Validation of the “purfling sign” for differentiating primary central nervous system lymphoma from high-grade glioma: a retrospective multicenter cohort study
- 1Department of Radiology, The Second Affiliated Hospital of Soochow University
- 2Department of Radiology, Second Hospital of Tianjin Medical University
- 3Department of MRI, Zhumadian Central Hospital
Abstract
Background The study aimed to evaluate whether the imaging marker “purfling sign” can reliably distinguish primary central nervous system lymphoma (PCNSL) from high-grade glioma and systematically assess its diagnostic performance, differential utility and clinical value. Materials and methods This retrospective multicenter cohort study included 209 patients with PCNSL and 285 patients with glioma who underwent contrast-enhanced magnetic resonance imaging (CE-MRI). Two board-certified neuroradiologists independently reviewed CE-MRI features including lesion number, “purfling sign”, tumor necrosis and cystic changes, and tumor parenchymal enhancement heterogeneity, with inter-rater reliability assessed using Cohen’s kappa coefficient. Group comparisons were performed between the PCNSL group and the glioma group, and the diagnostic performance of the “purfling sign” was evaluated by calculating its sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy, with 95% confidence intervals (CIs) reported for all metrics. Results PCNSL and glioma showed significant between-group differences in lesion number, tumor necrosis and cystic changes, and tumor parenchymal enhancement heterogeneity (all P < 0.001). The purfling sign also differed significantly between groups (P < 0.001): it was detected in 100 PCNSL cases (47.80%) and 34 glioma cases (11.93%), yielding a sensitivity of 47.85% (95% CI: 41.1%–54.6%), specificity of 88.07% (95% CI: 84.3%–91.8%), PPV of 74.63% (95% CI: 67.3%–82.0%), NPV of 69.72% (95% CI: 64.9%–74.5%), and diagnostic accuracy of 71.05% (95% CI: 67.1%–75.0%) for PCNSL diagnosis. Notably, the target sign was exclusive to PCNSL (14/14, 100%), resulting in 100% specificity and PPV. In terms of inter-rater agreement, excellent consistency was achieved for the purfling sign and tumor necrosis and cystic changes (κ= 0.982 and 0.869, respectively), with good agreement for parenchymal enhancement heterogeneity (κ= 0.709). Conclusion Consistent with prior findings, the “purfling sign” serves as a valuable auxiliary diagnostic indicator for differentiating PCNSL from high-grade glioma, thereby facilitating improved diagnostic confidence and providing supportive evidence for clinical management.
Related
- Clinical utility of CT-based deep learning for differentiating pulmonary aspergillosis from bacterial pneumonia: a multicenter retrospective study
- Value of delayed post-contrast phase hyperintensity on gadobenate dimeglumine-enhanced MRI for differentiating atypical splenic hemangiomas from cysts: an exploratory retrospective study with pathology validation.
- Lymphoma-associated pancreatitis: a multicenter retrospective cohort study with a prediction model
- Identification and validation of early vital sign trajectory subphenotypes for risk stratification in sepsis-associated liver injury: a multicenter retrospective cohort study
- Development and Validation of Temperature Trajectory-Based Phenotypes in Pediatric Sepsis: A Multicenter Retrospective Cohort Study, 2012–2018
BibTeX
@article{wu2026validation,
title = {{Validation of the “purfling sign” for differentiating primary central nervous system lymphoma from high-grade glioma: a retrospective multicenter cohort study}},
author = {Xiaofen Wu and Kuan Lu and Qi Guo and Chenchen Liu and Peng Ji and Dai Shi},
journal = {BMC Medical Imaging},
year = {2026},
month = aug,
doi = {10.1186/s12880-026-02650-3},
url = {https://doi.org/10.1186/s12880-026-02650-3},
note = {CC BY},
}
RIS
TY - JOUR
TI - Validation of the “purfling sign” for differentiating primary central nervous system lymphoma from high-grade glioma: a retrospective multicenter cohort study
AU - Xiaofen Wu
AU - Kuan Lu
AU - Qi Guo
AU - Chenchen Liu
AU - Peng Ji
AU - Dai Shi
PY - 2026
DA - 2026/08/01
JO - BMC Medical Imaging
DO - 10.1186/s12880-026-02650-3
UR - https://doi.org/10.1186/s12880-026-02650-3
AB - Background The study aimed to evaluate whether the imaging marker “purfling sign” can reliably distinguish primary central nervous system lymphoma (PCNSL) from high-grade glioma and systematically assess its diagnostic performance, differential utility and clinical value. Materials and methods This retrospective multicenter cohort study included 209 patients with PCNSL and 285 patients with glioma who underwent contrast-enhanced magnetic resonance imaging (CE-MRI). Two board-certified neuroradiologists independently reviewed CE-MRI features including lesion number, “purfling sign”, tumor necrosis and cystic changes, and tumor parenchymal enhancement heterogeneity, with inter-rater reliability assessed using Cohen’s kappa coefficient. Group comparisons were performed between the PCNSL group and the glioma group, and the diagnostic performance of the “purfling sign” was evaluated by calculating its sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy, with 95% confidence intervals (CIs) reported for all metrics. Results PCNSL and glioma showed significant between-group differences in lesion number, tumor necrosis and cystic changes, and tumor parenchymal enhancement heterogeneity (all P < 0.001). The purfling sign also differed significantly between groups (P < 0.001): it was detected in 100 PCNSL cases (47.80%) and 34 glioma cases (11.93%), yielding a sensitivity of 47.85% (95% CI: 41.1%–54.6%), specificity of 88.07% (95% CI: 84.3%–91.8%), PPV of 74.63% (95% CI: 67.3%–82.0%), NPV of 69.72% (95% CI: 64.9%–74.5%), and diagnostic accuracy of 71.05% (95% CI: 67.1%–75.0%) for PCNSL diagnosis. Notably, the target sign was exclusive to PCNSL (14/14, 100%), resulting in 100% specificity and PPV. In terms of inter-rater agreement, excellent consistency was achieved for the purfling sign and tumor necrosis and cystic changes (κ= 0.982 and 0.869, respectively), with good agreement for parenchymal enhancement heterogeneity (κ= 0.709). Conclusion Consistent with prior findings, the “purfling sign” serves as a valuable auxiliary diagnostic indicator for differentiating PCNSL from high-grade glioma, thereby facilitating improved diagnostic confidence and providing supportive evidence for clinical management.
SN - 1471-2342
ER -