Scrotum

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Scrotum
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Scrotum

• Ultrasound is the imaging modality of choice
• High frequency ultrasound imaging combined with
  color and spectral Doppler provide valuable
  information in assessment of scrotal pain or a
  mass

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Scrotum

• Color Doppler has a central role in the
  evaluation of a suspected testicular torsion by
  demonstrating the absence of flow
• Color Doppler has plays a role in evaluating
  testicular infection
• Imaging helps differentiate between
  extratesticular masses and intratesticular masses
• Helps determine cystic vs solid masses

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Anatomy

• Scrotum
• Sac of skin continuous with the abdomen
• Contains the testicles, epididymis, vas deferens
  and spermatic cord
• Divided into two compartments by the medium raphe

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Anatomy

• Testes
• Symmetric, oval shaped glands residing in the
  scrotum
• 3-5 cm in length
• 2-4 cm in width
• Approx 3 cm in height
• Decrease in size with age

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Anatomy

• Testes
• Completely covered by a dense fibrous tissue
  called the tunica albuginea
• Mediastinum testis septum reflected into the
  tesis from the posterior aspect of the tunica
  albuginea
• Supports the vessels and ducts coursing within
  the testis
• Seen as a bright line coursing longitudinally
  within the testes

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Anatomy

• Testes
• Mediastinum Testis

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Sonographic appearance

• Testes
• Tunica vaginalis
• Lines the inner walls of the scrotum covering
  each testis and epididymis
• Consists of two layers
• Parietal inner lining of the scrotal wall
• Visceral surrounds the testis and epididymis
• The space between these two layers is where
  hydroceles form.
• It is normal to see a small amount of fluid in
  this space
• There is a bare area posterior where the testicle
  is against the scrotal wall, preventing torsion
• Blood vessels, lymphatics, nerves and spermatic
  ducts travel through this area

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Anatomy

• Epididymis
• A 6-7 cm tubular structure beginning superiorly
  and then coursing posterolateral to the testis
• Divided into
• Head
• Body
• Tail

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Anatomy

• Epididymis - Head
• Largest portion of epididymis (6-15 mm in width)
• Located superior to the upper pole of the testis
• Contains 10-15 efferent ductules from the rete
  testis which converge to form a single duct in
  the body and tail
• This duct is the ductus epididymis and becomes
  the vas deferens and continues in the spermatic
  cord
• Epididymal appendix a small protuberance which
  may be seen from the epididymal head

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Anatomy

• Epididymis Body
• Much smaller than the head
• Difficult to see with ultrasound if no
  abnormalities are present
• Follows the posterolateral aspect of the testis
  from the upper to lower pole

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Anatomy

• Epididymis Tail
• Slightly larger than the body
• Positioned posterior to the lower pole

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Anatomy

• Epididymis

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Sonographic Appeance

• Testes
• Appears sonographically as smooth medium gray
  structures with a fine echo texture

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Sonographic appearance

• Testes

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Sonographic appearance

• Testes

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Sonographic Appearance

• Epididymis
• Isoechoic or hypoechoic compared with the testis
• Coarse echotexture

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Sonographic Appearance

• Epididymis

Head of the epididymis white Body of the
epididymis black
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Sonographic Appearance

• Rete Testis
• Tiny tubules adjacent to the epididymal head

Transverse image showing the rete testis
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Sonographic Appearance

• Appendix Testes
• Located on the upper pole of the testis
• Located between the testis and epididymis

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Scanning Protocol

• Positioning
• Supine position
• Penis is positioned on the abdomen and covered
  with a towel
• Patient is asked to lift scrotum and cross his
  legs with thighs close together to provide
  support for the scrotum or palce a rolled up
  towel under scrotum for support.

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Scanning Protocol

• Exam is always bilateral
• The size, shape, contour and echogenicity of each
  organ is evaluated
• The testicular parenchyma should be uniform with
  equal echogenicity between the two sides
• Color Doppler is used to assess flow to the
  testicles and epididymis

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Scanning Protocol

• Longitudinal images
• Mid testis with longitudinal measurement
• Medial testis
• Lateral testis
• Superior testis showing the epididymal head

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Scanning Protocol

• Transverse images
• Mid testis with AP and transverse mesurement
• Superior testis
• Inferior testis
• Epididymal head
• Transverse image of both testicles in the same
  image to compare echogenicity

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Scanning Protocol

• Transverse images
• Doppler images
• Color Doppler of epididymal head
• Color Doppler of mid testis
• Spectral Doppler of artery
• Spectral Doppler of vein
• Doppler protocols may vary between offices and
  depending on reason for exam

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Prostate

• Surrounds proximal urethra
• Four zones of the prostate
• Peripheral- 70
• Central- 25
• Transition- 5
• Periurethal- 1

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Prostate

• Peripheral Zone- posterior, lateral and apical
  portions- homogenous and isoechoic
• Central Zone- base of gland surrounds ejaculatory
  duct- more echogenic than peripheral.
• Transition lat. To prox. Uretheral segment-area
  common for hyperplasia.

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Assignment

• There will be quiz next week over todays material

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Reference

• Textbook of Diagnostic Ultrasonography 6th
  edition
• Hagen-Ansert