Transperineal ultrasound: Role in inflammatory bowel disease management

Table 1 Studies evaluating transperineal ultrasound in pediatric perianal Crohn’s disease

Ref.	Patients (n)	Main findings	Concordance or accuracy vs MRI
Hwang et al[11], 2014	43	TPUS feasible in all; 47% with active fistula, 19% with abscess; well tolerated	No MRI comparison; pain severity correlated with activity
Lee et al[12], 2018	38	TPUS sensitivity 76% (fistula), 56% (abscess); better concordance with MRI than colonoscopy	κ = 0.296 for fistula, 0.624 for abscess
Jung et al[13], 2022	29	TPUS detected 80% of fistulas; excellent PPV (95%) and specificity (93%) for response	κ = 0.486; sensitivity 63%, accuracy 73%
Jung et al[13], 2022 (MRI/TPUS) analysis	56 fistulas analyzed	TPUS more likely to miss superficial/thin tracts; intersphincteric better detected	Detection correlated with thickness (P = 0.009); 80.4% of MRI fistulas seen on TPUS

TPUS: Transperineal ultrasound; MRI: Magnetic resonance imaging; PACD: Perianal Crohn’s disease; PPV: Positive predictive value, κ: Cohen’s kappa coefficient.

Table 2 Summary of studies comparing transperineal ultrasound with magnetic resonance imaging or surgical findings in perianal Crohn’s disease and inflammatory bowel disease

Ref.	No. of patients	Patient characteristics	Concordance rate (TPUS vs MRI or surgery)	Main findings
Maconi et al[2], 2013	59	Adults with CD, prospective	κ = 0.78 (fistulae classification)	TPUS sensitivity 94%, PPV 93%; less accurate for extrasphincteric/suprasphincteric tracts and deep abscesses
Bor et al[16], 2016	23	Adults with complicated CD	Not specified	TPUS 100% sensitivity for fistulae and abscesses; outperformed MRI and TRUS
Jung et al[13], 2022	29	Pediatric CD on biologics	κ = 0.49	TPUS had high specificity (93%) and PPV (95%) for assessing treatment response vs MRI
Lee et al[12], 2018	38	Pediatric CD with PACD	κ = 0.30-0.62	TPUS better concordance with MRI than colonoscopy; sensitivity 76% for fistulae, 56% for abscesses
Wedemeyer et al[18], 2004	25	Adults with active PACD	κ > 0.83	TPUS detected 90% of fistulas and 86% of abscesses; comparable to MRI; especially useful in anal stenosis
Terracciano et al[17], 2016	28	IBD patients	Sensitivity 100% for RVF and superficial abscess; κ = 0.34 for deep abscess	TPUS highly concordant with MRI for Parks (κ = 0.67) and AGA (κ = 0.83) classifications; superior for RVF and superficial abscesses

TPUS: Transperineal ultrasound; MRI: Magnetic resonance imaging; CD: Crohn’s disease; PACD: Perianal Crohn’s disease; TRUS: Transrectal ultrasound; RVF: Rectovaginal fistula; AGA: American Gastroenterological Association, κ: Cohen’s kappa statistic; PPV: Positive predictive value.

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.