JC Block C - Diagnostic Radiology - HBP

Question 1

Indications for imaging the liver

Answer 1

1. Suspected focal/ diffuse liver lesion,
   e.g.:
    Cirrhosis
    Hepatocellular carcinoma (HCC)
    Pyogenic liver abscess
2. Abnormal LFT
3. Staging of known extrahepatic malignancy (e.g. breast cancer, colorectal cancer)
4. Assessment of portal vein patency and flow (for assessment and therapy of cirrhosis)
5. To facilitate placement of needles for biopsy

Question 2

Imaging modalities for the liver

Answer 2

 USG
 CT
 MRI
 PET/CT
 Angiography

Question 3

Indications for imaging the biliary tree

Answer 3

Biliary tree obstruction

Benign causes:

• Stones
• Strictures
• Gallbladder and Sphincter of Oddi dysfunction

Malignant:

• Cholangiocarcinoma
• Gallbladder CA

Question 4

Imaging modalities for biliary tree

Answer 4

USG

MRCP

EUS for microlithiasis, regional LN, Microlithiasis, ampullary and periductal structures

Question 5

Indications for imaging the pancreas

Answer 5

Assessment of pancreatitis

Pancreatic cancer

Question 6

Causes of pancreatitis

Complications of pancreatitis

Answer 6

Causes:
Gallstones, HL, Ethanol, Steroids, Mumps, Autoimmune pancreatitis, Post-ERCP, Trauma, Drugs…

Complications:
Necrotizing pancreatitis
Pseudocyst formation
Pseudoaneurysm, Splenic vein thrombosis, Fistula

Question 7

Modalities for imaging the pancreas

Answer 7

CT
MRI/ MRCP
EUS
Radio nuclei imaging (neuroendocrine tumors)

Question 8

Possible radiological findings of HBP pathologies on AXR?

Answer 8

 Gallstones
 Gas in biliary tree
 Pancreatic calcifications

Question 9

Advantages and disadvantages of ultrasound exam of HBP system

Answer 9

Question 10

Possible liver pathologies identified by US exam

Answer 10

 Steatosis (fatty liver)

 Diffuse cirrhosis & its complications: portal hypertension, splenomegaly, ascites

 Focal HCC

 Hepatic cyst

 Haemangioma

Doppler for Portal vein, Hepatic vein and Hepatic artery

Question 11

Possible biliary tree pathologies seen in US exam

Answer 11

 Gallstones (e.g. in gallbladder)
- Mobile, shadowing, echogenic, Hypoechoic tail

Acute cholecystitis:

• Gallstones seen
• Gall bladder wall >3mm
• Gall bladder enlargement >4 x 10cm
• Pericholecystic fluid
• Positive Sonographic Murphy’s sign

Gallbladder polyp

Gallbladder cancer

Dilated intrahepatic ducts

Question 12

Possible pancreas pathologies seen on US exam

Answer 12

 Pancreatic head mass (likely carcinoma)

 Pancreatic calcifications (chronic pancreatitis)

Question 13

Advantages and disadvantages of CT abdomen

Answer 13

Question 14

Indicators of CT scan of HBP

Answer 14

 Identification of focal lesions (e.g. haemangioma)

 Assessment of infections and Surgical Complications, e.g. post-pancreatitis: Pancreatic necrosis, Pseudocyst, Pseudoaneurysm

Lesions seen:
Cirrhosis 
HCC, Cholangiocarcinoma, Haemangioma, Metastasis 
Liver abscess 
Pancreatic cancer

Question 15

Signs of cirrhosis on CT

Answer 15

 Irregular contour
 Fatty changes
 Nodularity (regenerative/ dysplastic nodules)
 Segmental hypertrophy
 Heterogenous enhancement
 Iron accumulation

Question 16

Signs of portal hypertension on CT

Answer 16

 Portal vein enlargement (distended)
 Portal vein thrombosis
 Varices
 Ascites
 Splenomegaly

Question 17

Use of CT in HBP cancers

Answer 17

 Identify the lesion, Characterize the lesion
 Staging
 Resectability
 Evaluation of tumor progression
 Treatment response/ post-therapy recurrence at treatment site

Question 18

Advantages and disadvantages of MRI scan of HBP

Answer 18

Question 19

Use of MRI in HBP scans

Answer 19

 Assessment of the biliary tree, e.g. MRCP: gallstones in gallbladder

 Characterization of liver lesions, e.g. hepatocellular carcinoma

Cirrhosis:
 MR spectroscopy measures fat content (degree of steatosis)
 MR elastography measures degree of fibrosis/ cirrhosis

Question 20

Specific imaging sign of pancreatic head cancer

Answer 20

Double duct sign:

1) Dilated pancreatic duct
2) Dilated common bile duct (pancreatic head wraps around D2 - if there is a tumor, it can compress on the biliary tree and obstruct it as well)

Question 21

Pancreatic tumor types

Answer 21

adenocarcinoma

Cystic tumors like IPMN

 Neuroendocrine tumor
 Serous cystic neoplasm (SCN)
 Mucinous cystic neoplasm (MCN)
 Pseudocyst with debris

Question 22

Use of PET/CT on HBP system

Answer 22

Application on HCC:
 Staging
 Identification of extrahepatic disease
 Characterize liver lesions
 Monitor treatment response of HCC

Combination 18-FDG + C-11 acetate/ dual-tracer dramatically increases sensitivity

Question 23

Use of angiography in HBP system

Answer 23

E.g. hepatic angiography for HCC treatment – transarterial chemoembolization (TACE):

Administer chemotherapy directly to liver tumor via a catheter inserted into hepatic artery through
groin)

Question 24

Sources and bacteriology of pyogenic liver abscess

Answer 24

Question 25

ERCP

• possible interventions
• Risks

Answer 25

 Sphincterotomy
 Brushing (cytology if suspect malignancy)
 Plastic/ metallic stent (relieve/ bypass obstruction)

Risks:
 Pancreatitis
 Bleeding (sphincterotomy)
 Perforation

Question 26

Indications of PTC over ERCP

Answer 26

Past surgery with anastomotic/ anatomical alteration: e.g. Gastrectomy and Roux- en-Y reconstruction

Ampullary obstruction

Intra-hepatic lesion not reachable by ERCP