ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Scientific Session • Relaxometry Applications Throughout the Body

Monday 1 June 2015

Room 701 B

14:15 - 16:15


Oliver Bieri, Ph.D., Rexford D. Newbould, Ph.D.

14:15 0121.   
Regional brain T1 and T2 relaxometry in healthy volunteers using magnetic resonance fingerprinting
Chaitra Badve1, Alice Yu2, Matthew Rogers2, Dan Ma2, Jeffrey Sunshine1, Vikas Gulani1, and Mark Griswold1
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.

14:27 0122.   In vivo assessment of age-related white matter differences using T2* relaxation
Erika P. Raven1,2, Peter van Gelderen2, Jacco A. de Zwart2, Diana H. Fishbein3, John VanMeter1,4, and Jeff H. Duyn2
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.

14:39 0123.   Extensive and Intensive Measures of Corpus Callosum Health in Multiple Sclerosis
Manoj K. Sammi1, Yosef A Berlow1, John G Grinstead2, Dennis M Bourdette3, and William D Rooney1
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.

14:51 0124.   Quantitative 3D Whole Liver T1rho Mapping at 3.0T
Weibo Chen1,2, Xin Chen3, Guangbin Wang3, Queenie Chan4, He Wang5, Jianqi Li1, Xuzhou Li6, Shanshan Wang3, Bin Yao3, and Dongrong Xu6,7
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.

15:03 0125.   Leveraging transverse relaxation processes and Dixon oscillations to achieve high-quality segmentation of bone marrow
Mukund Balasubramanian1,2, Delma Y. Jarrett1,2, and Robert V. Mulkern1,2
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.

15:15 0126.   
Significant alterations on T2-spectra observed in the calf of myopathic patients
Ericky Caldas de Almeida Araujo1 and Pierre G Carlier1,2
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.

15:27 0127.   Endogenous assessment of diffuse myocardial fibrosis with T1ρ-mapping in patients with dilated cardiomyopathy - permission withheld
Joep van Oorschot1, Johannes Gho1, Sanne de Jong1, Aryan Vink1, Fredy Visser2, Jacques de Bakker3, Steven Chamuleau1, Peter Luijten1, Tim Leiner1, and Jaco Zwanenburg1
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).

15:39 0128.   What are the blood T1 and T2 values in neonates?
Peiying Liu1, Lina Chalak2, Lisa Krishnamurthy1, Imran Mir2, Shin-Lei Peng1, Hao Huang1, and Hanzhang Lu3
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.

15:51 0129.   
Combined T1 and T2 Measurement for Non-Invasive Evaluation of Blood Oxygen Saturation and Hematocrit
Sharon Portnoy1, Mike Seed2, Julia Zhu2, John G. Sled1,3, and Christopher K. Macgowan1,4
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.

16:03 0130.   
Delta relaxation enhanced magnetic resonance (dreMR) imaging of a healthy mouse for determination of spin-lattice relaxation rates and R1 dispersion at 1.5 T
Yonathan T. Araya1, Francisco M. Martinez-Santiesteban1, Chad T. Harris2, William B. Handler3, Blaine A. Chronik3,4, and Timothy J. Scholl1,4
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

Spin-lattice relaxation rates (R1) and its associated dispersion over a range of magnetic field shifts (ΔB0) provide useful quantitative tools to differentiate normal and abnormal tissues. We present preliminary imaging results for whole-body R1 and R1 dispersion maps of ±0.11 T magnetic field shifts about 1.5 T at 37oC for a healthy mouse using delta relaxation enhanced magnetic resonance (dreMR) imaging. The findings demonstrate unenhanced tissues exhibit little magnetic field dependence about 1.5 T.