Segmentation-based morphometric analysis of neck abscesses on MRI: associations with disease severity

Abstract Objectives Abscess diameter on MRI is an established predictor of clinical severity in neck infections, but this single measurement does not characterize three-dimensional morphology. This study evaluated whether segmentation-derived volume, sphericity, and compactness provide incremental prognostic value beyond conventional diameter. Materials and methods In 227 consecutive patients with surgically confirmed neck abscesses, abscess masks were segmented on post-contrast T1-weighted MRI. Three morphometric features were extracted: volume, sphericity, and compactness; their associations with intensive care unit (ICU) admission and a prolonged hospital stay (exceeding 5 days) were evaluated using multivariable models. Results Of 227 patients, 33 (15%) required ICU admission, and 40 (18%) had a prolonged hospital stay. Sphericity was lower in ICU patients (median 0.35 vs. 0.45, p = 6.6 × 10 − 5 ) and in those with prolonged stay ( p = 9.1 × 10 − 6 ). In multivariable models, volume improved upon manual diameter for ICU prediction (area under the curve 0.841 [95% CI 0.78–0.90] vs. 0.816 [0.74–0.88]); adding sphericity improved prolonged stay prediction (R 2 0.246 vs. 0.216, p = 0.005). Interobserver agreement was excellent (ICC 0.97–0.99). Conclusion Segmentation-derived abscess volume, sphericity, and compactness provide complementary prognostic information beyond conventional diameter measurement for assessing neck infection severity. Key Points Question Can segmentation-derived morphometric features of neck abscesses (volume, sphericity, compactness) improve prognostication of ICU admission and prolonged hospital stay beyond conventional diameter measurement on MRI? Findings Abscess volume outperformed manual diameter for predicting ICU admissions, and lower sphericity independently predicted prolonged hospital stay beyond abscess size in multivariable models . Clinical relevance Segmentation-derived morphometric features offer reproducible, quantitative tools for stratifying neck abscess severity in surgically managed patients; their value for guiding individual treatment decisions was not directly evaluated and warrants prospective validation .