Table 2.

Ulcerative colitis.

Author	Total no. patients	Treatment	Time of assessment	Reference standard	IUS response/remission definition	BWT decrease or no. of patients with/without increased BWT	CDS decrease or number of patients with/without increased CDS	IUS remission	IUS response/remission association with reference standard
Socaciu 201527b	25	N/A	Baseline, 3 months	Truelove-Witts	N/A	Median decrease 0.15 mm [3%]	N/A	N/A	Wilcoxon [Z = 085, p = NS], Spearman: [rho = 0.28 p = NS]
Goertz 201828b	7	VEDO	Baseline, 2 weeks, 6 weeks,14 weeks	Mayo score	N/A	Responders: N = 4, 10 mm [17%]. Non-responders: N = 3, NS	N/A	N/A	N/A
Parente 201039	74	CS	Baseline, 3 months, 9 months, 15 months	Baron endo-scopic score	US severity [0–3] Grade 0 = BWT <4 mm, CDS 0–1 Grade 1 = BWT 4–6 mm, CDS ≥2 Grade 2 = BWT 6–8 mm, CDS ≥2 Grade 3 = BWT >8 mm, CDS ≥2	N/A	N/A	N/A	3 months: κ = 0.76 9 months: κ = 0.88 15 months: κ = 0.9
Maaser 201940	224	CS, AZA/6-MP, Anti-TNF, Anti-integrin	Baseline, 2 weeks, 6 weeks, 12 weeks	SCCAI	Normal colon =  sigmoid colon ≤4.0 mm, descending, transverse and ascending colon ≤3.0 mm	Increased BWT: sigmoid colon at baseline, 2, 6, and 12 weeks 89%, 39%, 35%, and 32%Descending colon at baseline, 2, 6, and 12 weeks 83%, 43%, 43%, and 38%	Improvements in CDS: sigmoid colon at baseline, 2, 6, and 12 weeks 35%, 23%, 16%, and 13%. Descending colon at baseline, 2, 6, and 12 weeks 15%, 7%, 5%, and 7%	N/A	N/A
Maconi 199941	30	CS ± 5-ASA ± salazopyrine	Baseline, 2 months	Truelove-Witts X-ray double-contrast barium enema	Abnormal BWT ≥4 mm	2 months: 16 [53%] improved.Decrease of 2.3 mm [31%].14 [47%] did not improve +0.7 mm, p = NS	N/A	N/A	N/A
Yoshida 201142	26	Cytapheresis ± CS + 5-ASA	Baseline, 2–3 weeks	UC-DAI score, at baseline and 12 months	Early ultrasonic response [EUR]: decrease in BWT by >2.5 mm	EUR in 11 [42%]	N/A	N/A	1-year relapse: 1 in EUR group, 9 in non-EUR group
Hean 201943a	9	N/A	Baseline + 11 months [mean]	N/A	N/A	BWT improvement: onographic remission 1.6 mm, p = 0.04. No sonographic remission 0.1 mm, p = NS	2 [22%]	N/A	N/A
Maaser 201944a	65/224 [29%] from study nr 4	Anti-TNF	Baseline, 2 weeks, 6 weeks, 12 weeks	SCCAI, CRP, FCP	Abnormal BWT sigmoid colon, >4 mm, descending colon >3 mm	Week 6: 44 received anti-TNF21 [48%] normalised.15 [34%] decrease in BWT	Increased CDS at Weeks 6 and 12 had higher SCCAI than no CDS [p <0.001]	N/A	N/A
Arienti 199645	57	High doses of IV CS	Baseline, 10 days	Truelove-Witts	Normal BWT <3mm “ultrasonic activity index”  = the sum of maximum BWT in all four segments [in mm]	IUS activity in the severe group. All: before treatment: 1.89 mm, after treatment 1.49 mm, p = 0.001 Non-operated: before 1.84 mm, after 1.27 mm, p = <0.001. Operated: before 197 mm, after 184, p = NS US activity in the moderate group. All: before 1.02 mm, after 6.3 mm, p <0.001. Non-operated: before: 9.9 mm, after 5.6 mm, p <0.001. Operated: before: 1.20, after 1.10 ± 1.1, NS	N/A	N/A	In the 8/41 [19.5%] patients that underwent surgery 3 months later, none had an improvement in IUS parameters, some worsening 5/41 [12%] non-operated patients had no IUS response, with clinical parameters fully recovered
De Voogd 202146a	29	TOF	Baseline,8 weeks	Endoscopic Mayo score, Robarts Histology Index	N/A	Endoscopic remission group: BWT sigmoid mean reduction, 2.59 ± 1.44 mm, descending colon, 1.82 ± 1.01 mm, p = <0.05.Endoscopic remission showed a cut-off value for BWT in sigmoid ≤2.87 mm [AUROC: 0.91 [0.83–0.99], sensitivity 83% and specificity 100%] and for descending, ≤2.80 mm [AUROC: 0.98 [0.94–1.00], sensitivity 91% and specificity 92%]	N/A	N/A	BWT and endoscopic Mayo score showed high correlation [rho 0.68 sigmoid colon, rho 07.5 descending colon, p <0.05]. BWT and Robarts Histology Index moderate correlation [rho 0.49, p <0.05]
Helwig 202137b	171	AZA/MTX ± Anti-TNF, Anti-integrin, systemic CS	Baseline,12 ± 4 weeks	SCCAI	Response: BWT reduction >25% or a normalisation of BWT.Remission: three different definitions. 1] Normalisation of BWT [ileum ≤2 mm, sigmoid ≤4 mm, rest of colon ≤3 mm] and normalised CDS. 2] Normalised BWT and CDS, restored BWS and no I-fat [minus one factor that could not be assessed]. 3] All factors normalised	12 weeks: no. of patients with response: 100/131 [76%]	N/A	12 weeks: Definition1] 90/171 [53%].2] 105/171 [61%].3] 77/171 [45%]	N/A
Jessen 202038c	21 CD, 20 UC	IFX	Baseline, Week 6	HBI, partial Mayo score	N/A	N/A	Data not stratified by disease. Responders: median 1 CDS point decrease.Non-responders: median 0 CDS points decrease	N/A	N/A
Kucharzik 202047a,c	21 CD, 29 UC	Biologics, JAK2 inhibitor	Baseline, Week 12	HBI, SCCAI	Abnormal BWT: sigmoid colon >4 mm, rest of colon and ileum >3 mm	Data not stratified by disease. Pathological segments baseline: 121 [54.8%]. Week 12: 53 [24%], p <0.05	Data not stratified by disease. Baseline: 25 [50%] patients with increased CDS. Week 12: 7 [14%], p <0.05	N/A	N/A
Maaser 202048a	244	N/A	Baseline, Week 12	Stool frequency and rectal bleeding	Abnormal BWT: sigmoid colon >4 mm	N/A	N/A	N/A	Rectal bleeding correlation with abnormal BWT: r = 0.417. Stool frequency correlation with abnormal BWT: r = 0.483. The two combined: r = 0.518

Anti-TNF, infliximab, adalimumab, or golimumab; AZA/6-MP, azathioprine/mercaptopurine; AZA/MTX, azathioprine/methotrexate; biologics, no data on which biologics; BWT, bowel wall thickness; CDS, colour Doppler signal; CRP, C-reactive protein; CS, corticosteroids; FCP, faecal calprotectin; IFX, infliximab; N/A, not available; SCCAI, Simple Clinical Colitis Activity Index; TOF, tofacitinib; UC, ulcerative colitis; UC-DAI, Ulcerative Colitis Disease Activity Index; VEDO, vedolizumab; IUS, intestinal ultrasound; IV, intravenous; CD, Crohn’s disease; HBI, Harvey-Bradshaw Index; AUROC, area under receiver operating characteristc curve.

^aAbstract.

^bReport data on both Crohn’s disease and ulcerative colitis, stratified by disease.

^cReport data on both Crohn’s disease and ulcerative colitis, not stratified by disease.