| Hepatic Storage Disease |
|
Tuesday 21 April 2009 |
| Room 316A |
10:30-12:30 |
Moderators: |
Hero K. Hussain and
Joachim Lotz |
|
|
| |
|
10:30 |
202. |
Simultaneous Estimation of
Water-T2 and Fat Fraction Using a Single Breath Hold
Radial GRASE Method |
|
|
|
Christian Graff1,
Zhiqiang Li2, Eric W. Clarkson2,
Chuan Huang3, Ali Bilgin4,
Maria I. Altbach2
1Program in Applied Mathematics, University of
Arizona, Tucson, AZ, USA; 2Department of
Radiology, University of Arizona, Tucson, AZ, USA;
3Department of Mathematics, University of
Arizona, Tucson, AZ, USA; 4Department of
Electrical and Computer Engineering, University of
Arizona, Tucson, AZ, USA |
|
|
|
A new algorithm for
processing radial GRASE data has been developed.
With this algorithm one obtains both fat-water
information and T2 of the water component within a
breath hold. This novel method is fast and should
provide valuable information for the
characterization of pathologies in the clinic. |
|
|
|
|
|
10:42 |
203. |
Breath-Hold FSE for Accurate
Imaging of Myocardial and Hepatic R2 |
|
|
|
Daniel Kim1,
Jens H. Jensen1, Ed X. Wu2,
Sujit S. Sheth3, Gary M. Brittenham3
1Center for Biomedical Imaging and Radiology,
NYU Langone Medical Center, New York, NY, USA;
2Electrical and Electronic Engineering, The
University of Hong Kong, Pokfulam, Hong Kong; 3Pediatrics
and Medicine, Columbia University College of
Physicians and Surgeons, New York, NY, USA |
|
|
|
MRI provides a means to
non-invasively assess tissue iron concentration by
exploiting the paramagnetic effects of iron on T2 or
T2*. The most widely used method is T2* imaging is
sensitive to non-iron related magnetic field (B0)
inhomogeneities, which can confound T2* measurements
within the whole heart and liver. An alternative
method is T2 imaging, but they are generally
performed during free breathing with respiratory
gating due to their low data acquisition efficiency.
The purpose of this study was to develop a
breath-hold fast spin echo (FSE) sequence for fast
and accurate imaging of myocardial and hepatic T2. |
|
|
|
|
|
10:54 |
204. |
Hepatic Fat Quantification in Children Using
Multi-Echo Gradient-Echo Imaging and Fat Spectral
Modeling at 1.5 T |
|
|
|
Masoud Shiehmorteza1,
Takeshi Yokoo1, Gavin Hamilton1,
Mark Bydder1, Manuel Rodriguez1,
Joel E. Lavine2, Jeffrey B. Schwimmer2,
Claude B. Sirlin1
1Radiology, University of California San
Diego, San Diego, CA, USA; 2Pediatrics,
University of California San Diego, San Diego, CA,
USA |
|
|
|
Fatty liver disease is
currently the most common cause of liver disease in
children (12-17% prevalence). Although MR imaging
has been applied to children previously, the
accuracy of fat quantification has not been
verified. Confirming that MR imaging is accurate in
children is necessary because they may not be able
or willing to cooperate with MR examinations. Also,
the histological features of pediatric FLD differ
from those of adult FLD, and generalization of adult
study’s data may not be valid. In this dedicated
pediatric study, we assessed fat estimation accuracy
of MR imaging, using single-voxel MR spectroscopy as
the reference. |
|
|
|
|
|
11:06 |
205. |
Correlation of T1 and T2*
Corrected Dual-Echo MRI Vs. MRS for Hepatic Fat
Determination in a Multicenter Clinical Trial:
Results of the Phase II Study of the MTP Inhibitor
AEGR-733 |
|
|
|
Mark Rosen1, Sarah Englander1,
Harish Poptani1, Evan Siegelman1,
James Gimpel2, Dena Flamini2,
Matthew Parris3, Bill Sasiela3,
Bruce Hillman4
1Radiology, University of Pennsylvania,
Philadelphia, PA, USA; 2American College
of Radiology Imaging Network, Philadelphia, PA, USA;
3Aegerion, Inc., Bridgewater, NJ, USA;
4Radiology, University of Virginia,
Charlottesville, VA, USA |
|
|
|
A multisite trial of the
MTP inhibitor AEGR-733 using hepatic MRI/MRS for
liver fat determination was performed. Both single
voxel (SV) MRS and multiple dual-echo gradient echo
MRI data were used to quantify hepatic fat. A total
of 1160 exams with evaluable MRI and MRS data sets
were obtained. Correlation of hepatic fat by SV-MRS
and several dual-echo MRI methods ranged from
0.870-0.890 for all data sets, 0.935-0.942 for
protocol compliant MRI data, and 0.949-0.955
high-quality MRS data. Dual-echo MRI with correction
for T1 and T2* effects outperformed other methods,
with lower mean squared variation and fewer outlying
data points. |
|
|
|
|
|
11:18 |
206. |
Quantification of Abdominal
Fat Accumulation During Hyperalimentation Using MRI |
| |
|
Olof Dahlqvist
Leinhard1,2, Andreas Johansson1,
Joakim Rydell1, Johan Kihlberg2,
Örjan Smedby1,2, Fredrik H. Nyström1,
Peter Lundberg1,2, Magnus Borga1,2
1Linköping University, Linköping, Sweden;
2Center for Medical Image Science and
Visualization (CMIV), Linköping University,
Linköping, Sweden |
|
|
|
The abdominal fat
content was quantified using in- and out-of-phase
imaging after phase sensitive reconstruction and an
initial intensity correction procedure.
Classification of all tissue as subcutaneous,
intraabdominal or retroperitoneal was performed
using a novel completely automatic segmentation
procedure. This technique was used to determine
intraabdominal fat before and after a two-fold
increase in daily caloric intake. A significantly
lower increase of intraabdominal fat tissue was
observed in women than in men. The study highlighted
the suitability of MR for accurate and user
independent investigation of the
compartmentalization of fat deposits in the body. |
|
|
|
|
|
11:30 |
207. |
Validation of Chemical Shift
Based Fat-Fraction Imaging with MR Spectroscopy |
|
|
|
Sina Meisamy1,
Catherine DG Hines1,2, Gavin Hamilton3,
Karl Vigen1, Jean H. Brittain4,
Charles A. McKenzie5, Huanzhou Yu6,
Scott K. Nagle1, Yu Grace Zeng1,
Claude B. Sirlin3, Scott B. Reeder1,2
1Radiology, University of Wisconsin, Madison,
WI, USA; 2Biomedical Engineering,
University of Wisconsin, Madison, WI, USA; 3Liver
Imaging Group, Department of Radiology, University
of California, San Diego, CA, USA; 4Applied
Science Laboratory, GE Healthcare, Madison, WI, USA;
5Medical Biophysics, University of
Western Ontario, London, Ontario, Canada; 6Applied
Science Laboratory, GE Healthcare, Menlo Park, CA,
USA |
|
|
|
Nonalcoholic
steatohepatitis is a form of liver disease, which
affects nearly 30% of the US population and 75% of
obese individuals. 1H-MRS is regarded by many as the
non-invasive gold standard for quantification of
hepatic steatosis. In this study we compare a
chemical shift based fat-fraction imaging method
(IDEAL) of the liver with 1H-MRS for quantification
of hepatic steatosis. The results of our study show
that overall, there is excellent correlation between
IDEAL and MR spectroscopy with the highest
correlation and excellent one-one agreement seen
when both T2* correction and accurate spectral
modeling of fat is applied. |
|
|
|
|
|
11:42 |
208. |
A Dynamic Study of Changes in
Hepatic and Skeletal Muscle Lipid and Glycogen
Levels, Due to 24h Starvation and Re-Feeding: A
1H and 13C MRS Study |
|
|
|
Mary Charlotte
Stephenson1, Sherif Awad2,
Elisa Placidi1, Luca Marciani2,
Kenneth C. H. Fearon3, Ian A. Macdonald4,
Robin C. Spiller2, Penny A. Gowland1,
Peter Gordon Morris1, Dileep N. Lobo2
1SPMMRC, School of Physics and Astronomy,
University of Nottingham, Nottingham, UK; 2Nottingham
Digestive Diseases Centre Biomedical Research Unit,
University of Nottingham, Nottingham, UK; 3Department
of Surgery, University of Edinburgh, Ednburgh, UK;
4School of Biomedical Sciences,,
University of Nottingham, Nottingham,
Nottinghamshire, UK |
|
|
|
Short-term starvation
has been shown to induce insulin resistance in
hepatic and skeletal muscle tissue although the
metabolic processes involved are unknown. The aim of
this study was to measure changes in hepatic and
skeletal muscle glycogen and lipid content in order
to understand substrate metabolism leading to an
insulin resistant state following short-term
starvation and re-feeding using a carbohydrate rich
drink. Short-term starvation induced decreases in
hepatic liver glycogen and lipid stores, with
associated decreases in liver volume. Lipid levels
in calf muscle increased due to starvation which may
be the mechanism via which tissue becomes insulin
resistant. |
| |
|
|
|
11:54 |
209. |
Spectrally-Modeled Hepatic Fat Quantification by
Multi-Echo Gradient-Recalled-Echo Magnetic Resonance
Imaging at 3.0T |
| |
|
Takeshi Yokoo1,
Masoud Shiehmorteza1, Mark Bydder1,
Gavin Hamilton1, Yuko Kono2,
Alexander Kuo2, Joel E. Lavine3,
Claude B. Sirlin1
1Radiology, UCSD, San Diego, CA, USA; 2Medicine,
UCSD, San Diego, CA, USA; 3Pediatrics,
UCSD, San Diego, CA, USA |
| |
|
Several groups recently
suggested that accurate fat quantification by MR
requires correction of the relaxation effects as
well as modeling of multi-component fat signal.
Using non-T1-weighted multi-echo GRE imaging and
3-peak fat spectral modeling, high fat estimation
accuracy was demonstrated at 1.5 T in fatty liver
patients. In principle, this general approach would
be independent of the field strength and therefore
is also applicable at 3.0 T. In this first human
study on spectrally-modeled hepatic fat
quantification at 3.0 T, we assessed fat estimation
accuracy of MR imaging using MR spectroscopy as the
reference standard. |
| |
|
|
|
12:06 |
210. |
Identification of Brown
Adipose Tissue in Mice Using IDEAL Fat-Water MRI |
| |
|
Houchun Harry
Hu1, Daniel L. Smith, Jr. 2,
Tim R. Nagy2, Michael I. Goran3,
Krishna S. Nayak1
1Ming Hsieh Department
of Electrical Engineering, University of Southern
California, Los Angeles, CA, USA; 2Department
of Nutritional Sciences, University of Alabama,
Birmingham, AL, USA; 3Department of
Preventive Medicine, University of Southern
California, Los Angeles, CA, USA |
|
|
|
The fat-signal fraction
derived from IDEAL-MRI is used to discriminate white
(WAT) and brown adipose tissue (BAT) depots in mice.
We found in both excised tissue samples and in
vivo that WAT has a fat-signal fraction range of
90-93%. In contrast, BAT exhibits a much wider and
significantly lower range of 39-62%. Analysis from
high-resolution (0.6 mm isotropic) 3T results in
whole juvenile and adult mice clearly identified BAT
in the interscapular region, as well as perirenal
and intercostal sites. We thus conclude that BAT can
be non-invasively identified based on MRI
measurements of IDEAL fat-signal fraction. |
|
|
|
|
|
12:18 |
211. |
On the Definition of
Fat-Fraction for in Vivo Fat Quantification with
Magnetic Resonance Imaging |
|
|
|
Scott B. Reeder1,2, Catherine DG Hines1,3,
Huanzhou Yu4, Charles A. McKenzie5,
Jean H. Brittain6
1Radiology, University of Wisconsin, Madison,
WI, USA; 2Medical Physics, University of
Wisconsin, Madison, WI, USA; 3Biomedical
Engineering, University of Wisconsin, Madison, WI,
USA; 4Applied Science Laboratory, GE
Healthcare, Menlo Park, CA, USA; 5Medical
Biophysics, University of Western Ontario, London,
Ontario, Canada; 6Applied Science
Laboratory, GE Healthcare, Madison, WI, USA |
|
|
|
The most commonly used
metric for fat quantification with MRI is
“fat-signal-fraction”. After correction for
confounding factors (eg. T2*-decay, etc)
fat-signal-fraction is synonymous with
fat-proton-density-fraction. Unfortunately, gold
standard assays used to validate MRI provide
estimates of fat-volume-fraction or
fat-mass-fraction. The purpose of this work is to
clarify fat-fraction definitions, and to estimate
fat-volume-fraction and fat-mass-fraction from
separated fat/water signals. Theory and experiment
demonstrate that for fat, signal-fraction is
equivalent to volume-fraction and mass-fraction. The
same is not true, however, for other combinations of
chemical species such as acetone and water, which
require correction factors to determine volume or
mass fraction. |
|
|
|
|
|