Usefulness of three-dimensional magnetic resonance cholangiopancreatography with partial maximum intensity projection for diagnosing autoimmune pancreatitis

Shin Yanagisawa; Yasunari Fujinaga; Takayuki Watanabe; Masahiro Maruyama; Takashi Muraki; Masaaki Takahashi; Akira Fujita; Sachie Fujita; Masahiro Kurozumi; Kazuhiko Ueda; Hideaki Hamano; Shigeyuki Kawa; Masumi Kadoya

doi:10.1016/j.pan.2017.05.001

Usefulness of three-dimensional magnetic resonance cholangiopancreatography with partial maximum intensity projection for diagnosing autoimmune pancreatitis

Pancreatology. 2017 Jul-Aug;17(4):567-571. doi: 10.1016/j.pan.2017.05.001. Epub 2017 May 5.

Affiliations

¹ Department of Radiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan. Electronic address: shiny@shinshu-u.ac.jp.
² Department of Radiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
³ Department of Gastroenterology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
⁴ Department of Medical informatics, Gastroenterology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
⁵ Center for Health, Safety, and Environmental Management, Shinshu University, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.

PMID: 28506431
DOI: 10.1016/j.pan.2017.05.001

Abstract

Purpose: To compare three-dimensional magnetic resonance cholangiopancreatography (MRCP) with/without partial maximum intensity projection (MIP) and endoscopic retrograde cholangiopancreatography (ERCP) in patients with autoimmune pancreatitis (AIP).

Materials and methods: Three-dimensional MRCP and ERCP images were retrospectively analyzed in 24 patients with AIP. We evaluated the narrowing length of the main pancreatic duct (NR-MPD), multiple skipped MPD narrowing (SK-MPD), and side branches arising from the narrowed portion of the MPD (SB-MPD) using four MRCP datasets: 5 original images (MIP₅), 10 original images (MIP₁₀), all original images (full-MIP), and a combination of these three datasets (a-MIP). The images were scored using a 3- or 5-point scale. The scores of the four MRCP datasets were statistically analyzed, and the positive rate of each finding was compared between MRCP and ERCP.

Results: The median scores for SB-MPD on MIP₅ and a-MIP were significantly higher than those on MIP₁₀ and full-MIP. In other words, partial MIP is superior to full-MIP for visualization of detailed structures. The positive rate for SB-MPD on full-MIP was significantly lower than that on ERCP, whereas the positive rate on MIP₅, MIP₁₀, and a-MIP was not significantly different from that on ERCP. Moreover, the positive rate for NR-MPD and SK-MPD on the MRCP images was significantly higher than that on the ERCP images.

Conclusion: Partial MIP is useful for evaluating the MPD and is comparable with ERCP for diagnosing AIP.

Keywords: Autoimmune pancreatitis; Endoscopic retrograde cholangiopancreatography; Magnetic resonance cholangiopancreatography; Magnetic resonance imaging; Partial maximum intensity projection.