{"title":"Characteristics of imaging in hepatic inflammatory pseudotumors: a comparison between IgG4-related and IgG4-unrelated cases.","authors":"Hua Lin, Ying Liu, Youyong Wei, Xiaohui Guan, Shuilian Yu, Yuping Man, Demao Deng","doi":"10.1186/s13244-024-01782-w","DOIUrl":null,"url":null,"abstract":"<p><strong>Objectives: </strong>The objective of this study was to examine the imaging features of hepatic inflammatory pseudotumors (IPTs) associated with IgG4-related and IgG4-unrelated conditions and to enhance the approach toward distinguishing between these two types of IPTs.</p><p><strong>Methods: </strong>A retrospective study was conducted, involving 20 patients diagnosed with hepatic IPTs. Imaging procedures were conducted within a timeframe of 4 weeks prior to hepatectomy or biopsy. The imaging features were then analyzed and compared using chi-squared analysis.</p><p><strong>Results: </strong>Seventeen (81.0%) IPTs were located in the hepatic subcapsular area; six (66.7%) IgG4-related IPTs were distributed around the hepatic hilum; and eleven (91.7%) IgG4-unrelated and three (33.3%) IgG4-related IPTs had unclear boundaries. All lesions exhibited similar characteristics in CT scans, T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI), with the apparent diffusion coefficient (ADC) values slightly higher than the surrounding liver tissue. Delayed hypoenhancement, observed in five cases (55.6%), was exclusively present in IgG4-related IPTs. The remaining IPT lesions displayed progressive enhancement, septal and marginal enhancement, and persistent enhancement. Central enhancement was absent in three IgG4-related IPTs (33.3%) and ten IgG4-unrelated IPTs (83.3%). The duct-penetrating sign was identified in two IgG4-unrelated IPTs (16.7%) and seven IgG4-related IPTs (77.8%). Furthermore, seven patients with IgG4-related IPTs had additional lesions outside the liver.</p><p><strong>Conclusions: </strong>IgG4-related lesions are frequently found in the vicinity of the hepatic hilum; they display the duct-penetrating sign and affect other organs as well. Both groups exhibited progressive or persistent contrast enhancement in typical IPT lesions, but delayed hypoenhancement was only observed in the IgG4-related IPT group. IgG4-unrelated IPT lesions often exhibited indistinct boundaries lacking central enhancement.</p><p><strong>Critical relevance statement: </strong>Differences in imaging features differentiate IgG4-related and -unrelated inflammatory pseudotumors (IPT). IgG4-related lesions are frequently near the hepatic hilum, display duct-penetrating sign, and affect other organs. Only the IgG4-related group demonstrated delayed hypoenhancement. IgG4-unrelated IPT lesions often exhibited indistinct boundaries lacking central enhancement.</p><p><strong>Key points: </strong>Compared with IgG 4-unrelated IPTs, IgG4-related IPTs show delayed hypoenhancement and affect other organs. IgG4-unrelated IPTs have unclear boundaries and lack central enhancement. Improved IPT diagnostic capabilities can help minimize additional, potentially unnecessary, interventions.</p>","PeriodicalId":13639,"journal":{"name":"Insights into Imaging","volume":"15 1","pages":"203"},"PeriodicalIF":4.1000,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11315856/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Insights into Imaging","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s13244-024-01782-w","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives: The objective of this study was to examine the imaging features of hepatic inflammatory pseudotumors (IPTs) associated with IgG4-related and IgG4-unrelated conditions and to enhance the approach toward distinguishing between these two types of IPTs.
Methods: A retrospective study was conducted, involving 20 patients diagnosed with hepatic IPTs. Imaging procedures were conducted within a timeframe of 4 weeks prior to hepatectomy or biopsy. The imaging features were then analyzed and compared using chi-squared analysis.
Results: Seventeen (81.0%) IPTs were located in the hepatic subcapsular area; six (66.7%) IgG4-related IPTs were distributed around the hepatic hilum; and eleven (91.7%) IgG4-unrelated and three (33.3%) IgG4-related IPTs had unclear boundaries. All lesions exhibited similar characteristics in CT scans, T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI), with the apparent diffusion coefficient (ADC) values slightly higher than the surrounding liver tissue. Delayed hypoenhancement, observed in five cases (55.6%), was exclusively present in IgG4-related IPTs. The remaining IPT lesions displayed progressive enhancement, septal and marginal enhancement, and persistent enhancement. Central enhancement was absent in three IgG4-related IPTs (33.3%) and ten IgG4-unrelated IPTs (83.3%). The duct-penetrating sign was identified in two IgG4-unrelated IPTs (16.7%) and seven IgG4-related IPTs (77.8%). Furthermore, seven patients with IgG4-related IPTs had additional lesions outside the liver.
Conclusions: IgG4-related lesions are frequently found in the vicinity of the hepatic hilum; they display the duct-penetrating sign and affect other organs as well. Both groups exhibited progressive or persistent contrast enhancement in typical IPT lesions, but delayed hypoenhancement was only observed in the IgG4-related IPT group. IgG4-unrelated IPT lesions often exhibited indistinct boundaries lacking central enhancement.
Critical relevance statement: Differences in imaging features differentiate IgG4-related and -unrelated inflammatory pseudotumors (IPT). IgG4-related lesions are frequently near the hepatic hilum, display duct-penetrating sign, and affect other organs. Only the IgG4-related group demonstrated delayed hypoenhancement. IgG4-unrelated IPT lesions often exhibited indistinct boundaries lacking central enhancement.
Key points: Compared with IgG 4-unrelated IPTs, IgG4-related IPTs show delayed hypoenhancement and affect other organs. IgG4-unrelated IPTs have unclear boundaries and lack central enhancement. Improved IPT diagnostic capabilities can help minimize additional, potentially unnecessary, interventions.
期刊介绍:
Insights into Imaging (I³) is a peer-reviewed open access journal published under the brand SpringerOpen. All content published in the journal is freely available online to anyone, anywhere!
I³ continuously updates scientific knowledge and progress in best-practice standards in radiology through the publication of original articles and state-of-the-art reviews and opinions, along with recommendations and statements from the leading radiological societies in Europe.
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The journal went open access in 2012, which means that all articles published since then are freely available online.