Standardized pancreatic MRI-T1 measurement methods: comparison between manual measurement and a semi-automated pipeline with automatic quality control

Journal article

Objectives
Scanner-referenced T1 (srT1) is a method for measuring pancreas T1 relaxation time. The purpose of this multi-centre study is two-fold: (1) to evaluate the repeatability of manual ROI-based analysis of srT1, (2) to validate a semi-automated measurement method with an automatic quality control (QC) module to identify likely discrepancies between automated and manual measurements.

Methods
Pancreatic MRI scans from a scan-rescan cohort (46 subjects) were used to evaluate the repeatability of manual analysis. 708 scans from a longitudinal multi-centre study of 466 subjects were divided into training, internal validation (IV), and external validation (EV) cohorts. A semi-automated method for measuring srT1 using machine learning is proposed and compared against manual analysis on the validation cohorts with and without automated QC.

Results
Inter-operator agreement between manual ROI-based method and semi-automated method had low bias (3.8 ms or 0.5%) and limits of agreement [-36.6, 44.1] ms. There was good agreement between the two methods without automated QC (IV: 3.2 [-47.1, 53.5] ms, EV: -0.5 [-35.2, 34.2] ms). After QC, agreement on the IV set improved, was unchanged in the EV set, and the agreement in both was within inter-operator bounds (IV: -0.04 [-33.4, 33.3] ms, EV: -1.9 [-37.6, 33.7] ms). The semi-automated method improved scan-rescan agreement versus manual analysis (manual: 8.2 [-49.7, 66] ms, automated: 6.7 [-46.7, 60.1] ms).

Conclusions
The semi-automated method for characterization of standardized pancreatic T1 using MRI has the potential to decrease analysis time while maintaining accuracy and improving scan-rescan agreement.

Advances in knowledge
We provide intra-operator, inter-operator, and scan-rescan agreement values for manual measurement of srT1, a standardized biomarker for measuring pancreas fibro-inflammation. Applying a semi-automated measurement method improves scan-rescan agreement and agrees well with manual measurements, while reducing human effort. Adding automated QC can improve agreement between manual and automated measurements.

Summary statement
We describe a method for semi-automated, standardized measurement of pancreatic T1 (srT1), which includes automated quality control. Measurements show good agreement with manual ROI-based analysis, with comparable consistency to inter-operator performance.

Authors: Triay Bagur, A; Arya, Z; Waddell, T; Pansini, M; Fernandes, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: British Institute of Radiology
• Journal: British Journal of Radiology
• Volume: 98
• Issue: 1170
• Pages: 965–973
• Place of publication: England
• Publication date: 2025-03-19
• Acceptance date: 2025-03-12
• DOI: 10.1093/bjr/tqaf062
• EISSN: 1748-880X
• ISSN: 0007-1285
• Pmid: 40108439
• Language: English
• Keywords: pancreas; T1 mapping; standardised; fibro-inflammation; quality control