Background

Dual-energy CT enterography (DECTE) has been shown to be useful in characterizing Crohn disease activity compared with clinical markers of inflammation but, to the knowledge of the authors, comparison has not been made with histopathologic specimens.

Purpose

To compare mucosal iodine density obtained at DECTE from Crohn disease–affected bowel with histopathologic specimens from surgically resected ileocolectomy bowel segments or terminal ileum colonoscopic biopsies in the same patients.

Materials and Methods

This was a retrospective study. Bowel segments in adults with Crohn disease who underwent DECTE from January 2017 to April 2019 within 90 days of ileocolectomy or colonoscopy were retrospectively evaluated with prototype software allowing the semiautomatic determination of inner hyperdense bowel wall (mucosal) mean iodine density, normalized to the aorta. Mean normalized iodine density and clinical activity indexes (Crohn Disease Activity Index [CDAI] and Harvey-Bradshaw Index [HBI]) were compared with histologic active inflammation grades by using two-tailed t tests. Receiver operating characteristic curves were generated for mean normalized iodine density, CDAI, and HBI to determine sensitivity, specificity, and accuracy. A P value less than .05 was considered to indicate statistical significance.

Results

The following 16 patients were evaluated (mean age, 41 years ± 14 [standard deviation]): 10 patients (five men, five women; mean age, 41 years ± 15) with 19 surgical resection specimens and six patients with terminal ileum colonoscopic mucosal biopsies (four men, two women; mean age, 43 years ± 14). Mean normalized iodine density was 16.5% ± 5.7 for bowel segments with no active inflammation (n = 8) and 34.7% ± 9.7 for segments with any active inflammation (n = 17; P < .001). A 20% mean normalized iodine density threshold had sensitivity, specificity, and accuracy of 17 of 17 (100%; 95% CI: 80.5, 100), six of eight (75%; 95% CI: 35, 97), and 23 of 25 (92%; 95% CI: 74, 99), respectively, for active inflammation. Clinical indexes were similar for patients with and without active inflammation at histopathologic analysis (CDAI score, 261 vs 251, respectively [P = .77]; HBI score, 7.8 vs 6.4, respectively [P = .36]).

Conclusion

Iodine density from dual-energy CT enterography may be used as a radiologic marker of Crohn disease activity as correlated with histopathologic analysis.

© RSNA, 2021

See also the editorial by Ohliger in this issue.

中文翻译：

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克罗恩病活动性炎症评估与双能 CT 肠造影碘密度：与组织病理学分析的比较

背景

与炎症的临床标志物相比，双能 CT 小肠造影 (DECTE) 已被证明可用于表征克罗恩病活动，但据作者所知，尚未与组织病理学标本进行比较。

目的

比较在 DECTE 从受克罗恩病影响的肠道获得的黏膜碘密度与来自相同患者的手术切除回肠结肠切除术肠段或末端回肠结肠镜活检的组织病理学标本。

材料和方法

这是一项回顾性研究。使用原型软件对 2017 年 1 月至 2019 年 4 月在回肠结肠切除术或结肠镜检查后 90 天内接受 DECTE 的克罗恩病成人的肠段进行回顾性评估，该软件允许半自动确定内部高密度肠壁（粘膜）平均碘密度，归一化为主动脉。通过使用双尾t检验将平均标准化碘密度和临床活动指数（克罗恩病活动指数 [CDAI] 和 Harvey-Bradshaw 指数 [HBI]）与组织学活动性炎症等级进行比较。为平均标准化碘密度、CDAI 和 HBI 生成接受者操作特征曲线，以确定敏感性、特异性和准确性。一个P 小于 0.05 的值被认为表明具有统计显着性。

结果

对以下 16 名患者进行了评估（平均年龄，41 岁 ± 14 [标准差]）：10 名患者（5 名男性，5 名女性；平均年龄，41 岁 ± 15 岁）有 19 个手术切除标本，6 名患者有末端回肠结肠镜黏膜活组织检查（四名男性，两名女性；平均年龄，43 岁 ± 14 岁）。没有活动性炎症的肠段 ( n = 8) 的平均标准化碘密度为 16.5% ± 5.7，有任何活动性炎症的肠段为34.7% ± 9.7 ( n = 17; P< .001）。20% 平均标准化碘密度阈值的敏感性、特异性和准确性为 17 个中的 17 个（100%；95% CI：80.5, 100），8 个中的六个（75%；95% CI：35, 97）和 23对于活动性炎症，分别为 25 (92%; 95% CI: 74, 99)。在组织病理学分析中，有和没有活动性炎症的患者的临床指标相似（CDAI 评分，分别为 261 对 251 [ P = .77]；HBI 评分，分别为 7.8 对 6.4 [ P = .36]）。

结论

双能 CT 肠造影的碘密度可用作与组织病理学分析相关的克罗恩病活动的放射学标志物。

©北美放射学会，2021

另请参阅 Ohliger 在本期中的社论。