causes of incomplete bladder emptying
1)Effect of sedation
2)Dysuria following catheterisation
3)Neurogenic bladder
4)Refilling of bladder from above where there
is significant VUR

20. Complications
 Due to technique
1) Urinary tract infection
2) Urethral or bladder
trauma
3) Rupture of bladder from
overdistension
 Due to contrast medium
1) Adverse reactions due
to absorbed contrast
medium
2) Contrast-induced
cystitis

21. SPECIFIC DISEASES OF THE
URINARY BLADDER
Congenital
 Bladder agenesis
 Bladder hypoplasia
 Bladder duplication
 Congenital diverticulum
of bladder
 Urachal anomalies
• Urachal sinus
• Urachal cyst
• Urachal diverticulum
• Patent urachus
 Bladder exstrophy etc.
Acquired bladder
diverticulum
 Bladder calculi
 Cystitis
 Bladder fistula
 Bladder injury
 Detrusor hyperreflexia
 Detrusor areflexia etc
Acquired

22. A 2YR OLD
CHILD H/O
RECURRENT
UTI

23. Vesico-ureteric reflux
Vesicoureteric reflux (VUR) is the term for abnormal flow of
urine from the bladder into the upper urinary tract and is
typically a problem encountered in young children.
 VCUG is indicated after a first UTI only if ultrasound reveals
hydronephrosis, scarring, or other abnormalities suggestive of
high-grade VUR or obstructive uropathy or in patients with
complex clinical conditions. VCUG is also recommended if
there is a recurrence of a febrile UTI
IDENTIFIED BY MCU
 presence and grade of VUR
 whether reflux occurs during micturition or during bladder
filling
 presence of associated anatomical anomalies

24. Etiology
• Primary Reflux:
- fundamental deficiency in the function
of the
UVJ
- bladder and ureter remain normal
- reflux occurs despite an adequately low-
pressure
urine storage profile in the bladder
- length-diameter ratio is almost always
less than
that described by Paquin
- inadequate tunnel length has greater
implication
5:1 ratio of tunnel length to ureteral
diameter
in nonrefluxing junctions ( Paquin, 1959
Secondary reflux:The cause of this form of reflux is most often from failure of
the bladder to empty properly, either due to a blockage or failure of the
bladder muscle or damage to the nerves that control normal bladder emptying
bladder dysfunction : congenital, acquired, or
behavioral

25. Anatomical causes:
- PUV’s
- Prostatomegaly
- Ureteroceles
- Ureteral duplication
• Neuro-functional causes:
- Neurogenic bladder – Spina bifida
- Infant voiding patterns
- Dysfunctional voiding
- Uninhibited bladder contractions

26. Complications of VUR:
 Recurrent UTI & consequent renal
scarring
 Reflux atrophy/nephropathy

27. Grades of VUR
 Vesicoureteric reflux (VUR) grading divides vesicoureteric reflux
according to the height of reflux up the ureters and degree of dilatation
of the ureters:
 grade 1: reflux limited to the ureter
 grade 2: reflux up to the renal pelvis
 grade 3: mild dilatation of ureter and pelvicalyceal system
 grade 4
 tortuous ureter with moderate dilatation
 blunting of fornices but preserved papillary impressions
 grade 5
 tortuous ureter with severe dilatation of ureter and pelvicalyceal
system
 loss of fornices and papillary impressions.

28. Grade 1: reflux limited to the ureter

29. Grade 2: reflux up to the renal pelvis

30. Grade 3: mild dilatation of ureter and
pelvicalyceal system

31. Grade 4 : tortuous ureter with moderate
dilatation blunting of fornices but preserved
papillary impressions

32. Grade 5: tortuous ureter with severe dilatation
of ureter and pelvicalyceal system
loss of fornices and papillary impressions.

33. Fusiform dilatation &
elongation of
proximal posterior urethra
Persist during voiding
Transverse/curvilinear filling
defect in
posterior urethra
A 2YR OLD BOY
PRESENTED WITH
DIFFICULTY IN
MICTURATION
MCU SHOWS

34. Posterior urethral valves
 Posterior urethral valves (PUVs), also referred as congenital obstructing posterior
urethral membranes (COPUM), are the most common congenital obstructive
lesion of the urethra and a common cause of obstructive uropathy in infancy.
 Congenital thick folds of mucous membrane located in the posterior urethra
(prostatic + membranous) distal to the verumontanum.
 Most common cause of severe obstructive uropathy in children.Almost exclusively
in males.
 Leading cause of end stage renal disease in boys.
 The valves (thickened mucosal folds) can be identified on VCUG or USG associated
with proximal dilatation of the posterior urethra.

35. According to Young's classification, there are
three types of posterior urethral valves
Type
Type 1
• most common
• occurs when
the two
mucosal folds
extend
anteroinferiorly
from bottom of
verumonatum
and fuse
Type
Type 2
• rare
• mucosal folds
extend along
posterolateral
urethral wall
from ureteric
orifice to
verumontanum
Type
Type 3
• circular diaphragm
with central opening
in membranous
urethra
• located below the
verumontanum and
occurs due to
abnormal canalization
of urogenital

36. Radiographic features
Ultrasound
 Bladder is typically
thick-walled and
trabeculated with an
elongated and
dilated posterior
urethra (keyhole
sign)
 Hydonephrosis (most
commonly), although
it is important to
note this is absent in
up to 10% of cases
 kidneys may be
hyperechoic with loss
of normal
corticomedullary
differentiation, a
manifestation of
renal dysplasia

37.  Voiding cystourethrogram (VCUG) is
the best imaging technique for the
diagnosis of posterior urethral valves.
The diagnosis is best made during the
micturition phase in lateral or oblique
views, such that the posterior urethra can be imaged
adequately. Findings include :
 dilatation and elongation of the posterior urethra (the equivalent of the
ultrasonographic keyhole sign)
 linear radiolucent band corresponding to the valve (only occasionally seen)
 vesicoureteral reflux (VUR): seen in 50% of patients
 bladder trabeculation / diverticula

38. Anterior urethral valve
• Rare anamoly , In most cases, the valve is in fact
the dorsal wall of a congenital urethral
diverticulum.
• Etiology - Anomalous developmental
membranes / congenital cystic dilation of
normal or accessory urethral glands
• Cusp / Iris / Semilunar shaped.
• The degree of obstruction is variable - may be
subclinical or rarely may result in severe
obstruction.
• PRESENTATION
• Infants / young children – obstruction.
• Older children – Diurnal enuresis , UTI.
Dilated proximal urethra
Normal distal urethra
AUV

39. Meatal stenosis
• Congenital narrowing of the urethral orifice /
may be caused by meatal webs.
• Can occur in both male and females.
• Associated with hypospadias.
• Acquired more common
• Presentation - Weakness of the urinary stream, and straining
during micturition.
• Diagnosis – clinical , imaging if obstructive features are present.

40. Bladder diverticulum
 Sac formed by herniation of bladder mucosa and submucosa through
muscular wall
 Mostly acquired : males .
 In the early stages, multiple small protrusions of the bladder lumen appear
between the trabeculae (sacculations).
 As they enlarge above 2 cm they become defined as diverticula
 Most found close to the ureteric orifices
 Stasis in diverticula may lead to stone formation.
 2% cases leads to carcinoma, MC tumour is Squamous cell carcinoma

41. • A wide-necked diverticulum
empties readily when the
bladder empties while A
narrow-necked diverticulum
empties slowly
• Classical symptom of double
micturition; when the patient
empties the bladder a significant
amount of urine is stored in the
diverticulum, which then empties
back into the bladder, causing a
desire to micturate almost
immediately after the first
micturition.

42. Bladder herniation
• At least 95% of bladder herniation is into
the inguinal or femoral canals
• usually small(2-3 cm)& asymptomatic
• Painful, partly obstructed micturition because the
tends to remain in normal position,
• Usually narrow neck and fill poorly on routine contrast
images
• So best seen on prone or erect films
• Most commonly is paraperitoneal in location, bladder
remaining extraperitoneal and medial to a true inguinal
hernia sac

43. Bladder stones
• Most are mixture of calcium oxalate and
calcium phosphate
• Primary : forming de novo in bladder
• Secondary : drop from kidneys
• Stasis: Bladder outlet obstruction, neurogenic bladder, bladder
diverticula
• Infection, especially Proteus mirabilis
• Foreign bodies: Nidus for stone
• Suture material, migrated IUDs
• Pubic hairs introduced by catheterization
• Usually midline with patient supine

44.  MC cause in developing countries
=>prolonged obstructed labour
 MC cause in developed countries
=>abdominal hysterectomy
 Rarely due to pelvic
malignancy, radiation ,
 Painless constant dribbling of urine
from the vagina.
 Relatively easy to demonstrate during
urography or cystography
 Lateral and oblique films best
 Vesicouterine fistulae are a rare result
of cesarean delivery
 May present with cyclic hematuria
pattern (Youseff s syndrome)
Vesicovaginal fistula

45. Bladder trauma
Causes :
 External penetrating agents (such as
bullets, stab wounds and bone
fragments)
 Internal penetrating agents (such as
cystoscopes or resectoscopes), lower
abdominal surgery or blunt trauma:
Blows to the lower abdomen, steering
wheel/seat belt
 More the bladder distension => more
severe the injury
 Clinically : Suprapubic
pain, Hematuria, Urge to void may be
present or absent
 Traditionally retrograde cystography
 Minimum 300 ml dilute(30%)
contrast
 Post drainage film important
Bladder injury
classification
 Type 1-Bladder
contusion
 Type 2-
Intraperitoneal rupture
 Type 3-Interstitial
bladder injury
 Type 4-
Extraperitoneal
rupture
a. Simple b. Complex
 Type 5-Combined
bladder injury

46. Bladder contusion : ( Type 1 )
This is commonly seen but
sometimes not classed as true
rupture, since it involves an incomplete tear of
the mucosa.
 Only finding may be pelvic hematomas
If unilateral , may displace bladder to one side
But mostly bilateral they will compress and elevate
the inferior portion of the bladder so that it looks
like an upside-down teardrop (tear drop bladder)

47. Intraperitoneal rupture (type 2)
 Occurs in approximately ~15% of
major bladder injuries, and
typically is the result of a direct
blow to the already distended
bladder.
 Cystography demonstrates
intraperitoneal contrast material
around bowel loops, between
mesenteric folds and in the
paracolic gutters.
 Treatment is surgical repair.

48. Interstitial injury (type 3)
• Very rare type
• Intramural or partial-thickness laceration with intact serosa
• Incomplete perforation; seen on either intra- or
extraperitoneal portion of bladder
• Intramural and submucosal extravasation of contrast without
transmural extension
• Subserosal rupture causes elliptical extravasation adjacent
to the bladder

49. Extraperitoneal rupture (type 4)
• Extraperitoneal rupture is the most
common type of bladder injury,
accounting for ~85% (range 80-90%)
of cases. It is usually the result of
pelvic fractures or penetrating
trauma. Cystography reveals a
variable path of extravasated
contrast material
Simple (type 4A): Flame-shaped
extravasation around bladder
Complex (type 4B): Extravasation
extends beyond the pelvis

50. Combined rupture (type 5)
 Simultaneous intraperitoneal and extraperitoneal
injury. Cystography usually demonstrates extravasation
patterns that are typical for both types of
injury.Cystography must be performed in all patients
with gross haematuria associated with pelvic fractures
 Cystography is performed after urethral injury has been
excluded and when retrograde bladder catheterization is
safe.
 The accuracy of cystography for the diagnosis of bladder
injury varies from 85% to 100%

51. Ascending urethrography (RGU)
 Retrograde urethrography is considered to be the best
initial study for urethral and periurethral imaging in men
and is indicated in the evaluation of urethral injuries,
strictures, and fistulas.

52. Indications
Urethral stricture.
Pelvic trauma
Urethral foreign body.
Urethral diverticulum.
Periurethral / prostatic abscess.
Fistula / false passages.
Urethral mucosal tumours
Post operative evaluation
 1) Acute UTI
 2)Recent urethral
instrumentation
 3)Hypersensitivity to
contrast medium
Contraindications

53. Examination
technique
 The external meatus is prepared in a standard sterile
fashion for the placement of a conventional 16- or 18-F
Foley catheter. The catheter, with both the irrigating
syringe and inflating (saline solution) syringe attached,
should be flushed before use.
 When the balloon portion of the catheter is seated in
the fossa navicularis of the penile urethra, the balloon is
inflated with 1.0–1.5 mL of saline solution while the port
is held with the free hand to partially inflate the balloon
.
 The patient is placed in a supine 45° oblique position.
The penis should be placed laterally over the proximal
thigh with moderate traction. The patient should be
reassured about the discomfort that is experienced
during balloon inflation.

54.  Then, 20–30 mL of 60% iodinated contrast material is injected under
fluoroscopic guidance so that the anterior urethra is filled.
Commonly, spasm of the external urethral sphincter will be
encountered, which prevents filling of the deep bulbar, membranous,
and prostatic urethras. Slow, gentle pressure is usually needed to
overcome this resistance.
 Spot radiographs are obtained when there is visual confirmation of
contrast material flowing into the bladder ,If properly administered,
contrast material can be seen to jet through the bladder neck into the
bladder.

55. The anterior urethra extends from its origin at
the end of the membranous urethra to the
urethral meatus. It is divided into the bulbar
(most proximal) segment and the penile
(pendulous) segment. There is usually mild
angulation of the urethra where these two
segments join at the penoscrotal junction.
Contraction or spasm of the constrictor nudae
muscle, a deep musculotendinous sling of the
bulbocavernous muscle, may cause anterior or,
less frequently, circumferential indentation of
the proximal bulbous urethra at retrograde
urethrography .
• This bulbous urethral indentation should not
be confused with urethral stricture
• Filling of the Cowper ducts should not be
misinterpreted as extravasation

56. FILMING
 Contrast medium is injected
under fluoroscopic control &
spot films are taken in
following positions:
1: 30° LAO
2: supine AP
3: 30° RAO

57. COMPLICATIONS
 Contrast reaction ( due to absorption through bladder mucosa )
 UTI
 Urethral trauma.
 Intravasation of contrast – due to use of excessive pressure in
stricture.

58. Urethral trauma
 Classified Anatomically as - Anterior - Posterior
Anterior urethral injury
 MC iatrogenic (due to instrumentation)
 May occur if pt falls on a blunt object or direct injury to
perineum
 Straddle Injury - compression of urethra against anterior
pelvic ring
Posterior urethral injury results from
 A crushing force to the pelvis
 Is associated with pelvic fractures.

59. Goldman & Sander classification
(Based on findings at retrograde urethrography)
Type I injury
Rupture of the puboprostatic ligaments which stretches the prostatic
urethra
Continuity of the urethra is maintained

60. Type II injury (15%)
The membranous urethra is torn above an intact urogenital
diaphragm, which prevents contrast material extravasation from
extending into the perineum

61. Type III injury (MC)
The membranous urethra is ruptured but the injury extends into the
proximal bulbous urethra because of laceration of the urogenital
diaphragm
Extravasation not only into the pelvic extraperitoneal space but also
into the perineum.

62. • Type IV
Bladder neck injury with extension to the urethra.

63. Type V injury
Injury to the Anterior urethra - partial or complete.
Extravasation seen to penile soft tissue.

64. Role of urethrography in stricture
• Accurately delineates the anatomy of urethra.
• Location, number and extent of the strictures
are
very well displayed
• Delineation of the bladder neck and urethra is
best
achieved on the MCU in the oblique projection.
• Secondary changes in the bladder.
• To demonstrate the VUR
• Visualisation of any associated fistulas

67. Common causes of urethral strictures include:
•infection
• gonococcal urethritis (more common)
• non-gonoccocal urethritis (less common)
•inflammatory
• balanitis xerotica obliterans
•trauma
• straddle injury (most common)
• pelvic fractures
•iatrogenic
• instrumentation
• prolonged catheterisation
• transurethral resection of the prostate
• open radical prostatectomy
• urethra reconstruction (hypospadias/epispadias)
•congenital
• uncommon
• not to be confused with posterior urethral valves
Although gonorrhoea remains the most common sexually transmitted
disease, urethral strictures are far less common than previously due to early
treatment.
Instrumentation-related strictures usually occur in the
bulbomembranous region and, less commonly, at the
penoscrotal junction

68. RUG/ASU vs VCUG/MCU
 Generally, a RUG/ASU is carried out to visualise anterior urethral
abnormalities and a VCUG/MCU for posterior urethral abnormalities.
 Additionally, although the bladder is not generally the main target of the
exam, as with a cystogram, a VCUG/MCU may be useful in detection of
bladder abnormalities and vesico-ureteric reflux (VUR).
 In a trauma situation, an RUG/ASU should be performed first. A
VCUG/MCU should not be performed first because blindly trying to
introduce a Foley catheter into the bladder in a trauma setting may lead to
creating additional urethral damage with the catheter.

69. Thank you