Current tecniques and new perpectives research of magnetic resonance enterography in pediatric Crohn's disease

Abstract

Crohn's disease affects more than 500000 individuals in the United States, and about 25% of cases are diagnosed during the pediatric period. Imaging of the bowel has undergone dramatic changes in the past two decades. The endoscopy with biopsy is generally considered the diagnostic reference standard, this combination can evaluates only the mucosa, not inflammation or fibrosis in the mucosa. Actually, the only modalities that can visualize submucosal tissues throughout the small bowel are the computed tomography (CT) enterography (CTE) with the magnetic resonance enterography (MRE). CT generally is highly utilized, but there is growing concern over ionizing radiation and cancer risk; it is a very important aspect to keep in consideration in pediatric patients. In contrast to CTE, MRE does not subject patients to ionizing radiation and can be used to detect detailed morphologic information and functional data of bowel disease, to monitor the effects of medical therapy more accurately, to detect residual active disease even in patients showing apparent clinical resolution and to guide treatment more accurately.

Keywords: Crohn’s disease; Enterography; Imaging; Magnetic resonance imaging; Pediatric.

Figure 1

Magnetic resonance enterography in 15-year-old patient with Crohn’s disease. MR fluoroscopic (∞/950) image A shows luminal narrowing of the terminal ileum (arrow). Coronal half-Fourier RARE (1000/90, 150° flip angle) image; B shows wall thickening of the terminal ileum (arrow). Coronal contrast- enhanced fat-saturated T1-weighted VIBE (4.2/mini-mum, 10° flip angle) image; C shows stratified contrast enhancement with avid enhancement of mucosa relative to submucosal and muscular layers and layered appearance. Note high-signal-intensity linear structure due to increased vascularity close to mesenteric border of the small-bowel segment involved-the so-called comb sign (short arrows). These MR findings are indicative of active Crohn’s disease. MR: Magnetic resonance.

Figure 2

Magnetic resonance enterography in 16-year-old patient with Crohn’s disease. Contrast coronal T1 GRE A shows marked enhancement of wall of the terminal ileum (arrow). Axial contrast-enhanced fat-saturated T1-weighted VIBE (4.2/mini-mum, 10° flip angle) image; B shows stratified contrast enhancement with avid enhancement of mucosa relative to submucosal and muscular layers and layered appearance (arrow); axial HASTE image C shows wall thickening of the terminal ileum (arrow). GRE: Gradient Echo.

Figure 3

Coronal T2 haste image. A: Marked thickening of wall of the terminal ileum (arrow). Axial T2 fat-saturated HASTE image; B: Marked hypersignal of wall of the terminal ileum due to edema (arrow).

Figure 4

Magnetic resonance enterography in 17-year-old patient with Crohn’s disease. Coronal GRE image (A) shows marked enhancement of wall of the terminal ileum (arrows). Axial T2 fat-saturated HASTE image (B) (arrow) shows marked hypersignal of the wall due to edema (arrow) with adjacent fluid collection (short arrow). GRE: Gradient Echo.

Figure 5

Magnetic resonance enterography in 15-year-old patient with Crohn’s disease. Coronal half-Fourier RARE (1000/90, 150° flip angle) A and coronal contrast- enhanced fat-saturated T1-weighted VIBE (4.2/mini-mum, 10° flip angle) B show wall thickening lesions in the middle part of transverse colon (arrow). Coronal T2-w image A shows superficial ulcers that appears as a nidus of high signal intensity (short arrow in B surrounded by a rim of moderate signal intensity. Colonoscopy confirmed these findings.

Figure 6

Coronal half-fourier RARE and axial fat sat (1000/90, 150° flip angle) images. A and B shows wall thickening of the terminal ileum wall (arrows). Coronal contrast-enhanced T1-weighted fat-saturated VIBE (4.2/minimum, 10° flip angle) image C of terminal ileum shows uniform wall enhancement of terminal ileum with abnormal thickness a finding that indicates chronic inflammatory changes (arrow).

Figure 7

Magnetic resonance enterography in 14-year-old with Crohn’s disease. Coronal fat-suppressed T2-weighted half-fourier RARE A (1000/90, 150° flip angle) image shows high-signal-intensity edematous wall thickening of terminal ileum. Note inflamed adjacent tissue with hyperintense fluid collection with thick hypointense rim. Axial B and coronal C contrast-enhanced T1-weighted fat-saturated VIBE (4.2/minimum, 10° flip angle) images show marked enhancement of wall of the collection. D Coronal contrast-enhanced T1-weighted fat-saturated VIBE (4.2/minimum, 10° flip angle) image shows marked enhancement of wall of the collection. Note small fistula between the small bowel and the abscess (arrow).

Figure 8

Magnetic resonance enterography of 16-year-old with Crohn’s disease. Axial true-FISP (4.3/2.2, 50° flip angle) A and contrast axial T1 VIBE B show marked thickening with evidence of enhancement of the wall of terminal ileum, that shows hypersignal on diffusion weighted Imaging (b = 800) image C and restriction of diffusion on ADC map D (arrows).