Applied Radiological Anatomy

Chapter 13: The male pelvis

Bladder

Seminal vesicle
Prostate
Rectal wall

Fig. 13.23 Longitudinal transrectal ultrasound showing seminal vesicle.

Fig. 13.24 Transverse transrectal ultrasound showing position of ejaculatory Suspensory
ducts (arrowed). ligament of penis
Corpus cavernosum

Corpus spongiosum

Testis (Fig. 13.26) Vas deferens
Testis
• Ovoid reproductive and endocrine organs.
• Average testicular dimensions are 5 cm (length), 2.5 cm Fig. 13.25 MR image of the male pelvis: coronal section of the perineum.

(breadth), 3 cm (anteroposterior). mediastinum testis), from whence 10–15 efferent ductules
• Each testis has an upper pole (usually tilted slightly pierce the tunica, near the upper pole, to enter the head of
the epididymis.
forwards) and a lower pole. • The appendix testis, a remnant of the Müllerian duct, is
• The left testis lies lower than the right in 85% of subjects. present in 90% of cases and may be seen as a small sessile
• The right and left testes are separated by a fibrous median projection just below the head of the epididymis

scrotal septum, which is deficient superiorly. Blood supply and lymphatic drainage
• Each testis is invested by three coats, which are from • Arterial supply:

outside inwards: · The testicular artery arises directly from the aorta at
the level of the renal artery.
· the tunica vaginalis, a remnant of the fetal processus
vaginalis, which has visceral and parietal layers · The epididymis and spermatic cord are supplied by
branches of the inferior vesical artery and inferior
· the tunica albuginea, a thick fibrous capsule, which is epigastric artery.
thickened posteriorly to form a fibrous septum known
as the mediastinum testis; fibrous septa extend from
the mediastinum into the testis, dividing it into 200–
300 seminiferous tubules

· the vasculosa contains a plexus of blood vessels and
loose connective tissue.

• The seminiferous tubules drain to the rete testis (an
anastomosing network of tubules located in the

241

Section 2: Thorax and Abdomen

A Appendix of Vas deferens
epididymis

Efferent ductules Head Epididymis
Body
Rete testis Tail
Fibrous septum
Tunica albuginea

Lobule

B Testicular a. Seminiferous
and v.
Appendix of C tubules
epididymis Vas deferens
Scrotum
Appendix of Artery and
testis veins of Tunica vaginalis
vas deferens
Upper Tunica albuginea
pole
Septum
Testis Head Epididymis Seminiferous tubules
Body
Lower Tail Rete testis
pole
Epididymis

Artery and
veins of

epidiymis
Vas deferens

Artery and
veins of

vas deferens

Fig. 13.26 Testis and epididymis. (A) Internal architecture. (B) Blood supply. (C) Transverse section.

· The scrotum is supplied by the external pudendal · Vessels coursing through the testis are often identified
branch of the femoral artery. as hypoechoic linear structures.

• Venous drainage: · The mediastinum testis can be identified as an
echogenic line posteriorly, parallel to the epididymis.
· Via the pampiniform plexus of veins above and behind
the testis, which anastomose to become one single · Occasionally the rete testis is prominent as multiple
vein at the upper end of the inguinal ring. The right anechoic tubular structures adjacent to the epididymis.
testicular vein drains into the inferior vena cava and
the left into the left renal vein. · The appendix testis may be seen, especially in the
presence of a hydrocoele.
• Lymphatic drainage:
• MRI:
· The testes drain to para-aortic lymph nodes at the level
of L1–2. · On T1W sequences, the testis is of homogeneous low
signal intensity.
· The scrotum drains to the superficial inguinal lymph
nodes. · On T2W sequences, normal testicular tissue returns
high signal intensity.
Imaging of the testis
• Ultrasound (Figs. 13.27–13.30): · The tunica albuginea, mediastinum testis and fibrous
septa are of low signal intensity on T2W sequences.

· The epididymis is of variable intensity.

· Oval structure having a homogeneously granular
echotexture with uniform medium-level echoes.

242

Chapter 13: The male pelvis

AB

Tunica
albuginea
Testis

Fig. 13.27 (A) Ultrasound of the testis: longitudinal (left) and transverse
(right) images. (B) Colour Doppler ultrasound showing normal testicular blood
flow throughout the gland.

Testis
Head of
epididymis
Mediastinum
testis

Fig. 13.28 Ultrasound of testis.

Large hydrocoele

Tunica albuginea
Testis

Appendix testis

Fig. 13.29 Ultrasound of the testis showing ectasia of the rete testis – a Fig. 13.30 Ultrasound of the testis.
normal variant.
Head of epididymis
Congenital anomalies of the testis Cyst in head of
• Congenital hydrocoele: epididymis

· a collection of fluid in the scrotum between layers Body of epididymis
of the tunica vaginalis; it may be isolated or may
communicate with the abdominal cavity through a Fig. 13.31 Ultrasound of the testis.
patent processus vaginalis.
• Has a role in the concentration, maturation and storage of
• Cryptorchidism: sperm.

· failure of one or both testes to descend into the • Each epididymis has a head at the superior pole and a tail at
scrotum; cryptorchidism affects about 3% of term the inferior pole of the testis.
infants and up to 30% of preterm infants.
• The head of the epididymis may have a small sessile
Epididymis (Fig. 13.31) projection, known as the appendix of the epididymis.

• A tightly-coiled tube, about 6 m long when unravelled,
lying posterior and lateral to the testis.

• Connects the efferent ductules from the rear of each testis
to the vas deferens.

243

Section 2: Thorax and Abdomen attach to the inferior part of the corresponding
ischiopubic ramus
Vas deferens – internally lie numerous smooth muscle-lined
interconnected sinusoids
• A muscular tube, about 30–45 cm long, connecting the – within each corpus cavernosum lies a centrally
epididymis to the ejaculatory duct. located cavernosal artery

• Extends from the tail of the epididymis through the · corpus spongiosum (ventrally)
inguinal canal and pelvis to fuse with the duct of the
seminal vesicles, to form the ejaculatory duct in the – expanded to form the bulb proximally and the
prostate gland. glans penis distally

Penis (Fig. 13.32) – the posterior part of the bulb is penetrated by the
bulbar urethra, which then runs in the corpus
• The penis consists of an attached root (radix) in the spongiosum to the external meatus.
perineum and a free, pendulous body (corpus).
• All three corpora are bound together by three surrounding
• The body of the penis comprises three cylinders of layers of fascia (from deep to superficial):
endothelium-lined erectile tissue which arise from the
perineum: · tunica albuginea (a thick fibrous capsule)
· deep fascia of the penis (Buck’s fascia)
· paired corpora cavernosa (dorsally) · superficial fascia of the penis.

– fused in the median plane but diverge
posterosuperiorly to form the crura, which

Superficial dorsal v. Dartos fascia
Deep dorsal v. Circumflex v.
Dorsal a. Sinusoidal spaces
Dorsal n. Corpus spongiosum
with urethra
Tunica albuginea
Cavernosus a. Skin
Deep (Buck’s) fascia
Septum of penis Corpus cavernosum

Fig. 13.32 Cross section of the body of the penis. Septum of penis

Fig. 13.33 Ultrasound of the penis. Tunica albuginea
Corpus spongiosum
244

Glans penis Chapter 13: The male pelvis
Corona of glans
Bladder
Rectus m. Rectum
Corpus cavernosum Prostate
Anal canal
Penile urethra Perineal body
Corpus spongiosum Body of pubis
Bulbospongiosus
Testis m.

Fig. 13.34 MR image of the penis: sagittal section through the midline. Bowel loops

Ilium Iliacus m.
Bladder
Acetabulum
Femoral head Perivesical
venous plexus
Superior Corpus cavernosum
pubic ramus Corpus spongiosum

Fig. 13.35 MR image of the pelvis: coronal section though the root of penis.

Blood supply and lymphatic drainage Imaging of the penis
• Arterial supply: • Ultrasound (Fig. 13.33):

· originates from internal pudendal arteries; paired deep · The corpora demonstrate low-level echoes.
dorsal arteries chiefly supply the glans and give off the · The urethra appears as a circular echogenic structure,
cavernosal arteries and the artery to the bulb.
with a central anechoic area, and is best seen when
• Venous drainage: distended.
· Colour flow Doppler ultrasound allows visualization
· the corpora cavernosa drain mainly via cavernous of the penile arteries, which is important in the
veins, and via the deep dorsal vein into the internal assessment of erectile dysfunction.
iliac system; increased arterial flow and sinusoidal
distension during sexual arousal compresses the • MRI (Figs. 13.34, 13.35):
draining veins, resulting in erection.
· Variable appearances depending on the imaging
• Lymphatic drainage: sequence and the state of erection.

· superficial and deep inguinal lymph nodes. · On T1W sequences, the corpora are indistinguishable
and return signal that is lower than fat and higher than

245

Section 2: Thorax and Abdomen · ventral or rotational curvature of the penis, which
is most apparent with erection and is caused by
muscle. The tunica albuginea and Buck’s fascia are of fibrous tissue along the usual course of the corpus
low signal intensity. spongiosum; often associated with hypospadias.
· On T2W sequences, all three corpora have increased
signal, in contrast to the fascial layers. • Other anomalies:
· The corpora are very vascular on contrast-enhanced
images. · less common anomalies include penile agenesis,
duplication and lymphoedema; microphallus results
Congenital anomalies of the penis from androgen deficiency or insensitivity.
• Chordee:

246

Section 2 Thorax and Abdomen

Chapter The female pelvis

14 Catriona L. Davies

Plain radiography/hysterosalpingography/ Transbadominal imaging enables visualization of the entire
fluoroscopy pelvis. It requires a distended bladder to act as an acoustic
window. A high-frequency transducer should be used (5.0–
This is still the best technique for evaluating the gross bony 7.5 MHz). Both sagittal and transverse planes should be visual-
anatomy of the female pelvis as well as the trabecular bone ized. In 85–90% of patients the uterus and ovaries should be
pattern. visualized by this method.

Hysterosalpingography is often used in the investigation of Transvaginal imaging using a high-frequency probe is an
infertility as it allows evaluation of the uterine cavity and fal- essential part of pelvic ultrasound examinations, allowing for
lopian tubes. better resolution of both the uterus and ovaries. Colour and
spectral Doppler ultrasound should also be used to distinguish
Fluoroscopy can also be used to evaluate the other pelvic vascular structures from other pathology. This should be per-
organs – bladder, urethra and vagina. formed with an empty bladder in both sagittal and coronal
planes.
However, it is important when imaging women to consider
the radiation dose to the pelvic organs. Also the ‘10 day rule’ CT and MRI provide excellent information on the soft tis-
recommends that non-urgent X-ray examinations that entail sues of the female pelvis. MRI has the advantage of not utiliz-
pelvic irradiation in the female of child-bearing age should be ing ionizing radiation. It also provides excellent detail of the
restricted in order to avoid irradiating the fetus. At a low dose, internal anatomy using either dedicated surface array or endo-
i.e. 1 mGy, the dose to an embryo/fetus should present no risk cavitary coils. T1-weighted sequences provide us with the basic
of fetal death, malformation, growth retardation or impair- anatomy whereas T2 enables pathological evaluation.
ment of mental development.
CTA/MRA/angiography/US/Doppler
Effective doses in CT and radiographic US (both colour flow and pulsed-wave Doppler technique)
examinations is  able to visualize much of the vasculature. Conventional
angiography still remains the gold standard, especially in
Table 14.1 evaluating the internal iliac vasculature, but MRA is being
increasingly used in the evaluation of fibroids pre- and
CT Effective dose Radiographic Effective post-embolization.
examination (mSv) examination dose (mSv)
Head 2 Skull 0.07 CT positron emission tomography (CT PET)
Chest 8 Chest PA 0.02 The metabolic information obtained with fluorine 18 fluoro-
Abdomen 10–20 Abdomen 1.0 deoxyglucose (FDG) can be combined with the morphological
Pelvis 10–20 Pelvis 0.7 information obtained with CT. It can depict lymph node and
Ba swallow 1.5 distant metastases in the female pelvis.
Ba enema 7
HSG 1.0 True pelvis
Plain radiographic anatomy
Cross-sectional imaging
The pelvis is divided into:
Ultrasound is often first line investigation in the evaluation of • pelvis major (false pelvis)
the female genital tract. • pelvis minor (true pelvis)

Applied Radiological Anatomy, 2nd Edition ed. Paul Butler, Adam W.M. Mitchell and Jeremiah C. Healy. Published by Cambridge University Press.
© Cambridge University Press 2011.

247

Section 2: Thorax and Abdomen

Promontory
Sacroiliac joint

Promontory Pubic tubercle
Margin of ala Pubic symphysis
Arcuate line
Linea Pecten pubis
terminalis
Pubic crest
Fig. 14.1 Female pelvic inlet.

Ischial Pubic • Sacrum:
tuberosity symphysis · five fused vertebrae
Body of pubis · articulates with lumbar spine superiorly and coccyx
inferiorly
Pubic arch · four pairs of anterior and posterior sacral foraminae
which transmit sacral nerves
Sacrotuberous Coccyx · the spinal canal ends posteriorly in the sacral hiatus
ligament · hiatus is a midline opening that transmits the fifth
sacral nerve.
Fig. 14.2 Female pelvic outlet.
• Coccyx:
The false pelvis lies above the pelvic brim and is part of the
abdominal cavity. · composed of 3–5 fused vertebrae
· first segment is often separate.
The true pelvis lies below the pelvic brim and contains the
pelvic viscera: The female pelvis differs from the male pelvis as follows
(Fig. 14.4):
Inlet: a plane passing through the promontory of the
sacrum, arcuate line of the ilium, the iliopectineal · oval obturator foramen
line (oblique ridge on the internal surface of the ilium · wider pubic arch >90°
which continues on the pubis) and posterior surface · wider and shallow pelvis
of the pubic crest (Fig. 14.1). · oval or rounded inlet, larger outlet
· wide sciatic notch
Outlet: a plane passing through the ischiopubic rami, ischial · less prominent muscle attachments
spines, inferior symphysis pubis, sacrotuberous · small acetabulae
ligaments and the coccyx (Fig. 14.2). · less curved sacrum.

The bones of the pelvis are the paired innominate bones, Four common terms used to describe female pelves:
the sacrum and the coccyx (Fig. 14.3).
1. Gynaecoid pelvis (50%):
• Innominate
· it is the normal female type
These articulate with each other anteriorly and with the · inlet is slightly transverse oval
sacrum posteriorly. They are composed of three parts which · sacrum is wide with average concavity and inclination
fuse at the acetabulum: · side walls are straight with blunt ischial spines
· sacro-sciatic notch is wide
· Ilium · subpubic angle is 90–100°.
· Pubic bone
· Ischium 2. Anthropoid pelvis (25%):

· all anteroposterior diameters are long
· all transverse diameters are short
· sacrum is long and narrow
· sacro-sciatic notch is wide
· subpubic angle is narrow.

248

Sacral ala Chapter 14: The female pelvis

Anterior superior Iliac crest
iliac spine Sacroiliac
joint
Anterior inferior
iliac spine Arcuate line
of ilium
Obturator
foramen Superior pubic
ramus

Symphysis
pubis
Ischial
tuberosity

Pubic bone Pubic angle

Fig. 14.3 X-ray of the female pelvis.

Circular Heart shaped
pelvic inlet pelvic inlet

Prominent
promontory

Prominent ischial
spines

80–85o 50–60o

Fig. 14.4 Structure of the bony pelvis: left, in women; right, in men.

3. Android pelvis (20%): The anterior pelvic wall is formed by:
• continuation of the upper abdominal musculature –
· it is a male type
· inlet is triangular or heart-shaped with anterior external oblique, internal oblique, transversus abdominis,
rectus abdominis
narrow apex • linea alba
· side walls are converging (funnel pelvis) with • rectus sheath.

projecting ischial spines The posterior pelvic wall is formed by:
· sacro-sciatic notch is narrow • psoas
· subpubic angle is narrow <90°. • iliacus.

4. Platypelloid pelvis (5%): The boundaries of the pelvic floor are;

· it is a flat female type • anterior: symphysis pubis, bodies of the pubic bones,
· all anteroposterior diameters are short obturator internus, levator ani
· all transverse diameters are long
· sacro-sciatic notch is narrow • lateral: ilium, ischium, piriformis, obturator internus,
· subpubic angle is wide. levator ani

Cross-sectional anatomy • posterior: sacrum, coccyx, piriformis, coccygeus
• inferior: pelvic diaphragm.
Pelvic walls and floor
CT enables excellent visualization of the female pelvic walls MRI is particularly well suited to demonstration of the
and the musculature (Fig. 14.5). pelvic floor due to its multiplanar ability.

249

Section 2: Thorax and Abdomen

A External
oblique
Rectus
abdominis Internal
oblique
Common
iliac a. Transversus
and v. abdominis
Psoas
Iliac major
crest Erector spinae

B Linea alba
Rectus
Iliac bone abdominis
Erector spinae
Psoas
C Iliacus
Sacral ala
Iliopsoas
Ilium External iliac
vessels
Piriformis Gluteus
minimus
Fig. 14.5 Axial CT scans through the female pelvis. Gluteus
medius
250 Gluteus
maximus

Sartorius D Chapter 14: The female pelvis

Iliopsoas Linea alba
Anterior
Gluteus inferior
minimus iliac spine
Gluteus
medius External iliac
Gluteus vessels
maximus
Piriformis
Femoral E
vessels Uterus

Sartorius Rectus
Rectus femoris abdominis

Iliotibial band Tensor
Obturator fasciae
internus latae

Iliopsoas

Ischiorectal
fossa

Levator ani

Femoral F
vessels

Rectus Tensor
femoris fasciae
Iliotibial latae

band Gluteus
maximus
Obturator
internus

Levator
ani

Ischiorectal
fossa

Fig. 14.5 (cont.)

251

Section 2: Thorax and Abdomen A

Gluteus medius Iliac bone
Iliacus
Gluteus minimus
Pectineus Iliopsoas
Superior pubic
Obturator externus ramus
Adductor longus Symphysis
pubis
Iliacus B
Psoas
Gluteus
medius Bladder

Gluteus Adductor
minimus brevis
Adductor
Obturator magnus
internus Gracilis

Obturator Gluteus medius
externus Broad ligament
Gluteus minimus
C
Vestibule
Body of uterus
Obturator internus
Obturator externus

Bulb of vestibule

Fig. 14.6 Coronal T1-weighted MR scans through the female pelvis.

252

D Chapter 14: The female pelvis

Obturator Lumbar
internus spine

Body of
uterus

E Sacroiliac
joint
Obturator
internus Piriformis

Ischiorectal Levator ani
fossa muscle
complex

Ischial
tuberosity

Fig. 14.6 (cont.)

• The pelvic floor is composed of a sling of muscles and • A line drawn between the ischial tuberosities passing
fasciae known as the pelvic diaphragm. just anterior to the anus divides the perineum into
an anterior urogenital triangle and a posterior anal
• It separates the true pelvis from the perineum. triangle.
• This supports the pelvic viscera and is pierced by the
• The midpoint of this line is the perineal body or central
rectum, urethra and vagina. tendon of the perineum.
• It closes the pelvic outlet except for a gap between the
The boundaries of the perineum are as follows:
anterior edges of levator ani. This gap is closed by the • anteriorly: pubic symphysis
urogenital diaphragm. • posteriorly: coccyx
• anterolaterally: ischiopubic rami, ischial tuberosities
The muscle groups are clearly visualized using MRI, especially • posterolaterally: sacrotuberous ligaments.
on T1-weighted sequences where the low signal of the muscles
contrasts with the high signal of the pelvic fat. The female perineum differs from the male perineum as
follows:
The muscle groups are divided into: • urogenital triangle is pierced by both the urethra and vagina
• superior: pelvic diaphragm – levator ani/coccygeus • urethra is in anterior wall of vagina
• inferior: superficial muscles – perineum • clitoris does not contain part of urethra
• labia majora corresponds to the scrotal sac of the male
· anteriorly urogenital perineum • it contains the vestibular bulbs
· posteriorly anal perineum. • the perineal membrane is less well defined
• the perineal body is behind the vagina.
Female perineum

• The perineum is the area inferior to the pelvic diaphragm,
i.e. below levator ani.

253

Section 2: Thorax and Abdomen

A Loops
of small
Iliacus bowel

B Rectum

Body of Bladder
uterus Broad
ligament
Right ovary
Left ovary
C
Obturator
External iliac internus
vessels Gluteus
maximus
Cervical canal Rectum

D Bladder
Femoral
Femoral head
vessels Obturator
internus
Ischiorectal Gluteus
fossa maximus

Levator ani

Fig. 14.7 Axial T2-weighted MR scans through the female pelvis.

254

Urinary Chapter 14: The female pelvis
bladder
Vagina
Fig. 14.8 Proctogram demonstrating pelvic floor anatomy.
Rectum
A
Pubococcygeal
S1 line
Myometrium
Junctional zone Thecal sac and
n. roots
Bladder External cervical
Vagina os
Posterior fornix
B of vagina
Coccyx
Rectus Endometrium
abdominis
Sacrum
Bladder
Pubic bone Rectum

Fig. 14.9 Sagittal T2 MRI of the female pelvic floor. Coccyx
Levator ani

Vagina
Obturator
internus
m.

255

Section 2: Thorax and Abdomen Urethral orifice
Vaginal orifice
Bulb of

A vestibule

Urogenital
triangle

Perineum Anal aperture

Anal triangle

B Ilium

Pelvic fascia Obturator internus
Bladder Obturator membrane
Levator ani
Urethra Ischiopubic ramus
Deep transversus Crus of clitoris
Bulb of clitoris
perineal m.
Perineal membrane

Ischiocavernosus
Bulbospongiosus

Fig. 14.10 (A) Axial line diagram of the female perineum. (B) Coronal line diagram of the female perineum.

Urogenital triangle 3. levator ani
4. ischiorectal fossae on each side.
• Contains:
Deep perineal space
1. mons pubis
2. labia majora and labia minora • Enclosed superficially by the perineal membrane and
3. clitoris deeply by a fascial sheath – a condensation of the parietal
4. vaginal and urethral orifices. pelvic fascia.

• It is divided into two parts by a perineal membrane. • Between these two layers lie the deep transverse perinei
• This is a triangular membrane which stretches horizontally superficial to the compressor urethrae and sphincter
urethrovaginalis.
across the deep perineal pouch.
• It is attached laterally to the ischiopubic rami with its apex • The internal pudendal artery enters this pouch on each
side and gives off arteries to the clitoris.
attached to the arcuate ligament of the pubis.
• Posteriorly it fuses with the deep part of the perineal body. Perineal Dorsal vein Urethral orifice
membrane of penis Vaginal orifice
It is less well defined in the female. Anal orifice
• It is divided into two halves by the vagina and urethra, and clitoris

thus forming a triangle on each side of these structures. Sacrotuberous ligament Obturator
The pubo-urethral ligament links the two sides behind the internus muscle
pubic arch. Lesser sciatic
foramen Pudendal nerve
Anal triangle Internal pudendal
Sacrospinous ligament vein and artery
• It is the same in both males and females.
• Contains: Fig. 14.11 Areas of communication between the perineum and other regions.

1. anal canal
2. anal sphincters

256

Perineal Chapter 14: The female pelvis
membrane
Ischiocavernosus
Bulbospongiosus

Superficial Perineal body
transverse
Uterus
perineal
m. Levator ani

Fig. 14.12 Muscles of the female perineum. Deep
perineal
Ovary space
Superficial
Bladder perineal fascia

Urethra Pectineus
Urethra
Ischiopubic Obturator
ramus externus
Obturator
Deep tranverse internus
perineal m. Gluteus
maximus
Skin of perineum
and thigh Urethra

Fig. 14.13 Muscles and fasciae of the female perineum – coronal T2-weighted MRI. Vagina
Puborectalis
A sling

Pubic
bone

Vagina

Levator
ani

Ischiorectal
fossa

Anal canal

B

Pectineus

Obturator
externus

Ischiorectal
fossa

Anal canal

Fig. 14.14 Axial T2 MRI of the female perineum.

257

Section 2: Thorax and Abdomen

Superficial perineal space

• Enclosed by fatty and membranous (Colles’) fascia. Broad ligament
• Colles’ fascia attaches posteriorly to the posterior
Uterus
border of the perineal membrane and laterally to the
pubic arch. Ascites
• Anteriorly this is continuous with the anterior abdominal Bladder
wall (Scarpa’s) fascia and is continuous over the clitoris.
Fig. 14.15 Coronal CT of the female pelvis showing the broad ligament.
It contains:
2. Posterior mesovarium – attached to hilum of the
1. greater vestibular or Bartholin’s glands at the posterior ovary
limit of each bulb
3. Inferior mesometrium – largest part and extends
2. bulbospongiosus muscles which cover the bulb of the from the pelvic floor to the ovarian ligament and the
vestibule and separated in the midline by the vagina uterine body.
and urethra
Uterovesical and rectovaginal folds
3. fibromuscular perineal body – small mass of fibrous • The anterior/uterovesical fold consists of peritoneum
tissue located at the centre of the perineum – to
which the anal sphincter, bulbospongiosus, transverse reflected onto the bladder from the uterus forming the
perineal and levator ani muscles attach vesico-uterine pouch.
• The posterior/rectovaginal fold consists of peritoneum
4. root of the clitoris reflected from the posterior vaginal fornix onto the front
5. superficial perineal muscles. of the rectum thus creating the pouch of Douglas or recto-
uterine pouch.
Pelvic ligaments
These ligaments can be divided into true ligaments due to their Round ligaments
fibrous structure and the support they provide to the pelvic vis- • Flattened bands 10–12 cm in length.
cera whilst others are simply folds of peritoneum. CT and MRI • Originate from the uterine cornu and pass through the
allow visualization of several of these ligaments.
Peritoneal folds inguinal canal into the labia majora.
• broad ligament • The canal of Nuck (processus vaginalis) is a peritoneal
• vesicouterine ligament
• rectovaginal folds. diverticulum created where the round ligament enters the
inguinal canal.
True ligaments
• round ligaments Cardinal ligaments
• cardinal ligaments/transverse cervical ligaments/ • Condensations of pelvic fascia at the base of the broad

Mackenrodt ligament ligament.
• uterosacral ligaments • Pass to the cervix and upper vagina from the pelvic
• ovarian ligament /round ligament of ovary
• suspensory ligament of the ovary/ infundibulopelvic side walls.

ligament. Uterosacral ligaments
• Extend from the cervix and vagina to the sacrum.
The broad ligament • They form two ridges on either side of the pouch of

• Formed by anterior and posterior reflections of peritoneum Douglas, i.e. rectouterine folds
passing over the fallopian tubes.
Ovarian ligaments
• It is a double layered sheet that extends from the sides of the 1. Suspensory ligament of ovary attaches ovary to pelvic
uterus to the lateral walls and floor of the pelvis. wall and contains ovarian artery and vein
2. Ovarian ligament attaches the inferomedial extremity of
• The upper border is free. the ovary to the lateral angle of the uterus. It lies in the
• The lower border is continuous with the peritoneum over posterior aspect of the broad ligament and is continuous
with the medial border of the round ligament.
the bladder, rectum and pelvic sidewall. 3. Mesovarium.
• It holds the uterus in place and contains the fallopian

tubes in its free border, connective tissue/ smooth muscle
(parametrium), the round ligaments, uterine vessels,
lymphatics and laterally the ovarian ligaments.
• Divided into:

1. Upper mesosalpinx - attached above to the
fallopian tube, posteroinferiorly to the mesovarium.
Superiorly it is attached to the suspensory ligament
of the ovary and medially to the ovarian ligament.

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Chapter 14: The female pelvis

Ureter

Recto-uterine fold

Broad ligament Recto-uterine pouch
Round ligament
Round ligament
of uterus Uterine cavity
Inferior epigastric artery

Lateral umbilical fold
Medial umbilical fold
Median umbilical fold
Vesico-uterine pouch

Fig. 14.16 Peritoneal folds in the female pelvis.

Round ligament

Fig. 14.17 Axial CT showing the round ligaments.

Cardinal ligament Cervix

Ascites in posterior
cul-de-sac

Fig. 14.18 Axial CT showing the cardinal ligaments.

259

Section 2: Thorax and Abdomen

Presacral • The umbilical artery is the first branch of the internal iliac
space artery in the fetus and ascends on the deep surface of the
anterior abdominal wall to the umbilicus. After birth it
Vesicovaginal persists as the fibrous medial ligament.
space
• Anterior to the internal iliac artery are the ureter, ovary
Prevesical Rectovaginal and fimbriated end of the fallopian tube.
space space
• Posterior are the internal iliac vein, lumbosacral trunk
Fig. 14.19 Sagittal T2 MRI of pelvis showing spaces. and sacroiliac joints.

Pelvic spaces • Lateral is the external iliac vein and the obturator nerve.
These spaces contain loose connective tissue but are important • Medial is the parietal peritoneum.
surgical dissection planes. • The internal iliac artery divides into anterior and posterior

• Vesicovaginal/vesicocervical space – between lower urinary branches at the sciatic foramen.
tract and vagina/cervix • The anterior branch continues down to the ischial spine

• Rectovaginal space – contains fascia which provides giving off the following branches (visceral):
support for the rectum
· superior vesical artery branch of umbilical artery
• Paravesicle and pararectal spaces · obturator artery – in 25% may arise from the inferior
• Presacral space – between rectum and sacrum/coccyx.
epigastric artery
Extends as far as aortic bifurcation · vaginal artery – corresponds to inferior vesical artery
• Parametrium – pelvic visceral fascia and contents adjacent
in the male
to the cervix · uterine artery
• Space of Retzius/ prevesical/ retropubic space – · middle rectal artery
· internal pudendal artery
separated from the anterior abdominal wall by · inferior gluteal artery.
transversalis fascia.
• The posterior branch divides as follows (muscular):
Neurovascular anatomy of the female
pelvis · iliolumbar artery
Pelvic vasculature · lateral sacral arteries
· superior gluteal artery.
• The aorta bifurcates anterior to the fourth lumbar vertebral
body at the level of the iliac crests. • The external iliac artery is separated from the bowel by the
peritoneum.
• The common iliac arteries enter the pelvis anterior to the
common iliac veins on the medial border of the psoas • It is crossed at its origin by the gonadal vessels, genital
muscles. branch of the genitofemoral nerve, deep circumflex iliac
vein and by the round ligament.
• The left common iliac artery is shorter than the right
artery. • Posteriorly it is separated from the medial border of psoas
by the iliac fascia.
• The common iliac arteries pass posteriorly to the
ureters. • It gives off two branches just above the inguinal ligament:

• The common iliac arteries bifurcate at the pelvic brim · inferior epigastric artery
anterior to the sacroiliac joints into the internal and · deep circumflex iliac artery.
external iliac arteries.
• The external and internal iliac veins accompany the
• At the pelvic inlet the internal iliac arteries pass medially arteries. They are medial lower down and then pass
and posteriorly towards the sciatic notch. posteriorly as they ascend.

• The external iliac arteries run along the medial aspect Lymphatics
of the iliopsoas muscle under the inguinal ligament to
enter the thigh. • Lymph drainage accompanies the vasculature.
• Three chains accompany the external iliac vessels and drain
• The internal iliac artery is smaller than the external iliac
except in the fetus when it gives rise to the umbilical to the common iliac and paraaortic nodes:
artery.
· one anterolateral to artery
· one posteromedial to the vein
· middle chain anteriorly to the vessels – contain

obturator nodes.

• The internal iliac nodes drain to the common iliac nodes
and then to the para-aortic nodes.

260

Lumbar a. Chapter 14: The female pelvis
Median sacral a.
Right common iliac Abdominal aorta
Left common
a. iliac a.
Anterior trunk of right
Left external iliac
internal iliac a. a.

Posterior trunk of Left internal iliac
right internal iliac a. a.

Obturator a. Deep circumflex
iliac a.
Uterine a.

Fig. 14.20 Angiogram demonstrating vascular anatomy of the female pelvis.

Right common
iliac a.

Anterior trunk of Dilated
internal iliac ovarian v.
a. secondary to
ovarian varices

External iliac
a.

Profunda
femoris a.

Superficial
femoral a.

Fig. 14.21 Maximum-intensity projection image obtained from a gadolinium-enhanced MRA of the pelvis.

• Sacral nodes drain to the internal chain. • Equally a corpus luteum cyst can transiently increase
• Normal lymph nodes are rarely seen on CT. The ovarian uptake.

obturator group is especially important in the • Any postmenopausal uptake is abnormal.
assessment of pelvic malignancy. The short axis is
<8 mm. Most external iliac and common iliac nodes Important nerves of the pelvis
have a short axis <10 mm.
• The pelvis contains the lumbosacral trunk, sacral and
CT PET coccygeal plexuses and the pelvic parts of the sympathetic
and parasympathetic systems.
• Depicts lymph node metastases.
• However, in premenopausal women it is important • The lumbosacral plexus (L4, 5 and S1–4) lies on the
piriformis muscle. Four major nerves arise from it:
to remember when interpreting these images that
endometrial FDG uptake changes cyclically, increasing 1. sciatic nerve – largest nerve in body and largest branch
during the ovulatory and menstrual phases. seen on CT/MR as it passes through greater sciatic
foramen into the gluteal region

261

Section 2: Thorax and Abdomen Thoracic duct

T12 Lateral aortic
Pre-aortic node

node Ovarian
a.
Ovarian
lymph Lymph from
rectum
Internal iliac Lymph from
node bladder

External iliac
node

Fig. 14.22 Pelvic lymphatics.

Uptake in
the

endometrial
cavity

Uptake in the
left ovary

Fig. 14.23 CT PET showing normal physiological uptake in the endometrium and left ovary.

2. pudendal nerve (S2, 3, 4) – leaves the pelvis between • It is pyramidal in shape with a base, apex, superior and
the piriformis and coccygeus muscles; enters the two inferior surfaces. The apex lies behind the symphysis
perineum through the lesser sciatic foramen pubis. It is from here that the urachal remnant passes
up to the umbilicus, forming the median umbilical
3. obturator nerve (L2, 3, 4) – descends medial to psoas, ligament. The base is triangular and the ureters enter
runs along lateral pelvic wall, posteromedial to the the posterolateral angles. The inferior angle or neck
common iliac vein to enter obturator canal gives rise to the urethra surrounded by the internal
urethral sphincter. The body of the uterus rests on its
4. femoral nerve (L2, 3, 4) – descends between the psoas posterosuperior surface and the cervix and vagina are
and iliacus muscles before passing under inguinal posterior.
ligament into the thigh.
• It is extraperitoneal, with peritoneum being loose over it
Pelvic viscera except posteriorly. Although less fixed than in the male the
Bladder and urethra bladder is attached to the back of the pubis, lateral walls of
the pelvis and rectum by condensations of pelvic fascia.
• In the female pelvis the bladder lies at a lower level as it rests
directly on the pelvic fascia above the perineal membrane. • The distal ureters enter the pelvis anterior to the iliac
bifurcation. They run inferoposteriorly anterior to the

262

Superior gluteal Chapter 14: The female pelvis

Inferior gluteal L4
Obturator L5
Sciatic n.
Lumbosacral trunk
To obturator internus and superior gemmellus S1
To quadratus femoris and inferior gemellus
Posterior femoral cutaneous n. Pelvic splanchnic n.
Perforating cutaneous n. To piriformis
Coccygeal
Fig. 14.24 Sacral and coccygeal plexuses. plexus
To levator ani, coccygeus,
external anal sphincter

Pudendal n.

Femur Sciatic n.

Quadratus Ischial
femoris tuberosity
Gluteus

maximus

Fig. 14.25 Axial T1 MRI demonstrating the sciatic nerve.

internal iliac artery and at the level of the ischial spine Vascular supply
turn anteromedially to enter the posterolateral bladder. • Arterial:
They run just above the lateral fornices of the vagina,
lateral to the cervix and inferior to the uterine vessels · bladder – superior and inferior vesical arteries
within the broad ligament. The intramural ureters · urethra – internal pudendal and vaginal arteries
course for 2 cm before entering the bladder lumen. • Venous
· bladder – via a venous plexus to the internal iliac vein
• The female urethra is 4 cm long. It extends from the · urethra – internal pudendal and vaginal veins
bladder neck to the vestibule, where it opens 2.5 cm
behind the clitoris. It crosses the diaphragm anterior to Lymph supply
the vagina. The external sphincter is at the diaphragm • Bladder – internal iliac and para-aortic nodes
but less well developed than the involuntary internal • Urethra – internal iliac nodes
sphincter at the bladder neck. Small paraurethral glands
open into the vestibule on either side of the urethral
orifice. They are equivalent to the male prostate.

263

Section 2: Thorax and Abdomen

Anterior rami • An impression on the dome of the bladder in a female
L4 after contrast administration is often seen and is due to the
fundus of the uterus.
L5
Cross-sectional anatomy
Lumbosacral trunk Sacral Ultrasound is used to assess the bladder wall.
plexus • This should be <4 mm.
• The distal ureters can often be visualized.
S1 • Colour Doppler enables identification of the ureteric jets.

S2 MRI
• On T1-weighted sequences the bladder wall and contents
S3
are homogeneous, returning low signal.
S4 • T2-weighted sequences enable good contrast between the

S5 Coccygeal high signal urine and the low signal bladder wall.
plexus
Lower genital tract
C0
Vulva
Sciatic n.
• The female external organs are known collectively as
Superior gluteal Posterior femoral cutaneous n. the vulva: mons pubis, labia majora/minora, vestibule
Inferior gluteal Perforating cutaneous n. of vagina, clitoris, bulb of vestibule, greater vestibular
Pudendal n. glands.
Common fibular part of sciatic n. Pelvic splanchnic n.
Tibial part of sciatic n. Anococcygeal n. • The vestibule is the cavity that lies between the labia
To obturator internus To piriformis minora. It contains the vaginal and urethral orifices and the
openings of the greater vestibular glands (Bartholin’s).
To quadratus femoris and To levator ani, coccygeus,
inferior gemellus external anal sphincter • The vestibular bulbs correspond to the bulb of the penis
and lie on either side of the vestibule into which both the
Fig. 14.26 Components and branches of the sacral and coccygeal plexuses. vagina and urethra open. These have erectile tissue and
are covered by the bulbospongiosus muscles and then by
Nerve supply the skin of the labia minora.
• Bladder – vesical nerve plexus which is continuous with the
Vascular supply
inferior hypogastric plexus
• Urethra – pudendal nerve • Arterial: superficial and deep external pudendal branches
of the femoral artery and the internal pudendal artery on
Internal anatomy each side.
• The bladder wall is trabeculated except at the trigone – the
• Venous: vulval skin via the external pudendal veins to the
triangular area between the two ureteric orifices and the long saphenous vein. Clitoral via deep dorsal veins to the
urethral orifice. internal pudendal vein and the superficial dorsal veins to
the external pudendal and long saphenous veins.
Plain radiographic anatomy
Intravenous urogram / cystogram Lymph supply
• Demonstrates the kidneys and bladder.
• The plain film often shows the bladder as a rounded soft • Superficial and deep inguinal nodes.
• Lymph vessels in the perineum and lower part of labia
tissue mass surrounded by darker perivesical fat.
majora drain to the rectal lymphatic plexus.

Nerve supply

• Anterior 1/3 labia – ilioinguinal nerve
• Posterior 2/3 labia – perineal nerve
• Lateral aspect – perineal branch of the posterior cutaneous

nerve (S2)

Vagina

• A fibromuscular tube that is approximately 7–9 cm in
length and ascends up and back from the vestibule (cleft
between labia minora) to surround the cervix at an angle of
>900 to the uterine axis.

• The anterior and posterior walls are in close apposition

264

Chapter 14: The female pelvis

Left pelvicalyceal pubocervical and uterosacral ligaments and inferiorly by
system the perineal membrane and perineal body. The vagina
shrinks in length following the menopause and the
Left ureter fornices virtually disappear.

Uterine Relations
indentation • Anterior : cervix, bladder base and urethra
• Posterior:
Contrast in bladder
lumen · upper – rectouterine pouch of Douglas separating
vagina from rectum
Fig. 14.27 Female IVU showing bladder with superior indentation from
uterus. · mid – Denonvillier’s fascia separating vagina from
ampulla of rectum
to each other except at the superior end where the cervix
enters its cavity. · lower – perineal body separating vagina from anal
• The posterior wall is 1 cm longer than the anterior wall and canal
is in contact with the external os.
• The recess around the cervix is divided into anterior, • Lateral: anterior fibres of levator ani, pelvic fascia and
lateral and posterior fornices. The posterior fornix is ureters
the deepest and related to the rectouterine pouch.
• Inferiorly it pierces the perineal membrane with the urethra. • Inferior: bulb of vestibule and perineal membrane
• The superior aspect of the posterior wall of the vagina is
usually covered by peritoneum. The vagina is supported Vascular supply
superiorly by the levator ani, transverse cervical, • Arterial from vaginal, uterine, internal pudendal and

middle rectal branches of internal iliac arteries
• Venous from vaginal veins which form a plexus around

the vagina that drain to the internal iliac veins

Lymph supply
• Upper: internal/external iliac nodes
• Middle: internal iliac nodes
• Lower: superficial inguinal nodes

High signal Bladder wall
urine Rectum

Cervix

Fig. 14.28 Axial T2 MRI showing high-signal urine and low-signal bladder wall.

Low signal Vaginal
urine vault

Rectum

Fig. 14.29 Axial T1 MRI showing low-signal urine within bladder lumen.

265

Section 2: Thorax and Abdomen

Nerve supply BLADDER

• Upper vagina: pelvic splanchnic nerves Echogenic
• Lower vagina: pudendal nerve lining of the
vagina
Internal anatomy
Endometrium
• Inner mucosa and external muscular layer composed of
inner circular and thicker outer longitudinal muscle. Fig. 14.30 Transabdominal US showing the echogenic stripe of apposed
surfaces of vaginal mucosa.
• There are two longitudinal ridges on its epithelial surface
anteriorly and posteriorly. Transverse rugae extend from Urethra
these. They are divided by sulci of varying depths.
Enhancement
Cross-sectional anatomy of vaginal wall
Ultrasound post contrast
• Seen as a highly echogenic stripe which makes an acute
Anal canal
angle with the uterus
Fig. 14.31 Axial T1 MRI post gadolinium showing the enhancement pattern
MRI of the vaginal wall and submucosa.
• The internal anatomy can be visualized on the T2
• Version refers to the axis of the cervix relative to the
sequences. vagina.
• In the early proliferative stage the wall returns low signal
• In the nulliparous female it is often anteverted
and the mucosa and mucus high signal. and anteflexed, i.e. the long axis of the uterus lies
• In the secretory stage both the wall and mucus are horizontally in the sagittal plane.

thickest and of highest signal. • In 10–15% of females it is retroverted, i.e. the cervix is
• In the postmenopausal phase the signal intensity of directed back and up but still anteflexed.

the mucosa decreases and the central mucus becomes • If retroflexed the uterus is directed posteriorly to that of
thinned. the cervix.
• Post gadolinium both the wall and submucosa enhance.
Relations
Uterus • Anterior: uterovesical pouch and superior surface of

• An inverted pear-shaped organ lying between the bladder bladder
and rectum. • Posterior: pouch of Douglas with large and small bowel

• Divided into a fundus, body and cervix. The body within it
narrows to a waist called the isthmus, below which lies • Lateral: broad ligaments and uterine vessels
the cervix.
Size and shape
• The vagina divides the cervix into supravaginal and
vaginal parts. Vascular supply
• Arterial: dual blood supply from the uterine artery – a
• The fallopian tubes enter each superolateral angle at the
cornu of the uterus. branch of the internal iliac. It passes over the ureter at
the level of the internal os. It then courses superiorly
• The cavity of the uterus is triangular in coronal section along the lateral margin of the uterus in the broad
and flat in anteroposterior plane. It measures 6 cm from ligament where it anastomoses with the ovarian artery.
the external os to the fundus. The cavity communicates
with the cervical canal via the internal os and the cervical
canal communicates with the vagina via the external os.

• The cervix is narrower and more cylindrical than the
body and measures approximately 2.5 cm.

• The uterus is extraperitoneal – the peritoneum covers
the uterus anteriorly and superiorly except for the
vaginal part of the cervix. The peritoneum is reflected
up over the anteroinferior surface of the uterus forming
the vesicouterine pouch before passing off the posterior
surface of the uterus and up over the rectum to form the
rectouterine pouch of Douglas.

Position

• Lies in the true pelvis but its position may change.
• Flexion refers to the axis of the body relative to the cervix.

266

Chapter 14: The female pelvis

Table 14.2 Length AP diam. Features
(cm) (cm)
Neonatal
2.3–4.6 0.8–2.1 Echogenic Cervix >
Prepubertal endometrium/ uterus
fluid
Adult
2–3.3 0.5–1.0 Tubular Cervix 2/3
   Nulliparous length of
Retroverted    Primiparous uterus
uterus    Multiparous
Post- Pear-shaped Body diameter
Bladder menopausal and length
double cervix
Rectum
85

+1 +1

+2 +2

3.5–6.5 1.2–1.8

Fig. 14.32 Sagittal T2 MRI showing a retroverted uterus.

Uterine arteries give rise to the arcuate arteries seen in Right ovary
the outer one-third of the uterus. Uterus
• Venous: the uterine vein accompanies the artery and Rectum
drains into the internal iliac vein. Bladder

Lymph supply Fig. 14.33 Sagittal T2 MRI of a child’s pelvis.
• Fundus: para-aortic nodes
• Body/cervix: internal and external iliac nodes, a few Cross-sectional anatomy

accompany the round ligament through the inguinal canal Ultrasound
to the superficial inguinal nodes Transabdominal ultrasound enables evaluation of the entire
pelvis. Size and position of the uterus can be determined as well
Nerve supply as gross pathology.
• Derived from inferior hypogastric plexus especially
• Transvaginal US allows detailed evaluation of the internal
uterovaginal plexus which lies in the broad ligament structure of the uterus.
• Parasympathetic fibres are from the pelvic splanchnic nerves
• The muscular myometrium forms most of the uterine
Internal anatomy wall.
Uterine wall consists of three layers:
• outer serous coat or perimetrium – peritoneum supported • It is composed of three layers that can be identified by
ultrasound:
by a thin layer of connective tissue 1. inner layer or junctional zone – thin, compact,
• middle muscular coat or myometrium hypoechoic layer surrounds echogenic endometrium
• inner mucous layer or endometrium – formed by a layer forming a subendometrial halo

of connective tissue or stroma. Lined by columnar (non- 2. intermediate layer – thickest, uniform low to moderate
ciliated) epithelium and tubular glands. Divided into two echogenicity
layers:
3. outer layer – less echogenic than intermediate layer,
1. stratum functionalis (shed during menstruation) separated from it by arcuate vessels.
2. stratum basalis (permanent and adjacent to

myometrium) contains spiral arteries.

Cervix:
• Endocervical canal lined by mucus-secreting columnar

epithelium; often seen as folds called plicae palmatae
• Ectocervix lined by stratified squamous epithelium.

267

Section 2: Thorax and Abdomen

BLADDER Early proliferative stage days 0–6; 4–8 mm
Thin echogenic line as a result of specular reflection from the
Vagina interface between opposing surfaces of endometrium. Note
Fundus of thin hypoechoic inner layer of myometrium (Fig. 14.37)
uterus
Late proliferative stage days 6–14; 6–10 mm
Endometrium Triple layer appearance of endometrium – central echogenic
line due to opposed endometrial surfaces surrounded by thick-
Myometrium er hypoechoic functional layer, bounded by outer echogenic
basal layer (Fig. 14.38)
Fig. 14.34 Transabdominal US showing the uterus in longitudinal section.
Secretory phase days 15–28; 7–14 mm
BLADDER The functional layer surrounding the echogenic line has become
more hyperechoic due to increased mucus and glycogen within
the glands as well as increased number of interfaces caused by
the tortuosity of the spiral arteries (Fig. 14.39).

Post menopausal < 8 mm
Endometrium becomes atrophic and is seen as a thin echogenic
line

Endometrium 3D ultrasound allows multiple views to be reconstructed from
of uterus a single sweep. The data are displayed in three simultaneous
planes. Multiplanar and rendered images can then be rotated
Fig. 14.35 Transabdominal US showing the uterus in transverse section. and sliced through as with CT or MR. A central localizer
point  on each image shows the precise location in all three
• The arcuate arteries branch into the radial arteries which planes.
run in the intermediate layer to the level of the inner layer. CT
These radial arteries then branch into the spiral arteries • Seen as a homogeneous soft tissue mass dorsal to the
which supply the functional layer of the endometrium.
bladder. May be a central area of low attenuation.
• The uterine veins are larger than the arteries and often seen • If a vaginal tampon is used seen as a tubular air-filled
as anechoic areas.
structure.
• The Doppler waveform of the uterine arteries shows a high- • Post intravenous contrast the uterus enhances and the
velocity, high-resistance pattern.
ureters can be identified laterally to the cervix.
• The endometrium is a mucosal layer which lines the • The broad ligament appears as a thin soft tissue density
myometrium.
extending anterolaterally from the uterus to the pelvis
• It is continuous below with the vaginal mucosa through the sidewalls.
external os and with the peritoneum above through the os MRI
of the fallopian tubes. • Uterus
· T1 – uniform signal of both the uterus and cervix
• On ultrasound it is a thin echogenic line as a result of · T2 – three distinct zones:
specular reflection from the interface between opposing
surfaces of the endometrium. – endometrium – high signal

• The endometrium is composed of a superficial functional Endometrium
layer and a deep basal layer. Arcuate a.

• The functional layer thickens throughout the menstrual Fig. 14.36 Normal Doppler flow of the myometrium showing prominent
cycle and is shed with menses. flow in the arcuate arteries.

• The basal layer remains intact during the cycle and contains
the spiral arteries, which become tortuous and elongate to
supply the functional layer as it thickens.

268

Fig. 14.37 Transvaginal ultrasound showing normal thin early proliferative Chapter 14: The female pelvis
endometrium.
– junctional zone – low signal 2–8 mm, thick inner
Fig. 14.38 Transvaginal ultrasound showing normal late proliferative myometrium, low water content
endometrium with triple-layer appearance. Central echogenic line due to
opposed endometrial surfaces surrounded by thicker hypoechoic functional – outer myometrium – intermediate signal
layer bounded by outer echogenic basal layer.
· Post gadolinium
– pattern of enhancement dependent on
menstrual cycle and hormonal status
– peak enhancement of myometrium at 120 s post
injection and decreases over time
– absence of junctional zone
– slight enhancement only of endometrium in
early phase with marked enhancement on
delayed images

· Premenopausal
– endometrium thickens in secretory phase up to
1 cm
– myometrial signal increases in secretory
phase due to increased water content and
vascular flow
– low signal uterine contractions which may bulge
the uterine contour
– OCP – both endometrium and junctional zone
become thin

· Postmenopausal

– small, indistinct zonal anatomy
– endometrium <2–3 mm
– low signal myometrium
– no cyclical variation
– similar appearance to postradiation therapy
– loss of ovarian function

· HRT

– compares to reproductive age but no cyclical
variation

Fig. 14.39 Transvaginal sagittal ultrasound of the uterus performed during secretory stage of the menstrual cycle showing the appearances of the endometrium
at this stage (measured). The central echogenic line is due to the interface of the opposing surfaces of the endometrium. The functional layer of the endometrium
surrounding the echogenic line is hyperechoic at this stage.

269

Section 2: Thorax and Abdomen

AXIAL SAGITTAL

CORONAL REFORMAT Fig. 14.41 3D reformat showing the entire endometrial and fundal contour.

Fig. 14.40 3D ultrasound of the uterus and endometrium.

Endometrium Small follicles
in low signal
Outer outer stroma
myometrium
Left ovary

Inner myometrium Uterus
High signal
Fig. 14.42 Axial CT of the female pelvis post intravenous contrast showing stroma at hilum
uterine enhancement. of right ovary
Urinary bladder
· Cervix
– the appearances do not change with the Fig. 14.43 Coronal T2-weighted image through the female pelvis showing
menstrual cycle or the OCP the uterus and both ovaries with the high-signal central stroma and lower
– T2 – three distinct zones: outer stroma.
– endocervical canal – high signal 3.8–4.5 mm
– stroma – low signal 3.8–4.2 mm, elastic Myometrium
fibrous tissue, continuous with junctional
zone Endometrial
– outer layer – intermediate signal, smooth cavity
muscle, continuous with the outer Junctional zone
myometrium
Fluid in pouch
Fallopian tubes of Douglas
These connect the uterus to the peritoneal cavity and are
attached to the posterior broad ligament by the mesosalpinx. Cervix
• 7–12 cm in length Vagina
• They run in the upper free margin of the broad ligament.
• Composed of four segments: Bladder

· intramural/interstitial – pierces the uterine wall; Fig. 14.44 Sagittal T2-weighted sequence through the female pelvis showing
0.7 mm wide and 1 cm long; narrowest part; opens into the anatomical relations of the uterus.
cavity via uterine ostium

270

Left ovary Chapter 14: The female pelvis

Fluid in Bladder
Endometrial Right round
cavity ligament
Junctional zone Left round
Myometrium ligament
Right ovary Junctional zone
Cervix
Endometrial
cavity

Fig. 14.45 Axial T2-weighted sequence showing the anteverted uterus and Fig. 14.46 Axial T2 MRI scan of the female pelvis – small FOV.
both ovaries containing follicles.

AB

20 sec 180 sec

Fig. 14.47 (A) Dynamic contrast-enhanced axial T1 MRI: showing rapid early subendometrial enhancement at 20 seconds. (B) Dynamic contrast-enhanced axial
T1 MRI: showing maximal myometrial enhancement at 180 seconds.

· isthmus – 1–5 mm wide and 3 cm long; long and Lymph supply
narrow part lateral to the uterus • Para-aortic nodes

· ampulla – 1 cm wide and 5 cm long – dilated tortuous Nerve supply
outer part; fertilization usually occurs here • Ovarian and uterine plexuses
• Afferent fibres from the tubes are contained in T11,
· infundibulum – funnel-shaped lateral part which
extends beyond the broad ligament and overhangs the T12 and L1.
ovary with its fimbriae – one of which is attached to the
ovary; its opening into the peritoneal cavity is called Plain radiographic anatomy
the abdominal ostium. HSG
• The isthmus and internal os may be seen.
Vascular supply • The uterine cavity is often triangular and smooth-walled

• Ovarian and uterine arteries with corresponding venous leading to the narrowed isthmus and then the wider
drainage tortuous ampulla.
• Contrast should spill freely into the peritoneal cavity.

271

Section 2: Thorax and Abdomen Table 14.3

• Longitudinal ridges may be seen on the anterior and Volume Weight Size Follicles
posterior walls of the cervical canal. 0.523 ×
length ×
• In nulliparous females they may have branches running width ×
laterally – the plicae palmatae. height

• The walls of the uterus may show longitudinal folds and Neonatal 2.7 cm3 1.5 × 0.5 × Multiple due
polypoid filling defects may be seen in the secretory 0.5 cm to influence
phase. of maternal
hormones
Ovaries
1–8 years 1.7 cm3 Microcystic
• Paired reproductive and endocrine organs that lie in ovary – follicles
the ovarian fossae between the obliterated umbilical < 2 mm in
artery anteriorly and the internal iliac artery and ureter diameter
posteriorly.
> 8 years 4.2 Multicystic
• They are attached to the back of the broad ligament by the +/− 2.3 cm3 ovary
mesovarium.
> 6 follicles
• Their anterior borders are attached to the infundibulum of
the fallopian tube. > 4 mm in
diameter
• The suspensory ligament of the ovary is a part of the broad
ligament lateral to the mesovarium and running lateral to Adult 10 +/− 6 cm3 2–8 g 3 × 1.5 ×
the pelvic wall. It connects the superior end of the ovary to 2 cm
the lateral pelvic wall.
Double
• Further support is due to the ovarian ligament – a in size in
continuation of the round ligament which runs from the pregnancy
medial aspect of the ovary to the cornu of the uterus.
Postmenopausal 2–6 cm3 1–2 g 2 × 1.5 ×
> 8 cm3 0.5 cm
abnormal

Isthmus Tubal ostium
Ampulla
Endometrial
Infundibulum cavity

Free Internal
intraperitoneal spill cervical os

of contrast

Fig. 14.48 Hysterosalpingogram.

Right Left ovarian
common v.

iliac v. Psoas
muscle
Fig. 14.49 Axial CT showing a dilated left ovarian vein. Left common
iliac v.
272

Chapter 14: The female pelvis

Position Size and shape
• Ellipsoid in shape with their craniocaudal axes parallel to
• Variable, usually lateral or posterolateral to the anteflexed
uterus in ovarian fossa – depression on lateral pelvic the internal iliac vessels
side wall • Each ovary has a medial and lateral surface, anterior

• Lateral and superior to the retroflexed uterus and posterior borders and superior and inferior
• Free border is directed posterior to the ureter and internal poles

iliac vessels Vascular supply
• Inferior: levator ani • Arterial: ovarian artery from the aorta at L1/2. Enters the
• Lateral: parietal peritoneum separates the ovary from the
ovarian hilum via the mesovarium.
obturator vessels and nerves • Venous: from the pampiniform plexus into the ovarian
• Medial: uterus and uterine vessels in the broad ligament
• Posterior: ureter/internal iliac artery veins. These drain into the inferior vena cava on the right
• Anterior: obliterated umbilical vein and the renal vein on the left.

Ovarian stroma Dominant
follicle
Fig. 14.50 Transvaginal ultrasound showing a dominant follicle on the left ovary.
Internal iliac
a.

Fig. 14.51 Transvaginal colour Doppler showing normal arterial flow in an ovary – low-velocity, low-resistance waveform.

273

Section 2: Thorax and Abdomen

Fig. 14.52 Transvaginal colour Doppler ultrasound showing increased flow around a corpus luteum cyst – ‘ring of fire’ appearance.

Lymph supply Medullary
portion of
• Along the ovarian vessels to pre-aortic lymph nodes at ovary
L1/2.
Fig. 14.54 Axial T2 MRI showing ovaries.
Nerve supply
Cross-sectional anatomy
• Ovarian plexus formed from the aortic, renal, superior Ultrasound
and inferior hypogastric plexuses. • On ultrasound the ovary has a homogeneous

Internal anatomy echotexture with central echogenic medulla.
• Several small anechoic follicles are seen peripherally in
• The ovary consists of a central vascular medulla and an
outer cellular cortex. the cortex.
• Echogenic foci are common. These are non-shadowing and
• The cortex is composed of reticular fibres and spindle-
shaped cells which contain the follicles and corpus lutea. can be diffuse. They are caused by a specular reflection from
the walls of tiny unresolved cysts.
• The surface is not covered by peritoneum but by a • Focal calcification may be seen.
single layer of cuboidal/columnar cells called the • Doppler shows a low-velocity, low-resistance arterial
germinal epithelium that becomes continuous with the waveform.
peritoneum at the hilum. • Early proliferative phase – many follicles.
• Pre ovulation – one becomes dominant 2–2.5 cm and others
• Beneath the germinal epithelium the connective tissue atretic.
of the cortex is condensed to form the tunica albuginea – • Post ovulation
a fibrous outer capsule. · corpus luteum develops
· variable appearance
• The medulla is composed of fibrous tissue and vessels. · hypo/isoechoic

Suspensory
ligament of
ovary

Uterus

Fig. 14.53 Coronal T2 MRI showing ovaries.

274

Chapter 14: The female pelvis

Table 14.4 Agenesis; 1 uterine horn /1 cervix 10%
Arrested development uterus unicornis unicollis 20%
of Müllerian ducts 2 vagina / 2 cervices / 2 uterine horns 5%
Failure of fusion of Complete: 10%
Müllerian ducts uterus didelphys 1 vagina / 2 cervices / 2 uterine horns
1 vagina / 1 cervices / 2 uterine horns 55%
Failure of resorption of the Partial: Partial indentation of fundus with normal cavity
median septum uterus bicornis bicollis Distinguished from above by normal external contour

uterus bicornis unicollis

uterus arcuatus

Septate or subseptate uterus – commonest
abnormality

Uterus didelphys Uterus bicornis bicollis MRI
• T1: uniform intermediate signal with low signal
Uterus bicornis unicollis Uterus unicornis unicollis
follicles.
Septate uterus Arcuate uterus • T2: multiple high signal follicles with low signal capsule

Fig. 14.55 Line diagrams of congenital anomalies of the uterus. and medulla slightly higher signal than cortex.
• Postmenopausal ovaries are of homogeneous signal on
· thick echogenic ring
· haemorrhage common both T1 and T2.
· ‘ring of fire’ on colour Doppler. • Post gadolinium the stroma of the ovary enhances,

• Menstruation – corpus luteum involutes. making the low-signal follicles more prominent.
• Menopause – ovary atrophies and follicles disappear
Congenital anomalies
over subsequent years.
• The fused caudal ends of the two Müllerian ducts form the
uterus/cervix/upper vagina.

• The unfused ends form the fallopian tubes.
• The median septum formed by the medial walls of the

Müllerian ducts resorbs, leaving a single cavity.
• Failure of Müllerian duct development and/or fusion leads

to a spectrum of anomalies. Often associated with renal
anomalies.

Imaging during pregnancy

Accurate sagittal and transverse measurements of the mother’s
pelvic inlet and outlet can help in predicting the likelihood of a
vaginal delivery. These measurements include:
• the sagittal inlet (between the promontory and the top of

the pubic symphysis)
• the maximum transverse diameter of the inlet
• the bispinous outlet (the distance between ischial spines)
• the sagittal outlet (the distance between the tip of the coccyx

and the inferior margin of the pubic symphysis).

The acceptable values for these are 11, 11.5, 9 and 10 cm,
respectively.

The above measurements are sometimes made in clinical
practice using X-ray or MRI pelvimetry.

Diagnostic imaging may also be required during pregnancy
to assess the abdominal or pelvic viscera or the placenta.

Ultrasound remains the initial imaging modality of choice.
However, if it is non-diagnostic then further imaging with
CT/MRI may be required. CT includes the fetus in the field of
view, resulting in an estimated fetal dose of between 12.5 and
35 mSv.

275

Section 2: Thorax and Abdomen Uterine
cavity of
Sacrum second horn
Uterine cavity of
Cervical
one horn canal
Vaginal
Fallopian tube speculum

Contrast in Two uterine horns
pouch of
Douglas

Fig. 14.56 Hysterosalpingogram showing a uterus bicornis unicollis.

Two cervices

Fig. 14.57 3D coronal reformat of a uterus bicornis bicollis. B
A

Right ovary Left ovary 2 uterine
2 uterine horns horns

2 cervices

Fig. 14.58 (A) Coronal MRI showing a uterus didelphys. (B) Axial MRI showing a uterus didelphys.

Therefore MRI which does not utilize ionizing radiation fetus are not fully understood and the use of these agents should
may be beneficial. However, patients should only undergo be avoided in pregnancy. These agents are also excreted in low
MR imaging if information cannot be obtained by other non- concentrations in breast milk and as such it is advisable to
ionizing means as there are concerns regarding the safety in the interrupt breast feeding for 24–48 hours post administration.
setting of pregnancy. In particular imaging in the first trimester
is to be avoided as the safety of MR in this period is difficult to • MRI has an excellent role in evaluating the position of the
establish. placenta.

Equally the effects of gadolinium-based agents on the • The point of attachment is determined by the point where
the blastocyst becomes embedded. In early pregnancy the

276

Chapter 14: The female pelvis

Placenta Vertebral column
Fetal head
Myometrium Amniotic
Bladder fluid

Fig. 14.59 Sagittal T2-weighted scan showing a normal cephalic presentation. Lumbar spine

Twin 1

Twin 2 Placenta praevia -
Bladder low lying placenta
covering
internal cervical os

Fig. 14.60 Sagittal T2-weighted scan of a twin pregnancy with a placenta praevia overlying the internal cervical os.

placenta occupies a large proportion of the uterine cavity • Other placental variants include accreta, where the
and as such will often be situated near the internal os. placenta is adhered to the deciduas basalis, increta,
where it extends into the myometrium, and percreta,
• In 1% the placenta remains close to or over the os – where it passes through the uterine wall.
placenta praevia.

277

Section 3 Upper and Lower Limb

Chapter The upper limb

15 Gajan Rajeswaran and Justin Lee

Plain radiography/fluoroscopy Clavicle
The lateral 1/3 of its inferior surface allows attachment of the
Plain radiography demonstrates osseous anatomy and pro- coracoclavicular ligament with:
vides some detail of the soft tissue anatomy. Fluoroscopy • a bony protuberance, the conoid tubercle
allows real-time dynamic radiographic assessment of the • a lateral roughening, the trapezoid line.
osseous anatomy and assessment of the joints using fluoro-
scopic arthrography. Scapula
• The scapula has four main protuberances:
Cross-sectional imaging
CT · coracoid process: anteriorly
· glenoid fossa: laterally, for articulation with the
Multi-slice CT provides more information about the osseous
anatomy than plain radiography, showing the trabecular anat- humeral head
omy of the bone in much higher detail. High-resolution 3D · spine: posteriorly, dividing the posterior surface into
reconstructions of the upper limb allow interrogation in any
desired plane. Soft tissues including muscles, tendons and supra- and infra-spinous fossae
joints can also be identified but these are best assessed with · acromion process: forms the lateral aspect of the
ultrasound and MR imaging.
spine of the scapula, for articulation with the
Sonography clavicle.

Sonography allows high spatial resolution and dynamic imag- • The supra- and infraglenoid tubercles provide attachment
ing of the soft tissues not obscured by osseous structures. It is for the long head of the biceps and triceps brachii muscles
particularly optimal for visualization of small and superficial respectively.
structures (ligaments, tendons) as well as muscle compart-
ments. • Three types of morphological normal variations of the
acromion process have been classified by Bigliani, with a
MRI fourth type more recently classified by Vanarthos (Fig. 15.2):

MR imaging offers high contrast resolution imaging of the · type 1: flat undersurface
musculoskeletal anatomy. Intra-articular structures are best · type 2: concave undersurface
assessed using MR arthrography. · type 3: hooked undersurface
· type 4: convex undersurface.
Shoulder
• Type 3 and possibly type 2 morphologies predispose to
The upper limb consists of the shoulder, arm, forearm and rotator cuff tears as the acromion can impinge on the
hand. These regions are connected by the shoulder, elbow and supraspinatus tendon passing underneath it during
wrist joints overlain by transitional zones, the axilla, antecu- dynamic movement (Fig. 15.3).
bital fossa and carpal tunnel, which facilitate the passage of
neurovascular structures (Fig. 15.1). Proximal humerus
• Two bony protuberances, the greater and lesser tubercles,
Plain radiographic anatomy
help to define its anatomy. These are separated from:
The bones of the shoulder consist of the clavicle, scapula and
proximal humerus. · the head by the anatomical neck
· the diaphysis by the surgical neck
· each other by the bicipital groove (which allows the

passage of the long head of biceps tendon).

Applied Radiological Anatomy, 2nd Edition ed. Paul Butler, Adam W.M. Mitchell and Jeremiah C. Healy. Published by Cambridge University Press.
© Cambridge University Press 2011.

278

Glenohumeral joint Chapter 15: The upper limb
Shoulder
Rib 1
Arm Manubrium
of sternum
Elbow
Forearm Axilla

Wrist
Hand

Fig. 15.1 Diagram of the upper limb.

Anterior Posterior

Type 1 Type 2 Type 3 Type 4
Flat Concave Hooked Convex

Fig. 15.2 Classification of acromial morphology.

279

Section 3: Upper and Lower Limb

A B

Clavicle Surgical neck humerus
Acromion of scapula Acromion of scapula
Coracoid process scapula Head of humerus
Glenoid fossa scapula
Head of humerus Coracoid process scapula
Greater tuberosity humerus Clavicle
Scapula
Bicipital groove humerus
Lesser tuberosity humerus

Anatomical neck humerus
Surgical neck humerus
Glenoid fossa scapula
Scapula

Fig. 15.3 (A) AP radiograph of the right shoulder and (B) axial radiograph of the right shoulder.

Hypodermic needle • The axillary nerve and circumflex humeral artery wrap
and tube around the surgical neck and are at risk following fracture
here.
Outline of capsular
attachment of joint Shoulder (glenohumeral) joint (Figs. 15.3 and 15.4)

Fig. 15.4 AP fluoroscopic arthrogram of the left shoulder. Radio-opaque • Synovial, multiaxial ball-and-socket joint between the
contrast has been injected into the shoulder joint following needle insertion, hemispherical head of humerus and the shallow glenoid
to outline the joint capsule. fossa of the scapula.

• Wide range of movement (flexion, extension, abduction,
adduction, internal and external rotation and
circumduction of the upper limb) but inherent lack of
stability.

• On an AP radiograph, the articular surfaces of the
humerus and glenoid form parallel arcs.

Sternoclavicular joint (Fig. 15.5)

• Saddle-shaped, synovial joint.
• Separated into two cavities by intervening disc of

fibrocartilage which is attached to the joint capsule.
• Allows horizontal and vertical movement as well as some

rotation.

A Interclavicular
ligament
Articular
capsule Anterior
sternoclavicular
Clavicle ligament

Articular Costoclavicular
disc ligament

Manubrium

First costal
cartilage

Fig. 15.5 (A) Illustration of left sternoclavicular joint. (B) Axial fat-saturated proton-density MRI image in a patient with osteoarthritis of the right sternoclavicular
joint. The intra-articular disc (white arrow) can be seen as a low-signal linear structure within the joint compartment, highlighted on either side by high-signal joint
fluid secondary to the osteoarthritis. Note the cod liver oil capsule (white arrowhead) on the patient’s skin, localizing the patient’s pain. C = clavicle; S = sternum.

280

B Chapter 15: The upper limb

Fig. 15.5 (cont.) aspects of the clavicle and acromion normally lie in a
straight line.
• Enclosed by a joint capsule and strengthened by four
ligaments: Ossification of the shoulder
· anterior and posterior sternoclavicular ligaments • In the fetus, the skeleton consists initially of cartilage,
· interclavicular ligament
· costoclavicular ligament. which gradually turns to bone (ossification) during
growth.
Acromioclavicular joint (Fig. 15.6) • Each bone has a primary ossification centre (usually
• Synovial plane joint. at the centre of the bone) and sometimes one or more
• An incomplete disc of fibrocartilage hangs down into the secondary ossification centres (usually at the bone
ends).
upper part of the joint cavity. • When the secondary ossification centre does not unite
• Allows horizontal and vertical movement as well as some with the main bone an accessory ossicle (normal variant)
is formed.
rotation. • Accessory ossicles and secondary ossification centres
• Strengthened by: should not be mistaken for fractures.
• The os acromiale is an accessory ossicle occurring
· acromioclavicular ligament: the acromioclavicular in 1–15% of the population. It can result in shoulder
distance is 3–8 mm in adults impingement by decreasing the space below the
coracoacromial arch. There are up to three ossification
· coracoclavicular ligament: the normal coraco- centres in the acromion: preacromion, mesoacromion
clavicular distance is 10–13 mm and the inferior and metacromion. Depending on where failure of fusion
occurs, this can result in seven types of os acromiale
(Figs. 15.7 and 15.8).

Pre-acromion

Meso-acromion

Meta-acromion

Basi-acromion

AB C

D EF G

Fig. 15.6 AP radiograph of right shoulder. Normal acromioclavicular Fig. 15.7 Ossification of the acromion and types of os acromiale. There are
(0.3–0.8 mm) and coracoclavicular (1.0–1.3 mm) distances imply that the up to three ossification centres of the acromion separate to the basi-acromion:
acromioclavicular and coracoclavicular ligaments are intact. pre-acromion; meso-acromion and meta-acromion. Depending on where
failure of fusion (black shaded area) occurs, up to seven types of os acromiale
(types A–G) may be formed. The most common is type A, in which there is
failure of fusion between the meso- and meta-acromion.

281

Section 3: Upper and Lower Limb

A

Coracoid process Clavicle
scapula
Manubrium
Head of humerus sterni

Anatomical neck
humerus

Glenoid fossa scapula

Surgical neck
humerus
Scapula

Axillary a.

B Clavicle

Fig. 15.8 Axial fat-saturated proton-density MRI image of the shoulder Head of humerus
showing a type A os acromiale. There is failure of fusion between the meso-
acromion (MSA) and the meta-acromion (MTA). ACJ = acromio-clavicular joint, Glenoid fossa
C = clavicle. scapula
Scapula

Table 15.1 Ossification centres of the scapula

Body Appear Fuse C
Coracoid (two centres) 8th wk gestation 25 yrs
Glenoid 15–18 months 15 yrs Bicipital groove
Vertebral border 10–11 yrs 25 yrs humerus
Acromion (three centres) 14–20 yrs 25 yrs Lesser tuberosity
Inferior angle 14–20 yrs 25 yrs humerus
14–20 yrs 25 yrs Greater tuberosity
humerus
Table 15.2 Ossification centres of proximal humerus Head of humerus
Glenoid fossa
Diaphysis Appear Fuse scapula
Head 8th wk gestation 20 yrs Spine of scapula
Greater tubercle < 6 months 20 yrs
Lesser tubercle 1–2 yrs 20 yrs Scapula
5 yrs 20 yrs
Fig. 15.9 (A) Coronal CT surface shaded reformat right shoulder, (B) coronal
The scapula is ossified from seven or more centres CT right shoulder and (C) axial CT right shoulder.
(Tables 15.1 and 15.2).
· laterally to the anatomical neck of the humerus except
Cross-sectional anatomy (Fig. 15.9) infero-medially, where it is lax, forming the axillary
recess, allowing the joint a wide range of movement.
Shoulder joint capsule
• The fibrous capsule of the joint attaches: • The anterior joint capsule varies in the way it inserts onto
the glenoid:
· medially to the glenoid margin, enclosing the tendon
of the long head of the biceps brachii muscle which is
intracapsular

282

Chapter 15: The upper limb

· Zlatkin categorized this into three types, types 1–3, Type 1 Humerus
depending on the proximity of capsular insertion to Type 2 Anterior capsular insertion
the glenoid margin Glenoid articular surface

· the further away the insertion from the glenoid Anterior capsular insertion
margin, the more unstable the joint will be (Figs. 15.10
and 15.11). Type 3

Shoulder joint synovial membrane Anterior capsular insertion

• Lines the deep surface of the fibrous capsule, covering the Fig. 15.10 Classification of shoulder joint anterior capsular insertion. Divided
articular cartilage. into types 1–3 depending on the proximity of the anterior capsular insertion to
the glenoid articular surface. Type 1: onto the labrum/glenoid margin; Type 2:
• Surrounds the long head of biceps tendon in a synovial less than 1 cm medial to the glenoid margin; Type 3: greater than 1 cm medial
sheath which extends distally down into the bicipital to the glenoid margin.
groove, to the surgical neck of the humerus.

• Protrudes through the capsule in various areas, forming
numerous recesses or bursae:

· between the superior and middle glenohumeral
ligaments, hanging over the superior margin of the
subscapularis tendon (the superior subscapularis recess
or subscapularis bursa)

· between the middle and inferior glenohumeral
ligaments, deep to the subscapularis tendon (inferior
subscapularis recess)

· between the anterior surface of the subscapularis
tendon and the coracoid process (subcoracoid bursa)

· between teres major and the long head of triceps
brachii

· between the anterior and posterior tendons of the
latissimus dorsi muscle

· between the rotator cuff tendons and the acromion
process and deltoid muscle (the subacromial-
subdeltoid bursa) (Fig. 15.12).

• All of the recesses/bursae communicate with the joint
except for the subacromial-subdeltoid bursa and the
subcoracoid bursa, which may communicate with each
other.

• Fluid within the subcoracoid bursa can often be confused
with fluid in the superior subscapularis recess, that in the

A Long head of biceps
tendon
Capsular attachment of
joint to glenoid (anterior) Head of humerus
Glenoid labrum (anterior)
Fluid within joint
Glenoid
Glenoid labrum (posterior) Capsular attachment
of joint to glenoid
(posterior)

Fig. 15.11 (A) T1-weighted axial MRI arthrogram, left shoulder (post intra-articular gadolinium injection); (B) fat-saturated T1-weighted coronal MRI arthrogram, 283
left shoulder (post intra-articular gadolinium injection).

Section 3: Upper and Lower Limb

B

Head of humerus Glenoid
Long head of biceps tendon Axillary recess
Fluid within joint

Fig. 15.11 (cont.)

Subacromial Shoulder joint ligaments
bursa • The joint is strengthened by static and dynamic stabilizers.

Tendon of The ligaments are static stabilizers, namely:
supraspinatus
· the glenohumeral ligaments (Fig. 15.15):
Glenohumeral
joint cavity – thickenings of the anterior joint capsule
– three ligaments: superior, middle and inferior
– when viewed coronally (en face), form a ‘Z’ shape
– inferior glenohumeral ligament is most

important ligamentous joint stabilizer:

split into an anterior and posterior band, with
intervening axillary recess

Fig. 15.12 Illustration of the subacromial-subdeltoid bursa. The subacromial- · the transverse humeral ligament connects the
subdeltoid bursa lies superficial to the rotator cuff tendons and deep to the tuberosities and covers the long head of biceps tendon
acromion and deltoid muscle. As a result, on movement of the shoulder in the bicipital groove and prevents it from dislocating
(particularly during abduction) it can become easily impinged. out

former usually being pathological and that in the latter · the coracohumeral ligament
usually being physiological. · the coracoacromial ligament: forms part of the

Glenoid labrum coracoacromial arch (Fig. 15.16).

• Fibrocartilaginous rim around the periphery of the Biceps pulley system/rotator interval
glenoid. • Rotator interval:

• Deepens the articulating surface of the glenoid. · triangular interspace between the supraspinatus and
• Attachment site for long head of the biceps brachii muscle. subscapularis tendons, through which passes the long
• Low signal on all MRI sequences. head of biceps tendon.
• Varying morphology: triangular, round, cleaved, notched,
• Biceps pulley (Fig. 15.17):
flat (in order of frequency).
• Normal labral variants that can be mistaken for labral tears: · complex pulley system that:

· Buford complex: congenitally absent anterosuperior – prevents medial subluxation of the long head of
labrum associated with a thickened middle biceps tendon out of the bicipital groove
glenohumeral ligament
– stabilizes the tendon during biceps flexion
· sublabral foramen: detachment of the anterosuperior · formed by coracohumeral, superior glenohumeral and
labrum which does not extend posterior to the biceps
tendon attachment (Figs. 15.13 and 15.14). transverse humeral ligaments plus the subscapularis
tendon.

Muscles of the shoulder
• These are dynamic stabilizers of the shoulder joint, the

most important being the rotator cuff muscles.

284

Chapter 15: The upper limb
AB

Fig. 15.13 (A) Fat-saturated T1-weighted axial MRI arthrogram; (B) fat-saturated T1-weighted coronal MRI arthrogram. Left shoulder, post intra-articular
gadolinium injection. Buford complex: normal variant anatomy of the glenoid labrum which mimics a labral tear. There is deficiency of the anterosuperior glenoid
labrum (black arrowhead) with associated thickening of the middle glenohumeral ligament (white arrow). Note the normal appearance of the glenoid labrum
(black arrow). HH = humeral head; G = glenoid of scapula.

AB

Fig. 15.14 (A) Fat-saturated T1-weighted axial MRI arthrogram; (B) fat-saturated T1-weighted coronal MRI arthrogram. Right shoulder, post intra-articular
gadolinium injection. Sublabral foramen: normal variant anatomy of the glenoid labrum which mimics a labral tear. Contrast has been injected to distend the joint
capsule (black arrow). There is separation of the anterosuperior glenoid labrum from the underlying glenoid with contrast seen in between (white arrow). The
foramen never extends posterior to the attachment of the long head of the biceps tendon. A = acromion; C = clavicle; D = deltoid muscle; G = glenoid of scapula;
HH = humeral head; SS = supraspinatus muscle.

285

Section 3: Upper and Lower Limb • They comprise the supraspinatus, infraspinatus, teres
minor and subscapularis (SITS) and are important
Biceps tendon in providing stability to the shoulder joint, forming a
Superior glenohumeral ligament protective ‘cuff ’ around it (Figs. 15.18, 15.19, 15.20 and
Capsule Tables 15.3–15.5).
Middle glenohumeral ligament
Anterior band Coracoacromial arch
Inferior glenohumeral ligament
Posterior band • Formed (from anterior to posterior) by the coracoid
Inferior glenohumeral ligament process, coracoacromial ligament and acromion.

Fig. 15.15 Glenohumeral ligaments. • Located within it (from superior to inferior) are the
subacromial-subdeltoid bursa, supraspinatus tendon and
long head of biceps tendon.

• Anything that decreases the space of the arch can cause
shoulder impingement (Fig. 15.20).

Axilla
Cross-sectional imaging

The axilla is a pyramidal-shaped potential space through which
structures from the neck and chest pass into the upper limb
and vice versa.

A Supraspinatus tendon

Acromion of scapula Long head of biceps
Supraspinatus m. tendon
Coracohumeral ligament
Infraspinatus tendon Deltoid m.
Infraspinatus m. Capsule shoulder joint
Teres minor m. Head humerus

Subscapularis tendon

B Acromio-clavicular joint

Acromion of scapula Clavicle
Supraspinatus m.
Infraspinatus m. Coracohumeral ligament
Long head Glenohumeral ligament
of biceps tendon (superior)

Glenohumeral ligament Deltoid m.
(inferior) posterior band
Coracoid process
scapula
Glenohumeral ligament
(middle)
Subscapularis m.

Glenohumeral ligament
(inferior) anterior band
Capsule shoulder joint

Fig. 15.16 Sagittal oblique fat-saturated T1-weighted MRI arthrogram, right shoulder (lateral to medial, post intra-articular gadolinium injection).

286

C Chapter 15: The upper limb

Acromio-clavicular joint Clavicle
Acromion of scapula Coracohumeral ligament
Supraspinatus m. Deltoid m.
Infraspinatus m. Coracoid process
scapula
Glenohumeral ligament
(middle)
Subscapularis m.
Capsule shoulder joint

Fig. 15.16 (cont.)

Supraspinatus The nerve roots pass through the scalene triangle, formed by
Coracohumeral ligament the anterior and middle scalene muscles, with its apex at the
Long head of biceps tendon 1st rib.
Superior glenohumeral ligament
The roots are in close proximity to the subclavian artery
Subscapularis (below the clavicle), which can be used as an anatomical land-
mark when assessing MRI images (Fig. 15.23).

Fig. 15.17 Biceps pulley system. A Long head of
biceps tendon
The contents of the axilla include the major neurovascular Acromion Coracoid process
structures (subclavian and axillary artery and vein and the Supraspinatus
brachial plexus) of the upper limb, lymphatics and the proxi- Labrum
mal parts of the biceps brachii and coracobrachialis muscles Glenoid cavity Fibrous capsule
(Figs. 15.21 and 15.22).
Infraspinatus Subscapularis
Brachial plexus Teres minor
Nerve plexus made up of:
• five roots (anterior rami of C5 to T1), which form into Fig. 15.18 (A) Illustration of rotator cuff tendons; (B) sagittal T1-weighted MRI
• three trunks (upper, middle and lower), which divide image of the left shoulder.

into
• six divisions (anterior and posterior from each trunk),

which form into
• three cords (lateral, medial and posterior):

· the musculocutaneous nerve is the continuation of the
lateral cord

· the ulnar nerve is the continuation of the medial
cord

· the radial and axillary nerves are the continuation of
the posterior cord

· the median nerve is the continuation of a
communication between the lateral and medial cords.

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Section 3: Upper and Lower Limb

Spine of scapula B
Clavicle
Deltoid m.
Supraspinatus m. Infraspinatus m.
Body of scapula Teres minor m.

Subscapularis m. Long head of biceps
tendon
Fig. 15.18 (cont.) Head of humerus
Deltoid m.
A
Acromion of scapula
Coracobrachialis m. Supraspinatus tendon
Glenoid of scapula Head of humerus
Greater tuberosity of
Subscapularis m. humerus
Supraspinatus m. Deltoid m.

B

Acromio-clavicular joint
Clavicle

Glenoid labrum
Supraspinatus m.
Glenoid of scapula

Infraspinatus m.
Glenoid labrum

Fig. 15.19 (A) axial T1 MRI, left shoulder; (B) coronal T1 MRI, left shoulder.

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Chapter 15: The upper limb

Table 15.3 Muscles attaching the scapula to the humerus Table 15.5 Muscles attaching the upper limb to the spine

Muscle Origin Insertion Action Muscle Origin Insertion Action
Trapezius
Deltoid Lateral 1/3 Deltoid Abduction; flexion External occipital Lateral 1/3 of Acts with other
of clavicle; tuberosity on and internal Latissimus
acromion; spine lateral humeral rotation (anterior dorsi protuberance; clavicle; acromion muscles to steady,
of scapula diaphysis fibres); extension
and external Levator ligamentum and spine of elevate and rotate
rotation (posterior scapulae
fibres) nuchae; spine of scapula the scapula
Rhomboid
minor C7 and all thoracic

Rhomboid vertebrae
major
Spines of lower Floor of the Extends, adducts
and internally
Supraspinatus Supraspinous Greater Abduction; weak six thoracic bicipital groove rotates arm
fossa of scapula tuberosity of external rotator
humerus (upper and flexor vertebrae, of humerus
facet)
lumbar and sacral

vertebrae; iliac

Infraspinatus Infraspinous fossa Greater External rotation; crest; lower 3–4
abductor (upper
of scapula tuberosity of part); adductor ribs; inferior angle
(lower part)
humerus (middle of scapula

facet) Transverse Medial border of Elevates medial
processes of
Teres minor Upper 2/3 of Greater External rotation; 1st four cervical scapula border of scapula
lateral border of tuberosity of weak adductor vertebrae
scapula humerus (lower
facet)
Spines of C7 and Medial border of Elevates medial
Teres major Lower 1/3 of Bicipital groove of Internal rotation T1 vertebrae; scapula border of scapula;
lateral border of lower part of retracts and fixes
scapula humerus and adduction ligamentum scapula
nuchae

Subscapularis Subscapular Lesser tuberosity Internal rotation Spines of C2–C5 Medial border of Elevates medial
vertebrae scapula border of scapula;
fossa on anterior of humerus retracts and fixes
scapula
surface of scapula

Table 15.4 Muscles attaching the upper limb to the thoracic wall

Muscle Origin Insertion Action Cross-sectional anatomy
Pectoralis
major Clavicle; sternum; Lateral lip of Adduction; • The arm is encircled by a sheath of deep fascia.
1st six costal bicipital groove internal rotation • Lateral and medial intermuscular septae extend from it
Pectoralis cartilages and posterior
minor lamina of long to the respective supracondylar ridges of the humerus,
head of biceps dividing the arm into separate anterior and posterior
Subclavius tendon fascial compartments.
Serratus • Each compartment contains its own muscles and
anterior 3rd–5th ribs Coracoid process Depresses neurovascular supply (Fig. 15.25).
of scapula shoulder; elevates
3rd–5th ribs if Anterior (flexor) fascial compartment
scapula fixed • Muscular contents: biceps brachii, coracobrachialis and

1st costal cartilage Clavicle Depresses clavicle brachialis muscles
• Blood supply: brachial artery
1st eight ribs Medial border of Rotates scapula • Nerve supply: musculocutaneous nerve (Table 15.6 and

scapula and moves it Fig. 15.26).

anteriorly Posterior (extensor) fascial compartment
• Muscular contents: triceps brachii muscle
Arm • Blood supply: profunda brachii and ulnar collateral
Plain radiographic anatomy
arteries
Humerus (Fig. 15.24) • Nerve supply: radial nerve (Table 15.7).

• Deltoid tuberosity: roughened protuberance on the Elbow
humeral diaphysis for attachment of the deltoid muscle. Plain radiographic anatomy

• Spiral groove: accommodates the radial nerve. Distal humerus
• Lateral and medial supracondylar ridges: linear • The distal humeral articular surfaces are the capitellum

elevations on the lateral and medial aspects of the distal laterally and the trochlea medially.
humerus that provide attachment for the fascial septa of
the arm.

289

Section 3: Upper and Lower Limb

Subcutaneous fat A
Deltoid m.
Transverse
Greater tuberosity humeral
of humerus ligament

Subcutaneous B Long head of biceps
fat tendon
Lesser tuberosity of
Deltoid m. humerus
Bicipital groove
Long head of humerus
biceps tendon Head of humerus

Head of humerus Subcutaneous fat

C

Deltoid m.
Coracohumeral ligament
Superior glenohumeral
ligament
Subscapularis tendon
Long head of biceps tendon
Supraspinatus tendon
Head of humerus

Subcutaneous fat D E Subcutaneous fat
Deltoid m.
Deltoid m.
Subscapularis
tendon Supraspinatus
tendon
Head of humerus
Head of humerus

Fig. 15.20 (A) Axial ultrasound, right long head of biceps tendon; (B) longitudinal ultrasound, right long head of biceps tendon; (C) axial ultrasound, right rotator
interval; (D) longitudinal ultrasound, right subscapularis tendon; (E) longitudinal ultrasound, right supraspinatus tendon.

290