absolute quantification of in vivo water and fat content · square estimati between the cau n is...
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1Phy3Biome
Introdskeletadevelowater AsymmallowsreductmeasuabdomlimitinincapaHu et Imagebe usephantoassumcorrecphasedmeasuLockeuniforfat-wathe B1water-Metho40.0%IDEAL28cm,abovevalidadensit
Fowere cand bo1.8, 2.thicknResultphantoexcellthe dadensityto be 00.78 gDiscuallow B1 mato comquantiexperiacceleConclof absAcknothe CanRefere2007;5ISMRM50: 209
ysics and Astronomedical Engineering
duction: Obesityal muscles, and oping non-invasiand fat) in undemetry and Leasts differentiation tion in fat fractiourement in vitro;men where volumng image resolutable of measurinal. to in vivo quae Reconstructioed to produce fatom in FOV durin
ming the B1+ (tran
cted for B1+ and B
d array. 2) B1- (c
ured [5]. 4) Pixeler technique [6]. rm sensitivity SNater separated im1+ map from step-only and fat-onlods: Phantoms u
%, 100% volume L sequence [3,8, BW=±142.86kH, producing imag
ated by comparinies of the phanto
ollowing REB apcollected from thody coil. For bot.2, 2.6, 3.0] ms, ness=6 mm, flip ts: Figure 1 comom to the knownent agreement an
ata. Figure 2 demy in the calf. Th0.80 ± 0.08 g/mLg/mL[9]. ssion: Here we hthe use of phase
apping method fmpensate the inhification of abdoiments allow phaerate imaging is plusion: As long olute in vivo fat
owledgments: We nada Research Chaences: [1] Radiol58:354-364 [4] NM 2010: 2837 [7] 91–2103
Yifan Cui1, Issmy, University of Wg, University of We
y is an increasinorgans and is relive methods of arlying tissues act square estimatibetween the cau
on is due to decr however, their w
me coil acquisitiotion and volumetng the 3D B1
+ disantification of fa
on: T1 independt-only and water ng the measuremnsmit) and B1
- (rB1
- inhomogenecoil sensitivity) ml by pixel B1
+ tra5) The noise cov
NR optimal methmages that were c
p 4 [4]. 8) Finallly images produused in this expefraction of fat). ]. Images were aHz, slice thickneges with intensit
ng the calculatedoms. pproval and obtahe calf of a healtth images parammatrix 128×64, angle =3º.
mpares the calibrn water fat massend validates the
monstrates the use proton densityL, which is cons
have improved eed array imagingfast enough to beomogeneous B1
ominal or thoraciased array data apossible and wilas the relevant cand water contegratefully acknowairs program. logy 2011;258:767
Neuroimage 2008;MRM 1990;16, 1
Absolute Qsac Y. Yang2, TrevWestern Ontario, Lestern Ontario, Lo
gly severe healthlated to increaseassessing the distcross the full imaon) [1]. Howeve
uses of changes ieased fat or an inwork was limiteon will limit SNRtric coverage. Fustribution in a brat in humans usindent, T2* correct
only images whment allows calibreceive) fields caity we followed maps were generansmit flip anglevariance and B1
-
hod [7]. 6) The Bcorrected for T2
*
ly, the pure wateced in step 7 and
eriment are madePhantoms were
acquired with aness=5mm, flip anty units of proton
d proton density m
aining informed thy volunteer, us
meters are as folloFOV=36×18cm
rated water/fat mes. A linear fit toaccuracy of the e of this method
y of an ROI in thistent with value
existing absoluteg and demonstrate used for breath transit field, thu
ic water and fat cacquisitions, appll be investigatedcorrections are coent can be achievwledge support from
7-775. [2] JMRI ;41:706-717 [5] M92-225 [8]JMRI 2
uantification vor Wade2, Curtis London, Ontario, Condon, Ontario, Ca
Ontario, Lo
h issue in westerd risk of cardiovtribution of fat inaging volume haer, knowing the ain fat fraction. Foncrease in waterd to volume coilR and preclude turthermore, Hu ereath hold compang multichannelted chemical shihere signal intenbration of the sigan be measured. the following pr
rated using the Se maps (CB1) wer- measurements
B1- corrected coil
* variations. 7) Ter phantom (whid convert the sige with different cimaged at 3.0T
n 8 coil head arrangle =3°. The IDn density. The camaps to the know
consent, in vivosing an 8 coil abdows: TR=5.1ms,
m, BW=±62.50 kH
masses from ROIo these data demcorrection facto
d in vivo for imae calf muscle waes reported in the
e fat quantificatioted its use in viv
h hold applicationus making possibcontent. Since th
plication of parald in the future. onsidered, precisved. m GE Healthcare,
2008;28(6):1483-MRM 1999;42:952011;33:873-881.
of In Vivo WaN. Wiens1, Abraam
Canada, 2Medical anada, 4Imaging Rondon, Ontario, Ca
rn society. It cauvascular, endocrin the body. Accu
as been demonstrabsolute (insteador example, knor content due to el data acquisitionthe use of parallet al. used a timeatible acquisitionl coil data acquisft based fat-watesity is proportiongnal intensity so To acquire all throcedure: 1) Dat
SENSE method [re obtained overwere used to coml combined IDEAhe T2
* correctedch has a known
gnal intensities inconcentrations o(Discovery MR
ay: TR=8.2ms, TDEAL images wealibration was wn proton
IDEAL data dominal array , TE=[1.0, 1.4, Hz, slice
s in each monstrates ors applied to ging proton as determined e literature of
on methods to vo. Crucially, a ns is employed ble hese llel MRI to
se estimation
NSERC, and
-1491 [3] MRM 52-962 [6] Proc [9] J Clin Invest;
Figure 1: The watcorrelated with th
Figure 2: In vivo ithe calves is a peaand water imagesimages, particularmeasured in the R
ater and Fat Cm S. Soliman3,4, anBiophysics, Unive
Research Laboratoanada
uses increased adine and metabolurate measuremrated with IDEAd of relative) fat owing absolute faedema. Hu et al.n. This restricts el imaging methe consuming men. In this work, wsition and rapid Ber separation menal to proton denit can be conver
he data necessaryta suitable for ID[5]. 3) Noise covr the volume imambine IDEAL dAL data were re
d IDEAL imagesproton density)
nto units of protoof peanut oil and R 750, GE HealthTE=[1.2, 2.2, 3.1ere corrected for
ter and fat IDEALhe known water/fat
images of a voluntanut oil proton dens are noticeably morly at the periphery
ROI shown in the c
Content nd Charles A. McKersity of Western Oories, Robarts Rese
dipose tissue vollic diseases. Theent of the fat fra
AL (Iterative Decand water conte
fat and water con. [2] demonstrateits utility in hum
hods to accelerateasurement of thwe will demonstB1
+ measuremenethods with accunsity [3]. Placinrted to absolute pry to produce fat-DEAL fat-water variance among aged in step 1 usdata from the phaeconstructed withs were corrected was used to calion density [4]. water (0%, 2.5%
hcare, Waukesha1, 4.1, 5.0, 6.0] mr B1+ and B1- in
L signal corrected tt mass of the phan
teer’s calves. (Thensity reference.) Thore uniform than thy. The mean valuecalf was 0.80 ± 0.0
Kenzie1,2 Ontario, London, Oearch Institute, Un
lume as well as fre is considerabl
action (fat contencomposition withent is valuable inntent allows deteed absolute fat c
man imaging, parte data acquisitioe transmit B1
+ fitrate an extensiont. urate spectral mong a pure water oproton concentra-water separatedseparation werethe coils in the a
sing the double aased array using h T2
* IDEAL mefor flip angle va
ibrate the signal
%, 5.0%, 10.0%,a, WI) using a mms, matrix 128×nhomogeneity as
to units of mass ntoms.
e object between he corrected fat he uncorrected e of water density 08g/mL.
Ontario, Canada, niversity of Wester
fat content in le interest in nt relative to totah Echo n many cases as ermination if a content rticularly in the on, thus severelyield that is on of the work of
odeling of fat canor fat reference ation [2,4], d images acquired using array was angle Look-
Roemer’s ethod to produceariations using intensities of th
, 20.0%, 30.0%, multi-peak T2*
128, FOV=28 × s described
rn
al
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y
f
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363Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)