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

Kim, Jae-Woong; Choi, Jiye; Cho, Janggeun; Lee, Chulhyun; Jeon, Daejong; Park, Sung‐Hong

doi:10.1155/2015/565391

Cited by 7 publications

(6 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The current ALADDIN MTA study focused on the effects of flip angle (i.e., saturation power), but not on TR and RF bandwidth. Preliminary studies showed that MTA has higher specificity to WM than MTR [ 37 ] and suggested that TR and RF bandwidth affect the MTA contrast which may be potentially related to myelination [ 38 ], all of which requires further investigation. These technical advancements can reduce the scan time and/or improve the image quality further.…”

Section: Discussionmentioning

confidence: 99%

“…These technical advancements can reduce the scan time and/or improve the image quality further. Furthermore, ALADDIN can potentially be sensitized to directionality of local blood flow in each pixel [ 39 ], map myelination [ 37 ], and quantitatively map MT signals [ 40 ]. These factors along with potential clinical usefulness of imaging both perfusion and MT-related information together warrant further investigation.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Inter-Slice Blood Flow and Magnetization Transfer Effects as A New Simultaneous Imaging Strategy

et al. 2015

Self Cite

View full text Add to dashboard Cite

The recent blood flow and magnetization transfer (MT) technique termed alternate ascending/descending directional navigation (ALADDIN) achieves the contrast using interslice blood flow and MT effects with no separate preparation RF pulse, thereby potentially overcoming limitations of conventional methods. In this study, we examined the signal characteristics of ALADDIN as a simultaneous blood flow and MT imaging strategy, by comparing it with pseudo-continuous ASL (pCASL) and conventional MT asymmetry (MTA) methods, all of which had the same bSSFP readout. Bloch-equation simulations and experiments showed ALADDIN perfusion signals increased with flip angle, whereas MTA signals peaked at flip angle around 45°−60°. ALADDIN provided signals comparable to those of pCASL and conventional MTA methods emulating the first, second, and third prior slices of ALADDIN under the same scan conditions, suggesting ALADDIN signals to be superposition of signals from multiple labeling planes. The quantitative cerebral blood flow signals from a modified continuous ASL model overestimated the perfusion signals compared to those measured with a pulsed ASL method. Simultaneous mapping of blood flow, MTA, and MT ratio in the whole brain is feasible with ALADDIN within a clinically reasonable time, which can potentially help diagnosis of various diseases.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Inter-Slice Blood Flow and Magnetization Transfer Effects as A New Simultaneous Imaging Strategy

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…MTA could be considered a good biomarker for imaging myelination. [49] Grooming is the most common innate behavior in animals. In rodents, it consists of sequences of movements organized in four phases, executed symmetrically on both sides of the animal and creating a syntactic chain of behavioral events.…”

Section: Comparative Studies Of Cerebral Asymmetries Vol 1 Issue 1mentioning

confidence: 99%

Cerebral Asymmetry and Dominance in Man

Haroun¹

2015

Aanat

View full text Add to dashboard Cite

The two human cerebral hemispheres are not mirror images of each other. They show anatomical and functional differences that are termed as cerebral asymmetries. The most striking differences in right-handed people are Broca's motor areas of speech in the left inferior frontal gyrus and Wernicke's area for language comprehension and speech production in the left posterior temporal and inferior parietal lobules. These examples have lead to the overall concept of dominant left and subordinate right cerebral hemispheres. Other structural asymmetries are revealed in the perisylvian area, surface area around the central fissure, cortical thickness, cerebral rotation, the volume of the lateral ventricle, lateral geniculate body, posterior cerebral and circle of Willis arteries, deep medullary veins, and type of nervous system of individuals. Functional cerebral asymmetries are also reported regarding verbal and linguistic functions, mathematical skills, analytical thinking, functions of corticobulbar, corticospinal and corticobasal pathways, functional organization of the prefrontal cortex (PFC), orbitofrontal cortex (OFC) and ventromedial temporal cortex (fusiform gyrus, FG), as well as amyloid-β deposition and metabolism. Cerebral asymmetries are thought to play an essential role in the pathogenesis of clinical disorders as aphasia, unilateral left brain lesion, adiadochokinesa, autism spectrum disorder (ASD), corticobasal syndrome, Parkinson's disease (PD), Alzheimer's disease, and adolescents with idiopathic scoliosis (AIS). Age and sex related asymmetries have been sometimes postulated. Genetic, environmental and callosal factors are mentioned to underlie the etiology of cerebral asymmetries. Comparatively, functional, and neuroanatomical asymmetries do exist in nonhuman primates.

show abstract

“…The irradiation can also cause blood labeling effects when the slice acquisition order is aligned along the direction of blood movement . The effect can be compensated and separated by a unique combination scheme, which leads to simultaneous imaging of MT asymmetry and perfusion imaging in a short scan time . The incidental MT effect was further investigated in terms of interslice MT ratio imaging, showing perfusion, MT asymmetry, and MT ratio all together in brain tumor within a clinically reasonable scan time .…”

Section: Introductionmentioning

confidence: 99%

“…In sequential multislice scanning, excitation RF pulses used for imaging one slice act as off‐resonance pulses to the subsequent slices, inducing incidental MT saturations. The irradiation can also cause blood labeling effects when the slice acquisition order is aligned along the direction of blood movement . The effect can be compensated and separated by a unique combination scheme, which leads to simultaneous imaging of MT asymmetry and perfusion imaging in a short scan time .…”

Section: Introductionmentioning

confidence: 99%

Rapid framework for quantitative magnetization transfer imaging with interslice magnetization transfer and dictionary‐driven fitting approaches

Kim

Lee

Choi

et al. 2019

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

Purpose:To develop a rapid framework for quantitative magnetization transfer (qMT) imaging based on the 2D interslice MT and dictionary-driven fitting approaches. Methods: Sequential balanced steady-state free precession (bSSFP) scanning was performed on a whole human brain in a total of 12 conditions from six different interslice gaps and two different flip angles. To obtain qMT maps, the acquired 12 datasets were fitted to a dictionary predefined by using Bloch equation simulations based on the two-pool MT model. The proposed qMT method was compared to the conventional qMT methods, in terms of qMT parameter maps and processing time. Results: The proposed method yielded qMT maps similar to those of the conventional method, indicating feasibility of modulating MT saturation frequency and power with the interslice gap and flip angle. The whole-brain qMT imaging could be completed in 8 min because of the absence of separate MT pulses. The time for processing qMT parameters was significantly reduced through the dictionary-driven approach; it is 1000 times shorter than that without the dictionary-driven approach and 3 times shorter than that with the spoiled gradient recalled echo-qMT method that uses an analytical solution. Conclusion: The proposed dictionary-driven interslice qMT imaging provides qMT maps close to those from the conventional method with significantly reduced scan time and postprocessing time, which can make qMT imaging more clinically acceptable. K E Y W O R D Sbalanced steady-state free precession, dictionary analysis, interslice, magnetization transfer, quantitative imaging

show abstract

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

Cited by 7 publications

References 54 publications

Inter-Slice Blood Flow and Magnetization Transfer Effects as A New Simultaneous Imaging Strategy

Inter-Slice Blood Flow and Magnetization Transfer Effects as A New Simultaneous Imaging Strategy

Cerebral Asymmetry and Dominance in Man

Rapid framework for quantitative magnetization transfer imaging with interslice magnetization transfer and dictionary‐driven fitting approaches

Contact Info

Product

Resources

About