Hyejin Park¹, Jun Chen², Ivan Dimitrov^2,3, Jae Mo Park^2,4, and Qiu Wang^1
1Chemistry, Duke University, Durham, NC, United States, ²Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, ³Philips Healthcare, Dallas, TX, United States, ⁴Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States

In this work, we have developed a novel de novo ¹⁵N-molecular probe, ¹⁵N-boronobenzyl-4-cyanopyridinium (¹⁵N-BBCP), for in vivo detection of H₂O₂. The long spin-lattice relaxation time (T₁), high H₂O₂ sensitivity and selectivity, low cytotoxicity, and large chemical shift changes upon reaction suggest that the probe is suited for in vivo hyperpolarized ¹⁵N MRI. 

Myung-Ho In¹, Norbert G Campeau¹, Joshua D Trzasko¹, Daehun Kang¹, Kirk M Welker¹, John Huston III¹, Yunhong Shu¹, and Matt A Bernstein^1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States

Echo-planar based diffusion-weighted imaging (DWI) of the brain is prone to local image distortion which can lead to misdiagnosis or nondiagnostic image quality in areas prone to susceptibility effects. A novel distortion-free imaging scheme, termed DIADEM (Distortion-free Imaging: A Double Encoding Method) was recently introduced and optimized for brain imaging on a high-performance experimental Compact 3T system. In this study, we fully implement the DIADEM DWI technique on two 510-k cleared, whole-body 3T scanners and explore the clinical feasibility for its use in routine clinical practice.

Chathura Kumaragamage¹, Peter B Brown¹, Scott McIntyre¹, Terence W Nixon¹, Henk M De Feyter¹, and Robin A de Graaf^1
1Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States

The utility of ECLIPSE, a pulsed second order gradient insert allowing elliptical localization, was previously shown to provide high axial coverage for single slab MRSI acquisitions with robust lipid suppression. In this work we extend the ECLIPSE method with multi-slab localization that provides improved coverage, for applications in 3D MRSI acquisitions. A two-slab ECLIPSE-OVS method providing > 100-fold in mean lipid suppression was developed, with improved superior-inferior coverage. Simulation results show that a four-slab ECLIPSE method, based on OVS and IVS, can provide high-quality lipid suppression with whole-brain coverage.

Yilin Liu¹, Feng Cheng¹, Yong Chen², and Pew-Thian Yap^3
1Computer Science, UNC-Chapel Hill, Chapel Hill, NC, United States, ²Radiology, Case Western Reserve University, Cleveland, OH, United States, ³Radiology, UNC-Chapel Hill, Chapel Hill, NC, United States

We developed a novel deep-learning empowered pipeline for both rapid acquisition and reconstruction of high-resolution 3D MRF with 16X acceleration, thereby significantly improving the clinical feasibility of MRF for quantitative imaging.

Milica Medved^1,2, Aritrick Chatterjee^1,2, Ajit Devaraj³, Ambereen Yousuf^1,2, Aytekin Oto^1,2, and Gregory S Karczmar^1,2
1Department of Radiology, The University of Chicago, Chicago, IL, United States, ²Sanford J. Grossman Center of Excellence in Prostate Imaging and Image Guided Therapy, The University of Chicago, Chicago, IL, United States, ³Philips Research NA, Cambridge, MA, United States

Development of quantitative QC methods for prostate DWI is important in clinical practice, necessitating reliable estimates of spatially heterogenous noise. In data obtained at 3T with the use of an endo-rectal coil, we use raw noise measurements to simulate pure-noise k-space datasets that are post-processed to yield noise maps. Good agreement is found between noise levels measured from noise maps in the central prostate and the estimates of noise produced from the anterior rectal ROIs in high TE / high b-value DWI. Thus, noise can be estimated from an anterior rectum region when the endo-rectal coil is used.

Chaoyue Wang¹, Stephen M. Smith¹, Fidel Alfaro-Almagro¹, Gwenaëlle Douaud¹, Johannes C. Klein^1,2, Alberto Llera³, Aurea B. Martins-Bach¹, Cristiana Fiscone^4,5, Richard Bowtell⁴, Lloyd T. Elliott⁶, Benjamin C. Tendler¹, and Karla L. Miller^1
1Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, ²Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom, ³Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands, ⁴Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, ⁵Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy, ⁶Department of Statistics and Actuarial Science, Simon Fraser University, Vancouver, BC, Canada

In this abstract, we describe our findings from the phenotypic association analyses (univariate Pearson correlations) between 17,485 non-imaging phenotypes and QSM (and T2*) measures using data from 35,885 subjects in UK Biobank. In total, we identify statistically-significant associations of 251 phenotypes with QSM IDPs. Here we describe example associations in blood assays, health outcomes, food and drink, and alcohol consumption categories in detail. Our results demonstrate that QSM and T2* contribute complementary information. This new QSM resource provides an opportunity to investigate susceptibility contrast in previously unexplored territory, which might lead to advances in application of QSM in neuroscience.

Maryam Afzali^1,2, Tomasz Pieciak³, Derek K Jones², Jürgen Schneider^4,5, and Evren Özarslan^6,7
1Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom, ²Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom, ³LPI, ETSI Telecomunicación, Universidad de Valladolid, Valladolid, Spain, ⁴Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom, ⁵Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, ⁶Department of Biomedical Engineering, Linköping University, Linköping, Sweden, ⁷Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden

Diffusion MR is sensitive to the microstructural features of a sample. Fine-scale characteristics can be probed by employing strong diffusion gradients while the small gradient regime is determined by the cumulants of the distribution of particle displacements. However, the cumulant expansion suffers from a finite convergence radius and cannot represent the ‘localization regime’ that emerges at higher gradient strengths characterized by a stretched exponential dependence. Here, we propose a new representation for the diffusion MR signal. Our method provides not only a robust estimate of the first few cumulants but also a meaningful extrapolation of the signal decay.

Vinod Jangir Kumar¹, Klaus Scheffler^1,2, Gisela E Hagberg^1,2, and Wolfgang Grodd^1
1Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, ²Biomedical Magnetic Resonance, University Hospital and Eberhard-Karl’s University, Tuebingen, Germany

The subthalamic structures, like the zona incerta (ZI), fields of forel (FF), subthalamic nucleus (STN), and their surrounding structures, are poorly characterized regarding anatomical imaging. Using quantitative susceptibility mapping (QSM) at ultra-high-field, iron, and myelin mapping may allow an advanced characterization. Therefore, QSM data were acquired at 9.4 Tesla in 21 subjects to characterize the para- and diamagnetic properties of the ZI, FF, and their adjacent structures. In contrast to the FF, we found a higher contribution of diamagnetic and paramagnetic sources, i.e.,  iron, myelin, and calcium, in the STN and ZI. 

Ulrich Katscher¹ and Khin Khin Tha^2
1Philips Research, Hamburg, Germany, ²Hokkaido University, Sapporo, Japan

Electrical tissue conductivity is an emerging quantitative diagnostic parameter, particularly for oncology. Conductivity typically increases with tumor malignancy, however, high conductivity per se is no indication for abnormal tissue, since many tissue types are highly conductive without being abnormal. An empirical rule correlates tissue conductivity with tissue water content. One possibility to analyze abnormality of tissue is thus to compare conductivity as measured with conductivity as expected from water content. The obtained difference yielding “normalized” conductivity might serve as a more direct measure of tissue abnormality. This study presents this concept using pathologic and healthy in vivo example cases.

Ying Chu¹ and Jürgen Finsterbusch^1
1Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Slice-specific z-shimming reduces signal losses caused by through-slice dephasing in spinal cord fMRI acquisitions. Typically, the optimum values are determined from a reference acquisition covering a range of z-shim values by a user who identifies the setting with the least signal loss. However, this procedure requires some experience, is time-consuming, and user-dependent. Here, an automated calculation of the optimum values has been developed, implemented on the MR system, and evaluated in phantoms and in vivo. Without compromising the image quality, the approach is faster and user-independent and, thus, may help to facilitate the application of z-shimming in spinal cord fMRI.

Vincent Oltman Boer¹, Lucilio Cordero Grande², Jan Ole Pedersen³, Martin Prener⁴, Esben Thade Petersen^1,5, Olaf B Paulson^4,6, Mads Andersen^3,7, and Giske Opheim^4,8
1Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark, ²Biomedical Image Technologies, ETSI Telecomunicación, Universidad Politécnica de Madrid and CIBER-BBN, Madrid, Spain, ³Philips Healthcare, Copenhagen, Denmark, ⁴Neurobiology Research Unit, Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark, ⁵Section for Magnetic Resonance, DTU Health Tech, Kgs Lyngby, Denmark, ⁶Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, ⁷Lund University Bioimaging Center, Lund University, Lund, Sweden, ⁸Department of Radiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark

High-resolution multi-slice T2W imaging at ultra-high field is highly sensitive to motion due to high tissue-CSF contrast and the k-space filling pattern. In this study we investigated the combination of 3D prospective and in-plane retrospective motion correction to improve image quality. We observed that a combination of navigator based prospective and data-driven retrospective correction is able to correct most severe motion artifacts during scanning, and remove smaller residual artifacts in reconstruction.