Quantitative Susceptibility Mapping of Deep Grey Matter in MS: Association With Clinical Scores and Brain Volume Measures

Résumé fourni par la source

ABSTRACT Background Changes in quantitative susceptibility mapping (QSM) of the deep grey matter (DGM) in multiple sclerosis (MS) are thought to reflect tissue damage invisible in conventional magnetic resonance imaging (MRI) sequences, such as iron‐related neurodegeneration. Objective To explore the associations of clinical scores and MRI‐based volumes with QSM values in the DGM (thalamus, putamen, caudate, and pallidum) in a large cohort of people with MS, and to assess the predictive value of QSM values for clinical outcomes after three years. Methods A total of 771 MS patients (clinically isolated syndrome (CIS): n = 35, relapsing‐remitting: n = 637, progressive: n = 63) were scanned at 3T with T1‐weighted, T2‐FLAIR, and QSM sequences. All patients were included in the cross‐sectional analyses examining the relationship of DGM QSM values with MRI variables and clinical scores. Normalized brain volume (NBV) was computed using SIENAX, while total lesion volume (TLV) was derived from the lesion segmentation tool, LST‐AI. Clinical scores included the expanded disability status scale (EDSS), timed 25 foot walk (T25FW), Nine Hole Peg Test (9HPT), symbol digit modalities test (SDMT), and fatigue scale for motor and cognitive functions (FSMC). In the longitudinal analyses, only clinical scores were included, with various sample sizes across different clinical scores ( N EDSS = 396, N T25Fw = 284, N 9HPT = 284, N SDMT = 165, N FSMC = 288). These analyses evaluated the predictive value of baseline DGM QSM values for follow‐up clinical scores; these associations were compared to those of corresponding regional DGM volumes. Results At baseline, after adjusting for confounding factors, higher QSM values in the basal ganglia were significantly associated with greater TLV (β = 0.14 – 0.17; p < 0.001), higher clinical severity (EDSS: β = 0.13 – 0.19, p < 0.001), worse dexterity (NHPT: β = 0.14 – 0.16, p = 0.02), and lower cognitive functioning (SDMT: β = –0.13 – –0.15, p = 0.03). In contrast, lower thalamic QSM values were associated with greater TLV (β = –0.07; p = 0.03). Unlike regional volumes, DGM QSM values did not predict clinical outcomes at follow‐up. Conclusion DGM QSM values are robustly associated with MS severity and TLV cross‐sectionally. However, our large‐scale longitudinal analysis suggests that DGM QSM values lack prognostic value for short‐term clinical progression in early‐stage MS.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.