3. Introduction
Introduced in 1991.
Magnetic resonance cholangiopancreatography
(MRCP) is performed with heavily T2-weighted fast
spin-echo sequences.
Noninvasive, less costly, and sensitive alternative to
diagnostic ERCP
4. PATIENT PREPARATION
• It is very crucial to optimize imaging of the biliary
system with MRCP.
• The patient fasts for 4 hours to help reduce peristalsis
and gastroduodenal fluid before imaging.
5. PATIENT PREPARATION
• Oral contrast material that lowers the signal intensity
of intraluminal fluid in the bowel on T2-weighted
images.
• Superparamagnetic iron oxide particles, gadolinium-
meglumine compounds or pineapple juice
administered to suppress the signal from fluid in the
gastrointestinal tract.
7. PATIENT PREPARARTION
• Once in the scanning room, patient lie supine and
phased array torso-coil placed against the chest wall
& upper abdomen.
• The coil acts as antenna - improve the signal to noise
ratio of the images.
• Instructed to remain still and follow the breathing
instructions during the study.
8. MAGNET
• 1.5 Tesla -3Tesla magnet.
• Multiplanar thin-slice images -excellent spatial
resolution of the ducts.
• Stronger magnetic fields may provide better spatial
resolution.
9. TECHNIQUE
• Basic principle:
--Body fluids (bile and pancreatic secretions) have high
signal intensity on heavily T2-weighted MR
sequences therefore, appear white.
--Background tissues generate little signal appear
dark.
10. TECHNIQUE
• MR cholangiopancreatography uses
heavily T2-weighted images to visualize
stationary or slow moving fluids in the
biliary system and pancreatic duct with
high signal intensity.
11. TECHNIQUE
• Earlier sequences such as GRE & FSE provided
MRCP images ,but these long sequences often
suffered from motion artifact & poor spatial
resolution.
• Images are now acquired in one of the following
sequences that use heavy T2 weighting .
13. TECHNIQUE
• Since large component of residual background
signal from abdomen arises from fat, selective fat
suppression techniques used to improve overall
quality of the image.
14. TECHNIQUE
• Other refinements include development of breathing
independent sequences that suppress artifacts
associated with surgical clips, stents, and bowel gas
and allow image acquisition at thickness of 2-5mm.
15. TECHNIQUE
• Respiratory triggering : in which the imaging
procedure is timed to coincide with the patients
breathing.
• Can be used in patients who are unable to suspend
respiration.
16. TECHNIQUE
• Parameters for MRCP
- TE : 900 to -1000
- TR : Infinite
- Matrix : 256 x 256
- FOV : small, but without signal wrap of the biliary
structures.
- T1 axial – for any pancreatic lesion causing biliary
obstruction.
17. TECHNIQUE
• In general, the first step in performing MRCP is to
localize the biliary tract and pancreatic duct.
• Accomplished by acquiring a scout image of 30-70
mm – thick slab or single-shot projection. Depicts
majority of the biliary tract & pancreatic duct on a
single image.
18. TECHNIQUE
• To depict finer details of the ducts, thin-slab
technique is employed.
• By using the thick-slab images as guides ,
multiple, thin-slab (2-5mm)images of the
pancreaticobiliary tract in the coronal plane and at
a variety of angles which depict the ductal
systems.
19. TECHNIQUE
• The entire ductal systems are usually not located on a
single image.
• Although most diagnostic decisions are made on the
basis of 2D thin-slab images, the thin-slab images
may be manipulated with MIP algorithms MPR
techniques to generate 3D images of the ductal
systems.
20. TECHNIQUE
• Additional information may be obtained when
conventional MR is performed in conjunction with
MRCP.
• In suspected malignancy of the pancreaticobiliary
tract, MRA may also yield information important in
determining the resectability of neoplasms.
• The entire procedure takes about 10-30 minutes.
21. TECHNIQUE
• ROLE OF IV SECRETIN : IV injection of secretin,
at dose of 1ml/kg stimulates secretion by pancreas
thus allowing better distension of the pancreatic duct.
• The effect is rapid & resolves quickly.
22. TECHNIQUE
• Repeated imaging with thick-slab, every 15-30
seconds for 10-15 minutes is performed.
• This allows dynamic evaluation of the pancreatic duct
& ampullary regions.
• Secretin stimulation allows improved visualization of
the pancreatic duct compared with standard MRCP.
• This technique improves the detection of pancreas
divisum.
27. APPLICATIONS
• In choledochal cysts :
- MRCP is equivalent to ERCP.
- detects the presence of anomalous union of
pancreatic & bile ducts.
- the length of extrahepatic bile duct involved by the
cyst is known – an important consideration in
planning surgery.
- well suited for pediatric patients.
28.
29.
30. APPLICATIONS
• In anatomic variants of the bile ducts :
- Variations in the branching pattern of the IHBD occur
in 37% - detected well on MRCP.
- MC being accessory right & left hepatic ducts that
enter the bile duct caudal to the confluence.
- cystic duct anomalies.
- although these may be incidental findings they can
complicate surgery
31.
32. APPLICATIONS
• In Choledocholithiasis :
- USG & CT are often used in the initial evaluation in
suspected choledocholithiasis.
- On MRCP stones appear as signal void in the
background of high signal intensity bile.
- number, size & location are determined.
- stones as small as 2mm can be identified with current
techniques.
33.
34.
35.
36.
37. APPLICATIONS
• In Primary Sclerosing Cholangitis :
- MRCP depicts the subtle ductal abnormalities that
characterize PSC – mural irregularities, strictures
& diverticular outpouchings.
- Conventional abdominal MR + MRCP provides
useful information regarding the presence of cirrhosis
& portal hypertension in PSC patients.
38.
39. APPLICATIONS
• In post surgical complications:
- The utility of MRCP has been demonstrated in the
evaluation of the surgically altered pancreatobiliary
tract.
- These alterations include
1) biliary – enteric anastomoses
2) pancreaticoenteric anastomoses
3) duct-to-duct anastomoses
40. • MRCP demonstrates the anastomoses & also the
complications such as – strictures, intraductal stone
formation, & anastomotic leak.
41. APPLICATIONS
• In Cholangiocarcinoma :
- MRCP is very accurate in identifying the presence &
level of neoplastic obstruction of pancreatobiliary
tract.
- In conjunction with conventional MR + MRCP and ,
when necessary MRA permits not only diagnosis but
also staging of malignant tumors of pancreatobiliary
tract.
42. • In hilar cholangiocarcinoma, it depicts the length of
extra-hepatic bile duct involved by the disease as well
as the proximal extent of the disease – an important
factor in determining the resectability.
43.
44. APPLICATIONS
• In pancreatic divisum :
- occurs in 5.5 – 7.5% individuals
- MC variant of pancreatic duct, where the dorsal &
ventral anlage of the pancreas fail to fuse – resulting
in two separate drainage routes for pancreatic
secretions.
45.
46. APPLICATIONS
• In pancreatitis :
- especially when ERCP is contraindicated in ongoing
acute pancreatitis.
- in detecting common ductal manifestations of chronic
pancreatitis such as dilatation, strictures, stones &
thoracopancreatic fistulas.
47.
48.
49.
50. APPLICATIONS
• MRCP following the administration of secretin
shows improved depiction of pancreatic duct &
estimation of exocrine function as determined by the
amount of fluid filling the duodenum.
51. APPLICATIONS
• In pancreatic carcinoma :
- depicts the ducts obstructed by the pancreatic
mass & localizes the obstruction to pancreas.
- “double duct sign” is observed in case of
pancreatic head mass. ( non- specific as it may
seen in chronic pancreatitis)
- MRA done in conjunction – assesses the
resectability..
52.
53.
54. APPLICATIONS
• In failed / incomplete ERCP:
- most often technical in nature
- may be related to anatomic abnormalities such as
periampullary diverticula, duodenal stenosis, or
obstructing gastric neoplasms
55. APPLICATIONS
• In gall bladder :
- visualized as a high signal intensity structure owing to
its fluid content.
- fluid in the lumen allows the detection of stones that
are seen as low signal intensity foci.
- polyps, carcinoma and adenomyomatosis are also
detected.
56.
57. LIMITATONS OF MRCP
• Only diagnostic
• Small / impacted calculi may be missed.
• Air / metal artifacts limit visualization of entire duct.
• Volume averaging can mask small calculi in thick-
slab HASTE images.
• Artifacts due to – gas, clot, metallic clips, motion /
pulsation.
• Respiratory motion may simulate ductal stones or
strictures.
58.
59. LIMITATONS OF MRCP
• Pulsitality from the hepatic artery may simulate as
stricture in common duct.
• Overestimation of severity of biliary stenosis on MIP
images – thick slab HASTE images can overcome
this.
• Cannot be used in patients with aneurysms clips,
pacemakers etc.
• Can cause claustrophobia.
60.
61. LIMITATIONS OF MRCP
• Inappropriate selection of the region
• If negative contrast is not used, fluid in the duodenum
may obscure the common duct.
• Ampullary region shows poor visualization thus
hinders interpretation.
62. MRCP
• Non – invasive
• Only diagnostic
• Multiplanar
projection
• No risk of ionizing
radiation
• No post procedure
complications
ERCP
• Invasive
• Diagnostic &
therapeutic
• Less
maneuverability
• Risk of radiation
• Complications –
pancreatitis,
hemorrhage, GI
perforation
63. Advantages of 3.0 T over 1.5 T
• Improved image quality ( SNR at 3.0 T is twice that at 1.5 T).
• Distal arborization and intrahepatic bile duct variation more
easily detected.
• Relation of pancreatic parenchyma to the ductal system
better visualized on nonpostprocessed images obtained at 3.0
T than in those obtained at 1.5 T.
• Delineation of pancreatic duct, particularly side branches,
improved at 3.0 T.
• When oral contrast is used, the fluid signal in the
gastrointestinal tract more effectively suppressed at 3.0T.
• Thin sections of 3–4 mm can be acquired in less time at 3.0 T
than at 1.5 T, helping reduce motion artifacts.
64. SUMMARY
• Over the past decade, MRCP has evolved not only as
a feasible means of non-invasively evaluating the
pancreatobiliary tract but also as a technique with
documented clinical utility.
• In fact, at some institutions MRCP has replaced
diagnostic ERCP such that ERCP is preserved for
only therapeutic interventions.
• MRCP + abd MR + MRA – evaluates solid organs &
vessels of abd & ductal systems
65. REFERENCES
• Hemant T. Patel, Ankur J. Shah, Shikha R.
Khandelwal, Hiren F. Patel, Megha D. Patel:
MR Cholangiopancreatography at 3.0 T.
RadioGraphics 2009; 29:1689–1706 .
• Computed body tomography with MRI
correlation-Lee & Sagel.
