From the Department of Radiology, University of Naples "Parthenope," Via Acton 18, Naples, NA 80113, Italy (O.A.C., A.S.); Department of Radiology, Massachusetts General Hospital, Harvard University Medical School, Boston, Mass (M.S.G., D.G.); Department of Nuclear Medicine, SDN IRCC, Naples, Italy (E.N., M.S.); Department of Surgery, Second University of Naples, Naples, Italy (F.S., G.P.); Departments of Nuclear Medicine (A.C.) and Radiology (A.L., M.C.), University of Naples Federico II, Naples, Italy; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging (B.R.R., M.G.V.); and MGH Biostatistics Center (M.G.V.), Massachusetts General Hospital, Harvard University Medical School, Charlestown, Mass.
Radiology. 2016 Mar;278(3):792-800. doi: 10.1148/radiol.2015150566. Epub 2015 Oct 5.
To retrospectively evaluate positron emission tomography (PET)/magnetic resonance (MR) enterography for the differentiation of fibrotic strictures from inflammatory strictures in patients with Crohn disease.
This HIPAA-compliant retrospective study was approved by the institutional review board. Patients gave their written informed consent for study enrollment. PET/MR enterography images were evaluated in 19 patients with Crohn disease who had strictures that underwent surgical resection with pathologic confirmation. Two radiologists and a nuclear medicine physician in consensus evaluated the following bowel wall PET/MR enterography biomarkers: signal intensity (SI) on T2-weighted images, apparent diffusion coefficient (ADC), PET maximum standardized uptake value (SUVmax), SI on T2-weighted images × SUVmax, and ADC × SUVmax values at levels that corresponded to pathologic specimens. MR, PET, and hybrid PET/MR biomarkers were compared, and the performance for differentiation of inflammatory strictures from fibrotic strictures was assessed. Mixed-model regression analysis was used to compare the mean imaging parameters between groups; the P values were corrected for the five comparisons by using the Bonferroni method.
Three of the PET/MR enterography biomarkers, SUVmax, SI on T2-weighted images × SUVmax, and ADC × SUVmax, showed significant differences in the fibrosis group compared with the fibrosis with active inflammation group and the active inflammation only group. The best discriminator between fibrosis and active inflammation was the combined PET/MR enterography biomarker ADC × SUVmax cutoff of less than 3000, which was associated with accuracy, sensitivity, and specificity values of 0.71, 0.67, and 0.73, respectively.
PET/MR enterography offers a potential noninvasive technique for the differentiation of purely fibrotic strictures from mixed or inflammatory strictures. A hybrid biomarker that incorporates both MR and PET information performed better for stricture evaluation than either modality alone.
回顾性评估正电子发射断层扫描（PET）/磁共振（MR）肠造影术在克罗恩病患者中区分纤维化狭窄和炎症性狭窄的作用。
本 HIPAA 合规性回顾性研究获得了机构审查委员会的批准。患者对研究入组均签署了书面知情同意书。对 19 例经手术切除且经病理证实存在狭窄的克罗恩病患者的 PET/MR 肠造影图像进行评估。两位放射科医生和一位核医学医师共识性评估了以下肠壁 PET/MR 肠造影生物标志物：T2 加权图像上的信号强度（SI）、表观扩散系数（ADC）、PET 最大标准化摄取值（SUVmax）、T2 加权图像×SUVmax、以及与病理标本对应的水平上的 ADC×SUVmax 值。比较了 MR、PET 和混合 PET/MR 生物标志物，并评估了它们区分炎症性狭窄和纤维化狭窄的性能。采用混合模型回归分析比较组间平均影像学参数；使用 Bonferroni 法对 5 次比较进行校正，以比较 P 值。
与纤维化伴活动炎症组和单纯炎症组相比，3 种 PET/MR 肠造影生物标志物（SUVmax、T2 加权图像×SUVmax 和 ADC×SUVmax）在纤维化组中存在显著差异。区分纤维化和活动炎症的最佳鉴别标志物是联合 PET/MR 肠造影生物标志物 ADC×SUVmax 截断值＜3000，其准确性、敏感性和特异性值分别为 0.71、0.67 和 0.73。
PET/MR 肠造影术为区分单纯纤维化狭窄与混合性或炎症性狭窄提供了一种潜在的非侵入性技术。结合了 MR 和 PET 信息的混合生物标志物在评估狭窄方面比单一模态表现更好。
