Prognostic role of intestinal ultrasound in Crohn’s disease

Table 1 Predictive value of intestinal ultrasound parameters for response to treatment and course of Crohn’s disease

Ref.	Treatment	Timing of IUS after start of treatment	IUS parameter	Predictive value for
Albshesh et al[18], 2020	Anti-TNF	> 14 wk	BWT > 4 mm	Treatment failure
			BWT < 4 mm	Duration of failure-free response
Calabrese et al[52], 2022	Anti-TNF, vedolizumab, ustekinumab	Baseline	“Higher BWT”	Low risk of TR
			Colonic localization	High risk of TR
Chen et al[19], 2022	Anti-TNF	Baseline-2 wk	Reduction in BWT, vascularization, SWE	Response to treatment
De Voogd et al[17], 2022	Anti-TNF	Baseline-4/8 wk	BWT reduction > 18%	Endoscopic response and remission at 12-34 wk
Helwig et al[32], 2022	All available biological therapies	Baseline-12 wk	BWT reduction > 25%	Clinical remission and no therapy change at 52 wk
Les et al[20], 2021	5-ASA, budesonide, AZA, anti TNF		Worsened BWT, echopattern, vascularization	Need for treatment escalation, negative disease course
Orlando et al[29], 2018	Anti-TNF	Baseline	SWE strain ratio > 2	Surgery
Paredes et al[53], 2019	Anti-TNF	12 wk	BWT ≤ 3 mm	“Good outcome” (no treatment intensification, no surgery) at 1 yr
Ripollés et al[21], 2016	Anti-TNF	Baseline-12 wk	Sonographic response (BWT decrease > 2 mm, diminution of one grade of ECD, decrease > 20% of mural enhancement, disappearance of transmural complications or stenosi	1-yr sonographic response and further 1-yr clinical response and treatment efficacy
Smith et al[22], 2022	All available biological therapies and thiopurines	Baseline-14 wk	Sonographic response (BWT decreasing > 0.5 mm and vascularity improvement by ≥ one grade)	Treatment response at 46 wk
Zorzi et al[23], 2020	Anti-TNF, budesonide, thiopurines	Baseline-18 mo	Normalization of SICUS (BWT, disease extension, complications)	Long term lower cumulative probability of need for surgery, hospitalization, and need for steroids
Laterza et al[54], 2021	Anti-TNF	12 wk	CEUS increased PI and Pw	Clinical relapse within 6 mo
Ungar et al[55], 2020	Adalimumab	NA	Terminal ileum BWT < 4 mm	Therapy retention
Quaia et al[56], 2019	Anti-TNF	Baseline-6 wk	CEUS pretreatment values and % variations of peak enhancement, AUC, AUC during wash-in, AUC during wash-out	Long term response to therapy

IUS: Intestinal ultrasound; BWT: Bowel wall thickness; ECD: Eco-color-doppler; SWE: Shear wave elastography; UEI: Ultrasound elastography imaging; TR: Transmural remission; CEUS: Contrast enhanced ultrasound; AUC: Area under the curve; TNF: Tumor necrosis factor; NA: Not available; 5-ASA: 5-aminosalicylic acid; AZA: Azacitidine.

Table 2 Rate of transmural remission and intestinal ultrasound parameters predictive of transmural remission in Crohn’s disease patients treated with biologics

Ref.	Patients, n	TR definition	Study drug	Treatment duration	Rate of TR	IUS parameters predictive of TR
Calabrese et al[52], 2022	188	Normalization of BWT, no ECD, no extra bowel signs of inflammation	Adalimumab, infliximab, vedolizumab, ustekinumab	52 wk	27.5% (26.8% adalimumab; 37% infliximab; 27.2% vedolizumab; 20% ustekinumab	Colonic localization, lower BWT at baseline
Castiglione et al[57], 2013	66	NA	Anti-TNF	2 yr	25%
	67		Thiopurines		4%
Castiglione et al[58], 2017	40	BWT ≤ 3 mm	Anti-TNF	2 yr	25%
Castiglione et al[59], 2019	218	BWT ≤ 3 mm	Anti-TNF	12 wk	31.2%
Helwig et al[32], 2022	180	BWT ≤ 2 mm terminal ileum or ≤ 3 mm colon; BWT ≤ 2 mm terminal ileum or ≤ 3 mm colon + two factors among no ECD, no fibrofatty proliferation, normal stratification; normalization of all parameters	All available biologics	12 wk	33.3%; 38.5%; 24.4% (18.4% I; 29% C)
	78			46 wk	46.2%; NA; NA
Kucharzik et al[60], 2023	77	Normalization of all IUS parameters	Ustekinumab	48 wk	24.1% (13.2% I; 50.0% C)
Miranda et al[61], 2021	35	BWT ≤ 3 mm	Ustekinumab	52 wk	31.4%
Orlando et al[29], 2018	30	BWT ≤ 3 mm	Anti-TNF	14 wk	29%	UEI strain ratio
				52 wk	30%
Paredes et al[53], 2019	36	BWT ≤ 3 mm	Anti-TNF	52 wk	39%
Ripollés et al[21], 2016	51	BWT ≤ 3 mm, no ECD, absence of complications	Anti-TNF	12 wk	14%
				52 wk	29.5%
Civitelli et al[62], 2016	32	BWT < 3 mm, no ECD, normal stratification, absence of strictures and dilatation	Anti-TNF	9-12 mo	14%
Paredes et al[63], 2010	24	BWT < 3 mm, no increased ECD	Anti-TNF	2 wk	20.8%
Vaughan et al[64], 2022	79	BWT ≤ 3 mm, no increased ECD	Infliximab	12 wk	41%
Han et al[65], 2022	92	BWT ≤ 3 mm, no increased ECD	Anti-TNF	14 wk	12%
				52 wk (only 22 patients)	22.7%
Dolinger et al[66], 2021	13	BWT ≤ 3 mm	Infliximab	14 wk	23%
Zorzi et al[23], 2020	80	SICUS normal value for BWT, absence of any length of disease, and absence of perienteric inflammation, fistulas, phlegmon, or abscess)	Anti-TNF, budesonide, thiopurines	18 mo	41%

TR: Transmural remission; BWT: Bowel wall thickness; ECD: Eco-color-doppler vascular signal; I: Ileal Crohn’s disease; C: Colonic Crohn’s disease; UEI: Ultrasound elastography imaging; SICUS: Small intestine contrast ultrasonography; IUS: Intestinal ultrasound; TNF: Tumor necrosis factor; NA: Not available.