Chaitra Badve¹, Alice Yu², Matthew Rogers², Dan Ma², Jeffrey Sunshine¹, Vikas Gulani¹, and Mark Griswold^1
1Radiology, University Hospitals Case Medical Center, Cleveland, Ohio, United States, ²Case Western Reserve University, Ohio, United States

This is the first in vivo application of magnetic resonance fingerprinting in a large sample of normal subjects. MRF based relaxometry proves to be a fast and accurate tool to quantify microstructural patterns in brain based on aging, gender differences and differences between hemispheres. The study shows that aging related differences are seen more conspicuosly in certain brain regions over others. These findings not only serve to enhance understanding of physiological variations but also can serve as reference for evaluating various pathological states.

Erika P. Raven^1,2, Peter van Gelderen², Jacco A. de Zwart², Diana H. Fishbein³, John VanMeter^1,4, and Jeff H. Duyn^2
1Georgetown University, Washington, DC, United States, ²Advanced MRI, LFMI, NINDS, NIH, Bethesda, MD, United States, ³University of Maryland School of Medicine, Baltimore, MD, United States, ⁴Georgetown Center for Functional and Molecular Imaging, Washington, DC, United States

Experimental data suggest that the susceptibility effects of myelinated axons are best characterized by a three-compartment model, representing water trapped between myelin layers (“myelin water”), throughout the interstitial space, and within the axonal lumen. By examining cellular specific contributions of each compartment, we predicted that adolescents would have lower myelin water fractions in later-myelinating regions (genu, frontal white matter), while an early-myelinating region (splenium) would be comparable to adults. The current sample did not detect significant differences in myelin water amplitude for any region, possibly due to reduced susceptibility contrast at 3T or susceptibility-induced artifacts.

Manoj K. Sammi¹, Yosef A Berlow¹, John G Grinstead², Dennis M Bourdette³, and William D Rooney^1
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, ²Siemens Healthcare, OR, United States,³Department of Neurology, Oregon Health & Science University, Portland, OR, United States

In this study, we investigate Corpus Callosum morphology and quantitative R₁ in healthy controls and individuals with Multiple Sclerosis.

Weibo Chen^1,2, Xin Chen³, Guangbin Wang³, Queenie Chan⁴, He Wang⁵, Jianqi Li¹, Xuzhou Li⁶, Shanshan Wang³, Bin Yao³, and Dongrong Xu^6,7
1Shanghai Key Laboratory of Magnetic Resonance and Department of Physics,East China Normal University, Shanghai, China, ²Philips Healthcare, shanghai, China, ³Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, China, ⁴Philips Healthcare, Hongkong, China,⁵Philips Research China, shanghai, China, ⁶Key laboratory of Brain Functional Genomics (MOE & STCSM), Institute of Cognitive Neuroscience, East China Normal University, shanghai, China, ⁷Epidemiology Division & MRI Unit,Columbia University Department of Psychiatry, New York, United States

T1 Rho relaxation time has been proved to have relevance with collagen deposition1. The purpose of our study was to find a non-invasive MR method to evaluate the whole liver fibrosis severity.

Mukund Balasubramanian^1,2, Delma Y. Jarrett^1,2, and Robert V. Mulkern^1,2
1Department of Radiology, Boston Children's Hospital, Boston, MA, United States, ²Harvard Medical School, Boston, MA, United States

We demonstrate that gradient-echo sampling of single spin-echoes can be used to isolate the signal from bone marrow, with high-quality segmentation and surface reconstruction resulting from the application of simple post-processing strategies available on modern radiology workstations. Our approach exploits signal behavior due to reversible and irreversible transverse relaxation, in concert with "Dixon oscillations", i.e., signal oscillations due to chemical-shift interference effects. The resulting 3D reconstructions could prove useful for orthopedic surgical planning, providing an alternative to computed tomography (CT) in situations where eliminating exposure to ionizing radiation is a high priority, e.g., when imaging pediatric patients.

Ericky Caldas de Almeida Araujo¹ and Pierre G Carlier^1,2
1NMR Laboratory, Institute of Myology, Paris, Île-de-France, France, ²NMR Laboratory, CEA/I2BM/MIRCen, Paris, Île-de-France, France

1H-NMR relaxation in skeletal muscle is long known to be multiexponential and this has been demonstrated to reveal myowater distribution and exchange between histological compartments. The spectroscopic CPMG sequence allows the acquisition of T2-relaxation curves with echo-time sampling and SNR that are high enough to allow robust multiexponential analysis. This method allows extracting a T2-spectrum that characterizes the investigated volume in the muscle. We hypothesise that the analysis of T2-spectra in diseased tissue shall offer specificity to MRI T2 measurements by revealing the pathophysiological mechanisms underlying the observed alterations on the monoexponential T2-value.

Joep van Oorschot¹, Johannes Gho¹, Sanne de Jong¹, Aryan Vink¹, Fredy Visser², Jacques de Bakker³, Steven Chamuleau¹, Peter Luijten¹, Tim Leiner¹, and Jaco Zwanenburg^1
1University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, ²Philips Healthcare, Best, Noord-Brabant, Netherlands, ³AMC, Amsterdam, Netherlands

Quantitative methods such as T1 mapping and ECV mapping provide information on diffuse fibrosis formation in patients with DCM. Recently it was shown that a significantly higher T1ρ is found in compact myocardial fibrosis. Here we validate cardiac T1ρ-mapping in patients with DCM, and correlate with ECV-mapping and fibrosis histology. Three explanted hearts from DCM patients were scanned and histological fibrosis was compared to the corresponding T1ρ value, with a Pearson correlation r=0.27. In vivo T1ρ-mapping was performed in 6 DCM patients, where a significantly higher T1ρ (59.5±4 ms) was found compared to healthy controls (50±3 ms).

Peiying Liu¹, Lina Chalak², Lisa Krishnamurthy¹, Imran Mir², Shin-Lei Peng¹, Hao Huang¹, and Hanzhang Lu^3
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ²Department of Pediatrics, University of Texas Southwestern Medical Center, Texas, United States, ³University of Texas Southwestern Medical Center, Dallas, Texas, United States

Knowledge of blood T1 and T2 is of major importance in many applications of MRI in neonates. T1 and T2 relaxometry of neonatal blood is different from that of adult, because of their differences in hemoglobin molecular structure. Using healthy cord blood samples, we established a comprehensive relationship between hematocrit, oxygenation and neonatal blood T1/T2. We found that neonatal blood has a longer T1 and T2 comparing to adult blood. The neonatal blood T1 and T2 characteristics reported in this work may serve as a useful reference for future in vivo studies aiming to assess hemodynamic function in neonates.

Sharon Portnoy¹, Mike Seed², Julia Zhu², John G. Sled^1,3, and Christopher K. Macgowan^1,4
1Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada, ²Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada, ³Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada, ⁴Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada

We seek to establish whether a combination of vascular T₁ and T₂ relaxometry measurements can be reliably used to determine both oxygen saturation, sO₂, and hematocrit, Hct. This is in contrast to typical vascular oximetry methods which use a single T₂ measurement to compute sO₂ only, while assuming a normal value for Hct. Knowledge of Hct is highly valuable in our population of interest: fetuses potentially affected by hypoxia. Results on in-vitro blood samples indicate that, in general, combining T₁ and T₂ data improves the accuracy of sO₂ estimation and provides a reliable means for determining Hct.

Yonathan T. Araya¹, Francisco M. Martinez-Santiesteban¹, Chad T. Harris², William B. Handler³, Blaine A. Chronik^3,4, and Timothy J. Scholl^1,4
1Medical Biophysics, Western University, London, ON, Canada, ²Synaptive Medical, Toronto, ON, Canada, ³Physics and Astronomy, Western University, London, ON, Canada, ⁴Robarts Research Institute, Western University, London, ON, Canada