Liver, Biliary Tract And Pancreas

Question 1

What type of MRI is required for imaging of liver

Answer 1

Minimum of 1.5 T with a multichannel phased-array coil

Question 2

What are common MR pulse sequences used to image the hepato-biliary tree?

Answer 2

• T1 spoiled gradient echo (GRE)
• T1 GRE fat suppressed volume acquisition (obtained rapidly post GAD)
• T2 spin echo (SE), T2 fast spin-echo (FSE) or General Electric or turbo spin-echo (TSE, Siemens)

Question 3

Which very heavy weighted T2 sequences show water content in bile ducts and lesions?

Answer 3

1. Gradient echo breath-hold (FISP), fast imaging employing steady state acquisition (FIESTA)
2. Breath hold very fast spin echo - half Fourier acquisition single shot turbo spin echo (HASTE)
3. Non breath hold respiratory-gated sequences used for MRCP

Question 4

What other structures (short T1 relaxation time) does STIR suppress besides in the biliary tree - (delineates fluid containing structures well )

Answer 4

Haemorrhage, Mets, melanoma

Question 5

Name liver specific contrast agents for MRI

Answer 5

Hepatitis-biliary: Gadoxetic acid (Primovist)
Gadobenate dimeglumine (Multihance)

Reticuloendothelial: super paramagnetic iron oxides - withdrawn

Question 6

Which MRI sequence can give detail on hepatic artery, portal vein and hepatic venous system

Answer 6

Contrast enhanced spoiled GRE

Question 7

Describe technique for MRCP

Answer 7

Planes: axial, coronal oblique
Pancreatic head tumour - pancreatic and portal venous phase - best in oblique coronal then axial . Converse for body and tail tumours

1. T1 FS gradient echo. Pancreas hyper intense to liver normal
2. T1 spoiled gradient-echo (SPGR,GE med systems, fast low-angle shot (FLASH), Siemens). Normal pancreas isotense to liver
3. T2 turbo-spin echo
4. GAD T1 FS spoiled GRE. 45. 90 s and 10 min after contrast images. Bolus trigger for optimal arterial phase.
5. Secretin slow IV over 1 min to distend pancreatic ducts

Question 8

Technique for intraoperative cholangiography

Answer 8

Question 9

Technique for postoperative (T-tube) cholanhiography

Answer 9

Question 10

Technique for radionuclide hepatobiliary and gallbladder imaging

Answer 10

Dynamic study - if need to visualize progress of bile in detail eg. Post surgery

Patient lies supine with camera anterior and liver at top of FOV

Additional techniques - cholecystokinin and morphine provocation

Question 11

Technique for percutaneous transhepatic cholangiography

Answer 11

Images: PA, LAO, RAO
Non tilting table - rolling into left fills left ducts and common duct above obstruction