P0248Transperineal ultrasound vs MRI in the assessment of Perianal Crohn’s Disease: A comparative study using a validated scoring system

Abstract Background Perianal penetrating disease is a common phenotype in patients with Crohn’s disease (CD), with a substantial negative impact on quality of life. Pelvic magnetic resonance imaging (MRI) is the gold standard for detecting and classifying perianal fistulae and abscesses. The Magnifi-CD index has recently been validated, with activity cut-offs established1, 2. Transperineal ultrasound (TPUS) is a non-invasive and accessible tool for evaluating perianal penetrating disease, but data on its diagnostic accuracy and ability to classify disease activity remain limited. The aim of this prospective study was to compare TPUS and MRI using the Magnifi-CD validated scoring system in a cohort of patients with suspected or confirmed perianal penetrating CD. Methods All consecutive CD patients with suspected or confirmed perianal penetrating disease attending two IBD centers in Milan between November 2022 and November 2025 underwent both TPUS and pelvic MRI. Examinations were performed in a blinded fashion within a maximum interval of 30 days with no treatment modifications during this period. Magnifi-CD scores were calculated for both modalities and compared using a paired t-test. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of TPUS were computed using MRI as the reference standard. (Table 1 summarizes the MRI score items and their corresponding TPUS definitions). Results Thirty-nine CD patients (median age 43 years; 19 males) underwent 57 paired TPUS–MRI assessments. Mean MRIMagnifi-CD and TPUSMagnifi-CD scores were 8. 45 (SD 5. 55; IQR 3–12. 25) and 8. 33 (SD 5. 25; IQR 5–12), respectively, with no significant difference between modalities (p = 0. 81; Fig. 1). Active disease (Magnifi-CD 6) was detected in 32 examinations by MRI and 36 by TPUS. Sensitivity, specificity, accuracy, PPV, and NPV of TPUS for identifying active perianal penetrating disease were 90%, 72%, 82%, 80%, and 85%, respectively. Agreement between TPUS and MRI for diagnosing active disease was substantial (κ = 0. 637). Conclusion TPUS demonstrated high diagnostic performance and showed substantial agreement with MRI in detecting active perianal penetrating CD, supporting its use as an accurate and accessible assessment modality. References: 1. Hindryckx P, Jairath V, Zou G. Development and Validation of a Magnetic Resonance Index for Assessing Fistulas in Patients With Crohn’s Disease. Gastroenterology. 2019 Nov;157 (5): 1233-1244. e5; 2. Beek KJ, Mulders LGM, van Rijn KL, et Al. External validation of the MAGNIFI-CD index in patients with complex perianal fistulising Crohn’s disease. Eur Radiol. 2025 Mar;35 (3): 1428-1439. Conflict of interest: D’Amico, Ferdinando: Grant: ECCO fellowship grant 2020 ECCO grant 2021 Personal Fees: F D’Amico has served as a speaker for Abbvie, Alfasigma, Ferring, Lilly, Sandoz, Janssen, Fresenius Kabi, Galapagos, Giuliani, MSD, Pfizer, Takeda, Tillotts, and Omega Pharma he also served as an advisory board member for Abbvie, AnaptysBio, Ferring, Fresenius Kabi, Galapagos, Janssen, Lilly, MSD, Takeda, and Nestlè. Furfaro, Federica: Grant: IG-IBD Personal Fees: Pfizer, Biogen, J&J, Abbvie, Amgen, Janssen Bonifacio, Cristiana: Personal Fees: takeda janssen Bezzio, Cristina: No conflict of interest Faggiani, Ilaria: No conflict of interest Zilli, Alessandra: No conflict of interest Solitano, Virginia: Speaker’s fees from Pfizer, Takeda, Giuliani, Tillotts Pharma consulting fees from J & J travel grant from Abbvie Parigi, Tommaso Lorenzo: Tommaso L Parigi declares no relevant conflicts of interest Dal Buono, Arianna: speaker’s fees from AbbVie, Alphasigma, Ferring, Lilly, Janssen, and Celltrion Radice, Simona: Personal Fees: Takeda, Abbvie Pfizer Janseen Celtrion Jonhson & Jonhson Massironi, Sara: None to declare Saibeni, Simone: No conflict of interest Armuzzi, Alessandro: Consulting fees from AbbVie, Abivax, Alfa Sigma, Astra Zeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celltrion, Eli-Lilly, Enthera, Ferring, Galapagos, Gilead, Giuliani, Janssen, Lionhealth, MSD, Nestlé, Pfizer, Protagonist Therapeutics, Roche, Samsung Bioepis, Sanofi, Sandoz, Takeda, Teva Pharmaceuticals, Tillots Pharma Speaker’s fees from AbbVie, Abivax, AG Pharma, Alfa Sigma, Biogen, Bristol-Myers Squibb, Celltrion, Eli-Lilly, Ferring, Galapagos, Gilead, Janssen, Lionhealth, MSD, Novartis, Pfizer, Roche, Samsung Bioepis, Sandoz, Takeda, Teva Pharmaceuticals Research support from Biogen, MSD, Takeda, and Pfizer Non-financial support from Abbvie, Janssen, MSD, Pfizer, Takeda Danese, Silvio: Personal Fees: AbbVie, Alimentiv, Allergan, Amgen, Applied Molecular Transport, AstraZeneca, Athos Therapeutics, Biogen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Celltrion, Dr Falk Pharma, Eli Lilly, Enthera, Ferring Pharmaceuticals Inc. , Gilead, Hospira, Inotrem, Janssen, Johnson & Johnson, Morphic, MSD, Mundipharma, Mylan, Pfizer, Roche, Sandoz, Sublimity Therapeutics, Takeda, Teladoc Health, TiGenix, UCB Inc. , Vial, Vifor Lecture fees from Abbvie, Amgen, Ferring Pharmaceuticals Inc. , Gilead, Janssen, Mylan, Pfizer, Takeda Dr. Allocca, Mariangela: Personal Fees: consulting fees from Nikkiso Europe, Mundipharma, Janssen, Abbvie, Pfizer, Ferring, Galapagos, Sandoz, Lilly and Alfasigma