Article
Computer Science, Interdisciplinary Applications
Vasily L. Yarnykh
Summary: Correction of B-1 field non-uniformity is crucial for quantitative MRI methods like VFA T-1 mapping and MPF mapping. A new algorithm has been developed to retrospectively correct B-1 field in VFA R-1 and single-point MPF mapping, providing an alternative solution without the need for dedicated B-1 mapping sequences. The algorithm effectively reduces biases in R-1 and MPF values caused by B-1 non-uniformity, making it a promising approach for accurate myelin imaging.
IEEE TRANSACTIONS ON MEDICAL IMAGING
(2021)
Review
Neurosciences
Alena A. Kisel, Anna V. Naumova, Vasily L. Yarnykh
Summary: Macromolecular proton fraction (MPF) is a quantitative MRI parameter that has attracted significant interest as a biomarker of myelin. It provides a comprehensive and technically mature myelin imaging technology for various preclinical and clinical neuroscience applications.
FRONTIERS IN NEUROSCIENCE
(2022)
Article
Psychiatry
Liudmila P. Smirnova, Vasily L. Yarnykh, Daria A. Parshukova, Elena G. Kornetova, Arkadiy V. Semke, Anna V. Usova, Anna O. Pishchelko, Marina Y. Khodanovich, Svetlana A. Ivanova
Summary: This pilot study investigated myelin content abnormalities in white matter and gray matter of schizophrenia patients using a novel quantitative myelin imaging technique. The results showed that schizophrenia patients had significantly reduced myelin content in both white matter and gray matter, with the greatest decrease in gray matter. The study also found correlations between myelin content, disease duration, and symptoms in schizophrenia patients.
TRANSLATIONAL PSYCHIATRY
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Lucas Soustelle, Maria Cristina Antal, Julien Lamy, Laura-Adela Harsan, Paulo Loureiro de Sousa
Summary: The study aimed to determine optimal constrained tissue parameters and off-resonance sequence parameters for single-point macromolecular proton fraction (SP-MPF) mapping in healthy and demyelinated living mice at 7T. Through experimentation and analysis, it was found that a 600 degrees and 6 kHz off-resonance irradiation pulse yielded the best results in minimizing bias between reference and SP-MPF maps.
MAGNETIC RESONANCE IN MEDICINE
(2021)
Article
Neurosciences
Fanny Munsch, Gopal Varma, Manuel Taso, Olivier Girard, Arnaud Guidon, Guillaume Duhamel, David C. Alsop
Summary: The study implemented a 3D ihMT acquisition and analysis to characterize cortical gray matter myeloarchitecture, finding qualitative agreement between cortical ihMTsat and dual MTsat maps with previous work and cortical T(1)w map, but with important regional differences. The research demonstrated that ihMTsat shows unique contrast between cortical regions.
Article
Clinical Neurology
Biao Xiang, Jie Wen, Robert E. Schmidt, Alexander L. Sukstanskii, Daniel Mamah, Dmitriy A. Yablonskiy, Anne H. Cross
Summary: This study developed an alternative approach, Simultaneous-Multi-Angular-Relaxometry-of-Tissue (SMART) MRI, to generate a quantitative magnetization transfer MRI metric called the macromolecule proton fraction (MPF) that correlates with myelin concentration. The SMART-derived MPF metric was tested as a potential imaging biomarker of demyelination and was found to differentiate different types of multiple sclerosis lesions and correlate with clinical test scores. The results suggest that SMART-derived MPF metric holds promise for quantitatively assessing demyelination and remyelination.
ANNALS OF CLINICAL AND TRANSLATIONAL NEUROLOGY
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Jian Hou, Vincent W-S Wong, Yurui Qian, Baiyan Jiang, Anthony W-H Chan, Howard H-W Leung, Grace L-H Wong, Simon C-H Yu, Winnie C-W Chu, Weitian Chen
Summary: This study used MPF-SL technology to measure macromolecule levels in the liver and found that it can detect early-stage liver fibrosis, and is not confounded by liver iron concentration or fat fraction.
JOURNAL OF MAGNETIC RESONANCE IMAGING
(2023)
Article
Medicine, General & Internal
Saeed Jerban, Yajun Ma, Amir Masoud Afsahi, Alecio Lombardi, Zhao Wei, Meghan Shen, Mei Wu, Nicole Le, Douglas G. Chang, Christine B. Chung, Jiang Du, Eric Y. Chang
Summary: This study utilized UTE-MT modeling and MRI techniques to detect the correlation between tendon quality deterioration in osteoporosis patients and bone health, highlighting the importance of UTE-MT MRI techniques in evaluating tendon quality.
Article
Radiology, Nuclear Medicine & Medical Imaging
Choong Heon Lee, Piotr Walczak, Jiangyang Zhang
Summary: In this study, we investigated the ability of ihMT MRI to detect white matter structures in the hypomyelinated shiverer mouse brain. Our results showed that ihMT can provide clear visualization of the hypomyelinated corpus callosum, with higher myelin contrast compared to conventional MT. These findings suggest the potential use of ihMT as a marker for early myelination or myelin repair.
MAGNETIC RESONANCE IN MEDICINE
(2022)
Article
Biophysics
Alexander Drobyshevsky, Sylvia Synowiec, Ivan Goussakov, Vasily Yarnykh
Summary: Imaging fixed tissue offers improved signal-to-noise ratio and resolution, however, the accuracy of quantitative MRI parameters in fixed brain tissue needs validation. This study compares MR-derived markers of brain development, MPF and FA, between in vivo and fixed tissue measures. The results suggest that MPF can be used as a proxy for in vivo measurements, but its bias needs to be corrected.
NMR IN BIOMEDICINE
(2023)
Review
Neurosciences
Alberto Lazari, Ilona Lipp
Summary: The study conducted a systematic review and meta-analysis on MRI-based myelin markers, finding correlations between various myelin histology metrics and markers from different MRI modalities, but no single most sensitive strategy to measure myelin with MRI. The authors provided a detailed characterization of the evaluated studies and 12 recommendations for future research.
Article
Radiology, Nuclear Medicine & Medical Imaging
Lucas Soustelle, Thomas Troalen, Andreea Hertanu, Samira Mchinda, Jean-Philippe Ranjeva, Maxime Guye, Gopal Varma, David C. Alsop, Guillaume Duhamel, Olivier M. Girard
Summary: Concentrating RF saturation energy in ihMT-GRE sequences mitigates the sensitivity of ihMTR to B1+ variations, allowing for clinical-ready ihMT imaging at 3 T. Under optimal conditions, 73% of WM voxels presented delta(ihMTR) below 10%. Reproducibility analysis showed minimal systematic bias and high correlation between test and retest experiments.
MAGNETIC RESONANCE IN MEDICINE
(2022)
Article
Endocrinology & Metabolism
Marina Yu Khodanovich, Ilya L. Gubskiy, Marina S. Kudabaeva, Darya D. Namestnikova, Alena A. Kisel, Tatyana Anan'ina, Yana A. Tumentceva, Lilia R. Mustafina, Vasily L. Yarnykh
Summary: This study investigated the feasibility of monitoring demyelination and remyelination in experimental stroke using MPF. Results showed distinct sub-regions within the infarct with different patterns of myelin damage and repair, with remyelination zones demonstrating active axonal regrowth and neuronal proliferation while demyelination zones showed extensive astrogliosis. Overall, MPF mapping was validated as a novel approach for assessing myelin damage and repair in ischemic stroke.
JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM
(2021)
Article
Clinical Neurology
J. William L. Brown, Nick G. Cunniffe, Ferran Prados, Baris Kanber, Joanne L. Jones, Edward Needham, Zoya Georgieva, David Rog, Owen R. Pearson, James Overell, David MacManus, Rebecca S. Samson, Jonathan Stutters, Charles Ffrench-Constant, Claudia A. M. Gandini Wheeler-Kingshott, Carla Moran, Paul D. Flynn, Andrew W. Michell, Robin J. M. Franklin, Siddharthan Chandran, Daniel R. Altmann, Declan T. Chard, Peter Connick, Alasdair J. Coles
Summary: This study aimed to evaluate the safety and efficacy of non-selective retinoid X receptor agonist bexarotene in promoting remyelination in patients with multiple sclerosis. The results showed that the bexarotene treatment group had more adverse events and poor efficacy outcome, therefore not recommended for the treatment of multiple sclerosis.
Article
Neurosciences
Henrik Marschner, Andre Pampel, Roland Mueller, Katja Reimann, Nicolas Bock, Markus Morawski, Stefan Geyer, Harald E. Moeller
Summary: Cell membranes and macromolecules/paramagnetic compounds interact with water proton spins, providing MRI contrast and tissue composition information. Quantitative magnetization transfer (qMT) parameters were measured at high spatial resolution in a fixed marmoset brain slice and compared to histology results. R1obs and R2* were linearly correlated with iron content, while distinct differences were observed between gray and white matter for qMT parameters and relaxometry. These findings suggest that the water interacting macromolecular pool consists of myelin and non-myelin contributions, and R1obs and R2* are more sensitive for depicting microstructural differences between cortical layers than T.