Room 155 EF

10:00 - 12:00

Moderators:

Catherine D. G. Hines, Dimitrios Karampinos

Valentina Taviani¹, Diego Hernando², Christopher J. Francois², Scott K. Nagle¹, Mark L. Schiebler¹, Thomas M. Grist^2,3, Karl K. Vigen¹, Ann Shimakawa⁴, and Scott B. Reeder^1,3
1Radiology, University of Wisconsin, Madison, WI, United States, ²Radiology, University of Wisconsin-Madison, Madison, WI, United States, ³Medical Physics, University of Wisconsin, Madison, WI, United States, ⁴Global MR Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States

Whole-heart 3D water-fat imaging during free-breathing can provide high-resolution fat-suppressed morphological images in patients incapable of holding their breath. In this work we evaluated a 3D chemical-shift-encoded pulse sequence with ECG gating and navigators in 15 patients referred for a wide variety of clinically-indicated cardiac MRI exams. Images were graded by two experienced radiologists on a 4-point scale for overall image quality and level of residual artifacts. Diagnostic images of good/excellent quality were obtained in all patients.

Henrik J. Michaely¹, Katrin Koziel², Philipp Riffel², Johannes Budjan¹, Stefan O. Schoenberg², and Ulrike I. Attenberger^2
1IKRN, UMM, Mannheim, BW, Germany, ²UMM, Mannheim, BW, Germany

A new dynamic sequence is presented that combines CAIPIRINHA acceleration, Dixon fat-saturation and TWIST view sharing with a VIBE sequence. Dynamic imaging of the abdomen has been evaluated with this technique at 3T with a spatial resolution of 1.2x1.2x3mm and a temporal resolution of 2.9s/3D data set.

Xiaodong Zhong¹, Marcel D. Nickel², Stephan A.R. Kannengiesser², Brian M. Dale³, Berthold Kiefer², and Mustafa Bashir^4
1MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, ²MR Applications Development, Siemens AG, Healthcare Sector, Erlangen, Germany, ³MR R&D Collaborations, Siemens Healthcare, Cary, NC, United States, ⁴Division of Abdominal Imaging, Duke University Medical Center, Durham, NC, United States

In this work, a multi-step adaptive fitting approach was developed for fat and iron quantification using multi-echo 3D GRE data, which accounts for various factors such as T2* decay, T1 bias, multi-peak fat modeling, and noise bias. Numeric phantoms were created and used to validate the results measured by this approach with the ground truth, and showed that this approach is relatively insensitive to different field strengths, field inhomogeneity, monopolar/bipolar readout, and TE selections. An in vivo patient study showed consistency between the FP results measured with the proposed approach and a spectroscopy-based method.

Jennifer Leigh Rehm¹, Peter Wolfgram¹, Ellen Lacon Connor¹, Wei Zha², David Allen¹, Diego Hernando³, and Scott B. Reeder^4
1Pediatrics, University of Wisconsin, Madison, WI, United States, ²Medical Physics, University of Wisconsin, Madison, WI, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States, ⁴Radiology, University of Wisconsin, Madison, WI, United States

Hepatic steatosis (HS) is a serious and growing problem in pediatrics. HS screening, including ultrasound or aminotransferases, are insensitive to early disease. In a diverse group of 132 adolescents, we demonstrate that proton density fat-fraction (PDFF) measured with quantitative MRI is a clinically relevant, non-invasive method for early detection and quantitative staging of hepatic steatosis. PDFF correlates with metabolic risk but BMI and ALT were not predictive of HS in overweight subjects. PDFF measured with quantitative MRI is a promising method for early identification of HS, allowing intervention prior to development of irreversible hepatic injury and progression of metabolic disease.

Houchun Harry Hu¹, Larry Yin², Thomas G. Perkins³, Jonathan M. Chia³, Patricia Aggabao¹, and Vicente Gilsanz^1
1Radiology, Children's Hospital Los Angeles, Los Angeles, California, United States, ²General Pediatrics, Children's Hospital Los Angeles, Los Angeles, California, United States, ³Philips Healthcare, Cleveland, Ohio, United States

This work compares brown adipose tissue (BAT) fat-signal fractions (FFs) and T₂* values in nine infants (1.5±1.8m) and eighteen teenagers (12.5±1.9y). The teenagers were further divided into two sub-groups based on body-mass-index (BMI). mDIXON water-fat MRI was used to quantify FFs and T₂* values in supraclavicular BAT depots on a 3T system. Infants had lower FFs than teenagers (36.0±8.2% vs. 68.7±12.2%, p<0.001), but T₂* values were similar (18.7±2.6 vs. 17.2±3.8ms, p=0.29). Overweight teenagers had higher FFs (76.5±8.2% vs. 60.9±10.6%, p=0.003) and T₂* values (19.0±4.2 vs. 15.3±2.1ms, p=0.031) than leaner subjects. FF and T₂* values correlated with BMI (p<0.01) in teenagers.

Rosa Tamara Branca^1,2, Christian White¹, and Le Zhang^3
1Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States, ²UNC at Chapel Hill, Biomedical Research Imaging Center, Chapel Hill, North Carolina, United States, ³Material Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States

The detection of brown fat by conventional imaging methods (MRI, CT, 18FDG-PET) presents several challenges. This is because BAT fat-fraction can range from 40- 85%, while its metabolic activity relies mainly on fatty acid combustion. Here we demonstrate detection of BAT by in vivo HP-Xenon MR experiments and compare this methodology to 18FDG-PET and proton MRI. We show the possibility to directly map brown fat depot in the body, determine its fat fraction, measure the increase in BAT temperature and fatty acid consumption in real time by HP Xenon gas MR.

Pippa Storey¹, Stephen Honig², David R. Stoffel¹, and Sandra L. Moore^1
1Radiology Department, New York University School of Medicine, New York, NY, United States, ²Division of Rheumatology, New York University School of Medicine, New York, NY, United States

Early malignant infiltration of bone marrow, characterized by small or diffuse lesions, is difficult to detect using routine sequences. We propose a multiple gradient echo technique to quantify trabecular loss (via R2*) and altered marrow fat content (via chemical shift). For validation purposes, the technique was tested in 6 patients with osteoporosis or osteopenia, using 8 healthy young men as controls. Both fat content and R2* differed significantly between patients and controls (p=0.04 and p=0.0003 respectively). Among patients, fat content and R2* exhibited significant correlations with bone mineral density evaluated by DXA (r=-0.89 with p=0.02, and r=0.88 with p=0.02 respectively).

Patrick J. Bolan¹, Luke Arentsen², Thanasak Sueblinvong³, Yan Zhang⁴, Steen Moeller¹, Jori Carter³, Levi S. Downs³, Rahel Ghebre³, Douglas Yee^4,5, Jerry Froelich¹, and Susanta K. Hui^4,6
1Radiology, University of Minnesota, Minneapolis, MN, United States, ²Medical Physics, University of Minnesota, Minneapolis, Minnesota, United States, ³Obstetrics and Gynecology, University of Minnesota, Minneapolis, MN, United States, ⁴Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, United States, ⁵Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States, ⁶Therapeutic Radiology, University of Minnesota, Minneapolis, Minnesota, United States

This work demonstrates the feasibility of rapidly acquiring high-resolution 3D signal fat fraction (sFF) maps from mid-femur to the L3 lumbar vertebra, and that the sFF can detect and characterize marrow composition changes induced by chemotherapy and radiation therapy. The marrow fat fraction is potentially an imaging biomarker of bone marrow health and may be useful in planning and monitoring treatment of cancer patients.

Benjamin Leporq¹, Arnaud Le Troter², Yann Le Fur², Emmanuelle Salort-Campana³, Patrick J. Cozzone², Olivier Beuf¹, and David Bendahan^2
1CREATIS; CNRS UMR 5220; INSERM U1044; INSA-Lyon; UCBL, Université de Lyon, Villeurbanne, Rhone-Alpes, France, ²CRMBM; CNRS UMR 6612, Aix-Marseille Université, Marseille, PACA, France,³Reference Center for Neuromuscular Disorders, Timone Hospital, Assistance Publique Hopitaux de Marseille, Marseille, PACA, France

Due to its sensitivity to key processes in the diseased muscle such oedema, inflammation and fatty infiltration, MRI is emerging as a suitable quantitative method which could provide reliable surrogate markers of disease severity and progression. This work investigates the feasibility of a method to distinguish IMAT and SCAT, (ii) to measure muscle relaxation times (T1 andT2*) and to quantify the infiltrated fatty tissue fraction (IFTF) simultaneously. Our approach includes a magnitude-based fat volume fraction quantification method based on multiple-echo multiple angle acquisition with a dedicated automatic segmentation algorithm.

Saurav Chandra¹, Nicole Londraville², Samuel Cadena², and Erica C. Henning^1
1Global Imaging Group, Novartis Institutes for Biomedical Research (NIBR), Cambridge, MA, United States, ²Musculoskeletal Disease Area, Novartis Institutes for Biomedical Research (NIBR), Cambridge, MA, United States

Neurodegeneration is largely a consequence of aging, injury, or disease (eg., amyotrophic lateral sclerosis). Severe neurodegeneration is associated with muscle atrophy, impaired functional capacity, and in some cases, death. In this study, combined T2 and IDEAL MRI permitted non-invasive identification of nerve injury prior to distal muscle inflammation and atrophy, and nerve repair prior to muscle regrowth. This is with high sensitivity and reliability, without contrast agent. These findings provide selection of key time points for target identification and profiling of nerve injury/repair and muscle atrophy/regrowth.