A powerpoint presentation on the anatomy and imaging appearances of the male urethra as well as the imaging techniques.

1. DR AIMUA H.I
RADIOLOGY RESIDENT
NATIONAL HOSPITAL, ABUJA,NIGERIA.

3. SCOPE
 Brief Gross anatomy and radiological anatomy
 Techniques of investigation
 How they complement each other

4. OUTLINE
INTRODUCTION
GROSS ANATOMY
RADIOLOGICAL ANATOMY
TECHNIQUES OF IMAGING
CONCLUSION
REFERENCES

5. INTRODUCTION
 Fibromuscular tube.
 Extends from the internal
urethral sphincter at the
neck of the bladder to the
external urethral orifice at
the tip of the penis.
 Conducts urine to the
exterior.
 Channel through which
semen is ejaculated.

6. DEVELOPMENT
The part proximal to the prostatic utricle-lower ends of
the mesonephric ducts
The rest from the pelvic and phallic parts of the
urogenital sinus and the genital tubercle
,supplemented ventrally in the penile part by the
fusion of the urogenital folds.

7. GROSS ANATOMY
 About 20cm (8 inches)
long.
 Divided into posterior and
anterior parts.
 Posterior Urethra consist
of :
 a) prostatic urethra (3cm)
 b) membranous
urethra(2cm)
 Anterior urethra consist of:
 a) bulbous urethra
 b) penile urethra

8. PROSTATIC URETHRA
 About 3-3.5cm long.
 Widest and most
distensible part.
 Traverses the ventral
portion of the prostate
gland.
 Longitudinal midline ridge
– prostatic/urethral crest.
 Crest bears a prominence
called the verumontanum,
which is oval in shape.

9. PROSTATIC URETHRA
CONTINUE
 At the centre of
verumontanum is the
prostatic utricle which
receives the ejaculatory
ducts.
 The lower part is immobile
and fixed by the
puboprostatic ligaments.
 Distal end of seminal
colliculus marks the
beginning of the
membranous urethra.

10. MEMBRANOUS URETHRA
 Traverses the urogenital
diaphragm.
 Enclosed by the external
sphinter.
 Shortest part, 1-2cm long.
 Least distensible.
 A pea shaped gland –
cowper gland

11. BULBOUS URETHRA
 Lies in the bulb of the
penis
 Extends from urogenital
diaphragm to the
penoscrotal junction
 Surrounded by the bulbous
spongiosum
 Has a localized dilatation
called the intrabulbar fossa

12. PENILE URETHRA
 Long and narrow
 Extends from the
penoscrotal junction to
external meatus
 PSJ is marked by a
suspensory ligament of the
penis causing a bend in the
urethra
 Localised dilatation-
Navicula fossa
 Surrounded by corpus
spongiosum

13. BLOOD SUPPLY
 Prostatic urethra : Inferior vesical artery – branch of
anterior division of internal iliac artery
 Membranous urethra : Bulbourethral artery
 Bulbous urethra : Bulbourethral artery , which is a branch
of Internal pudendal artery
 Penile urethral : Deep penile artery
 Venous drainage : prostatic venous plexus and dorsal vein
of the penis
 Lymphatics: Int and Ext Iliac Nodes

14. RADIOLOGICAL ANATOMY
Fluoroscopy : Retrograde Urethrography
 Micturating Cystourethrography
Sonography : Retrograde Urethrography
 Micturating Urethrography
Cross Sectional Imaging :
 CT
 MRI – Conventional/Urethrography

15. Fluoroscopic RUG
 Primary modality of
choice
 Demonstrate the anterior
urethra/ membranous
 Ant urethra seen as a
contrast opacified tubular
structure with smooth and
regular outline
 Change in course at the
penobulbar junction
 Change in calibre at the
intrabulbar fossa
Retrograde urethrogram showing
the anterior and posterior urethra
1.Balloon of foley’s catheter
2.Penile urethra
3.Bulbar urethra
4. Membranous urethra
5.Prostatic urethra

16. Fluoroscopic RUG contd
 Posterior urethra tapers from
the BMJ to the internal
sphincter
 Short membranous urethra
 Verumontanum seen as an ovoid
filling defect
 Utricle maybe filled
 P-penile
 b-Bulbar
 m-membraneous
 pr-prostatic B-Urinary bld

20. Fluoroscopic MCUG
Demonstrate the posterior urethra particularly the
prostatic urethra
Opacified bladder is seen in continuity with entire
urethra while voiding
Bladder neck funneling
Dilated prostatic urethra
Tapers at the PMJ

23. SONO- RETROGRADE
URETHROGRAPHY
To image the anterior urethra (saline
filled).
Lumen is anechoic
Echogenic smooth margin

24. Longitudinal view of the ant
urethral

29. CONTD…..

30. SUG

31. SONO -MCUG
 To image the posterior and ant
urethra while voiding
 Funneling of the bladder neck
 Luminal content of the bladder
is seen continuous with the
dilated prostatic urethra
(anechoic)
 Smooth echogenic mucosa
 Indentation of verumontanum is
seen posteriorly
 Tapering at the PMJ

32. MRI
Useful for evaluating peri-urethral
structures
For staging urethral tumours
On T1 it appears hypointense
On T2 it appears Hyperintense

33. 1) Axial T2Weighted
image through the
mid- prostate
2) Sagittal T2
weighted image
P = prostatic
urethra
M =
membranous
urethra
B = Bulbous
urethra

34. MRI
 Sagittal T2
Sag T2W MRI of the urethral
Sagittal T2 weighted image

35. CT
 The limited soft-tissue contrast on CT
depicts the urethra as isodense to adjacent
prostate and corporal tissues and therefore
indistinguishable unless it is dilated,
catheterized or contains contrast.
 Calcifications representing urethral stones
can be identified.

36. TECHNIQUES OF INVESTIGATION
 Fluoroscopic Urethrography
a) retrograde urethrography(RUG)
b) Micturating Cystourethrography (MUG)
 Sonourethrography
 MRI
1) Conventional
2) Urethrography
 CT

37. RETROGRADE URETHROGRAPHY
It refers to a special radiological
procedure for demonstrating the
urethra by a contrast medium injected
retrogradely through the urethral
catheter.
Also referred to as ;
-Ascending
urethrography/urethrogram.

38. Fluoroscopic RUG
 Better assesment of anterior urethra
 INDICATIONS
A.Congenital
-Urethral diverticulum
-Duplication of the urethra
-Epispadias/Hypospadias

39. B.Acquired
-Urethral trauma
-Infections
.strictures
.periurethral abscess/prostatic abscess
.fistulae + false passages
-Urethral tumors
-Urethral calculi
-Investigation of prostatic enlargement

40. RUG
 CONTRA-INDICATIONS
1) Acute UTI-urethritis , balanitis.
2) Recent Instrumentation
 CONTRAST MEDIUM
Pre- warmed HOCM or LOCM

41. Retrograde Urethrography contd
 EQUIPMENT
Tilting radiography table with fluoroscopic unit with
overcouch tube and spot film device.
Foleys catheter/Knutson Penile clamp
Sterile tray including disinfectant, cotton wool, sterile
water
 PATIENT PREPARATION
Consent
 PRELIMINARY FILM
Pelvic AP

42. TECHNIQUE
 Patient lies supine 45 degree oblique on x-ray table
 Catheter is prefilled with contrast medium with all air
bubbles expelled
 Aseptic technique is used for insertion of appropriate
size catheter
 Balloon is inflated – Fossa Navicularis
 With the patient lying oblique, Penis is placed laterally
over the thigh with moderate traction applied
 Contrast medium is injected under fluoroscopic
guidiance

43. Technique contd
 Spot radiographs are taken when contrast is seen flowing
into the bladder
 Views 300 LAO with right leg abducted and knee flexed
 300RAO
 Supine AP
 COMPLICATIONS
1) Due to contrast medium/ adverse rxn rare
2) Due to technique,
-Acute UTI,Urethral trauma,intravasation of
contrast medium esp if excessive pressure is used to
overcome a stricture.

44. FLUOROSCOPIC MICTURATING
CYSTOURETHROGRAPHY
 Contrast study - outlines posterior urethra during
voiding
 INDICATIONS
a) Vesicoureteric reflux
b) study of the urethra during micturation
c) Abnormalities of the bladder
d) Recurrent infection

45. MCUG Contd
 Contraindications
1) untreated urinary tract infection
2) Hypersensitivity to contrast media
3) Fever within the past 24hours
 CONTRAST MEDIUM
HOCM
LOCM
 EQUIPMENTS
1) Fluoroscopy unit with spot film
device/tilting table
2) Video recorder

46. MCUG Contd
3) Foley’s catheter
4) Feeding tube in infants(improvised)
 Preparation : patient void prior to procedure
 Preliminary Film
 * Coned view of the bladder

47. TECHNIQUE
 Patient lies supine on x-ray table
 Using aseptic technique an appropriate size catheter
lubricated with sterile gel is introduced into the
bladder
 Residual urine drained
 Use fluoroscopy to ensure catheter is well placed
 Contrast medium is slowly dripped in
 Bladder filling is observed intermittently
 Remove catheter when bladder is well filled

48. TECHNIQUE CONTD
 While standing erect oblique or in lateral position
patient micturates in a urine receiver
 Spot films are taken while voiding
 Children and infant are allowed to micturate on
absorbent pads while lying
 Suprapubic pressure maybe needed in children with
neuropathic bladder to initiate voiding

49. TECHNIQUE Contd
 VIEWS
LAO – Right hip and knee is flexed
RAO
 AFTERCARE
Analgesics / Antibiotics

50. COMPLICATIONS
 Due to contrast
1) Absorption of contrast by bladder mucosa
2) Contrast medium – induced Cystitis
 Due to technique
1) Acute UTI
2) Catheter trauma
3) Perforation of the bladder due to over distension
 4) Retention of foley’s catheter

51. SONOURETHROGRAPHY
 INDICATION
* Intraluminal mass lesions
* To evaluate stricture
i) location
ii) length and thickness
iii) Plan treatment
 Equipment
* USS machine with high frequency linear probe
(7.5Mhz), transrectal probe(5.0Mhz)

52. Anterior urethra
Technique – Sterile procedure
 Sterile water/ xylocaine gel is injected by means of
appropriate catheter
7.5MHz frequency linear probe is used
Transducer is directly applied over the ventral surface
of penis, scrotum and perineum
 Longitudinal scan is done
 Transverse scan is done to assess the lumen

53. Posterior urethra
 Transrectal USS is done using a transrectal probe
 Patient is placed in lithotomy / left decubitus position
 Longitudinal scan is done while patient voids

54. Advantages of USS over RUG
 Simple and convenient
 No risk of allergy
 No radiation involved
 It characterises anterior strictures in terms of the following:
1) length
2) diameter
3) periurethral pathology
 Intraluminal filling defect is more convincingly interpreted
 SET BACKS
Can’t demonstrate intravasation OR
reflux into prostatic and cowper's gland

55. Comparing sono RUG to fluro RUG

56. REFERENCES
 Anatomy for Diagnostic Imaging (3rd edition) by Ryan.
 Applied Radiological Anatomy 4th edition for medical
students by Paul Butler .
 Clinical Anatomy by Harold Ellis (11th edition).
 A Guide to Radiological Procedures –Chapman &
Nakielny (5th edition).