MRCP is a non-invasive imaging technique that uses heavily T2-weighted sequences to visualize the biliary and pancreatic ducts without the need for contrast injection or radiation. Various sequences such as 3D FSE, single-shot FSE, and balanced SSFP can be used to produce images with high resolution and without motion artifacts. MRCP is useful for diagnosing and evaluating cystic duct abnormalities, gallstones, pancreatic and biliary strictures, leaks, tumors and other conditions affecting the biliary tree or pancreas.

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.