Volumetric imaging of myelin in vivo using 3D inversion recovery‐prepared ultrashort echo time cones magnetic resonance imaging. (20th July 2020)

• Record Type: Journal Article
• Authors: Ma, Ya‐Jun; Searleman, Adam C.; Jang, Hyungseok; Fan, Shu‐Juan; Wong, Jonathan; Xue, Yanping; Cai, Zhenyu; Chang, Eric Y.; Corey‐Bloom, Jody; Du, Jiang
• Is Part Of: NMR in biomedicine. Volume 33:Number 10(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-07-20
• Subjects: adiabatic inversion recovery -- Myelin imaging -- 3D Cones; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.4326
• Languages: English
• ISSNs: 0952-3480

Abstract

Abstract : Direct myelin imaging is promising for characterization of multiple sclerosis (MS) brains at diagnosis and in response to therapy. In this study, a 3D inversion recovery‐prepared ultrashort echo time cones (IR‐UTE‐Cones) sequence was used for both morphological and quantitative imaging of myelin on a clinical 3 T scanner. Myelin powder phantoms with different myelin concentrations were imaged with the 3D UTE‐Cones sequence and it showed a strong correlation between concentrations and UTE‐Cones signals, demonstrating the ability of the UTE‐Cones sequence to directly image myelin in the brain. Quantitative myelin imaging with multi‐echo IR‐UTE‐Cones sequences show similar T2 * values for a D2 O‐exchanged myelin phantom (T2 * = 0.33 ± 0.04 ms), ex vivo brain specimens (T2 * = 0.20 ± 0.04 ms) and in vivo healthy volunteers (T2 * = 0.254 ± 0.023 ms), further confirming the feasibility of 3D IR‐UTE‐Cones sequences for direct myelin imaging in vivo. In ex vivo MS brain study, signal loss is observed in MS lesions, which was confirmed with histology. For the in vivo study, the lesions in MS patients also show myelin signal loss using the proposed direct myelin imaging method, demonstrating the clinical potential for MS diagnosis. Furthermore, the measured IR‐UTE‐Cones signal intensities show a significant difference between normal‐appearing white matter in MS patients and normal white matter in volunteers, which cannot be found in clinical used T2 ‐FLAIR sequences. Thus, the proposed 3D IR‐UTE‐Cones sequence showed clinical potential for MS diagnosis with the capability of direct myelin detection of the whole brain. Abstract : Myelin T2 * measurement using the proposed inversion recovery‐prepared UTE‐Cones (3D IR‐UTE‐Cones) sequence for a healthy volunteer (a 37‐year‐old male). The IR‐UTE‐Cones sequences with multi‐TEs are shown in (A)‐(D), respectively. A T2 * of 0.254 ± 0.023ms was calculated by fitting to a single‐component model (E). T2 * maps of myelin in white‐matter regions from four different slices are shown in (F)‐(I).