Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_585_Библиотеки_им_академика_М_И_Перельмана.pdf
ab
3 Imaging ofCommon Biliary Tract Diseases
83
c
d
Fig. 3.58 MRI ndings of normal intrahepatic bile duct. (a) T1WI of
the normal intrahepatic bile duct, which is not easily distinguished from
blood vessels; (b, c) T
WI axial and coronal planes of the normal intra-
2
3.5.2.1 Hilar Obstruction
Intrahepatic bile duct is dilated, but extrahepatic bile duct
dilatation is not obvious and the gallbladder is not distended
(Figs.3.62 and 3.63).
hepatic bile duct, showing high signal; (d) MRCP ndings of normal
intrahepatic bile duct
helpful to judge the location of obstruction. Generally, the
extrahepatic bile duct obstruction in the superior portion of
the pancreas occurs at the level below the opening of the
cystic duct, and the gallbladder is distended. However, the
opening of the cystic duct in some cases has a relatively low
3.5.2.2 Superior Pancreatic Obstruction
(Common Bile Duct Before Entering
thePancreas)
The dilated extrahepatic bile duct lies anteriorly to the portal
vein and laterally to the hepatic artery, with no surrounding
pancreatic tissue and the pancreatic duct is not dilated.
Whether the gallbladder and pancreatic duct are dilated is
position. In this situation, if the obstruction occurs at the
level above the opening of the cystic duct, the gallbladder
can either remain of normal size, or become contracted. The
main pancreatic duct generally does not dilate. It is noteworthy that gallbladder distension still can be observed if extrahepatic bile duct obstruction occurs above the conuence of
cystic ducts but the lesion invades the neck of the gallblad-
84
ab
X. Quan et al.
d
c
Fig. 3.59 MRI ndings of intrahepatic bile duct dilatation. (a) Axial
T2WI shows dilatation of the intrahepatic bile duct and the common
bile duct, and gallbladder stones; (b) Different levels of T2WI axis indi-
cates intrahepatic bile duct dilation; (c) MRI enhanced scan shows low
signal of intrahepatic dilated bile duct; (d) MRCP shows signicant
dilatation of intrahepatic bile duct and extrahepatic bile duct
der; gallbladder distension may not occur even if the obstruction after the cystic duct enters the common bile duct is
accompanied by cholecystitis atrophy (Fig.3.64).
3.5.2.3 Pancreatic Obstruction
The dilated extrahepatic bile duct is surrounded by pancreatic tissues. The cystic duct is dilated, and the gallbladder is
distended; occasionally the main pancreatic duct is dilated
(Figs.3.65 and 3.66).
3.5.2.4 Ampullary Obstruction (The common Bile
Duct Below thePancreas)
The dilated extrahepatic bile duct is located at the uncinate
process of the head of the pancreas. The main pancreatic
duct is signicantly dilated, showing “a double duct sign”
and the gallbladder is distended (Figs.3.67 and 3.68).
Fig. 3.60 Contrast-enhanced CT scan shows dilatation of extrahepatic
bile duct, common bile duct, and intrahepatic bile duct
3 Imaging ofCommon Biliary Tract Diseases
a b
c
85
d
Fig. 3.61 MRI ndings of normal extrahepatic bile ducts and dilated
extrahepatic bile ducts. (a) T2WI axis of normal extrahepatic bile duct;
(b) The T2WI axis indicates that the extrahepatic bile duct dilates with
a circular water-like length T2 signal, and the intrahepatic bile duct also
dilates. (c) Coronal contrast-enhanced MRI scan shows dilatation of
3.5.3 Signs ofCT andMRI forIdentifying
Benign andMalignant Obstruction
Common causes of biliary obstruction are biliary tumors,
stones, and inammation. Clinical differential diagnosis is
important. Imaging analysis is mainly performed by observing the shape and extent of bile duct dilatation, the location
of obstruction, the morphology of obstructive end, and signs
of tumor metastasis. It is generally believed that the dilated
bile ducts are predominantly benign lesions (repetitive
obstruction, biliary cirrhosis, periductal brosis) when they
exhibit a dendritic distribution and dilatation of the bile duct
is mainly mild or moderate; while the dilated bile ducts are
mostly caused by malignant tumors when the dilated bile
extrahepatic bile duct and intrahepatic bile duct. (d) MRCP shows obvious dilatation of both intrahepatic and extrahepatic bile ducts, and the
intrahepatic bile ducts are dilated with the appearance described as soft
rattan
ducts exhibit a soft rattan-like distribution or when they are
moderately or severely dilated. The higher the site of
obstruction (closer to the porta hepatis), the more likely it is
to be a malignant tumor; when obstruction occurs in the
pancreatic and ampullary segments, both tumors and stones
can occur.
3.5.3.1 The Dilated Extent andMorphology
oftheIntrahepatic Duct
The Dilated Extent ofIntrahepatic Bile Duct
Mild Dilation The dilated intrahepatic duct is located only
in the inner zone proximal to the porta hepatis, an intrahepatic bile duct diameter of 5mm is termed mild dilatation.
86
ab
cd
X. Quan et al.
Fig. 3.62 CT ndings of hepatocellular carcinoma involving hilar bile
duct in the left lobe of liver. (a) Plain CT scan shows dilatation of the
intrahepatic bile duct, and irregular mass of massive soft tissue can be
seen at the junction of the left and right hepatic hilum. (b) Contrastenhanced CT scan shows the primary lesion in the left lobe of the liver,
with uneven internal enhancement and circular edge enhancement. (c)
Contrast-enhanced CT scan shows intrahepatic bile duct dilation, with
the left lobe as the focal point. (d) Contrast-enhanced CT scan shows
that the intrahepatic bile duct is dilated in the shape of soft rattan, with
the left lobe of the liver as the focal point. (e, f) Contrast-enhanced CT
scan shows that the intrahepatic bile duct is dilated and resembles soft
rattan, and irregular and obviously enhanced mass of soft tissue can be
seen at the junction of the left and right hepatic ducts in the hilum
e
f
ab
3 Imaging ofCommon Biliary Tract Diseases
Fig. 3.62 (continued)
87
c
Fig. 3.63 Hilar cholangiocarcinoma. (a) Plain CT scan shows intrahe-
patic bile duct dilation; (b, c) Contrast-enhanced CT scan shows an
irregular soft tissue mass shadow in the hilar of the liver, with unclear
boundary. The intrahepatic bile duct is dilated and resembles soft rattan,
mainly in the left lobe of the liver
88
ab
X. Quan et al.
c
d
Fig. 3.64 CT ndings of superior pancreatic obstruction. (a) Plain CT
scan shows a large, round, high-density stone in the upper pancreatic
segment of common bile duct. (b) Plain CT scan at different levels
shows calculi in the upper segment of the pancreas of common bile
Moderate Dilation If the dilated intrahepatic bile duct
reaches to the middle part of hepatic parenchyma, and an
intrahepatic bile duct diameter of 5–9mm is called moderate
dilatation.
duct, dilatation of extrahepatic bile duct, enlargement of gallbladder,
and gallstone. (c) Contrast-enhanced CT scan shows signicant dilation
of intrahepatic bile duct; (d) Contrast-enhanced CT scan at different
levels shows signicant dilation of the intrahepatic bile duct
The Extent ofExtrahepatic Bile Duct Obstruction
Mild Extrahepatic Bile Duct Dilatation The extrahepatic
bile duct remains slender and spindle-shaped and its diameter ranges from 8 to 10mm. The outlines of extrahepatic bili-
ary ducts are clear but the section is not full.
Severe Dilation If the dilated intrahepatic bile duct
reaches to the outer zone of liver parenchymal and the
intrahepatic bile duct diameter is >9 mm, this is called
severe dilatation.
Moderate Extrahepatic Bile Duct Dilatation Between
mild and severe extrahepatic bile duct dilatation.
ab
3 Imaging ofCommon Biliary Tract Diseases
89
c
d
e
Fig. 3.65 CT ndings of pancreatic segment obstruction. (a) Plain CT
scan shows signicant dilation of the intrahepatic bile duct; (b) Plain
CT scan at different levels shows obvious dilation of intrahepatic bile
duct; (c) Plain CT scan shows a concentric circular high-density stone
in the pancreatic segment of common bile duct, with the above intrahe-
patic and extrahepatic bile ducts dilated; (d) Plain CT scan at different
levels shows calculous shadow within the pancreatic segment of com-
mon bile duct, and the above intrahepatic and extrahepatic bile ducts are
dilated. (e) The level of obstruction lies below the opening of the gall-
bladder, and the gallbladder is enlarged
90
ab
X. Quan et al.
c
d
Fig. 3.66 CT ndings of calculus in the pancreatic segment of common bile duct. (a) Plain CT scan shows a small high-density stone in the
pancreatic segment of common bile duct, combined with cholecystolithiasis and cholecystitis (thickened gallbladder wall); (b, c) Contrast-
Severe Extrahepatic Bile Duct Dilatation The extrahepatic bile duct loses its slender and “spindle-shaped” characteristics, and there is a feeling of fullness in the extrahepatic
enhanced CT scan shows branchlike dilated intrahepatic bile duct; (d)
Contrast-enhanced CT scan shows stones in the pancreatic segment of
common bile duct, bile duct dilatation, cholecystolithiasis, and thicken-
ing and strengthening of gallbladder wall
Residual Roots The proximal end of the intrahepatic bile
duct dilated more obviously, but the distal bile duct suddenly
tapered toward periphery.
bile duct section. The diameter of the extrahepatic bile duct
is more than 15mm.
Soft Vines (Fig. 3.70): The intrahepatic bile ducts dilated
from the hepatic hilum to the peripheral liver, showing a dis-
Morphology ofDilated Intrahepatic Bile Duct
torted course.
Dead Branches (Fig. 3.69): Only a few bile ducts devel-
oped near the hilum of the liver, showing narrow strips, and
gradually tapered off from front to back.
3 Imaging ofCommon Biliary Tract Diseases
ab
91
c
d
e
Fig. 3.67 Lower segment of common bile duct—duodenal ampullary
space occupation. (a) Plain CT scan shows intrahepatic bile duct dilation; (b) Plain CT scan shows that the gallbladder is enlarged, and a
large soft tissue mass is seen in the lower segment of the common bile
duct; (c, d) Contrast-enhanced CT scan shows dilatation of intrahepatic
bile duct, enlarged gallbladder, and slight dilatation of pancreatic duct;
(e) CT enhanced scan shows that the mass shadows in the lower seg-
ment of the common bile duct are signicantly enhanced
92
ab
ef
X. Quan et al.
c
d
Fig. 3.68 CT ndings of ampulla obstruction (carcinoma of the head
of pancreas). (a) Plain CT scan shows intrahepatic bile duct dilation;
(b) Plain CT scan shows enlargement of the head of the pancreas, with
a circular homogeneous mass shadow; (c) CT enhanced scan shows
intrahepatic bile duct dilation; (d) Contrast-enhanced CT scan shows
gallbladder enlargement, slight dilatation of the gallbladder inside and
outside the liver, and dilatation of the pancreatic duct; (e) Slight dilata-
tion of the gallbladder inside and outside the liver, and dilatation of the
pancreatic duct; (f) Contrast-enhanced CT scan shows a rounded soft
tissue mass enhancement in the head of the pancreas with unclear
boundary.