Time-interleaved parallel i maging approach to separation ...
1
1 Global Ap Introduction has been dem imaging of th differences b [4,5]. But this time-interleav temporal pha band excitatio phase. Theory: If N that the slices propose to ac using parallel employed. Fo acceleration f so that the ind 1 and 2. f 1 an of the slices. For the tGR 2, 4, 6, … as Where S 1 and direction. The tGRAPPA. Method: Pha channel head excited. In ea implemented along the wav Results and results for the seen, the slice to shorten ech In case of a throughout th out sampling tGRAPPA me References: 5(12), 2010 ( (7) Beatty P.J Figure 1 Time-interlea Suchandrima pplied Science Lab n: Simultaneous ex monstrated in impr he whole head [2,3 etween these slice s involves addition ved approaches su se, and calibration on scheme that tra N slices are excited s can be separated cquire data with on l imaging principl or the sake of sim factor R=2. The ex dividual coil imag d f 2 can be written In a matrix form RAPPA analogy w block 2, and their d the ρ 1 represent t e similarity betwe antom and in vivo d array (Nova Me ach scan, 12 time . Once the data co veform direction. Discussion: Figur e same 3 slices exc es have been unal ho-train length. By time series acquis he scan for a more pattern is employ ethods. (1) Breuer F et a (4) M. Blaimer et J, ISMRM 2007 #1 aved parallel i a Banerjee 1 , Yuval b, GE Healthcare, Science Lab xcitation of multip roving the tempor 3]. Slices that are e e locations and cal nal prescan, and m ch as tGRAPPA h n data is collected anslates to a simila simultaneously w d by some linear co nly one of these N les. Calibration da mplicity, let us xcitation scheme is es obtained from t n as S 1 · ρ 1 and S 2 ⋅ρ 2 with acceleration R corresponding im the coil sensitivity en [1a] and [1b] s o experiments wer edical, USA) on a e frames were acq orresponding to al re 2a) shows thre cited by the 3 band iased completely. y using this time-i sition such as func robust reconstruct ed for all tempora al, MRM 53: 684- al, JMRI 24, 444 1749 imaging appro Zur 2 , Atsushi Tak Menlo Park, Calif b, GE Healthcare, ple slices helps red ral resolution of ec excited simultaneo libration data can matching of the slic have been proposed from neighboring ar reconstruction p with N different exc ombination of the excitation wavefo ata is collected fro discuss the case o s shown in Figure these 2 waveforms 2 where S 1 , S 2 are t ൬ ଵ ଶ ଵ െ ଶ ൰ R = 2, if we denote ages as B1 and B2 ൬ ଵ ଶ ଵ െ ଶ ൰ and the “ideal” im hows that k space re conducted usin a GE 3.0 T MR75 quired. Slice t-AR ll the waveforms e slices that were d RF pulse, for the This technique ca interleaved approa ctional MRI, there tion and to improv l phases, the propo -691, 2005 (2) M (2006) (5) Setsom Figure oach to separa kahashi 1 , Ajit Shan fornia, United Sta San Francisco, C duce the time need cho-planar functio ously by a multi-b be acquired from ce prescription to s d for multi-phase s g k-space lines of n problem, even thou citations, the phase N signals, for ex. orms, and to synthe om the previous N of two slice excit 1. The phase of th s are I 1 = f 1 + f 2 an the coil sensitivitie ቀ ߩଵ ߩଶ ቁൌ ൬ ܫଵ ܫଶ ൰ e the set of odd k 2 respectively, an e ቀ ߩଵ ߩଶ ቁൌ ൬ ܤଵ ܤଶ ൰ mage respectively, e data of I 1 and I 2 ng an echo-planar 50 scanner (Wauk C, a time-interlea were synthesized, excited separately e 9 th time frame. Ca an be combined wi ach, slices are co-l e is also the flexib ve the calibration d osed method shou Moeller S et al, MR mpop K et al, MRM b) a) e 2 ation of simult nkaranarayanan 1 , a tes, 2 GE Healthca California, United S ded to acquire a fix onal MRI and for band excitation can a separate acquis slice locations exc scans where differ neighboring phase ugh the same sam e of each slice can . Fourier transform esize the rest N-1 N phases in each o tation only and co he second slice is i nd I 2 = f 1 – f 2 respe es at slice location ሾ1ሿ k-space lines 1, 3, equation similar to ሾ1ሿ S 2 and ρ 2 are S 1 a can also be arrang sequence incorpo kesha, WI). Three aved parallel imag , slices were sepa y by a single-ban alibration data wa ith in-plane accele localized between ibility of re-estima data by averaging uld be more robust RM 63: 1144-115 M 0?1-15,2011 (6 taneously exci and Douglas A.C. are, Tirat Carmel, I States xed number of slic reducing scan tim n be unaliased by sition where each cited by the multib rent sampling patte es [6]. In this work mpling pattern is em n be incremented a m (FT) or inverse waveform dataset of which a differen ompare it to conv inverted by the sec ectively, where f 1 a ns 1 and 2, and ρ 1 , 5, … as block 1 o [1a] can be writte and ρ 1 shifted by F ged in a block for orated with multib e slices 30 mm ap ging reconstruction arated in image sp nd RF pulse. Figur as collated from the eration to further r calibration and th ating the reconstru previous time fram to EPI phase erro 3, 2009 (3) Feinb 6) F. Breuer et al, M ited slices Kelley 3 Israel, 3 Global Ap ces [1]. Recently it me for diffusion sp exploiting coil sen slice is excited sep band RF pulse. Pre erns are employed k we will present mployed in each te across the excitatio Hadamard transfo ts from the first wa nt excitation wave ventional tGRAPP cond waveform (F and f 2 are images o , ρ 2 are the “ideal” and the set of ev en OV/2 in the phase rm and reconstruct band RF pulse, wi part were simulta n based on ARC pace by Fourier tra re 2b) shows slice e first 3 phases. A reduce acquisition he accelerated acqu uction kernel peri mes. Since the sam rs compared to tra berg D.A. et al, Pl MRM 53, 981-985 pplied ts utility pectrum nsitivity parately eviously d in each a multi- emporal ons such orm. We aveform eform is PA with Figure 1) of slices ” images ven lines e encode ted as in ith a 32 aneously [7] was ansform e t-ARC s can be n time or uisition. odically me read- aditional los One, 5 (2005) 2227 Proc. Intl. Soc. Mag. Reson. Med. 20 (2012)
Transcript of Time-interleaved parallel i maging approach to separation ...
1Global Ap
Introductionhas been demimaging of thdifferences b[45] But thistime-interleavtemporal phaband excitatiophase
Theory If Nthat the slicespropose to acusing parallelemployed Foacceleration fso that the ind1 and 2 f1 anof the slices
For the tGR2 4 6 hellip as
Where S1 anddirection ThetGRAPPA
Method Phachannel headexcited In eaimplementedalong the wav
Results and results for theseen the sliceto shorten echIn case of a throughout thout sampling tGRAPPA me
References 5(12) 2010 ((7) Beatty PJ
Figure 1
Time-interleaSuchandrima
pplied Science Lab
n Simultaneous exmonstrated in imprhe whole head [23etween these slices involves additionved approaches suse and calibrationon scheme that tra
N slices are excited s can be separatedcquire data with onl imaging principlor the sake of simfactor R=2 The exdividual coil imagd f2 can be writtenIn a matrix form
RAPPA analogy wblock 2 and their
d the ρ1 represent te similarity betwe
antom and in vivod array (Nova Meach scan 12 time Once the data coveform direction
Discussion Figure same 3 slices exces have been unalho-train length Bytime series acquis
he scan for a more pattern is employethods
(1) Breuer F et a(4) M Blaimer et J ISMRM 2007 1
aved parallel ia Banerjee1 Yuvalb GE Healthcare
Science Lab
xcitation of multiproving the tempor3] Slices that are ee locations and calnal prescan and mch as tGRAPPA h
n data is collected anslates to a simila
simultaneously wd by some linear conly one of these N les Calibration damplicity let us xcitation scheme ises obtained from t
n as S1 ρ1and S2sdotρ2
with acceleration Rcorresponding im
the coil sensitivity en [1a] and [1b] s
o experiments weredical USA) on ae frames were acqorresponding to al
re 2a) shows threcited by the 3 bandiased completely y using this time-isition such as funcrobust reconstructed for all tempora
al MRM 53 684-al JMRI 24 444 1749
imaging appro Zur2 Atsushi TakMenlo Park Califb GE Healthcare
ple slices helps redral resolution of ecexcited simultaneolibration data can
matching of the slichave been proposed
from neighboringar reconstruction p
with N different excombination of theexcitation wavefo
ata is collected frodiscuss the case os shown in Figure these 2 waveforms2 where S1 S2 are t
R = 2 if we denoteages as B1 and B2
and the ldquoidealrdquo imhows that k space
re conducted usina GE 30 T MR75quired Slice t-ARll the waveforms
e slices that were d RF pulse for theThis technique ca
interleaved approactional MRI theretion and to improvl phases the propo
-691 2005 (2) M(2006) (5) Setsom
Figure
oach to separakahashi1 Ajit Shanfornia United Sta San Francisco C
duce the time needcho-planar functioously by a multi-bbe acquired from
ce prescription to sd for multi-phase s
g k-space lines of nproblem even thou
citations the phaseN signals for ex
orms and to syntheom the previous Nof two slice excit1 The phase of th
s are I1 = f1 + f2 anthe coil sensitivitie
e the set of odd k2 respectively an e mage respectively e data of I1 and I2
ng an echo-planar 50 scanner (WaukC a time-interleawere synthesized
excited separatelye 9th time frame Caan be combined wiach slices are co-le is also the flexibve the calibration dosed method shou
Moeller S et al MRmpop K et al MRM
b)
a)
e 2
ation of simultnkaranarayanan1 ates 2GE Healthca
California United S
ded to acquire a fixonal MRI and for band excitation can
a separate acquisslice locations excscans where differneighboring phaseugh the same sam
e of each slice can Fourier transformesize the rest N-1
N phases in each otation only and cohe second slice is ind I2 = f1 ndash f2 respees at slice location
1
k-space lines 1 3 equation similar to 1
S2 and ρ2 are S1 acan also be arrang
sequence incorpokesha WI) Threeaved parallel imag slices were sepa
y by a single-banalibration data waith in-plane accelelocalized between ibility of re-estimadata by averaging
uld be more robust
RM 63 1144-115M 01-152011 (6
taneously exciand Douglas AC are Tirat Carmel IStates
xed number of slicreducing scan tim
n be unaliased by sition where each cited by the multibrent sampling pattees [6] In this work
mpling pattern is em
n be incremented am (FT) or inverse waveform dataset
of which a differenompare it to convinverted by the secectively where f1 ans 1 and 2 and ρ1
5 hellip as block 1 o [1a] can be writte
and ρ1 shifted by Fged in a block for
orated with multibe slices 30 mm apging reconstructionarated in image sp
nd RF pulse Figuras collated from theeration to further rcalibration and th
ating the reconstruprevious time framto EPI phase erro
3 2009 (3) Feinb6) F Breuer et al M
ited slices Kelley3 Israel 3Global Ap
ces [1] Recently itme for diffusion spexploiting coil senslice is excited sepband RF pulse Preerns are employedk we will present mployed in each te
across the excitatioHadamard transfo
ts from the first want excitation waveventional tGRAPPcond waveform (Fand f2 are images o ρ2 are the ldquoidealrdquo
and the set of even
OV2 in the phaserm and reconstruct
band RF pulse wipart were simultan based on ARC
pace by Fourier tra
re 2b) shows slicee first 3 phases Areduce acquisitionhe accelerated acquuction kernel perimes Since the samrs compared to tra
berg DA et al PlMRM 53 981-985
pplied
ts utility pectrum nsitivity parately eviously d in each a multi-emporal
ons such orm We aveform eform is PA with Figure 1) of slices rdquo images
ven lines
e encode ted as in
ith a 32 aneously [7] was ansform
e t-ARC s can be
n time or uisition odically
me read-aditional
los One 5 (2005)
2227Proc Intl Soc Mag Reson Med 20 (2012)
