Diagnostics
CT Ventricular Volume Reference Percentile Curves Using Automated nnU-Net Segmentation: A Study with LLM-Facilitated Cohort Selection
Par Vishwanathan N, Wasserthal J, Yang S et 6 autres.
Contenu en anglais
Résumé
Background
Age- and sex-specific CT reference percentile curves of ventricular volume may support objective assessment of ventricular enlargement. We aimed to generate such curves by combining a locally deployed large language model (LLM) for cohort curation with nnU-Net 12-subcompartment segmentation.
Methods
This retrospective study did not require formal ethics approval under the Swiss Human Research Act. We screened 42,211 head CT reports from January 2019 to April 2024. A phrase prefilter identified 9622 candidates for German-tuned 70-billion-parameter LLM review of stroke, leukoencephalopathy, parenchymal defects, enlarged ventricles, and space-occupying lesions; 6516 remained. A second LLM workflow screened 210,761 clinical data warehouse summaries to exclude dementia, organic brain disease, or cognitive decline. After image-availability and series-mismatch exclusions, the final cohort comprised 2608 CTs from 2608 patients (1374 males, 1234 females; age 14-98 years). Ventricular masks were obtained using a validated nnU-Net tool integrated in TotalSegmentator.