Role of intestinal ultrasound in ulcerative colitis: A systematic review

Table 7 Summary of studies correlating blood (C-reactive protein/erythrocyte sedimentation rate) or fecal biomarkers (fecal calprotectin) with intestinal ultrasound in ulcerative colitis

Ref.	Study type	Number of patients	IUS comparator	Biomarker(s)	Time between IUS and biomarker testing	Conclusion
Bots et al[23]	Retrospective, single centre	65 UC (280 CD)	BWT, CDS, BWS, i-fat, haustrations, lymph nodes, motility	FCP, CRP	Within 1 wk	Higher FCP and CRP in IUS active disease Median FCP Active disease: 1720 µg/g; Inactive disease: 75 µg/g (P < 0.001); Median CRP Active disease: 3.6 mg/L; Inactive disease: 1.8 mg/L (P < 0.076)
Goodsall et al[4]	Prospective	19 severe UC (29 paired data)	BWT, CDI, BWS	FCP	Baseline	Log converted FCP had significant correlation with NHI (r = 0.027, 0 = 0.044), but not with MUC (r = 0.01, P = 0.064); Composite of MUC and FCP has 88% sensitivity, 80% specificity, 95% PPV, and 57% NPV (P = 0.007)
Ilvemark et al[34]	Blinded, prospective multi centre, observational	56 acute severe UC	BWT	CRP	Baseline	FCP is not a predictor of IV steroid response; BWT has significant association with CRP at 48 ± 24 h, r = 0.47, P < 0.005
Les et al[29]	Prospective	28 UC, 89 CD	BWT, loss of stratification, CD, mesenteric hypertrophy, lymph nodes	CRP, FCP	Baseline	FCP predicted immediate (AUC 0.86) and subsequent treatment intensification (AUC 0.81); CRP predicted immediate (AUC 0.81) and subsequent treatment intensification (AUC 0.55)
Lim et al[63]	Prospective cross-sectional	29 UC, 22 CD	BWT, BWS, vascularity, mesenteric fat, complications	FCP, CRP	Baseline	IUS parameters have good correlation with FCP (r = 0.489, P < 0.01) and CRP (r = 0.604, P < 0.01) significant
Maaser et al[28]	Prospective, multicentre	224 UC	BWT	FCP	Baseline, 2, 6, 12 wk	At 12 wk, 16% with increased BWT had FCP < 250 µg/g and 44.4% with normal BWT had FCP ≥ 250 µg/g
Sagami et al[57]	Single centre, prospective, cross-sectional	53 UC	BWT, CDS (rectum)	FCP	Baseline	BWT better than FCP (> 50 µg/g) for predicting histologic and endoscopic activity (MES > 1) in rectum by trans-perineal ultrasound; CDS not better than FCP
Sagami et al[78]	Prospective, single centre	100 UC	BWT, CDS (rectum)	FCP, CRP	Baseline 1, 8 wk	FCP and CRP were not independent predictors of remission at 8 wk; BWT and CDS were independent predictors of remission at 8 wk
Saleh et al[89]	Retrospective	39UC, 108 CD	BWT, BWS, CDS, mesenteric fat, complications	FCP, CRP	Baseline	54% of those with combined clinical and biochemical remission (ESR ≤ 40 mm/h and CRP ≤ 10 mg/L and FCP ≤ 50 µg/mg and fecal lactoferrin ≤ 30 µg/mL) had active IUS findings; 67% without combined remission had active IUS findings
de Voogd et al[2]	Prospective, single centre	16 UC, 22 CD	BWT, CDS, loss of haustration, bowel wall stratification, fatty wrapping	FCP	Baseline	Addition of FCP, decrease of FCP, or cutoff values for FCP did not improve the multivariate model (BWT, haustrations) to detect endoscopic remission, improvement, or response
St-Pierre et al[90]	Prospective, multicenter, observational cohort	18 UC, 123 CD	BWT, CDS	FCP	Baseline	Median FCP: IUS inactive inflammation: 50 µg/g, active inflammation 270 µg/g
Castellano et al[44]	Retrospective	44 pediatric IBD	CDS	FCP	Baseline	Median FCP low (median 92 µg/g) for low Doppler flow (≤ 2 /cm2) and high (median 2286 µg/g) for high Doppler flow (≥ 3 /cm2)

FCP: Fecal calprotectin; CDS: Color Doppler Signal; IBD: Inflammatory bowel disease; UC: Ulcerative colitis; CD: Crohn’ disease; IUS: Intestinal ultrasound; BWT: Bowel wall thickness; NPV: Negative predictive value; CRP: C-reactive protein.