Department of Radiology, University of Verona, Policlinico G.B. Rossi, P.le L.A. Scuro 10, 37134, Verona, Italy.
Radiol Med. 2012 Mar;117(2):268-81. doi: 10.1007/s11547-011-0783-5. Epub 2012 Jan 21.
The presence of disease activity in Crohn's disease (CD) is one of the main parameters used to establish whether optimal therapy should be drug therapy or surgery. However, a major problem in monitoring CD is the common mismatch between the patient's symptoms and imaging objective signs of disease activity. Bowel ultrasonography (US) has emerged as a low-cost, noninvasive technique in the diagnosis and follow-up of patients with CD. Accordingly, the use of contrast-enhanced US (CEUS) has made possible an evaluation of the vascular enhancement pattern, similar to the use of magnetic resonance imaging (MRI). The aim of our study was to evaluate the role of CEUS in comparison with small-bowel MRI for assessing Crohn's disease activity.
We prospectively enrolled 30 consecutive patients with known CD. Clinical and laboratory data were compared with imaging findings obtained from MRI and CEUS of the small bowel. MRI was performed with a 1.5-T system using phased-array coils and biphasic orally administered contrast agent prior to and after gadolinium chelate administration. We performed US with a 7.5-MHz linear-array probe and a second-generation contrast agent. The parameters analysed in both techniques were the following: lesion length, wall thickness, layered wall appearance, comb sign, fibroadipose proliferation, presence of enlarged lymph nodes and stenosis. We classified parietal enhancement curves into two types in relation to the contrast pattern obtained with the time-intensity curves at MRI and CEUS: (1) quick washin, quick washout, (2) slow washin, plateau with a slow washout.
Comparison between Crohn's disease activity index (CDAI) and MRI showed a low correlation, with an rho=0.398; correlation between CDAI-laboratory data and CEUS activity was low, with rho=0.354; correlation between MRI activity and CEUS activity was good, with rho = 0.791; high correlation was found between CEUS and MRI of the small bowel when assessing wall-thickness, lymph nodes and comb sign; good correlation was fund when assessing layered wall appearance, disease extension and fibroadipose proliferation. At MRI, time-intensity curves for 12/30 patients were active, compared with for 14/30 patients at CEUS; therefore there was a poor correlation between curve on CEUS and curve on MRI (r=0.167; p=0.36).
The use of CEUS can be recommended if there is a discrepancy between MRI and clinical/laboratory parameters. MRI of the small bowel remains the most accurate method for evaluating disease activity.
克罗恩病（CD）中存在疾病活动是确定是否应采用药物治疗还是手术治疗的主要参数之一。然而，监测 CD 的一个主要问题是患者症状与影像学疾病活动客观指标之间常见的不匹配。肠道超声（US）已成为诊断和随访 CD 患者的一种低成本、非侵入性技术。因此，对比增强超声（CEUS）的使用使得评估血管增强模式成为可能，类似于磁共振成像（MRI）的使用。本研究的目的是评估 CEUS 与小肠 MRI 相比在评估 CD 活动中的作用。
我们前瞻性纳入了 30 例已知 CD 的连续患者。临床和实验室数据与从小肠 MRI 和 CEUS 获得的影像学发现进行了比较。MRI 使用 1.5-T 系统和相控阵线圈进行，在钆螯合物给药前后口服双相造影剂。我们使用 7.5-MHz 线性阵列探头和第二代造影剂进行 US。两种技术分析的参数如下：病变长度、壁厚度、分层壁外观、梳状征、纤维脂肪增生、肿大淋巴结和狭窄。我们根据 MRI 和 CEUS 时时间-强度曲线获得的对比模式将壁强化曲线分为两种类型：（1）快速冲洗，快速清除，（2）缓慢冲洗，平台缓慢清除。
CD 活动指数（CDAI）与 MRI 之间的比较显示相关性低，rho=0.398；CDAI-实验室数据与 CEUS 活性之间的相关性低，rho=0.354；MRI 活性与 CEUS 活性之间的相关性良好，rho=0.791；评估壁厚度、淋巴结和梳状征时，CEUS 与小肠 MRI 之间相关性高；评估分层壁外观、疾病延伸和纤维脂肪增生时，相关性良好。在 MRI 上，与 30 例患者中的 12 例相比，30 例患者中有 14 例的时间-强度曲线活跃；因此，CEUS 上的曲线与 MRI 上的曲线相关性差（r=0.167；p=0.36）。
如果 MRI 与临床/实验室参数之间存在差异，建议使用 CEUS。小肠 MRI 仍然是评估疾病活动的最准确方法。
