Crohn’s disease: prevalence, MR features, and clinical significance of enteric and colonic sinus tracts

Abstract

Objectives Enteric and colonic sinus tracts are inflammatory complications that precede intestinal fistulas in patients with Crohn’s disease (CD). The aim of this study was to retrospectively determine the prevalence, morphologic features, and outcome of sinus tracts using MR imaging. Methods A consecutive cohort of 642 patients with known CD, referred for MR enterography or MR enteroclysis (study period 01/2014–09/2019), was evaluated retrospectively for the presence of sinus tracts, their locations, presence and length of coexisting strictures, bowel wall thickness, CDMI score, upstream dilation, and bowel distension. Clinical outcome was assessed using medical records. For metric data, means and standard deviation, as well as one-way ANOVA and Pearson’s correlation coefficient, were calculated. Results In 36/642 patients with CD undergoing MRE, 49 sinus tracts (forty in small intestine, nine in left-sided colon) were detected with a prevalence of 6.9% in patients with MR-visible signs of CD (n = 519, overall prevalence of 5.6%). Mean segmental bowel wall thickness was 8.9 mm, and mean CDMI score was 9.3. All sinus tracts were located within a stenotic segment, showing mesenteric orientation within the small bowel and upstream dilation in 13 patients. Of 36 patients, 19 underwent immediate surgery and seven developed clinical progression within the segment containing the sinus tract. Conclusions Sinus tracts occur in 6.9% of patients with visible signs of CD. They are located within stenotic, severely thickened bowel segments with high MR inflammation scores. Their detection is clinically important, because they indicate a more aggressive phenotype and, if left untreated, may show severe progression. Key Points • Sinus tracts occur in 6.9% of patients with MR-visible signs of Crohn’s disease. • Sinus tracts are a radiological indicator of early penetrating Crohn’s disease, with a high risk of progression, and require dedicated treatment. • Sinus tracts can be recognized by characteristic findings and typically occur in stenotic, severely thickened bowel segments with high MR inflammation scores.

The mutually complementary role of magnetic resonance enterography and conventional enteroclysis in patients with complicated and/or advanced stage of Crohn’s disease

“…Due to its lower spatial resolution, magnetic resonance enteroclysis/enterography is inferior to CE in the detection of these early changes (20, 22). Aphthous ulcers in the early stages may progress to deeper linear ulcers or fi ssures (22). This can be detected as thin, high signal lines in a thickened bowel wall segment on MRE (6,16,22).…”

“…Aphthous ulcers in the early stages may progress to deeper linear ulcers or fi ssures (22). This can be detected as thin, high signal lines in a thickened bowel wall segment on MRE (6,16,22). The cobblestone pattern defi nes a more chronic stage where there are patchy areas of involved and uninvolved segments seen as sharply demarcated high signal intensity areas on MRE.…”

“…The cobblestone pattern defi nes a more chronic stage where there are patchy areas of involved and uninvolved segments seen as sharply demarcated high signal intensity areas on MRE. Deep ulcers may proceed to sinus and fi stula formation (18,22) (Fig. 8).…”

“…8). Sinus tracts and fi stulae are seen as high signal intensity tracts on fl uid-sensitive sequences due to the fl uid content, and as linear enhancing areas on fat-suppressed T1weighted images (18,20,22). MRE allows to assess bowel wall thickening, as a thickness exceeding 4-5 mm in an optimally distended segment (18)(19)(20).…”

Crohn’s Disease: Basic Characteristics of the Disease, Diagnostic Methods, the Role of Biomarkers, and Analysis of Metalloproteinases: A Review

“…Images obtained as a result of magnetic resonance imaging are analyzed by radiologists based on an appropriately developed point scale [100]. The following are subject to assessment:…”