low-b DWI IVIM,MSDE -- -- Makoto Obara Philips Electronics Japan
Bfactor
IVIM: Diffusion & Perfusion MSDE: Black Blood imaging
IVIM: Diffusion & Perfusion MSDE: Black Blood imaging
40 2.5 * 10-3 mm 2 /sec 1 2.5 * 10-3 mm 2 Denis Le Bihan, Radiology 1998; 168:497-505
40 2.5 * 10-3 mm 2 /sec
90-180 RF Gz G δ Acquisition
90-180 RF Gz G δ Acquisition Diffusion time
Diffusion time( ): 50 100ms
Diffusion time( ): 50 100ms 2.5 * 10-3 mm 2 /sec x <x 2 >=2D*
Diffusion time( ): 50 100ms 2.5 * 10-3 mm 2 /sec x x = 16-22μm <x 2 >=2D*
Diffusion time( ): 50 100ms 2.5 * 10-3 mm 2 /sec x x = 16-22μm 10 m <x 2 >=2D*
(40 D = 2.5 *10-3 [mm 2 /sec]
(40 D = 2.5 *10-3 [mm 2 /sec] ADC = 0.5 1.5 *10-3 [mm 2 /sec] ADC
Kurtosis Diffusion Kurtosis Imaging (DKI)
S = exp (-bd) JMRI 31:589 600 (2010)
S = exp (-bd) (D=0.9) (D=1.5)
S = exp (-bd) Bfactor
b=700 b=1000 b=2000 Bfactor
noise B 500-2000
noise
S = exp (-bd) Log(S) = -bd Log
B-200 Low B
D* = 10 D = 0.71 10
Perfusion model Denis Le Bihan, Radiology 1998; 168:497-505 Perfusion Pseudo Diffusion D* Low B (<200)
Diffusion S diffusion =exp(-bd) Perfusion S perfusion =exp(-bd*)
Perfusion Volume < 5% Diffusion f: perfusion fraction S = (1-f) exp(-bd) + f exp(-bd*)
S = (1-f) exp(-bd) + f exp(-bd*) Perfusion f = 0.047 D* = 8.4 D = 0.71 Perfusion f = 0.22 D* = 57 D = 0.71
:
:
:
S = Sss exp (-bd) exp(-te/t2) T1 D T2
S = Sss exp (-bd) exp(-te/t2) IVIM T1,T2 T1,T2 T1,T2
D* D* SD
D* Low B
f & D Perfusion Diffusion D f Perfusion / (Diffusion Perfusion D*
f & D
f & D D(4):0.767 D(2):0.765
B B=600 D = 0.767 B=1000 D=0.714 B D
B B=600 B=1000 B 600 Slow diffusion
B B=600 B=1000 B=600 Slow diffusion B=1000
B: TR: TE: Matrix: high B nsa: Scan time: Parameter: 0, 200, 600 5000 57 128*128 *1 45sec f, D 0-1000 (8points*) 5000 65 128*128 *1 2min f, D*, D 8points: 0, 25, 50, 75, 100, 250, 500, 1000 0-1000 (8points*) 5000 65 128*128 *2 2min45sec f, D*, D
IVIM: Diffusion & Perfusion MSDE: Black Blood imaging
MSDE: Motion Sensitized Driven Equilibrium
μm/sec 10μm/sec B=500-2000 B<200 cm/sec B=3-20
Low B で反応する組織 90 180 RF G RF 90-180 EPI Acquisition EPI Acquisition Low-b (b=8) Black Blood imaging Basic Diffusion Sequence Courtesy: Kurashiki Central Hospital
Sequence design Concept 90 180 RF G RF 90 180 EPI Acquisition EPI Acquisition Low-b (b=8) Black Blood imaging Basic Diffusion Sequence 90-180 -90 RF Gz S* Acquisition (3D, TSE, TFE) MSDE (Diffusion Prepulse)
MSDE: Motion Sensitized Driven Equilibrium Initially called Diffusion Prepulse RF Gz 90 180-90 S* True FISP (bffe) High image quality Fast imaging 3D imaging Proc. Intl. Soc. Mag. Reson. Med. 14 (2006) 651 Proc. Intl. Soc. Mag. Reson. Med. 14 (2006) 652
MSDE flow suppression theory 90 180-90 Static spin Moving spin v φ = 0 φ = γm 1 v
MSDE flow suppression theory Laminar flow v Phase dispersion within a voxel Velocity gradient cause phase dispersion and voxel signal is reduced as same as IVIM theory.
MSDE vs Conventional (DIR) BB Conventional MSDE Through plane flow Volume Acquisition Conventional MSDE in plane flow Magnetic Resonance in Medicine 58:973 981 (2007) Conventional MSDE Post CE acquisition 55
imsde: improved MSDE Combined MLEV T2Prep & bipolar gradients concept Wider applications: larger FOV, 3.0T 90 180-90 RF G MSDE 90 180-180 -90 imsde
MSDE: Motion Sensitized Driven Equilibrium Improved MSDE (imsde) 90 180 180-90 90 180-90 RF G MSDE imsde imsde Jinnan Wang
imsde: improved MSDE 90 180-90 RF G MSDE 90 180 180-90 imsde JOURNAL OF MAGNETIC RESONANCE IMAGING 31:1256 1263 (2010)
imsde: improved MSDE 90 180-90 RF G MSDE 90 180 180-90 imsde
Many Applications thanks to imsde International Publication List (Japan Only) Obara M (Philips), ISMRM 2008 Obara M (Philips), ISMRM 2009 Nagao E (Kyushu Univ.), ISMRM 2009 Ito D (Tohoku Univ.), ISMRM 2009 Nakayama T (Kyushu Univ.), SMRM 2010 Nagao E (Kyushu Univ.), AJNR 2011 Yoneyama M (Yaesu Clinic), ISMRM 2011 Kanoto M et al (Yamagata Univ.), JCAT 2012 Yoneyama M (Yaesu Clinic), ISMRM 2012 Kikuchi K (Kyushu Univ.) RSNA 2012 Kanoto M et al (Yamagata Univ.), AJNR in Pre. Kanoto M et al (Yamagata Univ.), MRI in Pre. Neurovascular Compression Yamagata Univ. Kanoto M et al, JCAT 2012 Vessel Wall Tohoku Univ. Ito D et al, ISMRM 2009 Meta screening Kyushu Univ. Nagao E et al, AJNR 2011 SHINKEI Yaesu Clinic Yoneyama M et al, ISMRM 2011
imsde application: brain metastasis screening MSDE-TSE MPRAGE(standard) Easier to diagnose! (1) AJNR Am J Neuroradiol 32:664 70 Apr 2011 imsde
Whole Brain BBI imsde-thrive: 2min30sec MPRAGE 62
: 3D SHINKEI 63
: 3D SHINKEI 64
Bright Blood imaging Courtesy: Kurashiki Central Hospital
imsde application: low limb venography TRANCE (Systolic Phase) MSDE-TRANCE (Systolic Phase) Courtesy: Kurashiki Central Hospital 66
High B への試み 90-180 -90 RF Gz RF Gz S* Acquisition (3D, TSE, TFE) 90-180 -90 S* MSDE(B=10) (Diffusion Prepulse) Acquisition (3D, TSE, TFE) DSDE(B=500) (Diffusion Prepulse)
High B への試み 1mm isotropic B factor=500 scan time=5min
Bfactor
makoto.obara@philips.com