Mistakes in ... Booklet 2020 - 24

ueg education

Mistakes in... 2020

Mistakes in pancreatobiliary imaging and how to avoid them
Marianna Arvanitakis and Martina Pezzullo
Multidetector computed tomography (CT) and magnetic resonance imaging (MRI)
with magnetic resonance cholangiopancreatography (MRCP) are cross-sectional
imaging modalities largely used for patients with pancreatobiliary diseases.1-3
Despite recent technological advances, correct use and interpretation of related
radiological findings require good clinical judgment and collaboration between
gastroenterologists and radiologists. In this article, we highlight mistakes
frequently made during the radiological investigation and interpretation of findings
in patients with suspected pancreatobiliary diseases, based on the available
literature and on our clinical experience.
Mistake 1 Not describing or looking for
anatomical variants
Laparoscopic cholecystectomy is currently
the standard procedure for treatment of
symptomatic gallstone disease.4 Bile duct injury
can occur during the procedure with an incidence
up to 0.7% and, albeit rare, can be associated
with significant morbidity and even mortality.4
Biliary anatomical variations can lead to
perioperative misinterpretation and are a risk
factor for bile duct injury.5 If no preoperative MRI
is performed or biliary anatomical variations are
not taken into account when reporting the MRI
findings, the likelihood of bile duct injury and

a

b

a

b

Figure 1 | Imaging the cystic duct. a | 2D MRCP
showing that what looks like the cystic duct (arrow) is
actually the right posterior duct separately originating
from the common bile duct. b | The cystic duct (thick
arrow) is originating from the right posterior duct.

postoperative complications, such as biliary
leakage, is increased.

c

There are several biliary anatomic variations to
be aware of that may lead to perioperative biliary
injury: perihilar insertion of the cystic duct defined
as a short cystic duct with an insertion <1 cm from
the hilum; posterior insertion of the cystic duct
into the common bile duct (CBD); direct insertion
of a segmental/sectoral right hepatic duct into the
gallbladder or the cystic duct; and insertion of a
right sectoral/segmental hepatic duct directly into
the CBD (figure 1).3,5
MRCP is considered the gold standard
imaging modality for preoperative evaluation of
the biliary tree.3 Indeed, in a recent prospective
study including 402 patients undergoing
preoperative MRCP and subsequent laparoscopic
cholecystectomy, MRCP assisted in the
identification of anatomical variations in 105
patients (26%).5 Performing multiplanar
acquisition helps the detection of anatomical
variants on MRCP images.

Mistake 2 Misinterpreting MRCP images
regarding intraductal findings

d

e

f

Figure 2 | Interpreting intraductal findings. a-c | Intraductal filling defects. a | MRCP shows two intraductal filling
defects (arrows). b | T1-weighted image of the hepatobiliary phase shows that the structures have different
signals as one is a stone (thin arrow) and the other is a metallic clip (thick arrow) causing a blooming artefact.
c | CT confirms the presence of a metallic clip (thick arrow). d-f | Pulsation artefact. MRCP shows a pancreatic
tail duct stricture (arrow)(d) that is actually a pseudostricture caused by the adjacent splenic artery, as seen in
the T2-weighted image (arrow) (e) and the T1-weighted post-contrast image (arrow) (f).

© (2020) Arvanitakis and Pezzullo.
Cite this article as: Arvanitakis M and Pezzullo M.
Mistakes in pancreatobiliary imaging and how to avoid them.
UEG Education 2020; 20: 12-16.

12

MRCP can accurately detect biliary stones
and ductal strictures of the biliary and pancreatic
ducts.1,3 However, bile is a dynamic fluid and can
produce flow voids that mimic a stone, particularly
where the cystic duct joins the CBD. Additional
biliary stone mimics include pneumobilia
(the presence of air) related to previous
sphincterotomy, debris, mucin, haemobilia (the
presence of blood clots), clips and tumours within
the biliary tree.3 It is important to distinguish
between stones and air, as the presence of air does
not necessarily imply an indication to proceed to
biliary drainage by endoscopic retrograde
cholangiopancreatography (ERCP). In challenging
cases, concomitant radiological assessment with

Marianna Arvanitakis is a gastroenterologist in the Department of

Correspondence to: Marianna.arvanitaki@erasme.ulb.ac.be

Gastroenterology, Hepato-pancreatology and Digestive
Oncology, and Martina Pezzullo is a radiologist in the Department
of Radiology, Erasme University Hospital, Université Libre de
Bruxelles, Brussels, Belgium.

Conflicts of interest: The authors declare they have no conflicts

of interest.
Published online: August 27, 2020.



Mistakes in ... Booklet 2020

Table of Contents for the Digital Edition of Mistakes in ... Booklet 2020

Mistakes in ... Booklet 2020 - 1
Mistakes in ... Booklet 2020 - 2
Mistakes in ... Booklet 2020 - 3
Mistakes in ... Booklet 2020 - 4
Mistakes in ... Booklet 2020 - 5
Mistakes in ... Booklet 2020 - 6
Mistakes in ... Booklet 2020 - 7
Mistakes in ... Booklet 2020 - 8
Mistakes in ... Booklet 2020 - 9
Mistakes in ... Booklet 2020 - 10
Mistakes in ... Booklet 2020 - 11
Mistakes in ... Booklet 2020 - 12
Mistakes in ... Booklet 2020 - 13
Mistakes in ... Booklet 2020 - 14
Mistakes in ... Booklet 2020 - 15
Mistakes in ... Booklet 2020 - 16
Mistakes in ... Booklet 2020 - 17
Mistakes in ... Booklet 2020 - 18
Mistakes in ... Booklet 2020 - 19
Mistakes in ... Booklet 2020 - 20
Mistakes in ... Booklet 2020 - 21
Mistakes in ... Booklet 2020 - 22
Mistakes in ... Booklet 2020 - 23
Mistakes in ... Booklet 2020 - 24
Mistakes in ... Booklet 2020 - 25
Mistakes in ... Booklet 2020 - 26
Mistakes in ... Booklet 2020 - 27
Mistakes in ... Booklet 2020 - 28
Mistakes in ... Booklet 2020 - 29
Mistakes in ... Booklet 2020 - 30
Mistakes in ... Booklet 2020 - 31
Mistakes in ... Booklet 2020 - 32
Mistakes in ... Booklet 2020 - 33
Mistakes in ... Booklet 2020 - 34
Mistakes in ... Booklet 2020 - 35
Mistakes in ... Booklet 2020 - 36
Mistakes in ... Booklet 2020 - 37
Mistakes in ... Booklet 2020 - 38
Mistakes in ... Booklet 2020 - 39
https://www.nxtbookmedia.com