Wei Li^1,2, Justin Long¹, Lora Watts¹, Qiang Shen¹, and Timothy Q. Duong^1,2
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States, ²Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States

Diffusion, T2 and magnetic susceptibility MRI were used to characterize white matter changes following mild TBI using a rat controlled cortical impact model. Two groups can be differentiated based on these contrasts. The first group showed widespread diffusion and T2 changes, but localized susceptibility increase at day 2. The second group showed normal contrasts at all the time points. These results suggest that diffusion, T2 and susceptibility MRI may provide a unique combination to assess white matter damages, and to provide useful information regarding the spatial-temporal evolution of white matter edema and myelin disruptions post TBI.

Jiri M.G. van Bergen^1,2, Jun Hua^1,2, Paul G. Unschuld^3,4, Issel Anne L. Lim^1,2, Craig K. Jones^1,2, Russell L. Margolis^4,5, Christopher A. Ross^4,5, Peter C.M. van Zijl^1,2, and Xu Li^1,2
1Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States, ²F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States, ³Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Zurich, Switzerland, ⁴Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland, United States, ⁵Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States

Using Quantitative Susceptibility Mapping (QSM) on subjects with prodromal Huntington’s disease we found altered magnetic susceptibility in basal ganglia structures of the brain, as compared to controls. Increases were seen in caudate nucleus, putamen, and globus pallidus, while decreases were observed in hippocampus and substantia nigra. Susceptibility levels in the caudate and putamen correlated with the an estimate of time to onset of manifest HD. Changes in susceptibility in gray matter have been shown to relate to tissue iron content. Our data thus indicate potential clinical relevance of iron as a biomarker of disease progression. 

Ahmed M. Elkady¹, Hongfu Sun¹, Andrew J. Walsh¹, Gregg Blevins², Zhuozhi Dai¹, and Alan H. Wilman^1
1Dept. of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada, ²Division of Neurology, University of Alberta, Edmonton, AB, Canada

Susceptibility (SUS), Local Field Shift (LFS), and R2* conspicuity and contrast of 351 lesions were examined in 20 Multiple Sclerosis (MS) patients. Although the majority were not visible in SUS or LFS, visible lesions mostly appeared as hyper-core with no ring. Perls’ iron stain of 22 lesions in two postmortem MS subjects were also examined in pathology sections and matched to lesions’ conspicuity and contrast in registered in situ MRI. Results indicated that hyper-core lesion contrast in LFS or SUS and dipole field patterns in LFS could confirm the presence of iron, but could not predict iron absence.

Ikuko Uwano¹, Makoto Sasaki¹, Kohsuke Kudo², Ryota Sato³, Yuiko Sato⁴, Yasushi Ogasawara⁴, Hiroaki Saura⁴, Kuniaki Ogasawara⁴, Taisuke Harada¹, Kenji Ito¹, Fumio Yamashita¹, Jonathan Goodwin¹, and Satomi Higuchi^1
1Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate, Japan, ²Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido, Japan, ³Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, Japan,⁴Department of Neurosurgery, Iwate Medical University, Morioka, Iwate, Japan

This study aims to determine the accuracy of oxygen extraction fraction (OEF) maps generated from quantitative susceptibility mapping (QSM) at 7T. We compared relative OEF values of the affected cerebral hemisphere against the contralateral hemisphere between QSM and PET in patients with chronic unilateral internal carotid artery or middle cerebral artery stenosis/occlusion. Relative QSM-OEF values showed excellent agreements with the corresponding PET-OEF values. Therefore, OEF measurement using QSM at 7T is considered comparable to that using PET and can be applied for the assessment of patients with steno-occlusive cerebrovascular diseases.

Till Schneider¹, Andreas Deistung², Uta Biedermann³, Sabine Heiland¹, Martin Bendszus¹, and Jürgen Reichenbach^2
1Neuroradiology, University of Heidelberg, Heidelberg, Germany, ²Department of Medical Physics, University of Jena, Jena, Germany, ³Department of Anatomy, University of Jena, Jena, Germany

Using susceptibility-based image contrasts and Qutative Susceptibility Mapping to image Pallidofugal Fiber Tracts

Andreas Deistung¹, Andreas Schäfer², Ferdinand Schweser^3,4, and Jürgen Rainer Reichenbach^1
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany,²Department of Neurophysics, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ³Buffalo Neuroimaging Analysis Center, Dept. of Neurology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States, ⁴MRI Molecular and Translational Imaging Center Institution, Buffalo CTRC, State University of New York at Buffalo, Buffalo, NY, United States

We investigated the spatial distribution of both magnetic susceptibility and R2* across the cerebral cortex in vivo. We observed substantial variations of magnetic susceptibility and R2* across the cortical surface. Certain regions of magnetic susceptibility and R2* coincided with the boundaries of the probabilistic Brodmann atlas and other regions exhibited a heterogeneous distribution within the specific Brodmann area. In conclusion, cortical mapping of R2* and magnetic susceptibility reveals insights into tissue composition across the cerebral cortex and may be instrumental for understanding the relationship between tissue composition and functional roles of cortical gray matter.

John Schenck¹, Dominic Graziani¹, Ek Tsoon Tan¹, Seung-Kyun Lee¹, Luca Marinelli¹, Thomas Foo¹, Christopher Hardy¹, Tian Liu², and Yi Wang^3
1MRI Laboratory, General Electric Global Research, Schenectady, New York, United States, ²MedImageMetric, New York, New York, United States,³Radiology, Cornell Medical College, New York, New York, United States

The habenular nuclei are two small (mm-sized) cell masses deep in the brain near the midline on either side of the 3rd ventricle. They are currently of intense neuropsychological interest as they have been implicated as having major roles in normal brain functioning and in serious psychiatric disorders (e.g., depression). However, they are not normally seen as conspicuous brain components on conventional MRI images. We have demonstrated that using QSM imaging on normal volunteers using a conventional 3T scanner the habenulae can be identified and quantified as conspicuous, paramagnetic iron-rich structures.

Karin Shmueli¹, Jamie M Kawadler², David W Carmichael², Chris A Clark², and Fenella J Kirkham^3
1Department of Medical Physics & Biomedical Engineering, University College London, London, United Kingdom, ²Imaging & Biophysics Unit, UCL Institute of Child Health, London, United Kingdom, ³Neurosciences Unit, UCL Institute of Child Health, London, United Kingdom

Sickle cell anaemia (SCA) is a genetic disorder affecting haemoglobin. Previous studies suggest that the iron content in some deep-brain regions is higher in transfused SCA patients (TSCA) than in healthy controls (HC). We hypothesised that iron content in those regions is lower in non-transfused patients (NSCA) than in controls as NSCA have low haematocrit. A pilot study (5 TSCA, 5 NSCA, 5 HC) showed that susceptibility values were significantly lower in the globus pallidus of both TSCA and NSCA than in HC, supporting our second hypothesis. A larger study (20 NSCA, 18 HC) showed a trend in this direction.

Russell Dibb^1,2 and Chunlei Liu^3,4
1Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States, ²Biomedical Engineering, Duke University, Durham, NC, United States, ³Brain Imaging & Analysis Center, Duke University Medical Center, Durham, NC, United States, ⁴Radiology, Duke University Medical Center, Durham, NC, United States

Susceptibility tensor imaging may be used to probe the microstructure and fiber architecture of the myocardium in 3D. However, it currently is liable to image artifacts arising from imperfect background phase removal. Conjoint relaxation and susceptibility tensor imaging (CRSTI) is a useful step towards the robust estimation of tensor-valued tissue susceptibility and facilitates the application of susceptibility-based tractography to the whole heart for the first time. In addition to the myocardium, CRSTI may potentially aid in studying the source(s) of susceptibility contrast and anisotropy in other magnetically anisotropic tissues.

Hongjiang Wei¹, Bin Wang¹, Xiaopeng Zong², Weili Lin², Nian Wang¹, and Chunlei Liu^1,3
1Brain Imaging and Analysis Center, Duke University, Durham, NC, United States, ²Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, NC, United States, ³Depatment of Radoilogy, School of Medicine, Duke University, NC, United States

The knee joint is one of the most important joints in the human body with several intricate structures and complex interfaces including bones, tendons, muscles, fat, ligaments, cartilages and meniscuses. Each of these components has unique molecular and cellular composition and microstructures and thus may exhibit varying magnetic susceptibility. Quantitative susceptibility mapping (QSM) has been widely investigated in the brain, e.g. for quantifying iron deposits and myelination. However, these techniques have not been successfully implemented in the knee. The purpose of this work was to develop and demonstrate feasibility of water-fat separated QSM in the knee as well as to evaluate the susceptibility properties of different anatomical structures within the knee joint. Imaging susceptibility of the knee may aid in assessing knee joint diseases and disorders.