Magnetic Resonance Cholangiopancreatography

1. Rahman Ud Din
Lecturer Medical Imaging
NWIHS

2.  Wide spread clinical acceptance
 Replaced ERCP
 To visualise biliary and pancreatic tree
 Non-invasive
 No contrast injection
 No radiation

3.  Heavily T2-w images
 To visualise static fluid or bile in the PB-tree
 Longer TE 600-1200 ms
 Long TE, only fluid or tissues with high T2 relaxation
time will retain signal
 Background tissues with shorter TE do not retain
sufficient signal at longer TEs and are suppressed

4.  Seqs; used are 3D FSE and single-shot FSE
 Other seqs; include balanced SSFP and contrast
enhanced T1-w GRE seq
 3D FSE sequence
 High TE
 Respiratory triggering by tying bellows over abdomen
 MIP technique is used for 3D data
 Takes 4-5 minutes
 Limitations include respiration

5.  Single-shot FSE (SSFE/HASTE)
 Slab of 2-5 cm thickness
 Radial coronal slabs
 Acquired with breath hold
 No need for MIP
 Suppressed background tissues shows ducts
 Balanced SSFP (TrueFISP/FIESTA/bTFE)
 Breath hold
 Motion insensitive imaging
 Good quality imaging
 Shows ducts without motion artifacts

6.  Contrast-enhanced T1-w GRE sequences
(THRIVE/VBE/LAVA)
 IV injection
 Specific contrast gadobenate (Multihance), gadoxetate
(Eovist/primovist) and mangafodifir trisodium (Mn-
DPDP, Teslascan)
 Excreted through bile opacifying the bile ducts on T1-w
image
 Contrast-enhanced MRCP
 Detection of bile leak
 Visualisation of small ducts

7.  Secretin MRCP
 Secretin a hormone secreted by duodenal mucosa in
response to acid stimulation
 It increases secretion of water and bicarbonate by
pancreas
 IV (1 unit/kg) and T2-w images are acquired every 30
seconds for 10 minutes
 Distends pancreatic duct up to 3mm diameter
 Peak response occur at about 3-5 minutes after injection
and response completely vanish after 10 minutes
 S-MRCP improves visualisation of branches of pancreas
to diagnose chronic pancreatitis
 Main limitation is high cost of secretin

8.  Patient preparation
 NPO 8-12 hours
 No food in upper GIT
 Blue-berry juice and barium can empty GIT if any food
 NPO also dilate GB and bile ducts
 Examination
 Routine T2-w axial seq for planning MRCP
 3D FSE applied later (takes 4-5 minutes)
 Single-shot seq; applied
 Thin contagious section (3-4 mm) single-shot seq; in
coronal and axial plane (TE=200-300 ms)
 Coronal balanced-SSFP and axial T1-w fat sat seq;

9.  Cystic disease of bile duct
 Choledochal cyst
 Choledochocele
 Caroli’s disease

10.  Congenital anomalies
 Pancreas divisum
 Cystic duct insertion
 Medial cystic duct insertion
 Parallel course of the cystic and hepatic duct
 Aberrant right hepatic duct
 These variations are important to know in order to avoid
any complications during cholecystectomy especially
the laproscopic
Pancreas divisum

11.  Choledocholithiasis
 Accurate diagnosis of stone in CBD
 More accurate modality
 Compared to USG and CT
 Primary Sclerosing Cholangistis
 Characterized by multiple irregular strictures and
saccular dilatation of intraheptic and extrahepatic bile
ducts producing beaded appearance
 Good in diagnosis and in follow-up in such conditions
 ERCP may result in progression of cholestasis and may
not show ducts proximal to severe stenosis

12.  Postsurgical complications
 Benign strictures, retained stones, biliary leaks and
fistula
 Patency of biliary-enteric anastomosis can be seen by
MRCP

13.  Chronic pancreatitis
 It is characterised by pancreatic duct dilatation,
narrowing or stricture and irregularity
 Alcoholic chronic pancreatitis is usually heterogeneous
and characterised by side-branch dilatation and ductal
calcifications
 Whereas obstructive pancreatitis is more homogenous,
lack calcifications and is associated more often with
main duct dilatation
 MRCP is useful in such detection
 Identification of a surgically or endoscopically
correctable lesion

14.  Neoplasmic Lesions
 MRCP can show duct proximal to the obstruction
 Cause by i.e.
 Cholangiocarcinoma
 Pancreatic head carcinoma
 Fat saturated postcontrast T1-w images for the
evaluation of extent and spread of the lesion.