3D Automated Segmentation of Bronchial Abnormalities on Ultrashort Echo Time MRI: A Quantitative MR Outcome in Cystic Fibrosis.
Authors
Affiliations (8)
Affiliations (8)
- Univ. Bordeaux, INSERM, CRCTB, UMR 1045, Bordeaux, France.
- CHU de Bordeaux, Service D'imagerie Médicale, Bordeaux, France.
- CHU de Bordeaux, Service de Pneumologie, Bordeaux, France.
- Univ. Bordeaux, CNRS, Bordeaux INP, IMB, UMR 5251, Talence, France.
- Univ. Bordeaux, CNRS, Bordeaux INP, LaBRI, UMR 5800, Talence, France.
- Siemens Healthcare SAS, Courbevoie, France.
- Siemens Medical Solutions USA, Inc., Malvern, Pennsylvania, USA.
- Univ. Bordeaux, INSERM, IHU LIRYC, UMR 1045, Bordeaux, France.
Abstract
Cystic fibrosis (CF) monitoring relies on computed tomography (CT), but ultra-short echo time MRI (UTE-MRI) offers a radiation-free alternative. However, its clinical adoption is hindered by the laborious and subjective manual analysis, which prevents standardized quantification of bronchial abnormalities. To develop a deep learning (DL) system for the segmentation of CF bronchial abnormalities on UTE-MRI and assess clinical relevance in patients undergoing cystic fibrosis transmembrane conductance regulator (CFTR) modulator treatment. Retrospective. One-hundred and sixty-six CF patients were included (age = 23 ± 11, 48% male), comprising a training set (n = 97), a test set (n = 25), and an independent clinical validation cohort (n = 44). 1.5T/UTE-MRI 3D gradient-echo Spiral Volume Interpolated Breath-hold Examination (VIBE) sequence. The RiSeNet architecture was trained using paired UTE-MRI and CT scans. Its technical performance was evaluated against expert-refined segmentations and compared to state-of-the-art segmentation models using topology-aware metrics: Normalized Surface Dice (NSD) and CenterLine Dice (clDice). Clinical validation was performed by correlating automated measurements at baseline (M0) and 1-year post-CFTR modulator treatment (M12) with Bhalla scores and pulmonary function tests (FEV1%p). Student's t-test, Mann-Whitney, Wilcoxon, and Chi-square tests were used for group comparisons. The Spearman test was used to assess correlations. A p value < 0.05 was considered statistically significant. In the test group, RiSeNet achieved significantly superior performance versus state-of-the-art with NSD scores of 0.84 for bronchiectasis, 0.90 for wall thickening, and 0.75 for mucus; and clDice scores of 0.69, 0.61, and 0.64, respectively. In the clinical validation group, significant correlations with Bhalla (ρ = -0.92/-0.85) and FEV1%p (ρ = -0.68/-0.67) were observed pre/post-CFTR modulator. Post-CFTR modulator, FEV1%p improved (69%-92%) with significant reductions in bronchiectasis (3.88-1.25), wall thickening (30.43-3.05), and mucus (53.30-11.80). RiSeNet may enable semantic segmentation of CF abnormalities on radiation-free UTE-MRI. 3 TECHNICAL EFFICACY: 4.