Transperineal ultrasound: Role in inflammatory bowel disease management

Table 3 Studies evaluating transperineal ultrasound in ulcerative colitis

Ref.	No. of patients	Patient characteristics	Concordance rate	Main findings
Sagami et al[6], 2020	84	UC patients undergoing induction therapy; correlation with endoscopy and histology	BWT ≥ 4 mm correlated with MES > 1; sensitivity > 90%	TPUS can predict mucosal and histological healing with high accuracy
Sagami et al[19], 2022	100	UC patients on induction therapy; early TPUS response at week 1 vs remission at week 8	ΔBWT at week 1 predictive of week 8 remission (AUC = 0.75)	ΔBWT ≥ 1 mm at 1 week predicted treatment success; more accurate than CRP/FC
Greeve et al[21], 2024	8	Pregnant women with ulcerative proctitis	Feasibility and acceptability in pregnancy; no adverse events	TPUS feasible and safe during all pregnancy trimesters, including 3rd trimester
Tokushima et al[20], 2024	131	Pediatric patients with UC (MES 0-3) and non-IBD proctitis	RWT > 4.5 mm and MSWC positive had 100% sensitivity and specificity for active UC vs proctitis	TPUS with mSMI can differentiate UC from non-IBD proctitis with accuracy similar to colonoscopy
Pal et al[3], 2025	142	Adults with UC (proctitis, proctosigmoiditis, extensive colitis); compared TPUS, TAS, and EUS	TPUS AUC 0.73 (endoscopic remission), 0.66 (histologic remission)	TPUS moderately accurate for distal disease; TAS+TPUS improved diagnostic value but still inferior to EUS

TPUS: Transperineal ultrasound; UC: Ulcerative colitis; MES: Mayo endoscopic subscore; BWT: Bowel wall thickness; ΔBWT: Change in bowel wall thickness; CRP: C-reactive protein; FC: Fecal calprotectin; TAS: Transabdominal ultrasound; EUS: Endoscopic ultrasound; RWT: Rectal wall thickness; MSWC: Microvascular signal at wall circumference; mSMI: Microvascular superb microvascular imaging; AUC: Area under the curve.