7 Tesla MRI in Multiple Sclerosis: Insights From Its Use in Clinical Routine.

Background: 7 Tesla (7 T) magnetic resonance imaging (MRI) offers higher spatial resolution and signal-to-noise ratio, enhancing visualization of multiple sclerosis (MS) lesions, including cortical and deep gray matter lesions. It improves detection of MS biomarkers like paramagnetic rim lesions (PRLs) and central vein sign (CVS). Costs have impacted its adoption and experience in clinical practice.

Objectives: To present real-life data on the routine clinical use of 7 T MRI and its impact on patient management from a single-center perspective.

Methods: This retrospective study, approved by the local ethics committee (KEK Bern No 2020-02902), analyzed referrals for 7 T MRI (06/2020-06/2024) at University Hospital Bern for suspected CNS inflammatory disorders. Imaging reports were compared to clinical data from medical records. Statistical analysis evaluated the diagnostic value of 7 T MRI, focusing on sensitivity, specificity, Negative Predictive Value (NPV), and Positive Predictive Value (PPV). Exclusions included contraindications for 7 T MRI, incomplete medical records, or non-CNS conditions.

Findings: 61 patients underwent 7 T MRI, enabling lesion reclassification and MS diagnosis in 19/47 patients with indefinite diagnosis despite extensive diagnostic workup with adequate 3 T MRI. In 14 MS patients, it clarified diagnostic uncertainties, leading to diagnosis revision in 1/14 patients and informed treatment decisions in 4/14 (including treatment escalation (3/14) and discontinuation (1/14)). 7 T MRI showed 89.5% sensitivity and 78.6% specificity for MS (PPV 73.9%, NPV 91.7%). MS patients were more likely to exhibit CVS and PRLs compared to non-MS patients (p < 0.05).

Interpretation: 7 T MRI enhances MS diagnosis certainty in diagnostically challenging cases, potentially impacting clinical practice.