分子影像学与纤维化(四):肠纤维化显像之一

Molecular imaging and fibrosis(Ⅳ): non-invasive imaging in detecting intestinal fibrosis(part Ⅰ)

纤维化是由组织损伤或炎症引起的进行性瘢痕形成的过程,可导致器官损伤和衰竭。肠道的纤维化与炎性肠病特别是克罗恩病密切相关。30%的克罗恩病(CD)患者会因纤维化而造成肠道狭窄,导致肠管切除。目前,尚无预防或逆转纤维化抑制肠道狭窄的药物,内镜扩张术和外科手术治疗是主要手段,但复发率很高。只有在纤维化发生的早期确诊并干预才有可能逆转纤维化进程,避免肠道狭窄的产生。然而,炎症和纤维化在受损的肠段中不同程度地共存,有效鉴别诊断炎症和纤维化对治疗策略的选择非常重要。横断面成像技术如磁共振小肠造影、计算机断层扫描小肠造影和肠道超声,用于评估小肠和CD相关并发症(包括狭窄),有望鉴别狭窄中的炎症和纤维化程度以选择最佳疗法。目前,钆剂增强延迟显像和磁化转移磁共振成像,以及超声弹性成像是评估CD患者纤维化的重要工具。本文拟回顾纤维化的无创成像技术,例如扩散加权和磁化转移成像、应变弹性成像、剪切波成像和正电子发射断层扫描,以指导CD患者的治疗决策。

Fibrosis is a progressive process induced by tissue damage or inflammation that can lead to various organ failure. 30% of patients with Crohn’s disease(CD) develop fibrotic intestinal strictures. There are no effective drugs to prevent or reverse the progression of fibrosis-induced stricture. The intestinal stricture is usually treated by endoscopic dilatation and surgery with high rates of recurrence. With early diagnosis and intervention, fibrosis may be reversed resulting in inhibition of intestinal stricture. Because of varying degrees of inflammation and fibrosis in the damaged bowel segment, it is very important to differentiate fibrosis from inflammation for treatment planning. Magnetic resonance enterography(MRE), computed tomography enterography(CTE), and bowel ultrasound(US)have been performed to assess small bowel and CD-related complications such as strictures. We review diffusion-weighted and magnetization transfer MR imaging, strain elastography, shear-wave imaging, and positron emission tomography for treatment planning in CD patients with intestinal fibrosis and stricture.