scholarly journals Preliminary Observations on Sensitivity and Specificity of Magnetization Transfer Asymmetry for Imaging Myelin of Rat Brain at High Field

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jae-Woong Kim ◽  
Jiye Choi ◽  
Janggeun Cho ◽  
Chulhyun Lee ◽  
Daejong Jeon ◽  
...  
Keyword(s):  
White Matter ◽  
Rat Brain ◽  
Clinical Application ◽  
Sensitivity And Specificity ◽  
Gray Matter ◽  
High Field ◽  
Magnetization Transfer ◽  
High Sensitivity ◽  
Magnetization Transfer Ratio ◽  
Myelin Imaging

Magnetization transfer ratio (MTR) has been often used for imaging myelination. Despite its high sensitivity, the specificity of MTR to myelination is not high because tissues with no myelin such as muscle can also show high MTR. In this study, we propose a new magnetization transfer (MT) indicator, MT asymmetry (MTA), as a new method of myelin imaging. The experiments were performed on rat brain at 9.4 T. MTA revealed high signals in white matter and significantly low signals in gray matter and muscle, indicating that MTA has higher specificity than MTR. Demyelination and remyelination studies demonstrated that the sensitivity of MTA to myelination was as high as that of MTR. These experimental results indicate that MTA can be a good biomarker for imaging myelination. In addition, MTA images can be efficiently acquired with an interslice MTA method, which may accelerate clinical application of myelin imaging.

scholarly journals Lobar Distribution of Changes in Gray Matter and White Matter in Memory Clinic Patients: Detected Using Magnetization Transfer Imaging

2007 ◽  
Vol 28 (10) ◽  
pp. 1938-1942 ◽  
Author(s):  
A.C.G.M. van Es ◽  
W.M. van der Flier ◽  
F. Admiraal Behloul ◽  
H. Olofsen ◽  
E.L.E.M. Bollen ◽  
...  
Keyword(s):  
White Matter ◽  
Gray Matter ◽  
Magnetization Transfer ◽  
Magnetization Transfer Imaging ◽  
Memory Clinic

Characterization of white matter damage in animal models of multiple sclerosis by magnetization transfer ratio and quantitative mapping of the apparent bound proton fraction f*

2009 ◽  
Vol 15 (1) ◽  
pp. 16-27 ◽  
Author(s):  
M Rausch ◽  
PS Tofts ◽  
P Lervik ◽  
AR Walmsley ◽  
A Mir ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Animal Models ◽  
Tissue Damage ◽  
Magnetization Transfer ◽  
Transverse Relaxation Time ◽  
Magnetization Transfer Ratio ◽  
White Matter Damage ◽  
Transfer Ratio ◽  
Quantitative Mapping

Quantitative magnetization transfer magnetic resonance imaging (qMT-MRI) can be used to improve detection of white matter tissue damage in multiple sclerosis (MS) and animal models thereof. To study the correlation between MT parameters and tissue damage, the magnetization transfer ratio (MTR), the parameter f* (closely related to the bound proton fraction) and the bound proton transverse relaxation time T2B of lesions in a model of focal experimental autoimmune encephalomyelitis (EAE) were measured on a 7T animal scanner and data were compared with histological markers indicative for demyelination, axonal density, and tissue damage. A clear spatial correspondence was observed between reduced values of MTR and demyelination in this animal model. We observed two different levels of MTR and f* reduction for these lesions. One was characterized by a pronounced demyelination and the other corresponded to a more severe loss of the cellular matrix. Changes in f* were generally more pronounced than those of MTR in areas of demyelination. Moreover, a reduction of f* was already observed for tissue where MTR was virtually normal. No changes in T2B were observed for the lesions. We conclude that MTR and qMT mapping are efficient and reliable readouts for studying demyelination in animal models of MS, and that the analysis of regional f* might be even superior to the analysis of MTR values. Therefore, quantitative mapping of f* from human brains might also improve the detection of white matter damage in MS.

scholarly journals Differential Progression of Magnetization Transfer Imaging Changes Depending on Severity of Cerebral Hypoxic-Ischemic Injury

2008 ◽  
Vol 28 (9) ◽  
pp. 1613-1623 ◽  
Author(s):  
Ursula I Tuor ◽  
Shuzhen Meng ◽  
Min Qiao ◽  
Nicole B Webster ◽  
Shauna M Crowley ◽  
...  
Keyword(s):  
White Matter ◽  
Magnetization Transfer ◽  
Ischemic Injury ◽  
Subcortical White Matter ◽  
Cerebral Injury ◽  
Magnetization Transfer Ratio ◽  
Magnetization Transfer Imaging ◽  
Cerebral Hypoxia ◽  
Hypoxia Ischemia ◽  
Hypoxic Ischemic Injury

We hypothesized that magnetic resonance magnetization transfer (MT) imaging would be sensitive for detecting cerebral ischemic injury in white matter of neonatal brain. We compared the progression of changes in T2 and the MT ratio (MTR) after cerebral hypoxic-ischemic insults of differing severity in neonatal rats. Magnetization transfer imaging parameters were first optimized, and then MTR and T2 maps were acquired at various times after a mild (rather selective white matter) or substantial insult produced by unilateral cerebral hypoxia—ischemia. Depending on insult severity, time after insult, and region (e.g., subcortical white matter or cortex), cerebral hypoxia—ischemia produced reductions in MTR and an increase in T2. The exception was acutely at 1 to 5 h at which time points MTR was reduced ipsilaterally in white matter, whereas T2 was not affected significantly. Progression of imaging changes differed in rats grouped according to whether gross damage was present after chronic recovery. Behavioral changes were generally associated with chronic reductions in MTR and gross brain damage. Magnetization transfer imaging was capable of early detection of hypoxic-ischemic injury and particularly sensitive for identifying the progression of cerebral injury in white matter. Magnetization transfer ratio has potential for assisting with early diagnosis and treatment assessment for infants affected by perinatal hypoxia—ischemia.

Sign in / Sign up

Export Citation Format

Share Document