Pancreatic Duct Evaluation in Autoimmune Pancreatitis: MR Pancreatography

Pancreatic Duct Evaluation in Autoimmune Pancreatitis: Intraindividual Comparison of MR Pancreatography at 3.0 T and 1.5 T

A prospective intra-individual study to compare the image quality of magnetic resonance (MR) pancreatography at 3.0 T and 1.5 T in patients with autoimmune pancreatitis.

Study Overview

• Status: Completed
• Conditions: Pancreatitis, Chronic; Autoimmune Disease

Detailed Description

Autoimmune pancreatitis (AIP) is a unique form of chronic pancreatitis caused by an autoimmune mechanism that responds well to steroid therapy. One of the most important issues on AIP is to distinguish it from pancreatic cancer as the treatments are totally different from each other. An accurate differentiation of AIP from pancreatic cancer is therefore crucial.

Two most important image findings of AIP are pancreatic enlargement and pancreatic ductal stricture. When CT shows typical diffuse sausage-like swelling of the pancreas and peripancreatic hypodense rim, it is easy to differentiate AIP from pancreatic cancer. However, those typical cases are not very common and, moreover, 30% of AIP manifest as focal mass/enlargement of the pancreas, making a differential diagnosis very difficult. When pancreatic feature is atypical at CT, it is important to find diffuse or multifocal stricture of the main pancreatic duct that is characteristic feature of AIP. In AIP, a diffusely attenuated pancreatic duct is thinner than normal, and this does not appear at CT. Pancreatography is therefore necessary.

Two current imaging tools to demonstrate the pancreatic duct are endoscopic retrograde pancreatography (ERP) and MR pancreatography (MRP). ERP provides high resolution images using different projections and enables various procedures including aspiration/biopsy and stent insertion. However, the use of diagnostic ERP in diagnosing AIP has been debated as ERP is an invasive procedure, having potential complications including pancreatitis, perforation of the stomach or duodenum. Moreover, it is difficult to perform endoscopic procedure in patients who underwent gastric surgery. Whereas, MRP can noninvasively image the pancreatic and biliary systems at the same time without risks of procedure-related complications and can evaluate other intrabdominal organs on cross-sectional images. The relatively lower spatial resolution of MRP using 1.5 T compared with ERP images may make it difficult to demonstrate fine changes of the pancreatic duct in AIP and sometimes make false positive or negative findings.

The superiority of 3.0 T over 1.5 T MR systems has been observed in several studies. However, only a few studies using the 3.0 T MR systems in the pancreaticobiliary tract have been reported and, furthermore, the usefulness of 3.0 T MRP for the diagnosis of AIP has not yet been investigated.

The purpose of this study is to prospectively compare the image quality of MRP at 3.0 T and 1.5 T in patients with AIP using ERP as the reference standard.

• Study Type: Observational
• Enrollment (Actual): 30

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 138-736
    • Division of Abdomen, Department of Radiology & Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients with probable autoimmune pancreatitis based on clinical and CT findings

Description

Inclusion Criteria:

• Typical CT findings (diffuse sausage-like pancreatic swelling or multifocal pancreatic swelling with or without peripancreatic rim, multifocal biliary stricture, renal lesion, or retroperitoneal fibrosis)
• Serum level of immunoglobulin G fraction 4 > 135mg/dL

Exclusion Criteria:

• Patients under 20 years of age
• Women who are pregnant, lactating or who are of childbearing potential
• Patients with any physical or mental status that interferes with the signing of informed consent
• Patients with a contraindication for MRP or ERP examination

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Autoimmune pancreatitis; Patients with autoimmune pancreatitis based on clinical and CT findings

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Scoring for visualization of the main pancreatic duct on 1.5 T and 3.0 T MRP	Scoring for overall visualization of the main pancreatic duct (MPD): 1-4 points (1, entirely invisible; 2, faintly and partially visible; 3, faintly but entirely visible/clearly but partially visible; 4, clearly and entirely visible); Scoring for visualization of MPD stricture: 1-4 points (1, invisible; 2, poorly visible; 3, moderately visible; 4, clearly visible)Reference standard: ERP	Outcome measure will be assessed after a week following MRP examination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Signal-to-noise ratio of the main pancreatic duct on 1.5 T and 3.0 T MRP		Outcome measure will be assessed after a week following MRP examination
The rate of concordance in the stricture type of the main pancreatic duct between MRP and ERP	Stricture type of the main pancreatic duct: 1, diffuse; 2, segmental; 3, focal; 4, multifocal	Outcome measure will be assessed after a week following MRP examination
Scoring for confidence in diagnosing AIP based on MRP findings	Scoring for confidence: 1-4 points (1, low probability; 2, indeterminate probability; 3, moderate probability; 4, high probability)	Outcome measure will be assessed after a week following MRP examination

Collaborators and Investigators

• Sponsor: Jae Ho Byun
• Collaborators: Guerbet
• Investigators: Principal Investigator: Jae Ho Byun, MD, PhD, University of Ulsan College of Medicine, Asan Medical Center

Publications and helpful links

General Publications

• Finkelberg DL, Sahani D, Deshpande V, Brugge WR. Autoimmune pancreatitis. N Engl J Med. 2006 Dec 21;355(25):2670-6. doi: 10.1056/NEJMra061200. No abstract available.
• Kim JH, Kim MH, Byun JH, Lee SS, Lee SJ, Park SH, Lee SK, Park DH, Lee MG, Moon SH. Diagnostic Strategy for Differentiating Autoimmune Pancreatitis From Pancreatic Cancer: Is an Endoscopic Retrograde Pancreatography Essential? Pancreas. 2012 May;41(4):639-647. doi: 10.1097/MPA.0b013e31823a509b. Epub 2012 Jan 5.
• Park SH, Kim MH, Kim SY, Kim HJ, Moon SH, Lee SS, Byun JH, Lee SK, Seo DW, Lee MG. Magnetic resonance cholangiopancreatography for the diagnostic evaluation of autoimmune pancreatitis. Pancreas. 2010 Nov;39(8):1191-8. doi: 10.1097/MPA.0b013e3181dbf469.
• Onishi H, Kim T, Hori M, Murakami T, Tatsumi M, Nakaya Y, Nakamoto A, Osuga K, Tomoda K, Nakamura H. MR cholangiopancreatography at 3.0 T: intraindividual comparative study with MR cholangiopancreatography at 1.5 T for clinical patients. Invest Radiol. 2009 Sep;44(9):559-65. doi: 10.1097/RLI.0b013e3181b4c0ae.

Study record dates

Study Major Dates

• Study Start: January 1, 2013
• Primary Completion (Actual): March 1, 2015
• Study Completion (Actual): March 1, 2015

Study Registration Dates

• First Submitted: January 15, 2013
• First Submitted That Met QC Criteria: January 22, 2013
• First Posted (Estimate): January 23, 2013

Study Record Updates

• Last Update Posted (Estimate): December 30, 2015
• Last Update Submitted That Met QC Criteria: December 28, 2015
• Last Verified: December 1, 2015

More Information

Terms related to this study

• Keywords: Autoimmune pancreatitis; MR pancreatography
• Additional Relevant MeSH Terms: Digestive System Diseases; Immune System Diseases; Pancreatic Diseases; Pancreatitis; Autoimmune Diseases; Pancreatitis, Chronic; Autoimmune Pancreatitis
• Other Study ID Numbers: AMC-2012-1756