MRCP & MRI Pancreas. Zahir Amin. University College Hospital London

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1 MRCP & MRI Pancreas Zahir Amin University College Hospital London UKRC 2014

2 MRCP Liver, GB, CBD, Pancreas, MPD MRI Pancreas Add dynamic post contrast sequences

3 MRI/MRCP Best non-invasive modality for CBD & MPD If no artefacts! Excellent soft tissue contrast Fast sequences 3D sequences Functional assessment

4 Indications MRCP Biliary obstruction and pain Pre-cholecystectomy assessment MRI Pancreas Problem solving -?Mass Acute & Chronic pancreatitis Pancreatic Cysts Autoimmune cholangiopancreatopathy

5 MRCP - Technique Heavily T2 weighted sequences Static or slow moving fluid Ax/Cor T1W and T2W mm slice thickness Whole liver in FOV Motion suppression Breath hold sequences Respiratory triggering

6 MRCP - Preparation NBM 4hrs Reduce gut fluid GB distension Secretin response Negative oral contrast Pineapple/blueberry juice SPIO suspension Breathing instructions Biliary metal stent OK Matos C et al. Radiographics 2002;22:e2

7 Biliary Metal Stent

8 MRCP - Sequences Optimise to machine/preference Fast sequences T2 T1 One or a few breath holds; triggered 2D and 3D MRCP TSE and SSFSE +/- FS GRE 2D and 3D (Dixon) In/out of phase Dynamic post Gd

9 MRCP 2D Sequences Thick slab long TE 30-80mm block correct placement crucial Coronal and coronal oblique <3s Thin slab shorter TE 3-4mm Cor/Ax About 20s

10 MRCP Thin slabs Few artefacts Higher resolution Small filling defects better seen

11 Coronal T2W TSE Respiratory triggered 3D MRCP 1-2mm contiguous scans Steady breathing critical Scan time around 5 minutes Image quality can be excellent But often poor quality

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13 MRCP 3D reconstruction Volume averaging Reduced spatial resolution Important to assess source images Thick and thin slabs adequate

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15 MRCP Evaluates biliary tree and pancreatic duct T1W and T2W sequences To assess liver, GB and pancreas T1W essential Not always included in MRCP protocols!

16 Additional T2 sequences May use STIR or SPAIR sequences Better FS and CNR compared to spectral FS Lower SNR, but SPAIR>STIR truefisp or FIESTA Fast T2W, no flow voids, vessels bright Useful additional sequence minimal motion artefact

17 T1W Fatty Change Liver & Pancreas

18 Duct Stones May be high T1

19 MR Pancreas T1W Pancreas similar signal to liver Increased signal due to acinar aqueous protein Inflammation, fibrosis or mass Hypointense Fat-suppression Better definition of hyperintense pancreas

20 MR Pancreas Image assessment T1W

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22 MR Pancreas T2W Pancreas similar signal to liver Tumour slightly increased signal Duct, inflammation, fluid, cyst Hyperintense Clearly seen with fat-suppression

23 MR Pancreas 3D T1W Axial VIBE Thin contiguous slices in one breath hold Pre and post contrast Dynamic enhancement 25s, 60s, 180s Bolus tracking Contrast use: Tumour, acute pancreatitis

24 MR Pancreas Contrast Progressive and homogeneous enhancement Masses hypo or hyper-intense Arterial and venous structures well shown MIP reconstruction

25 MR Pancreas Contrast MIP reconstruction

26 Functional information Dynamic MRCP Hepatobiliary contrast agents MnDPDP, Teslascan Gd-BOPTA, Multihance Gd-EOB-DTPA, Primovist 3D T1W sequences (20-60min) Uses Liver donors biliary anatomy Assess biliary excretion Bile leaks

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28 Secretin MRCP Stimulates pancreatic secretions Water and bicarbonate Increases sphincter of Oddi tone Transient distension of pancreatic duct 1ml/10kg iv over 1 minute Thick slab coronal MRCP Every minute for 7-10 minutes Whole duct and duodenum in FOV

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30 Secretin MRCP Normal response Increase in pancreatic duct <1mm by 3min Calibre returns to baseline by 7min Increase in duodenal fluid Well tolerated Pancreatitis extremely rare Avoid secretin if recent severe pancreatitis Improves pancreatic duct assessment Assessment of exocrine function

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32 Abnormal response Secretin MRCP >1mm increase in duct at 3min Dilatation >3mm persisting >7min Indicate pancreatic outlet obstruction Side branches in body/tail?mild chronic pancreatitis Enhancement of parenchyma -?outlet obstruction Associated with recurrent pancreatitis Sphincterotomy indicated Reduced duodenal filling Impaired exocrine function

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35 MRCP/MR Pancreas Clinical CBD stones and anatomy Biliary strictures Pancreatic cysts Pancreatic collections Pancreatic duct strictures/stones

36 CBD stone versus air

37 Variant biliary anatomy

38 Pancreas divisum 7-10% Dorsal duct drains into minor papilla separate from short ventral duct Best seen with secretin stimulation Patent accessory duct in 44%

39 Malignant biliary strictures

40 Benign Biliary strictures AIP Post Cholecystectomy Anastamotic

41 Pancreatic Cysts

42 Severe Acute Pancreatitis

43 Chronic Pancreatitis

44 MRCP Artefacts & Pitfalls Incomplete scan Motion Vascular impression Flow artefact Aerobilia Duodenal diverticulum

45 False positive stenosis MRCP - Pitfalls

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47 Vascular compression Hepatic artery and GDA MRCP - Pitfalls Short signal voids, especially on MIPs CHD, Lt hepatic duct, mid CBD Correlate with anatomical images

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49 Aerobilia MRCP - Pitfalls Mimics stones or strictures Evaluate axial T1/T2W scans

50 MRCP - Pitfalls Duodenal diverticulum May mimic pancreatic cyst

51 MRCP & MR Pancreas Summary Unique Advantages No ionising radiation Best non-invasive modality for showing CBD and MPD Replaces diagnostic ERCP MR pancreas images comparable to CT Functional information Biliary excretion Pancreatic exocrine function

52 MRCP & MR Pancreas Summary Drawbacks Pacemakers, other implants Claustrophobic patients Long scan time Availability Artefacts frequent Review all sequences/source images

53 Developments 3T MR DWI MRI perfusion MR Elastography