Imaging of the small bowel in Crohn's disease: a review of old and new techniques

Abstract

The investigation of small bowel morphology is often mandatory in many patients with Crohn's disease. Traditional radiological techniques (small bowel enteroclysis and small bowel follow-through) have long been the only suitable methods for this purpose. In recent years, several alternative imaging techniques have been proposed. To review the most recent advances in imaging studies of the small bowel, with particular reference to their possible application in Crohn's disease, we conducted a complete review of the most important studies in which traditional and newer imaging methods were performed and compared in patients with Crohn's disease. Several radiological and endoscopic techniques are now available for the study of the small bowel; each of them is characterized by a distinct profile of favourable and unfavourable features. In some cases, they may also be used as complementary rather than alternative techniques. In everyday practice, the choice of the technique to be used stands upon its availability and a careful evaluation of diagnostic accuracy, clinical usefulness, safety and cost. The recent development of innovative imaging techniques has opened a new and exciting area in the exploration of the small bowel in Crohn's disease patients.

Figure 1

Small bowel enteroclysis. Evidence of narrowing and alterations in the terminal ileum and presence of an entero-vesical fistula.

Figure 2

Magnetic resonance, axial T2-weighted fast spin-echo. Mean age female patient with recurrent abdominal pain. This image shows homogeneus small bowel loops distention and thin wall, thus negative for Crohn's disease.

Figure 3

Magnetic resonance, coronal 3D T1-weighted gradient-echo, after intravenous administration of gadolinium contrast agent. Young male patient with known Crohn's disease, recurrent abdominal pain in MR staging of the disease before therapy. The straight white arrow shows the last segment of small bowel with thickened wall and typical selective submucosal enhancement in the arterial phase. The curved white arrow shows a normal intestinal segment with thin wall and no contrast enhancement.

Figure 4

Capsule endoscopy. Multiple ulcers of the terminal ileum leading to lumen sub-stenosis.

Figure 5

Capsule endoscopy. Linear ulcer of the jejunum.