Applied Radiological Anatomy

C Chapter 9: The anterior abdominal wall and peritoneum

Bare area of liver Diaphragm
Coronary ligament
Visceral peritoneum investing liver Superior recess of omental bursa
Aorta
Lesser omentum Epiploic foramen
Subhepatic space Omental bursa (lesser sac)
Visceral peritoneum investing Coeliac trunk
Pancreas
stomach Superior mesenteric a.
Transverse mesocolon Duodenum
Visceral peritoneum investing colon Mesentery of small intestine

Transverse colon Parietal peritoneum
Inferior recess of omental bursa
Rectouterine pouch
Greater sac (Pouch of Douglas)
Rectum
Greater omentum Vagina

Visceral peritoneum investing
small intestine
Uterus

Vesicouterine pouch
Urinary bladder

Symphysis pubis
Urethra

D Left coronary
ligament
Left subphrenic Left posterior
space perihepatic space

Left lobe of liver Omental bursa
Left anterior (lesser sac)

perihepatic space Left kidney
Lesser omentum Pancreas

Stomach Duodenum

Transverse Infracolic space
mesocolon

Transverse colon

Greater omentum

Fig. 9.12 (cont.) · communicates on the right with the left anterior
perihepatic space, and posteriorly with the posterior
· bounded on the left by the lesser curvature of the subphrenic (perisplenic) space.
stomach
• Posterior left subphrenic (perisplenic) space (Figs. 9.12e,
· communicates anteroinferiorly with the anterior left 9.14a,b, 9.15d)
perihepatic space.
· superior to gastric fundus and spleen
• Anterior left subphrenic space (Figs. 9.12d,e, 9.15a,b,c) · covers the superior and inferolateral surfaces of the

· this lies between the stomach and the left spleen
hemidiaphragm

141

Section 2: Thorax and Abdomen Left posterior
subphrenic space
E Spleen
Splenorenal
Left anterior ligament
subphrenic space Omental bursa
(lesser sac)
Gastrosplenic Tail of pancreas
ligament
Left kidney
Stomach
Colon

Fig. 9.12 (cont.)

Bare area · limited inferiorly by the splenorenal and
of liver phrenicocolic ligaments, and more superiorly by the
gastrosplenic ligament
Liver
Right · partially separated from the rest of the peritoneal
subphrenic cavity by the phrenicocolic ligament which extends
space from the splenic flexure to the diaphragm.
Right posterior
subhepatic Inframesocolic compartment (Fig. 9.12)
space
(Morison's Divided into two unequal spaces posteriorly by the root of the
pouch) small bowel mesentery.
Right anterior • Right inframesocolic space (Figs. 9.11, 9.13, 9.14d,e,f,
subhepatic
space 9.15c)
Right kidney
Right · bounded by the transverse mesocolon superiorly
inframesocolic and to the right, and by the root of the small bowel
space mesentery inferiorly and to the left.
Greater
omentum • Left inframesocolic space (Figs. 9.11, 9.14e,f, 9.15c)
Caecum
· larger than on the right
Fig. 9.13 Sagittal CT taken through the right lobe of liver and right kidney. · in free communication with the pelvis to the right of

the midline
· sigmoid mesocolon forms a partial barrier to the left

of the midline.

• Paracolic gutters (Figs. 9.11, 9.14d,e,f, 9.15b,c)

· peritoneal recesses on the posterior abdominal wall
lateral to the ascending and descending colon

· right paracolic gutter: continuous superiorly with
the right subhepatic and subphrenic spaces; larger
than the left

142

A Chapter 9: The anterior abdominal wall and peritoneum

Falciform ligament Left subphrenic space
Greater omentum
Gastrohepatic
ligament Stomach
Left posterior
Right subphrenic subphrenic
space (perisplenic) space
Spleen
Liver

Bare area of liver

B

Superior recess of Falciform ligament
lesser sac Stomach
Pancreatic tail
Fissure for Greater omentum
ligamentum venosum
Lesser sac
Gastrohepatic ligament Phrenicocolic
Right subphrenic space ligament

Posterior left perihepatic Gastrosplenic
space (gastrohepatic ligament
recess)
Liver Left posterior
(perisplenic) space
Small amount of fluid in the Spleen
right posterior subhepatic
space (Morison’s pouch) Splenorenal ligament

Right kidney

C Fat in the greater
omentum
Stomach
Phrenicocolic ligament
Right subphrenic space
Left kidney
Liver

Right posterior
subhepatic space
(Morison’s pouch)

Right kidney

Fig. 9.14 Axial CT sections in a patient with abdominal and pelvic ascites secondary to an ovarian malignancy. Ascitic fluid distends the potential space of the
peritoneal cavity, demonstrating the peritoneal spaces and reflections.

143

Section 2: Thorax and Abdomen Transverse mesocolon
Right inframesocolic
D space
Small bowel mesentery
Transverse colon containing mesenteric
Right paracolic gutter vessels
Duodenocolic ligament Left paracolic gutter
Right subphrenic space
Left kidney
Liver
Right posterior subhepatic Small bowel mesentery

space (Morison’s pouch) Small bowel
Left inframesocolic
E space
Left paracolic gutter
Right inframesocolic
space Descending colon

Ascending colon Mesentery of the
descending colon
Right paracolic
gutter Small bowel
mesentery
Small bowel
mesentery Root of small bowel
connecting mesentery open to
the retroperitoneum
posteriorly to the Left inframesocolic
retroperitoneum space

F Left paracolic
gutter
Greater omentum

Right inframesocolic
space

Right paracolic
gutter

Mesentery
of caecum
and appendix

Fig. 9.14 (cont.)

144

G Chapter 9: The anterior abdominal wall and peritoneum

Rectouterine pouch Uterus
(Pouch of Douglas) Rectum

Fig. 9.14 (cont.)

A

Right subphrenic Left subphrenic space
space Stomach
Gastrosplenic ligament
Liver Phrenicocolic ligament
Root of the transverse
Right subhepatic space mesocolon

Right paracolic gutter Left paracolic gutter
Small bowel mesentery
Sigmoid mesocolon
Malignant ovarian mass

Fig. 9.15 Coronal CT reformats in a patient with abdominal and pelvic ascites secondary to an ovarian malignancy. Ascitic fluid distends the potential space of the
peritoneal cavity, demonstrating the peritoneal spaces and reflections.

145

Section 2: Thorax and Abdomen

B

Right subphrenic Left subphrenic
space space
Gastrosplenic
Liver ligament
Root of small bowel
Right paracolic gutter mesentery

Small bowel mesentery Left paracolic gutter
Malignant ovarian mass
Sigmoid colon
Bladder
Left subphrenic space
C Gastrosplenic and
phrenicocolic ligaments
Right subphrenic Lesser sac
space Transverse mesocolon

Liver Left paracolic gutter
Left inframesocolic space
Portal v.
Malignant ovarian mass
Right paracolic gutter

Right inframesocolic
space

Fig. 9.15 (cont.)

146

D Chapter 9: The anterior abdominal wall and peritoneum

Right subphrenic Left subphrenic space
space Lesser sac
Gastrosplenic ligament
Liver Phrenicocolic ligament
Left paracolic space
Anterior aspect of
inferior vena cava Left psoas

Aorta Malignant ovarian
Right posterior mass
subhepatic space Bladder
(Morison’s pouch)

Right subhepatic space

Fig. 9.15 (cont.)

· left paracolic gutter: partially separated from the left · gastrosplenic ligament
subphrenic spaces by the phrenicocolic ligament · falciform ligament
· phrenicocolic ligament
· both paracolic spaces are in continuity with the · splenorenal ligament
pelvic peritoneal spaces. · hepatoduodenal ligament
· duodenocolic ligament.
Pelvic peritoneal spaces
• Two omenta:
• Inferiorly the peritoneum is reflected over the dome of
the bladder, the anterior and posterior surface of the · lesser omentum (gastrohepatic ligament)
uterus and upper posterior vagina in females, and on to · greater omentum (gastrocolic ligament).
the front of the rectum at the junction of its middle and
lower thirds. • Four mesenteries:

• The urinary bladder subdivides the pelvis into right and · small bowel mesentery
left paravesical spaces. · transverse mesocolon
· sigmoid mesocolon
• In men, there is only one potential space for fluid · mesoappendix.
collection posterior to the bladder, the rectovesical pouch.
The peritoneal reflections carry areolar tissue, vessels,
• In women there are two potential spaces: posterior to the nerves and lymphatics from the retroperitoneum to the
bladder, the uterovesical pouch (Fig. 9.12c) and, posterior
to the uterus, the deeper rectouterine pouch (of Douglas) Table 9.1 Peritoneal reflections: nomenclature
(Figs. 9.12c, 9.14g).
Term Definition
• The layers of peritoneum on the anterior and posterior Peritoneal
surfaces of the uterus are reflected laterally to the ligament Formed by two folds of peritoneum that enclose and
pelvic side walls as the broad ligaments, containing the support structures within the peritoneal cavity
Fallopian tubes. Omentum
Named according to the structures it joins
Peritoneal reflections (Table 9.1) Mesentery
Peritoneal ligament that joins the stomach to another
The peritoneal reflections in the upper abdomen comprise: structure
• Eight ligaments:
Two folds of peritoneum that attach a loop of bowel to the
· right coronary ligament retroperitoneum
· left coronary ligament

147

Section 2: Thorax and Abdomen

peritoneal organs, forming a natural connection between the · carries the portal triad (hepatic artery, portal vein and
retroperitoneum and peritoneum. common bile duct)

These reflections are generally recognizable as fat-con- · anterior margin of the epiploic foramen (of Winslow).
taining structures on cross-sectional imaging, either by their
typical location and organ relationships or by the landmarks 8. Duodenocolic ligament (Figs. 9.11, 9.14d)
provided by their major constituent vessels. · extends from the hepatic flexure to the descending
duodenum
Peritoneal ligaments · continuous with the transverse mesocolon
· carries the lymphatic drainage of the right-sided colon
1. Right coronary ligament (Fig. 9.12a,c) to the central superior mesenteric nodes.
· formed by the reflection of the peritoneum from the
diaphragm to the posterior surface of the right lobe of Omenta
the liver
· the triangular area of liver enclosed by these layers 1. Greater omentum (gastrocolic ligament) (Figs. 9.12b,c,d,
is the bare area devoid of peritoneal covering and is 9.13, 9.14a,b,c,f)
continuous with the anterior pararenal space. · largest peritoneal fold consisting of a double sheet
folded on itself (i.e. made up of four layers)
2. Left coronary ligament (left triangular ligament) · two layers of peritoneum descend from the greater
(Figs. 9.11, 9.12d) curve of the stomach and proximal duodenum
· flimsy structure formed by apposition of the passing inferiorly, anterior to the small bowel for
peritoneal reflections between the left lobe of liver a variable distance, and then turn superiorly again
and diaphragm to insert into the anterosuperior aspect of the
· little clinical significance. transverse colon
· the left border is continuous with the gastrosplenic
3. Gastrosplenic ligament (Figs. 9.11, 9.12e, 9.14b, 9.15a,b,c,d) ligament
· extends from the greater curve of the stomach to the · the right border extends to the origin of the
spleen duodenum
· continuous with the greater omentum · contains adipose tissue which is easily identified on
· contains the left gastroepiploic and short gastric vessels. CT anterior to the transverse colon superiorly and
loops of small bowel inferiorly.
4. Falciform ligament (Figs. 9.11, 9.14b)
· extends from the anterosuperior surface of the 2. Lesser omentum (gastrohepatic ligament) (Figs. 9.12b, c, d,
liver to the diaphragm and anterior abdominal 9.14b)
wall, carrying the ligamentum teres (obliterated left · extends from the lesser curvature of the stomach and
umbilical vein) in its free edge proximal 2 cm of the duodenum to the liver (attached
· in continuity with the fissure for the ligamentum to the fissures for the porta hepatis and ligamentum
venosum and coronary ligaments. venosum)
· forms the anterior surface of the lesser sac
5. Phrenicocolic ligament (Figs. 9.11, 9.14b,c, 9.15a,c,d) · the free edge forms the hepatoduodenal ligament
· extends from the splenic flexure to the diaphragm at · generally wedge-shaped and contains adipose tissue,
the level of the eleventh rib the gastric artery, the coronary vein, and the left
· continuous with the transverse mesocolon and gastric nodal chain
splenorenal ligament · identified on cross-sectional imaging by finding the
· supports the spleen fissure for the ligamentum venosum immediately
· potential barrier to the spread of infected fluid inferior to the gastro-oesophageal junction.
from the pelvis and left paracolic gutter to the left
subphrenic space. Mesenteries

6. Splenorenal ligament (Figs. 9.12e, 9.14b) 1. Small bowel mesentery (Figs. 9.11, 9.12b,c, 9.14d,e,f,
· extends from the tip of the pancreatic tail to the splenic 9.15a,b, 9.16)
hilum, carrying the splenic vessels · contains fat, the jejunal and ileal branches of the
· continuous with the gastrosplenic ligament, forming superior mesenteric arteries and their accompanying
the left lateral boundary of the lesser sac. veins, nerves and lymphatics
· suspends 20–25 feet of jejunum and ileum
7. Hepatoduodenal ligament (Fig. 9.11) · connected to the posterior abdominal wall by an
· represents the thickened free right edge of the lesser oblique 15 cm root extending from the duodenojejunal
omentum (gastrohepatic ligament) flexure to the ileocaecal valve
· extends from the flexure between the first and second
parts of the duodenum to the porta hepatis

148

Chapter 9: The anterior abdominal wall and peritoneum

Liver 2. Transverse mesocolon (Figs. 9.11, 9.12b,d, 9.15a,b)
Superior
mesenteric a. · connects the transverse colon to the posterior
within the small abdominal wall

bowel · formed by two layers passing from the anterior
mesentery surface of the head and the anterior border of the
Right external body of the pancreas to the posterior surface of the
oblique muscle transverse colon, where they separate to surround
Right internal the bowel
oblique muscle
Small bowel · the upper layer is adherent to, but separable from, the
greater omentum
Right
transversus · carries the middle colic vessels, autonomic nerves,
and lymphatics which supply the transverse colon
abdominis
muscle · becomes confluent with the root of the small
bowel mesentery near the uncinate process of the
Bladder pancreas.

Fig. 9.16 Coronal MRI image depicting the small bowel mesentery and the 3. Sigmoid mesocolon (Figs. 9.11, 9.15a)
lateral abdominal wall musculature.
· attaches the sigmoid colon to the pelvic wall in an
· the root is a bare area continuous with the left inverted V, the apex of which lies anterior to the left
anterior pararenal space superiorly and the right common iliac artery bifurcation and left ureter; the
anterior pararenal space inferiorly; it passes in left limb descends medially to the left psoas muscle;
front of the horizontal part of the duodenum (where the right limb descends into the pelvis and ends in the
the superior mesenteric vessels enter the mesentery), midline anterior to S3
abdominal aorta, inferior vena cava, right ureter and
right psoas muscle as it travels from left to right. · carries the sigmoid and superior rectal vessels.

4. Mesoappendix (Fig. 9.14f)

· surrounds the vermiform appendix and attaches to the
lower end of the small bowel mesentery close to the
ileocaecal junction

· usually extends to the tip of the appendix and
sometimes suspends the caecum.

149

Section 2 Thorax and Abdomen

Chapter The abdomen and retroperitoneum

10 Navin Ramachandran and Aslam Sohaib

Plain film

Plain abdominal radiographs have a very limited role in assess-
ing the anatomy related to the abdominal viscera and the
retroperitoneum.

The anatomical structures that can be visualized include:

• liver (Fig. 10.1)
• spleen (especially if enlarged)
• kidneys (Fig. 10.1)
• calcification in the following structures can sometimes be

seen: pancreas (Fig. 10.2), spleen, adrenals, aorta, lymph
nodes and gallbladder.

Cross-sectional anatomy
Liver

• Largest/heaviest solid organ in the body (1.5 kg)
• Anatomical position and relationships: see Figs. 10.3–10.8

Fig. 10.2 Plain abdominal film of a patient with pancreatic calcification due
to chronic pancreatitis.

Right kidney • Appearance on CT/MRI/US is illustrated in Figs. 10.3–10.8.
Table 10.1 shows the signal intensity of abdominal viscera
Inferior tip of on T1- and T2-weighted images with respect to liver.
Riedel’s lobe
• Segmental anatomy of liver (Figs. 10.9–10.12)
Fig. 10.1 Plain abdominal X-ray of a Riedel’s lobe, an inferior extension of the
right hepatic lobe (normal variant). · Previously the liver was divided into right, left,
quadrate and caudate lobes.

· This has been superseded by the Couinaud system of
liver segments which reflect function as well as gross
anatomy.

Table 10.1 Signal intensity of abdominal viscera, compared to the liver on
T1- and T2-weighted MR images

Structure T1-weighted T2-weighted
Liver Equal Equal
Spleen Lower Higher
Pancreas Higher (protein content) Equal / lower
Kidney Lower Higher
Adrenal Equal / lower Equal / lower
Muscle Lower Lower

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.

150

Chapter 10: The abdomen and retroperitoneum

AB

Hepatic v.

Aorta Coeliac a.
Spleen Inferior vena
cava
Splenic a.

Hepatic v.

CD

Splenic v.

Portal v.

Splenic a. Superior
Coeliac a. mesenteric a.
Renal a. Renal v.

Inferior Portal v.
vena cava branch

Hepatic v.

EF

Superior
mesenteric
a. branch

Superior Renal a.
mesenteric a.

Aorta

Inferior vena Inferior
cava vena cava

Fig. 10.3 Arterial phase CT through the upper abdomen. Compare appearances to portal venous scans (Fig. 10.4). Note the inhomogeneous opacification of the
spleen, as well as relative underenhancement of the portal venous system and systemic veins.

– nine segments (segments I–III, IVa and IVb, • Peritoneal ligaments (Fig. 10.13)
V–VIII)
· Falciform ligament = double-fold of peritoneum from
– caudate lobe = segment I umbilicus to liver. Contains ligamentum teres, the
– portal and hepatic veins used as landmarks remnant of the umbilical vein, which attaches to the
left portal vein.
to divide the remainder of the liver into eight
segments – in the fetus, umbilical vein carries oxygenated
– the three (left, middle and right) hepatic veins blood from the cord via the left portal vein and
divide the liver into four sections ductus venosus to the IVC
– the portal veins divide each of these into
superior and inferior segments, a total of eight. – umbilical vein can recanalize in portal
hypertension.
· Riedel’s lobe (Fig. 10.1), a normal variant, is an inferior
extension of the right lobe of the liver (around segment · Falciform ligament splits into coronary ligament
VI). May be mistaken for pathological hepatomegaly. (which becomes the right triangular ligament) and
Occurs in 5–10% of females. Rare in males. left triangular ligament, between which lies the bare

151

Section 2: Thorax and Abdomen B
A

Heart Pericardium

Liver Hepatic v.
Hepatic v.
Diaphragmatic
Stomach crus
Oesophagus
Inferior vena
cava
Aorta

CD

Left portal v.

Hepatic v. Portal v.
Stomach Pancreas

Diaphragmatic Hepatic v.
crus Left kidney
Inferior vena
cava

Spleen

First part of

E F duodenum

Superior

Fat around mesenteric v.

falciform Pancreatic
ligament head

Pancreatic duct Renal v.

Pancreas Transverse
colon

Splenic v. Gallbladder

Left adrenal Second part of
Spleen duodenum

Left kidney Pancreatic tail

Right adrenal Spleen
Aorta

Diaphragmatic
crus

Right kidney

Pylorus Transverse
colon
G Gallbladder H

Superior Stomach
mesenteric v.

Transverse Transverse
colon colon

Uncinate Third part of
process of duodenum
pancreas
Descending
Renal v. colon

Descending
colon

Inferior vena
cava

Fig. 10.4 Portal phase CT through the upper abdomen, axial images. Note the relations of the organs, the relatively higher opacification of the portal and
systemic veins compared to the arterial phase scans (Fig. 10.3), and the homogeneous appearance of the spleen.

152

I Third part of J Chapter 10: The abdomen and retroperitoneum
duodenum
Fig. 10.4 (cont.) Superior Aorta
A mesenteric v.
Inferior vena
C Aorta cava
Descending
E Inferior vena colon
cava Ascending
colon
Transverse
colon

Descending
colon

Ascending
colon

Heart B Hepatic v.
Fat around
falciform Left portal v.
ligament
Stomach
Stomach Pancreatic
body
Pylorus Splenic v.
Pancreatic
Liver head
Gallbladder
Transverse
colon Superior
mesenteric a.
Hepatic v. D
Coeliac a. F Superior
mesenteric v.
Pancreatic Uncinate
body process of
Superior pancreas
mesenteric a. Transverse
Splenic flexure colon

Portal v. Aorta
Stomach
First part of Inferior vena
duodenum cava
Aorta Spleen
Hepatic flexure Hepatic v.
Inferior vena Left adrenal
cava
Pancreatic
Diaphragmatic tail
crura Branch of
Stomach portal v.
Left kidney
Right adrenal Right kidney
Descending
Spleen colon
Caecum
Branch of
portal v. Stomach
Left kidney
Right kidney Hepatic v.
Right adrenal
Spleen

Left kidney

Right kidney

Psoas

Fig. 10.5 Portal phase CT through the upper abdomen, coronal images. Note the relations of the organs.

153

Section 2: Thorax and Abdomen

A B Splenic v.
Spleen
Stomach Stomach Splenic a.
Pancreas
Spleen Left kidney

Pancreatic Aorta
tail Superior
mesenteric a.
Transverse Descending Transverse Third part of
colon colon colon duodenum

C Splenic v. Pancreas D Right
Liver adrenal
Pancreas Left adrenal Right kidney
Stomach Left kidney Stomach Psoas
Renal a. Inferior vena
Third part of cava
duodenum Renal v.

Psoas

E F

Hepatic v. Inferior Liver
vena
Portal v. cava Portal v.

Stomach Third part of Stomach
Superior duodenum Third
mesenteric v.
part of
duodenum

Fig. 10.6 Portal phase CT through the upper abdomen, sagittal images. Note the relations of the organs.

154

G Chapter 10: The abdomen and retroperitoneum

Portal v. Hepatic v. H
Right kidney
First part of Psoas Portal v.
duodenum Hepatic v.
Gallbladder
Stomach
Ascending
colon

Fig. 10.6 (cont.)

A B Fat around
falciform

ligament

Left lobe of

liver Left lobe

of liver

Diaphragm Right lobe of

Branch of liver

portal v.

Heart

Branch of
hepatic v.

Aorta Caudate lobe

Aorta

Inferior vena
cava

Vertebral body

C Branch of D
portal v.

Hepatic v. Branch of
hepatic v.

Gallbladder Portal v.
Right lobe
of liver Common
bile duct
Portal v.
Diaphragm Aorta
Vertebral
Inferior body
vena cava

Figs 10.7 Ultrasound views of the liver derived from recommendations by the American Institute of Ultrasound in Medicine. (A) Longitudinal and (B) transverse
views through the left lobe. (C) Longitudinal and (D) transverse views through the right lobe. (E) Transverse image through the caudate lobe. (F) Appearances
on the high-frequency linear ultrasound probe. (G) Longitudinal and (H) transverse views comparing the echogenicity of the liver against the right kidney. (I–L)
Greyscale and colour Doppler views of the confluence of the hepatic veins and of the main portal vein. (M, N) Transverse images through the liver showing the left
and right branches of the portal vein.

155

Section 2: Thorax and Abdomen Fat around F
E falciform
ligament Liver surface
G
Left lobe of Branch of
I liver hepatic v.

K Right lobe of Liver
liver Gallbladder
Fig. 10.7 (cont.) Right
Branch of kidney
156 portal v.
Caudate lobe Vertebral
body
Inferior vena
cava

Aorta

H

Rib
Liver

Right kidney

Posterior
acoustic
shadow
artefact
from rib

Branch of J
portal v.

Hepatic v.

Inferior vena
cava
Diaphragm

L

Branch of
hepatic v.

Portal v.

Inferior
vena cava

Chapter 10: The abdomen and retroperitoneum

M Left branch N

of portal v.

Left lobe Right lobe of
of liver liver

Right lobe
of liver

Right branch of
portal v.

Fig. 10.7 (cont.) Liver B
A Hepatic v.

Inferior vena
cava

Stomach
Oesophagus
Spleen

Aorta

Common

C hepatic D

duct

Caudate lobe

Stomach

Pancreatic
body
Portal v.

Splenic v.

Inferior vena
cava

Spleen

Splenic a.

Aorta
Right adrenal

Fig. 10.8 Paired axial T1- (left) and T2-weighted (right) images through the upper abdomen, demonstrating the differing appearances of organs on the two
sequences. Note that appearances are not exactly the same on both sequences due to movement. Labels are provided mainly on the T1-weighted images. The
coeliac axis is best seen on the T2-weighted images and therefore only labelled here.

157

Section 2: Thorax and Abdomen Fat around F
E falciform
ligament Coeliac a.
G
Hepatic a.
I
Stomach
K
Pancreatic
Fig. 10.8 (cont.) body

158 Common bile
duct

Splenic v.

Inferior vena
cava
Diaphragmatic
crus

Spleen

Aorta

Right adrenal
Portal v.

Fat around H
falciform J
ligament L
Common bile
duct
Pancreatic
head

Splenic v.
Portal v.

Left adrenal

Spleen
Left kidney
Right kidney
Branch of
portal v.

Pancreatic
head
Superior
mesenteric v.
Splenic v.
Common bile
duct

Superior
mesenteric a.

Left adrenal
Inferior vena
cava

Left kidney
Right kidney

Common bile
duct

Superior
mesenteric v.

Superior
mesenteric a.

Uncinate
process
of pancreas

Renal v.

Right Chapter 10: The abdomen and retroperitoneum
hepatic v.
Left hepatic v.
VII I II
VIII IV
Middle
hepatic v.

III

VI V Portal v.

Hepatic a. Bile duct

Fig. 10.9 Segmental liver anatomy. B

A

CD
Fig. 10.10 Segmental anatomy of the liver, axial. Segments labelled.

159

Section 2: Thorax and Abdomen F
E

GH

Fig. 10.10 (cont.) – in 90%, right hepatic artery passes anterior to
portal vein.
area of the liver. These ligaments attach the liver to the
diaphragm. • Accessory arteries are present in addition to the normal
artery. Replaced arteries are present in the absence of the
• Blood supply (Figs. 10.14–10.23) normal artery (Fig. 10.19).

· The liver has a dual blood supply: hepatic artery and · In 18.5% of individuals, hepatic arteries arise from
portal vein. the superior mesenteric artery (SMA): 10% = replaced
right hepatic artery; 6% = accessory right hepatic
· Hepatic artery (Figs. 10.14–10.19) artery; 2.5% = replaced common hepatic artery.

– provides 15% of hepatic blood supply · 25% of individuals have left hepatic arteries arising
– branch of coeliac artery from the left gastric artery: 13% = accessory
– common hepatic artery passes over the head of 12% = replaced.

pancreas and gives off right gastric artery, then · Portal vein (Figs. 10.15–10.18, 10.20)
gives off gastroduodenal artery at the epiploic
foramen to become the hepatic artery proper – provides 85% of blood supply to liver
– hepatic artery continues in the free edge of the – formed by union of the splenic vein and superior
lesser omentum, anterior to the portal vein and
to the left of the common bile duct (CBD) mesenteric vein (SMV) posterior to neck of
– divides into left and right branches at the porta pancreas at L1/L2
hepatis – runs at posterior aspect of free edge of lesser
– anatomical variants: omentum to the porta hepatis; it lies posterior to
hepatic artery and CBD
– relatively common

160

Chapter 10: The abdomen and retroperitoneum
AB

CD

EF

GH
Fig. 10.11 Segmental anatomy of the liver, coronal. Segments labelled.

161

Section 2: Thorax and Abdomen B
A

CD

EF

Fig. 10.12 Segmental anatomy of the liver, sagittal. Segments labelled.

162

Chapter 10: The abdomen and retroperitoneum

Attachment of falciform ligament
Anatomical left lobe
Anatomical right lobe

Ligamentum teres
Gallbladder

AA Bare area

Left Coronary
triangular ligament ligaments

Fissure for
ligamentum venosum

Caudate lobe
Inferior vena cava

Porta hepatis

Ligamentum teres
Portal v.

Gallbladder
Hepatic a.
Bile duct

BB

Inferior vena cava

Hepatic a.
Bile duct
Portal v.

C Ligamentum
C Gall bladder teres

Quadrate lobe Area for
Area for hepatic flexure stomach

Porta hepatis
Area for duodenum

Inferior vena cava Caudate
Area for kidney lobe

Fig. 10.13 Peritoneal ligaments. (A) Anterior, (B) posterior, (C) semi-opaque anterior and (D) inferior views of the live. DD

163

Section 2: Thorax and Abdomen Left hepatic a.
Hepatic a.
Right
hepatic Common
hepatic a.
duct
Right Gastroduodenal a.
hepatic a.
Gallbladder Lesser omentum
Cystic duct Stomach
Hepatic a.
Common Gastrosplenic ligament
bile duct Short gastric vessel
Splenic a.
Fig. 10.14 Relations of the hepatic arterial system. Lienorenal ligament
Left kidney
Common bile duct
Portal v. Portal v.
Hepatic a.
Epiploic foramen Gastroduodenal a.
(of Winslow) Duodenum
Aorta Splenic v.
Superior
Inferior vena cava mesenteric v.

Fig. 10.15 Hepatic artery in lesser omentum.

Left hepatic duct
Right hepatic duct
Common bile duct
Neck of gallbladder

Cystic duct
Body of gallbladder
Fundus of gallbladder

Fig. 10.16 Relations of portal structures.

164

Left hepatic a. Left hepatic a. Chapter 10: The abdomen and retroperitoneum
Right hepatic a. Right hepatic a.
Left hepatic a.

Right hepatic a.

Hepatic a. Hepatic a.

Fig. 10.17 Relations of the bile ducts and hepatic artery.

Right hepatic a.

Portal v.

AA 90% BB 10%

Fig. 10.18 Variation in relations of hepatic artery and portal vein.

A

Coeliac a.

Replaced
hepatic a.
Superior
mesenteric a.

Aorta

Fig. 10.19 Normal variations in hepatic arterial tree. Coronal MIP CT images through the upper abdomen in arterial phase enhancement. Normal variant hepatic
arteries are seen to arise from the SMA. (A) If no hepatic artery arises from the coeliac axis, this is termed a replaced hepatic artery. (B) If a normal hepatic artery is
present from the coeliac axis, this is an accessory hepatic artery.

165

Section 2: Thorax and Abdomen Coeliac a.

B Superior
mesenteric a.
Usual hepatic
a. arising
from the

coeliac axis
Accessory
hepatic a.

Aorta

Fig. 10.19 (cont.)

Portal Oesophageal Short gastric 1 Portal
(8cm long) branches of Pancreatic 2 Splenic
left gastric 3 Inferior
Superior inferior Spleen
pancreatico- Right gastric Left gastroepiploic mesenteric
duodenal Splenic 4 Superior

Right colic Middle colic mesenteric

Superior Right, left Inferior mesenteric
mesenteric gastroepiploic
Anterior, posterior Jejunal Upper and lower
Ileal left colic
caecal
Ileocolic Sigmoid
Fig. 10.20 Portal vein branches. Appendicular Superior rectal

– the predominantly portal vein input means that vein and their branches) can be interrogated, each with
the liver enhances (Figs. 10.3–10.4) poorly in the their own characteristic traces on spectral Doppler
arterial phase and shows maximal enhancement (Fig. 10.21).
in the portal venous phase.
• Portosystemic anatomoses (Figs. 10.22–10.23)
• Venous drainage of the majority of the liver is via the
hepatic veins: · In portal hypertension tiny collaterals open
· unite to drain into the IVC at T9 close to the between the portal and systemic venous system.
diaphragmatic hiatus There are four common sites for these anatomoses
· caudate lobe drains directly into the IVC and to develop:
may therefore be spared in cases of hepatic vein – at the gastro-oesophageal junction between the
thrombosis. left gastric and the azygos veins
– at the rectum between the superior rectal veins
• The vasculature (hepatic artery, hepatic vein, portal and the inferior rectal vein

166

Chapter 10: The abdomen and retroperitoneum
ABC

Fig. 10.21 Typical spectral Doppler traces from (A) hepatic artery, (B) hepatic vein and (C) portal vein. Oesophageal
varices
AB Liver
Spleen
Liver
Heart Inferior
Inferior vena cava
vena cava Aorta
Oesophagus
Aorta
Oesophageal
varices

C Gallbladder and biliary tree

Oesophageal • Gallbladder:
varices
· pear-shaped sac up to 10 cm long and 3 cm diameter
Portal v. · hangs down from inferior surface of liver – fundus

Fig. 10.22 (A) Axial, (B) coronal and (C) coronal MIP images in a patient usually anterior and inferior to the body and neck
with an irregular cirrhotic liver with portal hypertension and splenomegaly – N. B. Hartmann’s pouch = ventral dilatation
with consequent formation of oesophageal varices, i.e. portosystemic
anastomosis. around gallbladder neck following gallstone
impaction at neck; not a feature of normal
– at the umbilicus between the umbilical veins and gallbladder
the superficial epigastric veins
· wall thickness < 4 mm
– in the retroperitoneum between the peritoneal · cystic duct arises from neck – runs along liver surface
veins and the retroperitoneal, renal, lumbar and
phrenic veins. to the porta hepatis
· gallbladder neck and cystic duct have a spiral

appearance to folds in the mucosa (spiral valve
of Heister; regulates flow of bile); on ultrasound
this is highly echogenic and may be mistaken for
gallstones
· covered by peritoneum on fundus and inferior
surface; occasionally hangs on its own mesentery.

• Anatomical relationships (Figs. 10.16, 10.24–10.25).
• Blood supply (Fig. 10.14)

167

Section 2: Thorax and Abdomen

Umbilical v. Left branch
Liver of portal vein

Right branch Main portal v.
of portal v.

Right kidney Spleen
Left kidney

Fig. 10.23 Axial MIP CT in a patient with portal hypertension. There has been recanalization of the umbilical vein arising from the left portal vein, travelling along
the falciform ligament to the umbilicus in the midline.

A Right B

kidney

Liver

Liver

Gallbladder

Gallbladder Duodenum
Portal v.
Portal v.
Vertebral
body

CD

Common bile

Hepatic a. duct

Gallbladder Fat around
falciform
Common bile ligament
duct Hepatic a.

Portal v. Portal v.
Inferior vena
cava Inferior vena
cava

Fig. 10.24 (A) Transverse and (B) longitudinal ultrasound images through the gallbladder. (C, D) Images of the CBD at the porta hepatis.

· Cystic artery usually from right hepatic artery, in · Segmental biliary ducts unite to form left and right
10% from left hepatic artery and less commonly from hepatic ducts, which unite to form the common
common hepatic artery or SMA. hepatic duct (CHD) at the porta hepatis; in two-thirds
of individuals, the CHD passes anterior to the right
· Cystic veins empty into the liver or the portal vein. hepatic artery.

• Biliary tree (Figs. 10.26–10.28):

168

A Chapter 10: The abdomen and retroperitoneum
B
Gallbladder
Cystic duct
Gallbladder

Fig. 10.25 The appearance of the gallbladder on CT. (A) Axial and (B) coronal CT images. Common bile duct
Pancreatic duct
Left hepatic duct
Right hepatic duct

Gallbladder

Fig. 10.26 Normal MRCP. Highly T2-weighted MR sequence which shows fluid within the pancreaticobiliary system.

Left hepatic duct

Right hepatic duct
Common hepatic duct

Cystic duct Endoscope
Common bile duct
Balloon

Fig. 10.27 Normal ERCP. The ampulla of Vater has been catheterized via the side-hole of the endoscope. A balloon is then inflated and contrast instilled to
opacify the biliary tree.

169

Section 2: Thorax and Abdomen Right posterior – non-union of left and right hepatic ducts
sectoral duct – cystic duct:
VIII VII
II – absence (gallbladder directly connects to
V hepatic duct)
VI IV III
– may join anywhere along length of the
Right anterior Left main hepatic duct
sectoral duct sectoral duct
– fistula to respiratory tract
Right main Common hepatic – variable position of the ampulla, from stomach
sectoral duct duct
to third part of duodenum
Cystic duct Common bile – separate openings for CBD and pancreatic
duct
duct (close to each other in 40% and far apart
Fig. 10.28 Segmental biliary drainage of the liver. in 4%).

· The CHD is joined by the cystic duct at a variable Pancreas
position (usually 3.5 cm) to form the CBD.
• Long (around 15 cm) epigastric structure extending from
· Divisions and relations of the CBD: duodenal loop to splenic hilum.
– upper – above the duodenum within the lesser
omentum, anterior to the portal vein and to the · similar density to liver on CT, but becomes atrophic
right of the hepatic artery and fatty with age
– middle – posterior to the first part of the
duodenum with the gastroduodenal artery, • Comprises the head (including uncinate process), neck,
sloping away to the right from the portal vein; body and tail
immediately anterior to the IVC
– lower – grooves the posterior aspect of the • Anatomical relationships and position: see Figs. 10.3–10.8
pancreatic head, anterior to the right renal and 10.29–10.30
vein; joined by the main pancreatic duct at the
ampulla of Vater, opening into the posteromedial • Pancreatic duct:
wall of the second part of the duodenum.
· begins at tail and runs to head, increasing in size
· Diameter of CBD is variable: · located in the anterior half of the pancreas
· joins CBD at ampulla of Vater
– up to 5 mm till age of 50 years then 1 mm/decade · accessory duct of Santorini arises from pancreatic head
after that age
and drains via the minor papilla into the duodenum,
– can be larger in post-cholecystectomy patients 2 cm proximal to the ampulla of Vater
(up to 10 mm)
– usually communicates with main duct
· Anatomical variations very common in intrahepatic – absent in some individuals.
ducts (40%), but rarely clinically significant.
Variations in extrahepatic ducts less common, but • Blood supply
may be associated with intraoperative damage during
laparoscopic surgery, if previously not known about. · Arterial supply to the pancreatic head is from
Examples: the superior pancreaticoduodenal artery (from
the gastroduodenal artery) and the inferior
– 5–10% have accessory ducts which may join the pancreaticoduodenal artery (from SMA). There are
remainder of the extrahepatic biliary tree at any multiple anastomoses between these two vessels.
point, including the gallbladder
· The remainder of the pancreas is supplied from the
splenic artery via multiple small direct branches and
arteria pancreatica magna. Other arterial supply is
from the dorsal pancreatic artery, which arises from
the coeliac or proximal splenic artery.

· Venous drainage from pancreatic head is to SMV and
portal veins and to the splenic vein from the rest of the
pancreas.

• Anatomical variants (Fig. 10.31)

· Pancreas divisum: failure of fusion of the ventral and
dorsal pancreatic buds. Accessory duct (of Santorini)
now drains the body and tail. The main duct (of
Wirsung) now drains the head via the ampulla of Vater.
Prevalence of 7% in autopsy series.

170

Superior mesenteric A Chapter 10: The abdomen and retroperitoneum
v.
Splenic v.
Pancreatic head Left lobe of
Vertebral body liver

Pancreatic body
Superior
mesenteric a.
Aorta

B Left lobe of liver

Splenic v. Pancreatic body
Superior mesenteric
Right lobe of a.
liver
Aorta
Inferior
vena cava
Vertebral body

Figs 10.29 Axial ultrasound images through the pancreas centred on (A) the head and (B) the body. The pancreas may initially be difficult to visualize, but can
be identified as it lies immediately anterior to the splenic vein. The pancreas is at least as echogenic as the liver, and is more echogenic with increasing age and
body fat.

· Annular pancreas: non-migration of ventral pancreatic · anteriorly attached to greater curve of stomach by
bud results in pancreatic tissue encircling second part gastrosplenic ligament which contains short gastric
of duodenum. and left gastroepiploic vessels

Spleen · posteriorly the lienorenal ligament attaches to the
kidney and contains the tail of pancreas and splenic
• Largest lymphoid mass in the body but also contains vessels.
haemopoietic tissue.
• Blood supply
· On non-enhanced CT spleen is homogeneous and has
an attenuation of 35–55 HU, i.e. 5–10 HU less than that · Arterial supply from the splenic artery, which divides
of liver. into 4–6 branches at the hilum. Drainage via the
splenic vein, which runs behind the pancreas to join
· The spleen normally enhances heterogeneously the superior mesenteric vein at the pancreatic neck,
immediately after injection of a bolus of contrast forming the portal vein.
material on CT and MRI. Only after a minute or
more does the splenic parenchyma achieve uniform • Variants
homogeneous enhancement (Fig. 10.32). This is
thought to reflect the variable blood flow within · the shape and position of the normal spleen can vary
different compartments of the spleen considerably

• The adult spleen measures approximately 12–15 cm length, · embryologically formed from fusion of multiple small
4–8 cm in anteroposterior diameter and 3–4 cm in splenunculi
thickness.
· accessory or unfused splenunculi seen in 10%.
• Positioned in the left upper quadrant adjacent to 9th–11th
ribs and has a diaphragmatic and visceral surface. Retroperitoneum

• Anatomical relationships: see Figs. 10.3–10.8 and 10.33. • Aorta (Figs. 10.34–10.36)
• Surrounded by peritoneum
· Enters abdomen through aortic hiatus of diaphragm
(T12)

171

Section 2: Thorax and Abdomen

A

Probe in bowel lumen Pancreatic duct
Splenic v.
Gastroduodenal a.
Pancreatic head

B Pancreatic tail

Probe in bowel lumen

Pancreatic body

Splenic v.

Fig. 10.30 Endoscopic ultrasound images of the pancreas. (Images courtesy of Dr Z. Amin, University College Hospital, London.)

· Branches: · Tributaries:
– unpaired branches to GI tract:
– coeliac artery (T12/L1) – hepatic veins × 3 (T9)
– SMA (L1) – genitourinary tract:
– IMA (L3)
– paired arteries to genitourinary tract: – right suprarenal vein (L1)
– middle suprarenal arteries (L1) – renal veins (L1); the left suprarenal and
– renal arteries (L2)
– gonadal arteries (L2) gonadal veins drain into the left renal vein
– arteries to diaphragm and abdominal wall: – right gonadal vein (L2)
– pair of inferior phrenic arteries (T12)
– four pairs of lumbar arteries (L1–4) – abdominal wall:
– single median sacral artery (L4)
– termination branches: – inferior phrenic vein (T8)
– common iliac arteries (L4) – two pairs of lumbar veins (L3–L4)
– median sacral vein (L5)
• IVC (Figs. 10.37, 10.38)
– at origin:
· Enters abdomen through caval hiatus of
diaphragm (T8) – common iliac arteries (L5)

172 • Posterior wall venous system (Fig. 10.39):

· Venous anastomosis between lumbar, sacral and
intercostal veins, IVC, azygos and hemiazygos
veins

· Ascending lumbar vein crosslinks the segmental
lumbar branches

Stomach Chapter 10: The abdomen and retroperitoneum

Dorsal pancreatic AA Ventral pancreatic
bud bud

Liver bud Dorsal pancreatic
bud
Gallbladder Duodenum
Bile duct
Ventral pancreatic
bud BB

Duodenum Bile duct
Head of pancreas
Bile duct CC (from ventral bud)
Dorsal pancreatic Main pancreatic
duct
duct Pancreas
Minor papilla Accessory duct

Major papilla D

Ventral pancreatic D
duct

Main pancreatic
duct

Accessory
pancreatic duct

Bile duct Non migrated
ventral pancreas

Ventral pancreatic E E FF
duct

Uncinate process

Fig. 10.31 Stages in development of the pancreas. (A) Frontal view of developing pancreatic buds. (B) Transverse view of (A). (C) AP view after migration of ventral
bud into final position. (D) Transverse view of (C). (E) AP view of buds following fusion of ducts. (F) AP view of annular pancreas.

173

Section 2: Thorax and Abdomen B C
A

Fig. 10.32 Examples of different normal patterns of splenic enhancement during arterial phase on CT and MRI. (A) Uniform portal venous enhancement on MRI
provided for comparison. (B) Wedge-like segmental arterial phase enhancement on MRI. (C) Ring-like arterial phase enhancement on CT.

A B

Left kidney Spleen
Spleen
Vessels
Diaphragm

C

Spleen
Vessels

Fig. 10.33 (A) Longitudinal ultrasound image through the spleen. Note the diaphragm above and the kidney below. The spleen is usually hyperechoic compared
to the kidney. (B) Greyscale and (C) colour Doppler images demonstrating vessels entering the splenic hilum.

174

Inferior phrenic Chapter 10: The abdomen and retroperitoneum
Suprarenal branch
Coeliac trunk (T12) Inferior phrenic
Suprarenal branch
Superior
mesenteric (L1) Suprarenal branch
Apical, upper,
Renal posterior, middle
and lower
Inferior branches of renal
mesenteric (L3)
Ureteric branches
Gonadal
Lumbar /spinal Gonadal
Lumbar /spinal
Bifurcation (L4)
Common iliac Median sacral
External iliac
Internal iliac

Fig. 10.34 Branches of the abdominal aorta.

· One median sacral vein and two lateral sacral · If the IVC is blocked or absent, this venous system
veins crosslink the segmental sacral branches becomes more prominent, with blood being channelled
through it back to the SVC.
· Azygos vein (right) and hemiazygos vein (left) can
be continuations of the ascending lumbar veins or • Lymphatic system (Figs. 10.40–10.42):
subcostal veins, or arise from the renal veins or IVC
· Retroperitoneal nodes are named after adjacent
– the hemiazygos vein drains into the azygos at T9 structures
– the azygos arches over the root of the right lung
· All lymph drains into the cisterna chyli, the
to drain into the SVC dilated proximal end of the thoracic duct

175

Section 2: Thorax and Abdomen B
A
Superior Liver
C mesenteric a.
Portal v.
Aorta
Inferior vena
Vertebral cava
body

Intervertebral
disc

Fig. 10.35 Ultrasound appearances of the abdominal vessels. Longitudinal
images through (A) the aorta showing the SMA and (B) the IVC. (C) Transverse
image through the coeliac artery.

Common
hepatic a.
Pancreas
Splenic a.
Splenic v.

Coeliac a.
Aorta

A Aorta B Aorta

Splenic a. Coeliac a.

Common Superior
hepatic a. mesenteric a.

Renal a.

Renal a.

Branches of
the superior
mesenteric a.

Fig. 10.36 The aorta and its branches. (A) 3D coronal and (B, C) left/right coronal oblique CT images through the upper abdomen in arterial phase. The origins of
the coeliac artery and SMA are obscured on the standard coronal view. (D) Axial MIP CT showing the coeliac axis, and (E) sagittal MIP CT showing the coeliac artery
and SMA in arterial phase. (F) Digital subtraction aortogram performed with an arterial catheter in the aorta.

lying between L1/2, the aorta and the right • On FDG-PET imaging the liver shows homogeneous

diaphragmatic crus. uptake (Fig. 10.43). FDG is transported into cells like

Radionuclide imaging glucose and accumulates within the cell in proportion to
the rate of glycolysis.

• Radionuclide imaging techniques predominantly provide • Tc-labelled aminodiacetic acid (IDA) compounds
functional information of the abdominal viscera with show biliary excretion through the biliary tree and
very limited anatomical detail. These techniques are often gallbladder and then into the small bowel.

combined or assessed in conjunction with cross-sectional • Gallium scan – normal accumulation is seen in the liver,

imaging. bone marrow and variably in the spleen (Fig. 10.43). There

176

Chapter 10: The abdomen and retroperitoneum

C Aorta D

Coeliac a.

Superior Common
mesenteric a. hepatic a.

Renal a. Coeliac a.

Splenic a.
Aorta

EF Aorta
Arterial
Coeliac a. catheter in a.
Splenic a.
Superior
mesenteric a. Common
Aorta hepatic a.

Fig. 10.36 (cont.) Renal a.
Superior
Inferior phrenic mesenteric a.
Hepatic
Inferior phrenic
(right, middle, left)
Suprarenal Suprarenal
Renal Renal
(segmental branches)
Gonadal
Ureteric branch
L3
L4 Gonadal
Lumbar

Bifurcation (L4) Median sacral
Common iliac External iliac
Internal iliac
Inferior epigastric Superior pubic branch

Deep Inguinal ligament
circumflex iliac

Cremasteric branch

Fig. 10.37 Branches of the IVC.

177

Section 2: Thorax and Abdomen

Lack of contrast
opacification at the
insertions of the renal veins

Inferior vena cava
Catheter in distal IVC

Fig. 10.38 Normal cavogram. Digital subtraction venogram following contrast injection via a catheter in the distal IVC. Note that the tributary veins of the IVC do
not opacify as blood flows in the reverse direction – indeed the insertions of the renal veins are identified by a lack of contrast opacification of the IVC at that level.

Azygos v. Subcostal v. 8
Lumbar veins Hemiazygos v.
Inferior vena cava
Left renal v.
Ascending
lumbar v. L5 1 Left para-aortic 42 1
2 Pre-aortic 73
Iliolumbar v. Median sacral 3 Retro-aortic
Lateral sacral v. 4 Aortocaval 5
5 Right paracaval 6
v. 6 Precaval
7 Retrocaval
Fig. 10.39 Posterior wall venous system. 8 Coeliac axis

178 Fig. 10.40 Abdominal lymph node groups.

Chapter 10: The abdomen and retroperitoneum
AB

Thoracic Cisterna
duct chyli

D

C

Cisterna
chyli

Abdominal
lymphatic

Fig. 10.41 Cisterna chyli. (A–C) Axial CTs, ordered superior to inferior, showing abdominal lymphatics draining into the cisterna chyli, the dilated proximal end of
the thoracic duct lying between the aorta and right diaphragmatic crus. (D) Coronal CT of the same patient.

AC

Inferior vena Inferior vena
cava cava

Aorta

Portal v.

Coeliac a. Left para-aortic
Coeliac axis node
node
Aortocaval
Aorta node

Retrocrural
node

Diaphragmatic
crus

B Inferior vena Fig. 10.42 (A, B) Axial and (C) coronal CT images of retroperitoneal
cava

lymphadenopathy to illustrate the position of nodal groups.

Superior
mesenteric v.
Pre-aortic node

Left para-aortic
node
Aorta

Retrocaval
node

Renal v.

179

Section 2: Thorax and Abdomen B Brain
A
Liver Heart
C Spleen
Liver Left kidney

Right kidney Bladder

Liver

Spleen
Left kidney
Right kidney
Bladder

2hr 2hr 5hr 5hr

Fig. 10.43 (Images courtesy of Dr Sue Chau, Royal Marsden Hospital.) Normal activity seen in the abdominal organs on (A) Ga-67, (B) FDG-PET and (C) In-111-
octreotide scans.

is significant excretion via the gut and some by the kidneys. Normal uptake is in thyroid, liver, spleen, kidneys and
Gallium is taken up at inflammatory sites and non- reticulo-endothelial system with excretion via the gut
specifically by some tumours. and kidneys (Fig. 10.43)

• Radiolabelled somatostatin receptor analogues • Denatured labelled red blood cell scans may be used to
(octreotide or lanreotide) bind to somatostatin receptors identify splenic tissue, for example postoperatively.
and are used in imaging neuroendocrine tumours.

180

Section 2 Thorax and Abdomen

Chapter The gastrointestinal tract

11 Nasir Khan

Introduction Midgut

Cross-sectional imaging plays a major role in the teaching • The midgut consists of the third and fourth part of the
of anatomy, especially in relation to the gastrointestinal (GI) duodenum, jejunum, ileum, caecum, appendix, ascending
tract. It demonstrates the relations of the GI tract with other colon and proximal two-thirds of the transverse colon.
abdominal structures and hence allows us to understand The blood supply is predominantly from the superior
local disease processes and the pathways of local and distant mesenteric artery and its branches.
spread.
• At 5 weeks, during in utero development, the midgut
In particular CT and MRI scanning are used to image the herniates into the umbilical cord, returning into the
small and large bowel in their entirety, whilst ultrasound has abdominal cavity at 10 weeks. As it returns, it performs a
taken its place as a more focused tool in the GI tract. It is used 270° anticlockwise rotation, resulting in the fourth part of
transabdominally at high frequencies (10 and 13.5 MHz) to the duodenum and jejunum lying to the left of the midline
image the pylorus for pyloric stenosis, the appendix, terminal and the proximal colon lying to the right. Failure of this
ileum for Crohn’s disease and the small/large bowel for intus- rotation results in the D-J flexure and jejunum remaining
susception in children. Endoscopic and endocavity ultrasound on the right and colon on the left, known as malrotation.
is used to visualize the proximal GI tract for tumour staging In this situation the small bowel mesentery is short and
and the anal canal for sphincter tears and fistulae. prone to twisting (volvulus), leading to potential duodenal
obstruction and ischaemia.
Barium studies are still widely used either as a diagnostic
tool or, in conjunction with CT or MRI, as a problem-solving • Failure of the midgut to return into the abdomen
tool. Therefore, knowledge of luminal anatomy and its variants is known as exompholos, whereby the child is born
remains crucial. with small and large bowel herniation through the
abdominal wall.
Embryology and development
Fig. 11.1 Line diagram shows the primitive GI tract.
The GI tract extends from the mouth to the anus, and
originates from the primitive foregut, midgut and hindgut
(Fig. 11.1).

Foregut

• The forgut consists of the pharynx, oesophagus, stomach
and the first and second parts of the duodenum. The
blood supply of these structures is predominantly derived
from the coeliac artery, apart from the mid oesophagus,
which derives its arterial supply from the thoracic aorta
directly and the proximal third of the oesophagus from the
inferior thyroid vessels.

• During development, the pancreas and liver arise from
buds of the foregut, in the region of the second part of the
duodenum, hence the intimate relationship with the bile
ducts, portal and hepatic vessels.

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.

181

Section 2: Thorax and Abdomen

Hindgut Larynx Nasopharynx

• The hindgut forms the distal transverse colon, descending Oropharynx
colon, sigmoid colon, rectum and anus. The vascular supply Epiglottis
is predominantly from the inferior mesenteric artery,
except the rectum, which also derives supply from the Thyroid Oesophagus
internal iliac arteries. cartilage

Pharynx Trachea

• Muscular tube extending from the base of the skull to the *
level of C6, where it connects to the cervical oesophagus.
*Incidental enlarged lymph node
• Three layers: mucosa, fibrous submucosal layer and the
muscular layer (made up of three constrictor muscles). Fig. 11.2 The pharynx and cervical oesophagus on sagittal T1-weighted MRI.

• Food passes over the erect epiglottis, through the piriform
fossae and into the cervical oesophagus.

Cross-sectional anatomy

The naso-, laryngo- and oropharynx are continuous.
• Superiorly – the soft palate.
• Inferiorly – the epiglottis, which protects the larynx during

swallowing.
• Anterior surface – formed by the base of the tongue and

epiglottis. The laryngopharynx is draped over the posterior
aspect of the larynx, creating two posterolateral recesses;
the piriform fossae (Fig. 11.2).
• Posteriorly to the oropharynx are the prevertebral muscles.

Valleculae

A

B

Epiglottis

Piriform fossa

Piriform
fossa

Cervical oesophagus

Cervical
oesophagus

Fig. 11.3 Barium swallow: AP (A, B) and lateral (C) views of the pharynx and cervical oesophagus.

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Chapter 11: The gastrointestinal tract

C

Valleculae
Hyoid bone

Cricoid impression

Post cricoid
venous plexus

Trachea

Cervical oesophagus
Clavicle

Fig. 11.3 (cont.)

Plain film and contrast study anatomy Cross-sectional anatomy

• Plain radiograph has a limited role, with the lateral view The cervical oesophagus
mainly used to locate the presence of swallowed foreign
bodies. • Begins at the lower limit of the cricopharyngeus, lying in
the midline anterior to the cervical vertebrae, and posterior
• Barium swallow, AP view, shows filling of the piriform to the trachea and thyroid gland inferiorly (Fig. 11.4A,B), at
fossae and valleculae with central filling defects of the base which level it moves to the left of the midline (Fig. 11.4C,D)
of the tongue and epiglottis (Fig. 11.3A). On the lateral view, and then enters the thorax, where it will return to the
the narrow posterior indentation of the cricopharyngeal midline at T5.
muscle contraction may be seen at the level of C5/6, which
if persistent and severe can cause dysphagia. Anteriorly, a • Laterally lies the common carotid artery on each side.
wider but shallow indentation is caused by a submucosal
venous plexus (Fig. 11.3C). Relations within the chest (Fig. 11.5)

Oesophagus • Anteriorly – as it descends, it passes behind the trachea, left
main bronchus, left atrium, left ventricle (upper part).
• Long muscular tube measuring approximately 25 cm.
• Extends from the level of the sixth cervical vertebra, • Posteriorly – thoracic duct and vertebrae, azygos vein,
right posterior intercostal arteries which arise from the
passing through the neck, posterior mediastinum, veering descending aorta directly.
anteriorly low within the thorax before it enters the
abdomen, through the diaphragmatic hiatus at T10. Its • Laterally – on the left, it is in contact with the origin of
short course within the abdomen is retroperitoneal and the left subclavian artery, arch of the aorta, left lung and
forms the gastro-oesophageal junction as it ends at the descending aorta. On the right, the azygos vein lies behind
cardia of the stomach, at T11. and to the right, crossing it at T4 where it terminates.
Above this level, it abuts the right lung.

183

Section 2: Thorax and Abdomen

Thyroid gland A

Wall of the Sternocleidomastoid
trachea muscle
Common carotid a.
Oesophageal
lumen Mucosal layers of
the oesophagus
Muscularis layers Sternocleidomastoid
of the oesophagus m.

B Internal jugular v.
Common carotid a.
Thyroid gland
Clavicle
Clavicle
Trachea Sternocleidomastoid
Sternocleidomastoid m.
Subscapularis m.
m. Supraspinatus m.
Subscapularis m. Trapezius m.

Supraspinatus m. Sternal notch
Clavicle
Trachea C Common carotid a.
Brachiocephalic v.
Clavicle Left subclavian a.
Lung apices
Brachiocephalic v. Muscularis layers
Mucosal layers of the oesophagus

of the oesophagus Subscapularis m.
Lung apices
Internal jugular v.
Supraspinatus m. Clavicle
Subclavian v.
Common carotid a. D Left subclavian a.

Subclavian v. Muscularis
layers of the
Trachea oesophagus

Mucosal
layers of the
oesophagus

Fig. 11.4 The cervical oesophagus : (A) ultrasound, and (B) axial CT at the level of the thyroid gland and (C) axial T2 MRI, (D) axial T1 FS MR post gadolinium, at the
thoracic inlet. On US and MRI the layers of the oesophagus can be delineated.

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Chapter 11: The gastrointestinal tract

Thoracic Manubrium
oesophagus Left common carotid
a. origin
Thoracic Aortic arch
oesophagus
Left main bronchus
Descending aorta Pulmonary trunk

Thoracic Left atrium
oesophagus
Left hemidiaphragm
Diaphragmatic Left lobe of the liver
hiatus
Stomach fundus
Descending aorta

Fig. 11.5 Multiplanar reformat CT showing the passage of the oesophagus within the chest.

The oesophagus has five layers, as demonstrated on Neurovascular and lymphatic anatomy
endoscopic ultrasound (Fig.  11.6), the superficial mucosa
(hyperechoic), deep mucosa or lamina propria (hypoechoic), Arterial supply and venous drainage
submucosa (hyperechoic), muscularis propria (hypoechoic) • Upper third – inferior thyroid artery, with drainage into the
and the adventitia (hyperechoic). The layers are poorly seen
on CT; however, MRI is showing some promise with newer inferior thyroid vein.
improved sequences (Fig. 11.4C,D). • Middle third – direct oesophageal branches from

Plain film and contrast study the descending aorta, with drainage into the
anatomy azygos vein.
• Distal third – oesophageal branches of the left gastric
Plain chest radiograph artery (Fig. 11.13B). Drainage into the oesophageal
branch of the left gastric vein which drains into the
• The oesophagus is difficult to see unless it is dilated and portal vein.
fluid filled.
Lymphatic drainage
• Below the level of T4/right hilum, the azygo-oesophageal Paraoesophageal lymphatic plexus draining:
line may be seen, where the azygos vein and oesophagus • superiorly to the posterior mediastinal lymph nodes and
abut the right lung.
then into the supraclavicular node
• Above T4, where the oesophagus abuts the left lung we • inferiorly to the left gastric /gastrohepatic and coeliac
can see the pleuro-oesophageal line.
lymph nodes.
Barium studies
This explains the pathway of spread of oesophageal tumours
• Show three impressions on the oesophagus – the via the lymphatics.
aortic arch, left main bronchus and the left atrium
(Fig. 11.7A). Nervous system
• Upper oesophagus – branches of the recurrent laryngeal
• Mild fusiform dilatation of the distal oesophagus
forms the physiological sphincter. nerve.
• Lower oesophagus – oesophageal plexus, which
• Bound superiorly and inferiorly by the A and B
(Schatzki’s) ring, respectively (Fig. 11.7B). These surrounds the lower oesophagus and is made up of the
are minor transient muscular contractions, which parasympathetic fibres of the vagus nerve and vasomotor
if persistent can lead to dysphagia and require sympathetic fibres from the upper 4–6 thoracic spinal
endoscopic dilatation. segments.

• Fewer than five folds on the double contrast images. Stomach
Folds should be thin, measuring less than 3 mm.
• Thick J-shaped muscular bag which is fixed at both orifices;
• More than five folds suggest stomach herniation. the inlet – the cardiac orifice, and outlet – the pylorus.

185

Section 2: Thorax and Abdomen

Superficial GI lumen
mucosal layer Radial endoscope
Paraoesophageal
Deep mucosa fat
(lamina propria)
Aorta
Submucosa
Aortic arch
Muscularis propria impressions of the
Adventitia oesophagus
Left main bronchus
Fig. 11.6 Oesophagus as seen on endoscopic ultrasound. impressions of the
oesophagus
Superficial A Oesophagus
mucosal layer Left atrial
impressions of the
Aortic arch oesophagus

Aortic arch impressions Right
of the oesophagus hemidiaphragm
Gas within the
Left main bronchus impressions stomach fundus
of the oesophagus Oesophageal
vestibule
Pulmonary trunk
Left atrium

Left atrial Impressions
of the oesophagus

Descending aorta
Right hemidiaphragm

Oesophagus
Left lobe of the liver

Stomach

Oesophagus B
A ring – upper limit

of the vestibule
Right hemidiaphragm

B ring (Schatzki’s
ring) – lower limit

of the vestibule
Gastro-oesophageal

junction

Body of the stomach

Fig. 11.7 Barium swallow: oblique view (A) shows the three normal impressions on the oesophagus with sagittal MPR CT correlation; (B) gastro-esophageal
junction and vestibule.

• Two surfaces: • The maximum volume in adults is 1500 ml and at puberty
1000 ml.
· anterosuperior surface – lesser curve
· posteroinferior surface – greater curve, which as the There are three muscle layers; inner oblique, middle circu-
lar and outer longitudinal layer. Circular muscle surrounds the
stomach fills, expands inferiorly and anteriorly as the body but is especially prominent at the pylorus and the oblique
majority of the stomach is mobile muscle forms a sling around the cardiac orifice to prevent
· covered by peritoneum and are divided by the reflux. The longitudinal layer is mostly centred on the lesser
peritoneal attachments of the lesser and greater and greater curves.
omentum.

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Chapter 11: The gastrointestinal tract

Plain film and contrast study anatomy gastric mucosa, measuring 3–5 mm. These run mostly along
the longitudinal axis of the stomach. Within the pylorus these
On the plain film, the stomach may not be seen if fluid-filled or have the appearance of fine lines. In the antrum, small nodular
empty, otherwise the gastric bubble is seen on the erect X-ray. mucosal elevations are seen, called areae gastricae, measuring
2–3 mm.
Geographically it is divided into (Fig. 11.8):
Cross-sectional anatomy
• fundus – lying above the cardiac orifice adjacent to the left
hemidiaphragm The anatomical layers are best seen on endoscopic ultrasound,
where there are five layers: mucosa, muscularis mucosa, sub-
• body – extends from the cardia to the incisura angularis mucosa, muscularis and serosa (Fig. 11.9).
(angulation of the lesser curve)
Relations (Figs. 11.8, 11.10)
• antrum – crosses the midline, extending from the incisura • Anteriorly – left lobe of the liver medially, anterior
to the sulcus intermedius
abdominal wall laterally and left hemidiaphragm
• pylorus – narrow thickened muscular canal from superiorly.
the sulcus to the pyloric orifice, 1–2 cm in length. It • Posteriorly – peritoneum of the lesser sac superiorly and
behaves as a physiological and anatomical sphincter stomach bed inferiorly.
and lies at the level of L1, 2.5 cm to the right of the
midline.

The gastric rugae are seen on the double-contrast
barium meal, and are thick linear elevations or folds of the

A

Distal oesophagus

Lesser curve Stomach fundus
Gastric antrum
Body of the stomach
Pylorus Greater curve
Duodenal cap

2nd part of Jejunal loops
the duodenum

4th part of the
duodenum

3rd part of the
duodenum

B Body of the
stomach
Left lobe of the liver Transverse colon
Gastric rugae
Lesser curve Greater curve
Left gastric
a. and v. Splenic flexure

Distal oesophagus Stomach fundus
Aorta
Spleen

Fig. 11.8 Barium meal (A), CT (B, C) and MR (D) of the stomach: gastric rugae and areae gastricae demonstrated.

187

Section 2: Thorax and Abdomen

C

Left lobe of the liver Gastric antrum
Pylorus Transverse
colon
Neck of the pancreas Superior
Duodenal cap mesenteric a.
Tail of the
Head of the pancreas pancreas
Superior mesenteric v. Spleen
Aorta
Right lobe of the liver Kidney

Inferior vena cava Left lobe of the liver
Stomach fundus
Lesser curve D
Body of the stomach
Right lobe of Greater curve
the liver Transverse colon

Gallbladder Jejunal loops
Incisura

Gastric antrum

Transverse colon

Greater curve

Fig. 11.8 (cont.)

Left lobe of the liver

Abdominal wall musculature
Stomach lumen

Mucosal layer⎫ Layers of the
⎬ stomach wall
Muscularis

propria ⎭

Portal v.

Fig. 11.9 The stomach as seen on transabdominal ultrasound.

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Chapter 11: The gastrointestinal tract

A 10b 10c 10d

Left
hemidiaphragm

B Oesophagus
GOJ
Left lobe of Incidental hiatus
the liver hernia
Left hemidiaphragm
Neck of the Left gastric a.
pancreas
Coeliac a.
Splenic v.
Gastric antrum Left renal v.

Superior Third part of the
mesenteric v. duodenum

Superior
mesenteric a.

Transverse colon

C Left hemidiaphragm

Left lobe of Gastric body
the liver
Left kidney
Body of the D-J flexure
pancreas Fourth part of the
duodenum
Gastric antrum

Transverse colon

Fig. 11.10 Multiplanar reformat CT showing the relations of the stomach: (A) coronal image and sagittal images through the (B) gastric antrum, (C) gastric body
and (D) gastric fundus.

189

Section 2: Thorax and Abdomen

D

Left lobe of the liver

Left hemidiaphragm Spleen
Gastric body Gastric fundus

Jejunum Tail of the pancreas
Jejunum
Left kidney

Transverse colon

Fig. 11.10 (cont.)

The stomach bed (Fig. 11.11) Arterial supply (Fig. 11.13)

• Laterally – the gastric surfaces of the spleen, left kidney and • Lesser curve and GOJ – left gastric artery arising
left adrenal gland. from the coeliac trunk and right gastric artery,
which variably arises from the common hepatic or
• Centrally – the full length of the pancreas. left hepatic artery.
• Medially – the aorta and coeliac axis.
• Inferiorly – transverse mesocolon which attaches • Greater curve – right gastroepiploic artery arising from the
gastroduodenal artery, a branch of the common hepatic
the transverse colon to the anterior surface of the artery, and the left gastroepiploic arising from the splenic
pancreas. artery.

Ultrasound is not routinely used because of gas within the • Fundus – short gastric arteries arising from the splenic
stomach; however, the pylorus can be seen and examined in artery, also contributes to supply to the greater curve.
the infant to look for pyloric stenosis (Fig. 11.12). The mucosa
is echogenic and muscle layers are echo-poor. Normal limits Venous drainage
are a length of < 15 mm and overall wall thickness < 8 mm. Same gastric distribution to arteries:
• gastric veins, left and right, drain into the portal vein
CT is not routinely used in the investigation of the stomach • short gastric veins and left gastroepiploic drain to splenic
as the stomach appears thick-walled when collapsed, giving
the appearance of pseudotumour. It is used to stage gastric vein
tumours or investigate outlet obstruction/extrinsic compres- • right gastroepiploic drains to the superior mesenteric
sion seen on endoscopy. MRI may show promise due to rea-
sonable visualization of the gastric wall. artery.

Hepatic a. Spleen Lymphatic drainage
Bile duct Portal v. Left suprarenal All drain to coeliac nodes, via lymph node chains along their
gland respective arteries.
Right adrenal Splenic a. • Lesser curve – left gastric drains to coeliac nodes directly
gland Left kidney
Pancreas and right gastric to the retroduodenal nodes.
Gastroduodenal • Fundus and greater curve – short gastric and left
a. Transverse
colon gastroepiploic drain to splenic hilar nodes and to the
Superior Descending peripancreatic nodes posteriorly. Right gastroepiploic
pancreatico- colon drains via the retroduodenal nodes.
duodenal a. Aorta
Right kidney Nervous system
Parasympathetic supply from left and right vagus nerves.
Ascending colon • Anterior vagal trunk – supplies the lesser curve, cardia and

Inferior vena cava pylorus. Fibres from the left vagus nerve.
• Posterior vagal trunk – supplies the majority of the
Fig. 11.11 Line diagram showing the stomach bed.
stomach, i.e. anterior and posterior body. Fibres from the

190