Untangling the R2 contrast in multiple sclerosis: A combined MRI-histology study at 7.0 Tesla

• Published in: PloS one 2018-03, Vol.13 (3), p.e0193839-e0193839
• Main Authors: Bagnato, Francesca, Hametner, Simon, Boyd, Emma, Endmayr, Verena, Shi, Yaping, Ikonomidou, Vasiliki, Chen, Guanhua, Pawate, Siddharama, Lassmann, Hans, Smith, Seth, Welch, E Brian
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Bioengineering; Biology and Life Sciences; Biomarkers; Brain; Brain - diagnostic imaging; Brain - metabolism; Brain - pathology; Brain research; Consent; Contrast Media; Development and progression; Diagnosis; Echo surveys; Female; Histology; Humans; Imaging, Three-Dimensional; Immunohistochemistry; Iron; Iron - metabolism; Iron content; Magnetic resonance; Magnetic resonance imaging; Magnetic Resonance Imaging - instrumentation; Magnetic Resonance Imaging - methods; Male; Medical research; Medicine and Health Sciences; Methods; Middle Aged; Multiple sclerosis; Multiple Sclerosis, Chronic Progressive - diagnostic imaging; Multiple Sclerosis, Chronic Progressive - metabolism; Multiple Sclerosis, Chronic Progressive - pathology; Myelin; Myelin Sheath - metabolism; Neuroimaging; NMR; Nuclear magnetic resonance; Nuclear relaxation; Pathological histology; Patients; Radiology; Research and Analysis Methods; Staining
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0193839

T2*-weighted multi-echo gradient-echo magnetic resonance imaging and its reciprocal R2* are used in brain imaging due to their sensitivity to iron content. In patients with multiple sclerosis who display pathological alterations in iron and myelin contents, the use of R2* may offer a unique way to untangle mechanisms of disease. Coronal slices from 8 brains of deceased multiple sclerosis patients were imaged using a whole-body 7.0 Tesla MRI scanner. The scanning protocol included three-dimensional (3D) T2*-w multi-echo gradient-echo and 2D T2-w turbo spin echo (TSE) sequences. Histopathological analyses of myelin and iron content were done using Luxol fast blue and proteolipid myelin staining and 3,3'-diaminobenzidine tetrahydrochloride enhanced Turnbull blue staining. Quantification of R2*, myelin and iron intensity were obtained. Variations in R2* were found to be affected differently by myelin and iron content in different regions of multiple sclerosis brains. The data shall inform clinical investigators in addressing the role of T2*/R2* variations as a biomarker of tissue integrity in brains of MS patients, in vivo.