Quantitative susceptibility mapping in pediatric neuroimaging: a systematic review of applications and advancements

Quantitative susceptibility mapping (QSM) is an advanced magnetic resonance imaging (MRI) technique that quantifies tissue magnetic susceptibility, offering non-invasive insights into brain microstructure, including iron content and myelination. While extensively applied in adult neuroimaging, its use in pediatric populations is rapidly expanding.

This systematic review aims to provide a comprehensive overview of QSM applications in pediatric brain imaging, highlighting methodological advancements, diagnostic potential, and current limitations.

A systematic literature search was performed using PubMed and Google Scholar up to April 2025. Inclusion criteria were original research articles written in English, involving only pediatric populations (0-17 years) and employing QSM in brain imaging. Twenty studies met eligibility criteria and were analyzed in terms of acquisition protocols, post-processing methods, study objectives, and main findings.

A systematic search on PubMed and Google Scholar found 54 QSM brain studies in children; after exclusions, 20 original research papers qualified for review and were quality-checked using Quality Assessment of Diagnostic Accuracy Studies version-2 (QUADAS-2). Most studies were recent (85% in the last 5 years), in Asia (55%, with China 35%), and used 3-tesla (T) MRI (80%). Typical imaging parameters: 8 echoes (TE=40 ms), slice thickness=2-2.5 mm, matrix often 256×256; Laplacian was the main phase-unwrapping method and variable-kernel sophisticated harmonic artifact reduction for phase data (VSHARP) the dominant background-field removal. Study aims clustered into improved detection, microstructural analysis, normative comparisons, clinical correlations, developmental patterns, and pathology tracking.

QSM emerges as a valuable tool in pediatric neuroimaging, offering quantitative biomarkers for brain development, disease monitoring, and potential clinical translation. Despite promising results, challenges remain, including motion artifacts, lack of normative pediatric data, and methodological heterogeneity. Future research should focus on longitudinal designs, standardization of protocols, and integration with complementary imaging modalities. With further refinement, QSM has the potential to become an integral component of pediatric neuroradiological assessment.