Intestinal Ultrasound Index Calculator – Ulcerative Colitis
Advanced tool for calculating validated ultrasound activity indices in IBD
Developed by Dr. J. Poza Cordon · Hospital Universitario La Paz, Madrid · 2025 ·
@joaquin_poza
Wall Thickness Measurements
Enter measurements to calculate the average
UC-UIS Score
Complete all fields to see UC-UIS Score
References & interpretation
BWT → endoscopic Mayo
· Bots S, et al. J Crohns Colitis 2021
≤ 2.1
Normal
> 2.1
Mayo ≥1
> 3.2
Mayo ≥2
> 3.9
Mayo 3
mm bowel wall thickness · correlates strongly with endoscopic Mayo
UC-UIS ≤ 2 → mucosal healing (Mayo ≤1)
Se 67.3%
Sp 91.4%
PPV 85.4%
NPV 79.0%
Komatsu H, et al. J Gastroenterol 2025
MUC – Milan Ultrasound Criteria
Complete both fields to calculate MUC
References & interpretation
MUC = 1.4·BWT + 2·Doppler
· Allocca M, et al. UEGJ 2021/2022 · Yuan B, et al. Eur J Gastroenterol Hepatol 2024
≥ 6.2
Endoscopic activity
Se 85 · Sp 94
> 8.54
Severe UC
Se 64 · Sp 93
> 10.54
IV steroid failure
Se 50 · Sp 91
> 12.5
Colectomy risk
Se 56 · Sp 97
escalating cut-offs · higher MUC = worse outcome
IBUS-SAS – Intestinal US Score (CU)
Complete all fields to calculate IBUS-SAS
References & interpretation
IBUS-SAS = 4·BWT + 7·Doppler + 15·fat + 4·echo
· Novak KL, et al. JCC 2020 · Fischer S, et al. UEG J 2025
< 15.9
Remission
·
≥ 15.9
Mild activity
Se 100 · Sp 80
≥ 38.4
Moderate
Se 78 · Sp 82
≥ 69.2
Severe
Se 67 · Sp 94
score capped at 100 · cut-offs Fischer 2025 (AUC 0.97 / 0.83 / 0.89)