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DWI findings of autoimmune pancreatitis: Comparison between symptomatic and asymptomatic patients
Author(s) -
Oki Hodaka,
Hayashida Yoshiko,
Oki Haruka,
Kakeda Shingo,
Aoki Takatoshi,
Taguchi Masashi,
Harada Masaru,
Korogi Yukunori
Publication year - 2015
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24508
Subject(s) - medicine , asymptomatic , autoimmune pancreatitis , hyperintensity , diffusion mri , radiology , magnetic resonance imaging , effective diffusion coefficient , nuclear medicine , receiver operating characteristic , imaging biomarker , area under the curve , pancreatitis , gastroenterology
Purpose To compare the MR findings including diffusion‐weighted imaging (DWI) between symptomatic and asymptomatic patients with autoimmune pancreatitis (AIP) and to determine whether DWI can be used as an objective biomarker for symptomatic AIP, which is considered an indication for steroid therapy. Materials and Methods This retrospective study was approved by our institutional review board. MRI scans from 37 patients with AIP (symptomatic, n = 19; asymptomatic, n = 18) were retrospectively evaluated. The imaging studies were performed on a 1.5 Tesla scanner and assessed for parenchymal enlargement, narrowing of the main pancreatic duct, hypointensity on fat‐suppressed T1‐weighted images (FS‐T1WI), a capsule‐like rim, extrapancreatic lesions, and hyperintensity on DWI. The findings were compared by univariate and multivariate logistic regression analysis. Apparent diffusion coefficient (ADC) values were also calculated. Results Multivariate analysis showed that hyperintensity on DWI were most significantly associated with the symptoms of AIP (odds ratio = 28.2; P = 0.003). Interobserver agreement for DWI was also high. The ADC values were significantly lower in symptomatic than in asymptomatic patients (0.94 ± 0.17 versus 1.16 ± 0.16 × 10 −3 mm 2 /s, P < 0.001). Receiver operating characteristic curve analysis of the ADC values to differentiate between symptomatic and asymptomatic patients showed that sensitivity was 68.4%, specificity 83.3%, and AUC 0.74. Conclusion Signal intensity on DWI and ADC value were well correlated with the active symptoms of AIP patients. DWI may be useful as an objective biomarker for determining the indication for steroid therapy. J. Magn. Reson. Imaging 2015;41:125–131. © 2013 Wiley Periodicals, Inc .