Modern imaging in patients with

obstructive jaundice
The evaluation of cholestatic jaundice is a common problem in
clinical practice.
J E J KRIGE, MB ChB, FACS, FRCS, FCS (SA)
Professor, Department of Surgery, Faculty of Health Sciences, University of Cape Town
Principal Specialist and Head, HPB Surgical Unit, Groote Schuur Hospital, Cape Town
Professor Krige is ad hominem Associate Professor in the Department of Surgery, University of Cape Town. He received his surgical training at the
University of Cape Town and the University of California in Los Angeles and is a Fellow of the Royal College of Surgeons of Edinburgh, the American
College of Surgeons and the College of Surgeons of South Africa. His major areas of clinical interest include portal hypertension and oesophageal varices,
upper gastro-intestinal interventional endoscopy and surgical diseases of the liver, bile ducts and pancreas.
S J BENINGFIELD, MB ChB, FF Rad (D) (SA)
Professor, Department of Radiology, Faculty of Health Sciences, University of Cape Town
Chief Specialist, Department of Radiology, Groote Schuur Hospital, Cape Town
Professor Beningfield undertook his radiology training at the University of Cape Town and is a Fellow of the College of Radiologists of South Africa. His
major areas of clinical interest include imaging and intervention in hepatobiliary disease, vascular imaging and intervention, and computer applications
in radiology.
J M SHAW, MB BCh, FCS (SA)
Full-time Consultant, Department of Surgery, Faculty of Health Sciences, University of Cape Town and HPB Surgical Unit, Groote Schuur
Hospital, Cape Town
Dr Shaw completed his postgraduate surgical training at the University of Cape Town. He is a Fellow of the College of Surgeons of South Africa and has
the Certificate in Surgical Gastroenterology from the Colleges of Medicine of South Africa.

Often, cholestatic jaundice caused by intrahepatic hepatocellular

disease may be clinically and biochemically indistinguishable
from cholestasis due to extrahepatic bile duct obstruction. The
most common intrahepatic causes of jaundice are viral hepatitis,
alcohol-induced hepatitis, cirrhosis and drug-induced jaundice.
Extrahepatic jaundice is most often due to a stone in the common
bile duct (CBD) or a pancreaticobiliary malignancy (pancreatic,
ampullary or cholangiocarcinoma). Pancreatic pseudocysts,
chronic pancreatitis, sclerosing cholangitis, benign bile duct
strictures or parasites in the bile duct are less common causes.
The principal clinical task is to distinguish obstructive jaundice
from jaundice due to parenchymal liver disease. If major bile
ducts are obstructed, surgery or therapeutic endoscopy may be
required, but should be avoided in parenchymal liver disease as
inappropriate intervention may aggravat the situation. In most
patients, a likely cause of jaundice can often be established by taking
a careful history, completing a thorough physical examination,
testing the urine and stool, and requesting basic haematology and
liver function tests, including viral serology (Table I). These easily
obtained blood tests may confirm the initial clinical diagnosis or
refine the differential diagnosis and direct further appropriate
investigations. Since most jaundiced patients are not critically ill
when initially assessed, diagnosis and therapy can be undertaken
in a stepwise fashion, with each subsequent test logically selected
according to the information available at that point. Only severe or
worsening cholangitis requires urgent intervention.
Over the past decade technical advances in imaging equipment
have significantly modified the investigation of biliary tract
328

Table I. First steps in the diagnosis of jaundice

 linical history
C
Physical examination
Urine examination
Stool examination
Biochemistry
Bilirubin
Alkaline phosphatase
Gamma GT
Transaminases
Haematology
Haemoglobin
WBC
Platelets
INR
Viral markers

diseases. A wide array of special investigations, including

expensive and invasive procedures, is now available for evaluating
the jaundiced patient with suspected biliary obstruction. Complete
assessment of biliary obstruction requires detailed imaging to
define the exact level and cause of the biliary obstruction, and to
implement treatment. Currently available technologies include
transabdominal ultrasonography (US), endoscopic retrograde
cholangiopancreatography (ERCP), percutaneous transhepatic
cholangiography (PTC), endoscopic ultrasound (EUS), magnetic

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resonance imaging with cholangiopancreatography(MRI,MRCP)and
helical (or spiral) computed tomography
(CT). Direct imaging techniques such as
ERCP and PTC are invasive and carry a
higher associated risk, but have the added
ability to sample tissue and perform biliary
drainage with stenting or stone removal.
Indirect techniques offer lower procedural
risk and permit staging of malignancies.
New direct radiological investigations
such as MRCP (often together with
solid-organ MRI), EUS, and spiral CT
provide improved imaging quality at
low risk. However, without a clear and
rational strategy, the inappropriate use
of imaging may lead to the duplication
of investigations with resultant increased
costs, delayed diagnosis and, possibly,
unwarranted morbidity.

Initial imaging in
obstructive jaundice

Radiological imaging is the cornerstone

of diagnosis in patients with suspected
extrahepatic obstructive jaundice. Several
algorithmic approaches have been described, all starting with an ultrasound
scan (Fig.1). If dilated ducts are seen on
ultrasound, referral to a specialist with
experience in hepatobiliary disease is wise,
as endoscopic or surgical intervention may
be required. Accurate information about
the level of biliary obstruction is essential
because therapy may be complex with
hilar obstructions, and these patients are
therefore best treated by a multidisciplinary
group.

Transabdominal
ultrasonography

Abdominal US is the initial imaging test

of choice in jaundiced patients because it
is non-invasive, inexpensive and readily
available. US is highly operator dependent
and requires skill and experience to
produce consistently good results. Dilated
ducts are indirect evidence of biliary
obstruction. As a rough guide, a CBD of
less than 7 mm internal transverse diameter
is regarded as normal, while a larger
diameter suggests biliary obstruction.
US is particularly useful because it offers
the ability to assess pancreaticobiliary
structures non-invasively and in real-time
without exposing the patient to ionising
radiation. A definitive diagnosis can be
made by demonstrating gallstones in
the gallbladder or CBD, or a mass in the
head of the pancreas. In patients without
dilated ducts, hepatocellular disease is the
likely diagnosis; however, parenchymal
liver disease or sclerosing cholangitis
may prevent biliary dilatation despite
obstruction being present.
Other than being nil per mouth little
preparation is required, so the procedure is
generally well tolerated. As new-generation
US scanners are compact and selfcontained, the equipment can be wheeled
to the patient in the ward, the ICU or the
operating theatre. A unique application of
US is colour Doppler imaging that can be
used to assess the patency, direction and
volume of blood flow in critical vessels
such as the portal, superior mesenteric
and hepatic veins, and hepatic artery.
2

Although US is widely used, there are

important limitations. The clearest images
Table II.
Obstructive jaundice

Ultrasound

Dilated bile ducts

Referral to HPB Specialist

Intrahepatic dilatation only:

Hilar or proximal biliary
obstruction

Distal CBD obstruction:

Bile duct stones,
pancreatic or distal cholangiocarcinoma

CT / MRCP with PTC

Fig. 1. Algorithmic approach to imaging in obstructive jaundice.

ERCP

Fig. 2. CT scan showing dilated bile ducts

(arrow).

are obtained in lean patients because

resolution deteriorates with depth and
obesity; bone and gas are impenetrable
and further limit visibility.

Computed tomography
(CT) scanning

CT technology has improved significantly

over the past two decades (Fig. 2). The
evolution has proceeded through several
stages, from conventional CT to helical
(or spiral) CT to new, multidetector CT
in which ultrafast detector rotation and
collimation can be combined to yield
high-resolution, three-dimensional
reconstructions of the liver, pancreas and
related structures with excellent vascular
enhancement.
Spiral CT after intravenous injection of
iodinated contrast medium allows the
rapid acquisition of images during the
arterial, portal, and delayed parenchymal
phases. It also provides high-quality, threedimensional reconstructions in various
formats and can depict up to third-order
intrahepatic branches.
These advances in technology have
expanded the role of CT in evaluating
the biliary tree. The high-resolution,
thin-slice images in single breath-holds,
and the ability to display these images in
cine mode and coronal views are ideal
for tracing the dilated bile ducts to the
point of obstruction. CT scanning is also
helpful in evaluating liver masses, often
complementing US. CT is now widely
accepted as the imaging method of choice
to detect, stage, and assess resectability of
pancreatic tumours.
The major advantages of spiral CT
over ERCP or EUS include its low
level of invasiveness, minimal operator
dependence, low technical failure rate and,
in contrast to ERCP, ability to produce a
three-dimensional image of the biliary
tree. The major limitations of CT are
the inability to detect small peritoneal
implants, small hepatic metastases, lymph
node metastasis in normal-sized nodes,
and intraductal tumour extent. Spiral CT
gives a relatively high dose of radiation to

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patients and a further drawback is a small
risk of adverse reaction to the iodinated
contrast agents. Its main limitation is in
patients with impaired renal function with
high serum creatinine levels, as contrast
may be nephrotoxic. Artefacts produced
by patient movement, respiration and
support devices also limit diagnostic
value.

Magnetic resonance
imaging (MRI)

MRI is the most recent advance in crosssectional imaging of the bile ducts and
liver. The physics of MRI is complex and
uses magnetic fields and radiowaves
to chart the regional density of mobile
hydrogen nuclei in the body. Although
spiral CT is usually the first choice in
cross-sectional imaging of the liver and
pancreas, MRI is rapidly evolving in the
evaluation of the patient with pancreatic
cancer as a one-stop shop. MRI is also
useful in patients with contrast allergy
or in those with reduced renal function,
provided gadolinium is avoided.

Magnetic resonance
cholangiopancreatography
(MRCP)

sedation and, in contrast to ERCP, MRCP

can demonstrate the biliary tree above
and below complete obstructions. In
cholangiocarcinoma, the main advantage
of MRCP is that it can non-invasively
provide a three-dimensional image of the
biliary tree, which can help in planning
treatment. The major disadvantages of
MRCP compared with ERCP are lower
resolution, unit availability, lack of any
immediate therapy for duct obstruction,
claustrophobia, and the inability to
evaluate patients with pacemakers or
ferromagnetic implants.

Endoscopic retrograde
cholangiopancreatography
(ERCP)

ERCP is regarded as the gold standard for

imaging the biliary system and combines
the advantage of diagnosis of biliary
obstructionwith therapeutic intervention,
if required. ERCP is the intervention of
choice in patients with CBD stonesand in the
palliation of malignant biliary obstruction
(Figs 4 - 6). The drawbacks of ERCP
include high equipment costs, the need
for conscious sedation, and dependence
on skilled interventional endoscopists.
The failure rate increases substantially

Fig. 4. An ERCP demonstrating a malignant

distal CBD stricture (arrow) secondary to a
pancreatic carcinoma.

Fig. 3. MRCP showing bile ducts obstructed

by a hilar cholangiocarcinoma(upper arrow)
and incidental gallstones in the gallbladder
(lower arrow).

330

in patients with altered anatomy, such

as after a Billroth II gastrectomy, or in
patients with duodenal narrowing due to
tumour infiltration. Stenting a proximal
hilar cholangiocarcinoma can be difficult,
and undrained contrast injection above
the site of obstruction usually mandates
urgent PTC biliary drainage because of
the risk of cholangitis. The most common
complications after ERCP are acute
pancreatitis and cholangitis, which are
severe in 1% of patients. Because of these
risks and the availability of MRCP, ERCP is
evolving into a predominantly therapeutic
procedure.

Percutaneous transhepatic
cholangiography (PTC)

This technique involves the manipulation

of a volume of data acquired by MRI. A
heavily T2-weighted sequence enhances
the signal of water-filled bile and
pancreatic ducts without the use of
contrast material or ionising radiation,
to produce high-quality images of ductal
anatomy (Fig. 3).

MRCP is accurate in demonstrating the

presence and level of biliary obstruction,
but is less sensitive for detecting small
stones. The major advantage of MRCP is
the non-invasive nature of the procedure.
It usually does not require conscious

Fig. 6. Endoscopic plastic transpapillary biliary stent (arrow).

PTC involves puncture, under local

anaesthesia, of either the left or right
liver lobe with a fine flexible needle
using fluoroscopic guidance to enter a
peripheral intrahepatic bile duct. Contrast
is injected to outline the biliary system
and identify the obstruction. A skilled
interventional radiologist can successfully
opacify the intrahepatic biliary tree in
nearly all patients with dilated ducts, and
in most patients with non-dilated ducts
(Fig. 7). The overall procedure morbidity
is less than 5%. Possible complications
include bleeding, bile leaks, cholangitis,
septicaemia, pneumothorax, and rarely
allergic reactions to the contrast medium.
PTC is performed primarily in patients
in whom ERCP has failed, or when
altered anatomy precludes access to the
ampulla, and for biliary drainage and
stenting in patients with irresectable hilar
cholangiocarcinoma.

Endoscopic
ultrasonography (EUS)
Fig. 5. ERCP basket extraction of CBD stone
(arrow).

This technique uses a small high-frequency

ultrasound probe mounted on the tip of
an endoscope that is positioned in the
duodenum by direct vision. The close

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than ERCP, is able to identify most
causes of obstructive jaundice such as
pancreaticobiliary malignancies and CBD
stones with similar or better accuracy than
ERCP (Fig. 8), and does not expose the
patient to radiation or contrast material.

Fig. 7. PTC showing a hilar cholangiocarcinoma (arrow).

Tissue sampling in the form of EUS-guided

fine-needle aspiration can also provide
a cytological diagnosis and important
staging information in pancreaticobiliary
malignancies. The limitations of EUS
include high operator dependency with a
steep learning curve, equipment cost and
availability, the inability to provide any
immediate therapeutic procedure and the
need for conscious sedation. Visualisation
is limited to within 8 cm from the probe,
and imaging can be obscured by stents,
surgical clips or calcific pancreatitis.

Applying further
imaging in obstructive
jaundice

Fig. 8. Endoscopic ultrasound showing a

gallstone in the CBD.

proximity of the probe to the bile ducts

and pancreas permits high-resolution
imaging. Several features make EUS a
very useful procedure. EUS is less invasive

If US demonstrates dilated intrahepatic

bile ducts and a hilar tumour is suspected,
MRCP is the next investigation of choice,
as more accurate non-invasive imaging
of the level and extent of the bile duct
obstruction is obtained (Fig. 1). CT
scanning is complementary to US and
provides information on liver parenchyma,
gallbladder pathology, bile duct dilatation
and pancreatic disease. CT is particularly
valuable for the recognition of lesions
as small as 1 cm in either the liver or

the pancreas. If further non-operative

intervention is necessary to define the
extent more accurately or relieve biliary
obstruction, either ERCP or PTC are the
second-line procedures used. ERCP is
advisable when the obstruction involves
the lower common bile duct such as with
gallstones or carcinoma of the head of
the pancreas. PTC is preferred for high
obstructions (hilar cholangiocarcinoma or
strictures of the hepatic duct bifurcation)
because of better biliary opacification
above the obstruction and a lower risk of
introducing sepsis.
In most patients, a low obstruction of
the CBD is drained endoscopically by
ERCP, either by sphincterotomy and stone
removal, or by inserting an intraluminal
transpapillary biliary stent. A stent may
be the definitive treatment for inoperable
carcinomas or in frail patients with large
CBD stones. For patients who have biliary
infection and who require surgery, stenting
provides effective preoperative biliary
drainage by allowing the infection and
jaundice to resolve and liver function to
recover. In patients who have irresectable
hilar cholangiocarcinoma, expandable
metal biliary stents provide effective
palliation. Percutaneous US-guided liver
biopsy may be required to determine
the nature and histological stage of
intrinsic parenchymal liver disease, while
laparoscopy with US is used in selected
patients to assess and stage liver, biliary or
pancreatic tumours before resection.

In a nutshell
Cholestatic jaundice caused by intrahepatic hepatocellular disease may be clinically and biochemically indistinguishable from
cholestasis due to extrahepatic bile duct obstruction.
The most common intrahepatic causes of jaundice are viral hepatitis, alcohol-induced hepatitis, cirrhosis and drug-induced jaundice.
Extrahepatic jaundice is most often due to a stone in the common bile duct or a pancreaticobiliary malignancy. Pancreatic pseudocysts,
chronic pancreatitis, sclerosing cholangitis, benign bile duct strictures or parasites in the bile duct are less common causes.
Ultrasound is a useful initial investigation because it is non-invasive and assesses pancreaticobiliary structures in real-time without
exposing the patient to ionising radiation.
Dilated ducts are indirect evidence of biliary obstruction.
If bile ducts are not dilated, hepatocellular disease is the likely diagnosis; however, parenchymal liver disease or sclerosing cholangitis
may prevent biliary dilatation despite obstruction being present.

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