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Enterography Assistant

CT / MR enterography for Crohn's disease. Add each involved segment and enter positive or negative findings; a copy-ready Findings block builds below, worded to separate active inflammation from chronic fibrosis.

Modality

selects wording and which signs are assessable

DWI in protocol

Paste findings

optional — drop in dictation or notes and auto-fill the segments

Involved segments

add one card per abnormal bowel segment

Remainder of the study

Uninvolved bowel

Perianal disease

Free text (optional)

Findings

Optional — sMaRIA activity readout (not inserted into the copied Findings)

Reference — how the wording discriminates active vs. fibrotic, and why some signs were dropped

The single most useful principle

On MR, mural T2 signal is the most intuitive discriminator: a thickened wall that is bright on fat-saturated T2 (edema) favors active inflammation; a thickened wall that is dark on T2 favors fibrosis. Intramural fat (T1 bright, non-fat-sat) indicates chronic remodeling and is unrelated to whether active inflammation is present.

What the tool treats as active vs. chronic

Feature	Active inflammation	Chronic / fibrotic
Mural T2 signal	High (edema)	Low despite thickening
DWI	Restricted (high b, low ADC)	Unrestricted — not used to call fibrosis
Enhancement	Avid mucosal-predominant, or transmural	Delayed / progressive gain
Cine / motility	Narrowing transient (peristalsis preserved)	Fixed narrowing, loss of peristalsis
Ulceration	Present (marker of severe activity)	Absent (healed)
Mural fat	—	Present (submucosal fat)
Mesentery	Comb sign, fat stranding/edema, reactive nodes	Fibrofatty proliferation (creeping fat)
Stricture + upstream dilation	May be inflammatory	Characteristic of fibrostenotic disease
Pseudopolyps	—	Reparative / post-inflammatory (quiescent)

Subtypes follow the four-category scheme (active inflammatory, fistulizing/perforating, fibrostenotic, reparative/regenerative), with a mixed category when active and fibrotic signs coexist — as they do in most strictures.

Why stratified (bi-/tri-laminar) enhancement was deliberately dropped

The SAR consensus notes a stratified/layered enhancement pattern can be produced by submucosal edema, intramural fat, or inflammation — so on its own it does not separate active from chronic disease. The tool therefore reports enhancement by avidity and distribution (mucosal-predominant vs. transmural) and leans on T2 signal, DWI, ulceration, and mesenteric signs to make the call, rather than layering.

Stricture definition

A stricture is luminal narrowing with unequivocal upstream dilation. SAR 2018 used a >3 cm upstream-caliber cut; the 2025 SAR update lowered the pre-stenotic dilation threshold to ≥2.5 cm. The tool flags dilation at ≥2.5 cm and notes the caliber. Most Crohn's strictures contain both inflammation and fibrosis — when active signs coexist with a stricture, the segment is called mixed.

CT enterography

CT cannot assess intramural edema, mural T2 signal, DWI, or mural fat the way MR does, so those inputs are hidden in CT mode and the wording shifts to attenuation/enhancement. Enhancement, wall thickening, ulceration, stricture, penetrating disease, comb sign, and fibrofatty proliferation remain assessable.

Scoring note (sMaRIA)

The optional readout is the simplified MaRIA (Ordás et al., Gastroenterology 2019): one point each for wall thickening >3 mm, mural edema, perienteric fat stranding, and ulcers. >1 = active; ≥2 = severe. It is gadolinium-free and validated against endoscopy, but is a research/trial index rather than routine dictation, so it is kept out of the copied Findings by default. MaRIA/sMaRIA require MR (the edema term needs T2) and so are not offered in CT mode.

Sources

Guglielmo FF, Bruining DH, et al. Small Bowel Crohn Disease at CT and MR Enterography — SAR consensus reporting recommendations, Radiology 2018. Somwaru AS, Levy AD, et al. MR Enterography of IBD with Endoscopic Correlation (four-subtype table), RadioGraphics 2017. Leyendecker JR, et al. MR Enterography of Crohn Disease — technique and subtype imaging (Clermont/London indices, cine differentiation). Sinha R, et al. MR Enterography of Crohn Disease (imaging-based subtypes), AJR. Timpone VM, et al. pictorial essay, AJR. Ordás I, et al. simplified MaRIA, Gastroenterology 2019. Rimola J, et al. MaRIA validation, Inflamm Bowel Dis 2011. Dane B, et al. SAR consensus on defining strictures, Radiology 2025.

Interpret findings with endoscopy, histology and the clinical picture.