Intestinal ultrasound for monitoring postoperative Crohn’s disease: A systematic review and clinical implications

Table 6 Summary of studies comparing fecal calprotectin and intestinal ultrasound for detecting postoperative recurrence in Crohn’s disease

Ref.	Year	Sample size	Timepoint	FCP cut-off	IUS threshold	FCP sensitivity/specificity (%)	IUS sensitivity/specificity (%)	Key insight
Orlando et al[19]	2006	39	3 months (IUS, FCP), 12 months (endoscopy)	> 200 mg/L	BWT ≥ 5 mm	63/75	26/90	Calprotectin more sensitive; IUS more specific at 3 months. Combining both could guide early colonoscopy
Furfaro et al[5]	2023	> 100	3-6 months post-operative	≥ 50 μg/g	BWT ≥ 3 mm	83/64	77/65	FCP and IUS individually useful; combination improved specificity and PPV. FCP < 50 μg/g + BWT < 3 mm had NPV 95.5%

IUS: Intestinal ultrasound; FCP: Fecal calprotectin; BWT: Bowel wall thickness; NPV: Negative predictive value.