Artificial intelligence-driven three-dimensional modeling of biliary strictures using magnetic resonance cholangiopancreatography for quantitative assessment and stent planning

Table 1 Baseline demographic and clinical characteristics of the study cohort, n (%)/mean ± SD

Characteristic	Controls (n = 242)	Cases (n = 142)	Total (n = 384)
Age (years)	48.8 ± 14.1	68.0 ± 11.2	55.9 ± 16.0
Sex
Male	121 (50.0)	81 (57.0)	202 (52.6)
Female	121 (50.0)	61 (43.0)	182 (47.4)
Stricture characteristics (cases only, n = 142)
Ground-truth severity
Grade 0 (none)	242 (100)	0 (0)	242 (63.0)
Grade 1 (mild)	0 (0)	77 (54.2)	77 (20.1)
Grade 2 (severe)	0 (0)	65 (45.8)	65 (16.9)
Etiology
Malignant		129 (90.8)
Benign		11 (7.7)
Indeterminate		2 (1.4)
Distribution
Focal		137 (96.5)
Diffuse		5 (3.5)
Location
Extrahepatic		106 (74.6)
Intrahepatic		7 (4.9)
Perihilar/hilar		29 (20.4)
Bismuth type
Bismuth type I		4 (2.8)
Bismuth type II		3 (2.1)
Bismuth type IIIa		7 (4.9)
Bismuth type IIIb		2 (1.4)
Bismuth type IV		5 (3.5)
Bismuth type, indeterminate		8 (5.6)
Stricture length, mm, median (range)		25.0 (6.7-120.0)
Max upstream duct diameter, mm		13.7 ± 3.0

Severity is an expert-assigned ordinal ground-truth grade (0 = no stricture, 1 = mild, 2 = severe). Bismuth-Corlette type was assessed for perihilar (hilar) strictures; “indeterminate” denotes cases spanning types (e.g., II-IIIa) or not classifiable. Malignant etiologies comprised cholangiocarcinoma (n = 78), pancreatic cancer (n = 36), gallbladder cancer (n = 9), ampullary cancer (n = 4), and metastatic/extrinsic disease (n = 1); benign/indeterminate causes included inflammatory (primary sclerosing cholangitis/immunoglobulin G4, n = 5), chronic-pancreatitis-related (n = 3), and postoperative/anastomotic (n = 2) strictures.