Clinical 7 Tesla magnetic resonance imaging: Impact and patient value in neurological disorders

Abstract

Magnetic resonance imaging (MRI) is a cornerstone of non-invasive diagnostics and treatment monitoring, particularly for diseases of the central nervous system. Although 1.5- and 3 Tesla (T) field strengths remain the clinical standard, the advent of 7 T MRI represents a transformative step forward, offering superior spatial resolution, contrast, and sensitivity for visualizing neuroanatomy, metabolism, and function. Recent innovations, including parallel transmission and deep learning-based reconstruction, have resolved many prior technical challenges of 7 T MRI, enabling its routine clinical use. This review examines the diagnostic impact, patient value, and practical considerations of 7 T MRI, emphasizing its role in facilitating earlier diagnoses and improving care in conditions, such as amyotrophic lateral sclerosis (ALS), epilepsy, multiple sclerosis (MS), dementia, parkinsonism, tumors, and vascular diseases. Based on insights from over 1200 clinical scans with a second-generation 7 T system, the review highlights disease-specific biomarkers such as the motor band sign in ALS and the new diagnostic markers in MS, the central vein sign, and paramagnetic rim lesions. The unparalleled ability of 7 T MRI to study neurological diseases ex vivo at ultra-high resolution is also explored, offering new opportunities to understand pathophysiology and identify novel treatment targets. Additionally, the review provides a clinical perspective on patient handling and safety considerations, addressing challenges and practicalities associated with clinical 7 T MRI. By bridging research and clinical practice, 7 T MRI has the potential to redefine neuroimaging and advance the understanding and management of complex neurological disorders.

Keywords: dementia; diagnosis; multiple sclerosis; neurology; radiology; vascular disease.

Fig. 1

(a) Comparative acquisitions of sagittal 3D T1‐weighted imaging at 1.5 and 3 T (1.0 mm isotropic resolution) as well as 7 T (0.7 mm isotropic resolution), from left to right. The lower signal at 1.5 T manifests as more noisy images. Meanwhile, high signal can be retained at 7 T, despite higher spatial resolution relative to 3 T. The 7 T acquisitions have been performed with both conventional single transmission (STx) and the more novel parallel transmission (PTx) technologies. PTx provides more homogeneous image intensities and retains the signal in the posterior fossa and spinal cord that is lost when using STx at 7 T. (b) Axial 2D T2‐weighted imaging at 7 T with STx (left) and PTx (right), showing clearly improved depiction of the temporal lobes using PTx. (c) Corresponding coronal images.

Fig. 2

Clinical 7 T magnetic resonance imaging (MRI) acquisitions across neurodegenerative disorders and vascular applications: (a) motor band sign in the medial primary motor cortex in a person with amyotrophic lateral sclerosis (ALS) with predominantly affection of the left lower extremity; (b) motor band sign in the hand motor cortex bilaterally in a person with ALS with bilateral hand motor weakness; (c) corticospinal tract hyperintensities on T2‐weighted fluid‐attenuated inversion recovery (FLAIR) in a person with ALS; (d) time‐of‐flight (TOF) angiography without contrast agents visualizing the circle of Willis and more peripheral arteries; (e) susceptibility‐weighted imaging (SWI) minimum intensity projection (minIP) visualizing the venous brain vasculature; (f) diffusion‐weighted imaging (DWI) visualizing pathological diffusion restriction in the cortex with typical topography for Creutzfeldt–Jakob disease.

Fig. 3

Epilepsy scanning on conventional field strengths and clinical 7 T magnetic resonance imaging (MRI) in a pediatric (a–d) and adult (e–h) patient: (a) focal glucose hypometabolism in the left parietal lobe demonstrated with PET‐MRI; (b) however, no clear anatomical correlate was seen on the corresponding anatomical coronal 2D T2‐weighted 2 mm thick slices; (c) similar imaging using a clinical 7 T scanner, providing higher in‐plane resolution and 1 mm slice thickness, showed a blurred gray–white matter boundary (arrow) consistent with a focal cortical dysplasia (FCD); (d) this finding was confirmed on axial T2*‐weighted, T2‐weighted, and fluid‐attenuated inversion recovery (FLAIR) imaging in the same 7 T scanning session; (e) coronal T2‐weighted imaging at 1.5 T reported as normal; (f) similar imaging with higher resolution with clinical 7 T MRI showing disruption of the internal architecture in the right hippocampus (arrow) as well as slightly lower size than the left; (g) corresponding axial slices on 1.5 T MRI; (h) corresponding axial slices on clinical 7 T MRI.

Fig. 4

Multiple sclerosis white matter and gray matter lesions using clinical 7 T magnetic resonance imaging (MRI) (axial 2D T2*‐weighted gradient‐recalled echo with a resolution of 0.3 × 0.3 × 0.9 mm³: (a) leukocortical (Type I) with a central vein sign; (b) subpial (Type IV) cortical lesion with full cortical coverage and a central vein sign. (c) white matter lesion with a central vein sign; (d) subpial (Type IV) cortical lesion with full cortical coverage, a central vein sign, and a paramagnetic signature; (e) periventricular white matter lesion with a paramagnetic rim and central vein sign; (f) leukocortical (Type I) lesion with a paramagnetic signature.