880 臨床技術 Inversion Recovery T 1-3D Variable Refocus Flip Angle Turbo Spin Echo SPACE Black Blood Imaging 1 井上裕二 2 米山正己 2 中村理宣 尾崎 3 聡 3 伊藤建次郎 4 日浦幹夫 2011 6 21 2012 5 21 Code No. 261 1 2 3 4 緒言 magnetic resonance image; MRI 1 3 T 1 weighted image WI 4 7 2 dimensions 2D turbo spin echo TSE T 1WI T 2WI Carotid Plaque Assessment Using Inversion Recovery T 1 Weighted-3 Dimensions Variable Refocus Flip Angle Turbo Spin Echo Sampling Perfection with Application Optimized Contrast Using Different Angle Evolutions Black Blood Imaging Yuji Inoue, 1 Masami Yoneyama, 2 Masanobu Nakamura, 2 Satoshi Ozaki, 3 Kenjiro Ito, 3 and Mikio Hiura 4 1 Ito Yokohama Clinic 2 Yaesu Clinic 3 Department of Neurosurgery, Yokohama Shintoshi Neurosurgery Hospital 4 Department of Faculty of Sports and Health Studies, Hosei University Received June 21, 2011; Revision accepted May 21, 2012 Code No. 261 Summary Vulnerable plaque can be attributed to induction of ischemic symptoms and magnetic resonance imaging of carotid artery is valuable to detect the plaque. Magnetization prepared rapid acquisition with gradient echo (MPRAGE) method could detect hemorrhagic vulnerable plaque as high intensity signal; however, blood flow is not sufficiently masked by this method. The contrast for plaque in T 1 weighted image (T 1 WI) could not be obtained sufficiently with black blood image (BBI) by sampling perfection with application optimized contrast using different angle evolutions (SPACE) method as turbo spin echo (TSE). In addition, an appearance of artifact by slow flow is a problem. Considering these controversial situations in plaque imaging, we examined the modified BBI inversion recovery (IR)-SPACE in which IR was added for SPACE method so that the contrast for plaque in T 1 WI was optimized. We investigated the application of this method in plaque imaging. As a result of phantom imaging, the contrast for plaque in T 1 WI was definitely obtained by choosing an appropriate inversion time (TI) for the corresponding repetition time. In clinical cases, blood flow was sufficiently masked by IR-SPACE method and the plaque imaging was clearly obtained in clinical cases to the same extent as MPRAGE method. Since BBI with IR-SPACE method was derived from both IR pulse and flow void effect, this method could obtain the blood flow masking effect definitely. The present study suggested that SPACE method might be applicable to estimate properties of carotid artery plaque. Key words: magnetic resonance image (MRI), plaque imaging, sampling perfection with application optimized contrast using different angle evolutions (SPACE), inversion recovery (IR) *Proceeding author
881 magnetization prepared rapid acquisition with gradient echo MPRAGE 8 3 dimensions 3D multi planar reconstruction MPR 9 11 3D gradient echo MPRAGE black blood image BBI inversion recovery IR pulse inversion time TI null point variable refocus flip angle VRFA 3D TSE flow void BBI 12, 13 VRFA 3D TSE sampling perfection with application optimized contrast using different angle evolutions SPACE 14 VRFA echo space turbo factor 3D TSE blur SPACE VRFA flip angle mode FA mode FA mode 3 heavy T 2WI T 2WI echo time TE constant mode T 2 var mode T 1WI TE PD var mode IR pulse FA mode PD var mode T 1 SPACE T 1-SPACE MPRAGE T 1 MPRAGE flow void SPACE IR pulse SPACE IR-SPACE T 1 SPACE 1. 使用機器 MR SIEMENS MAGNETOM Avanto 1.5 Tesla Syngo B17 Body coil head matrix coil neck matrix coil 2. 方法 2-1 T 1 gray mutter; GM white mutter; WM T 1 T 2 15, 16 GM T 1 1068.65 ms T 2 115.60 ms WM T 1 642.02 ms T 2 70.80 ms water T 1 3946.80 ms T 2 1936.95 ms fat T 1 212.15 ms T 2 100.20 ms T 1 2D IR-TSE T 1W fluid-attenuated inversion recovery IR-TSE T 1FLAIR 17 null point repetition time TR TI IR SPACE TR 1200 ms 2000 ms 400 ms TI 50 ms 950 ms 50 ms TE 23 ms turbo factor 41 echo train per slice 3 18 FA mode PD var mode band width 501 Hz/Px signal to noise ratio SNR contrast to noise ratio CNR IR-SPACE IR-SPACE IR pulse T 1-SPACE SNR CNR T 1-SPACE IR-SPACE TR 500 ms SNR CNR 19, 20 SNR=SI/SD bg CNR=(SI a SI b)/sd bg SI a SI b 2 SD bg 2-2 2-2-1 MR angiography MRA 7 012 MPRAGE T 1-SPACE IR-SPACE Vol. 68 No. 7 Jul 2012
882 Fig. 1 SNR change according to difference in TI for phantom study at SPACE. (a) TR 1200 ms (b) TR 1600 ms (c) TR 2000 ms CR CR 20, 21 CR=(SI a SI b)/(si a+si b) SI a SI b 2 2-2-2 2-2-1 MPRAGE 5 T 1-SPACE IR-SPACE 2 2 MPRAGE 5 5 Very good= 4 Good= 3 Fair= 2 Bad= 1 Poor= T 1-SPACE IR-SPACE MPR 3. 結果 3-1 IR-SPACE TR TI SNR Fig. 1 IR-SPACE TR null point TR 1200 ms Fig. 1a TI 500 ms TR 1600 ms Fig. 1b TI 670 ms TR 2000 ms Fig. 1c TI 850 ms IR-TSE T 1FLAIR null point T 1 TR TI CNR Fig. 2 TR WM-GM Fig. 2a fat-water Fig. 2b TR TI TR SNR CNR TR IR-SPACE TR 1200 ms TI 500 ms T 1-SPACE IR-SPACE SNR Fig. 3a CNR Fig. 3bWM SNR GM
883 a Fig. 2 b CNR change according to difference in TI for phantom study at SPACE. (a) CNR of fat-water (b) CNR of WM-GM a Fig. 3 b SNR a nd CNR f o r phantom study at T 1- S P A C E a n d I R - SPACE. (a) SNR of phantoms (b) CNR of WM-GM and fat-water Table Scan parameters MPRAGE T 1-SPACE IR-SPACE TR/TE (ms) 1200/3.75 560/23 1200/23 TI (ms) 580 500 Matrix 256/256 256/245 256/253 Field of view (mm) 250 250 250 Slice thickness (mm) 1.0 1.2 1.2 Slice per slab 64 52 52 PAT accel.factor 2 2 2 Turbo factor single shot 55 53 Band width (Hz/Px) 150 501 501 Average 1 2 2 Excitation slab-selective slab-selective slab-selective Flip angle mode PD var PD var Orientation coronal oblique oblique Scan time (min) 4:04 2:25 5:36 SNR IR-SPACE WM-GM CNR IR-SPACE T 1-SPACE IR-SPACE null point SNR T 1-SPACE fatwater CNR 3-2 3-2-1 MRA MPRAGE T 1-SPACE IR-SPACE Table CR Vol. 68 No. 7 Jul 2012
884 Fig. 4 Carotid artery-submandibular gland CR. Fig. 5 Visualized evaluation of scoring method at T 1-SPACE and IR-SPACE. Fig. 6 Clinical image of carotid artery. (a) TOF MRA maximum intensity projection (MIP) (b) MPRAGE MPR (c) T 1-SPACE MPR (d) IR-SPACE MPR Fig. 4 MPRAGE 2 3 5 7 CR T 1-SPACE 1 3 CR IR-SPACE 3 CR 3-2-2 MPRAGE 5 T 1-SPACE IR-SPACE Fig. 5 IR-SPACE Fig. 6 76
885 Fig. 7 Clinical image of carotid artery. (a) TOF MRA MIP (b) MPRAGE MPR (c) T 1-SPACE MPR (d) IR-SPACE MPR MRA MPRAGE MPR Fig. 6b T 1-SPACE Fig. 6c IR-SPACE MPRAGE Fig. 6d IR-SPACE 4. 考察 MPRAGE 22 IR-SPACE MPRAGE IR-SPACE MPRAGE IR-SPACE TR TI null point T 1-SPACE T 1 IR pulse WM T 1 GM null point GM T 1 23 null point T 1-SPACE IR pulse IR pulse SPACE VRFA SPACE 3D TSE turbo factor turbo factor blur SPACE TE FA mode PD var mode RFA pseudo steady state PSS turbo factor T 2 blur 24 T 1-SPACE turbo factor MPRAGE T 1 MPRAGE T 1-SPACE IR pulse T 1 heavy T 1 IR-SPACE T 1 TSE MPRAGE Fig. 7 MPRAGE Fig. 7b Fig. 7d Vol. 68 No. 7 Jul 2012
886 Fig. 8 Change in blood controlling effect of MPRAGE. a b c Fig. 9 Artifact by flow of clinical image. (a) MPRAGE MPR (b) T 1-SPACE MPR (c) IR-SPACE MPR MPRAGE TI null point T 1 TI white blood Fig. 8 T 1-SPACE MPRAGE SPACE TSE flow void SPACE VRFA TSE flow void RFA PD var mode VRFA turbo factor RFA PSS turbo factor SPACE flow void 25 MPRAGE IR-SPACE T 1-SPACE IR-SPACE Fig. 9 IR-SPACE SPACE flow void IR-SPACE T 1 IR pulse TI T 1 T 1-SPACE IR-SPACE
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888 図表の説明 Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 SPACE TR TI a TR 1200 ms b TR 1600 ms c TR 2000 ms SPACE TI a Fat-water CNR b WM-GM CNR T 1-SPACE IR-SPACE SNR CNR a SNR b WM-GM fat-water CNR T 1-SPACE IR-SPACE a TOF MRA maximum intensity projection MIP b MPRAGE MPR c T 1-SPACE MPR d IR-SPACE MPR a TOF MRA MI b MPRAGE MPR c T 1-SPACE MPR d IR-SPACE MPR MPRAGE a MPRAGE MPR b T 1-SPACE MPR c IR-SPACE MPR Table MPRAGE T 1-SPACE IR-SPACE 225-0002 2-17-2