Room 355 BC

10:30 - 12:30

Moderators:

Jongho Lee, Jesse L. Wei

Katharina Fuchs¹, Fabian Hezel¹, Sabrina Klix¹, and Thoralf Niendorf^1,2
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, ²Experimental and Clinical Research Center, a cooperation of the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Berlin, Germany

Both T₂ and T₂^* weighted Fast Spin Echo (FSE) sequences are frequently applied in clinical practice. This work presents an FSE technique which is simultaneously sensitive to T₂and T₂^* offering various applications including simultaneous mapping. The dual weighting of the proposed two-in-one sequence is generated via the separation of spin echoes and stimulated echoes. Applicability of the presented approach is examined in phantoms and healthy volunteers at 3.0 T and 7.0 T.

Di Xu¹, Clifford R. Weiss², Ozan Sayin¹, Wesley D. Gilson³, Jonathan S. Lewin², Elliot R. McVeigh¹, and Daniel A. Herzka^4
1Biomedical Engineering, The Johns Hopkins School of Medicine, Baltimore, MD, United States, ²Radiology, The Johns Hopkins School of Medicine, Baltimore, MD, United States,³Siemens Corporation, Corporate Technology, Baltimore, MD, United States, ⁴Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States

T2-weighted fat suppressed MR images are diagnostically relevant in lesion and critical structure characterization in vascular anomalies, oncology, and cardiology, etc. Current techniques used in MR-guided interventions have limited T2 contrast and fat suppression (e.g SSFP), are slow (e.g. T2W-TSE), or yield blurry images and inferior speed (HASTE). Hence, an imaging technique with sufficient speed for real-time procedure guidance in addition to T2 contrast and fat suppression is of interest. We present contrast-prepared SSFP (CP-SSFP), a technique for interventional guidance incorporating several technical improvements. The technique is evaluated on phantoms and patients undergoing therapeutic or diagnostic imaging for vascular malformations.

Alexander L. Sukstanskii¹ and Dmitriy A. Yablonskiy^1
1Radiology, Washington University, St. Louis, Missouri, United States

In this communication we analyze the effect of magnetic anisotropy associated with the presence of radially-oriented long-chain lipoprotein molecules in the myelin sheath of WM fibers on gradient echo MRI signal formation. We incorporate this effect into previously developed Generalized Lorentzian approach and calculate water frequency shifts in axons, myelin and extracellular space. Frequency shifts in axons and myelin sheath are shown to be highly anisotropic with respect to B₀. Importantly, both the cylindrical symmetry of WM tissue structure and of magnetic susceptibility contribute to this anisotropic effect. It is also shown that myelin water signal is substantially non-T2* type.

Se-Hong Oh¹ and Jongho Lee^1
1Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States

In this study, a new MRI sequence that selectively acquires myelin water signal is proposed. Compared to conventional myelin water imaging, the new myelin water imaging method provides substantially improved image quality showing potentials for clinical applications.

Wei Li¹, Bing Wu², Anastasia Batrachenko¹, Christian Langkammer³, Stefan Ropele³, Rajendra Morey^1,4, Vandana Shashi⁵, Allen W. Song^1,6, and Chunlei Liu^1,6
1Brain Imaging & Analysis Center, Duke University, Durham, North Carolina, United States, ²GE Healthcare China, Beijing, China, ³Neurology, Medical University of Graz, Graz, Austria, ⁴Psychiatry and Behavioral Sciences, Durham VA Medical Center, Durham, North Carolina, United States, ⁵Pediatrics, Duke University, Durham, North Carolina, United States, ⁶Radiology, Duke University, Durham, North Carolina, United States

The evolution of regional magnetic susceptibility in the human brain is assessed in 181 subjects from 1 to 83 years. The evolution of magnetic susceptibility over the lifespan was found to display differential trajectories between gray and white matter. Both cortical and subcortical white matter showed an initial decrease followed by a subsequent increase of magnetic susceptibility, while both cortical gray matter and iron-rich deep nuclei displays a monotonic increase. These results suggest that magnetic susceptibility may provide valuable information regarding the spatial and temporal patterns of brain myelination and iron deposition during brain maturation and ageing.

Timo Liimatainen¹, Alejandra Sierra¹, Hanne Hakkarainen¹, Djaudat Idiyatullin², Christine Storino², Silvia Mangia², Olli Gröhn¹, Michael Garwood², and Shalom Michaeli^2
1A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Fi, Finland, ²Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

Relaxation Along a Fictitious Field (RAFF) was used to characterize MRI tissue contrast in a rotating frames of rank n, where n was varied between 1 and 5. Relaxation times maps in high-rank rotating frames correlate with myelin content in the rat brain ex vivo better than T₁, T₂, T₁, T₂ or MT. The RAFFn provides high potential for mapping of myelination in the brain.

Wael Marashdeh¹, Bradley Gans¹, Brian Raterman¹, Eric Bourekas¹, and Arunark Kolipaka^1
1Radiology, ohio state university wexner medical center, Columbus, ohio, United States

Measuring the stiffness of the brain provides important diagnostic information.Magnetic Resonance Elastography(MRE)is a noninvasive method to estimate the stiffness of the brain.This study aims to determine the correlation between intracranial pressures and whole brain stiffness.Our results demonstrated no significant difference in MRE derived brain stiffness to the opening and closing intracranial pressures measured by lumbar puncture in a pool of 7 patients. However, more studies are warranted to establish the correlation between intracranial pressure and brain stiffness.

Temel Kaya Yasar¹, Dieter Klatt², Richard L. Magin², and Thomas J. Royston^2
1Department of Mechanical & Industrial Engineering, The University of Illinois at Chicago, Chicago, Illinois, United States, ²Department of Bioengineering, The University of Illinois at Chicago, Chicago, Illinois, United States

We introduce selective spectral displacement projection (SDP) as a new motion encoding concept for 3D multifrequency MRE. SDP-MRE can be applied to a vibration spectrum composed of three frequencies and exploits the filter condition of MRE for selecting one frequency each per spatial direction. The selected components are simultaneously encoded in the phase of the MR signal and the acquisition of temporally-resolved phase images enables the decomposition of the individual components. SDP-MRE reduces the number of temporally-resolved MRE experiments for data acquisition by a factor of 3, while providing the same wave images as found using conventional monofrequency MRE.

Anthony J. Romano¹, Jing Guo², Torben Prokscha³, Sebastian Hirsch⁴, Juergen Braun⁵, Ingolf Sack³, and Michael Scheel^3
1Physical Acoustics, Naval Research Laboratory, Washington, DC, United States, ²Department of Radiology, Charite - University Medicine Berlin, Berlin, Germany, ³Department of Radiology, Charite-Universitatsmedizin, Berlin, Germany, ⁴Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany, ⁵Institute of Medical Informatics, Charite - University Medicine Berlin, Berlin, Germany

We implemented a method called Waveguide Elastography in the analysis of orthotropic elastic parameters of the corticospinal tracts (CSTs) in the brains of five healthy volunteers. Here, we extend this method in an attempt to detect Amyotrophic Lateral Sclerosis (ALS) by analyzing the stiffness of the CSTs of 10 subjects: These included five healthy controls and five patients who present with ALS. We found that we were able to detect a 5% reduction in shear stiffness in the patients vs the controls, and using a Mann-Whitney-U test, we obtained a p = 0.008 demonstrating significant differences between the two groups.

Jing Guo¹, Sebastian Hirsch², Sebastian Papazoglou¹, Andreas Fehlner³, Michael Scheel¹, Jens Wuerfel⁴, Juergen Braun⁵, and Ingolf Sack^1
1Department of Radiology, Charite - University Medicine Berlin, Berlin, Berlin, Germany, ²Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany,³Department of Radiology, Charité University Medicine, Berlin, Berlin, Germany, ⁴Institute of Neuroradiology, University Luebeck, Luebeck, Schleswig-Holstein, Germany,⁵Department of Medical Informatics, Charite - University Medicine Berlin, Berlin, Berlin, Germany

We introduce a novel wave field reconstruction method which we used for analyzing 3D-multifrequency MRE brain data of 23 healthy volunteers providing viscoelastic parameter maps with a spatial resolution superior to former approaches. Individual parameter maps reflecting the magnitude of the complex modulus and the powerlaw exponent of the springpot model were normalized and averaged in order to obtain an atlas of the mechanical anatomy of the human brain.