Diagnostic imaging in Crohn's disease: comparison of magnetic resonance imaging and conventional imaging methods

Abstract

Conventional enteroclysis remains the method of choice in the diagnosis of inflammatory small bowel disease. The reported sensitivity rates, however, for the diagnosis of extraintestinal processes, such as fistulae and abscesses, are moderate. Computed tomography (CT) is the method of choice for the diagnosis of extraintestinal complications. The anatomical designation of the affected bowel segment may, however, prove difficult due to axial slices, and the applied radiation dose is high. The use of magnetic resonance imaging (MRI) in the diagnosis of inflammatory small bowel disease is a relatively new indication for the method; prerequisites were the development of breathhold sequences and phased array coils. Optimized magnetic resonance tomographic imaging requires a combined method of enteroclysis and MRI, which guarantees an optimal filling and distension of the small bowel. The high filling volume leads to a secondary paralysis of the small bowel and avoids motion artifacts. In a trial of 84 patients with histological and endoscopic correlation the sensitivity in diagnosing inflammatory bowel disease was 85.4% for enteroclysis and 95.2% for MRI, and the specificity was 76.9% for enteroclysis and 92.6% for MRI. As none of the abscesses was diagnosed with enteroclysis, the sensitivity was 0% for enteroclysis, but 77.8% for MRI. The sensitivity in diagnosing fistulae was 17.7% for enteroclysis and 70.6% for MRI. In summary, MRI can detect the most relevant findings in patients with inflammatory small bowel disease with an accuracy superior to that of enteroclysis.

What is the most accurate method for the assesment of small bowel in involvement in Crohn’s disease?

“…ting the small bowel involvement in CD (13,14). MRE and CTE can provide information about disease activation (15). In addition, it is possible to detect extraintestinal symptoms of the disease such as abscess, fistula, sacroilitis and renal calculi with cross-sectional imaging techniques such as MRE and CTE (16).…”

Diagnosing Crohn's Disease: An Economic Analysis Comparing Wireless Capsule Endoscopy with Traditional Diagnostic Procedures

“…It offers advantages over CT, especially in evaluation of the perineal region, and may have superior tissue contrast, no radiation exposure, and ability to select various cross-sectional planes. 53 Its main disadvantage in comparison to CT is poorer resolution.…”

Updating magnetic resonance imaging of small bowel: Imaging protocols and clinical indications

“…Most optimal distension is obtained with MR enteroclysis with instillation of contrast medium after nasojejunal intubation under fluoroscopic guidance. Although many authors reporting on MR enteroclysis administer antiperistaltic drugs to reduce motion artifacts, reflex atony is induced by high flow rates, theoretically allowing images (almost) free of motion artifacts [41,42] . Drawbacks are that this technique is uncomfortable for patients and exposes them to a considerable dose of ionizing radiation of up to 8 mSv during intubation [43] .…”

“…Fistulas and sinus tracts are also depicted, however, the reported sensitivity of MR imaging for depicting sinus tracts is 50%-75% when a conventional enteroclysis study is used as a reference [32,39,45] . Mesenteric lymphadenopathy ranging from 3 to 8 mm in size is depicted at MR imaging with a true fast imaging with steady state precession (FISP) or T2-weighted turbo spin-echo sequence [32,41] . If these sequences are not available, axial T1-or T2-weighted spinecho imaging should be added.…”

“…Scores ranging from 0 to approximately 600 with values below 150 are considered as remission and values over 150 as active disease. MR imaging was used to evaluate disease activity [9,[30][31][32][33][34][35]38,41,44,48,49] . Based on different experiences, contrast-enhanced(CE) fat-suppressed T1-weighted images offer the best correlation between MR findings and CDAI, although a correlation that used fatsuppressed T2-weighted images is also demonstrated.…”