臺灣博碩士論文加值系統

核磁共振頻譜 (magnetic resonance spectroscopy, MRS) 能以非侵入式的方法去量測大腦代謝物分布，可用於臨床的預防及診斷。面回訊氫原子核磁共振頻譜影像 (proton echo planar spectroscopy imaging, PEPSI) 是一種快速的磁振頻譜成像技術，可大幅度地縮短二維磁振頻譜影像掃描時間至一分鐘左右，並能提升核磁共振頻譜於臨床的實用性。
核磁共振逆影像 (inverse imaging, InI) 是一利用高度平行化核磁共振射頻線圈同步收取核磁共振信號以達成含括全腦視區以及 100 毫秒的時間解析度的成像技術。其基本原理是省略了使用梯度線圈於空間編碼的步驟，藉由多組射頻線圈的空間敏感度分布得以從二維投影影像重建出三圍的空間訊息。
本篇論文結合了上述兩種技術，藉由使用多通道陣列線圈，希望得到高倍數加速的資料截取，用以縮短頻譜影像的成像時間。然而射頻線圈空間敏感度通常較平滑，若以最小範數估計解 (minimum-norm estimate) 重建的影像多半會模糊，因此還要加入許多數學上的限制。雖然無法得到預期高倍速加速的結果，但利用此方法仍能加速頻譜影像截取資料時間，並可得到可信的大腦代謝物資料以供臨床診斷之用。

Magnetic resonance spectroscopy (MRS) is a non-invasive technique that has been used to investigate the metabolic changes in living tissues. Fast magnetic resonance spectroscopy imaging (MRSI) using the proton-echo-planar-spectroscopy-imaging (PEPSI) technique can provide spatial distribution of metabolites in one single radio-frequency (RF) excitation. This method significantly reduces the scan time of 2-dimension MRSI down to 1 minute.
Inverse imaging (InI) uses a highly parallel RF coil array to achieve 100-millisecond temporal resolution with the whole brain coverage. Combining PEPSI sequence with InI can further accelerate the MRSI data acquisition. InI reconstruction utilizes coil sensitivities to reconstruct the omitted partition/phase encoded data by solving an under-determined inverse problem.
This study shows that the acceleration rate of the combined PEPSI and INI method is not as fast as expected. Specifically, using a 32-channel head coil array, we can achieve up to 6-fold acceleration in 2D PEPSI. Such scan time reduction can still increase the potential of applying MRSI to clinical applications.

口試委員會審定書 #
誌謝 i
中文摘要 ii
ABSTRACT iii
CONTENTS iv
LIST OF FIGURES vi
LIST OF TABLES vii
Chapter 1 Introduction 1
Chapter 2 Material and Methods 7
2.1 Implementation of PEPSI sequence 7
2.2 Participates and tasks 9
2.3 Pulse sequence and data acquisition 10
2.4 InI-PEPSI reconstruction 15
2.5 Errors and metabolites quantification 19
Chapter 3 Results 21
Chapter 4 Discussion 31
REFERENCE 34

[1] Negendank W. Studies of the human tutors by MRS: a review. NMR biomed 1992; 5:303-324.
[2] Skoch A, Jiru F, Bunke J. Spectroscopic imaging: basic principles. Eur J Radiol 2008; 67:230-239.
[3] Brown TR, Kincaid BM, Ugurbil K. NMR chemical shift imaging in three dimensions. Proc Natl Acad Sci USA 1982; 79(11):3523-3526.
[4] Maudsley AA, Hilal SK. Spatially resolved high resolution spectroscopy by four dimensional NMR. J Magn Reson 1983; 51:147–152.
[5] Brateman L. Chemical shift imaging: a review. AJR 1986; 146(5):971-980.
[6] Maudsley AA, Matson GB, Hugg JW, Weiner MW. Reduced phase encoding in spectroscopic imaging. Magn Reson Med 1994; 31:645-651.
[7] Duyn JH, Moonen CT. Fast proton spectroscopic imaging of human brain using multiple spin-echoes. Magn Reson Med 1993; 30:409-414.
[8] Mansfield P. Multi-planar image formation using NMR spin echoes. Journal of Physics 1977; C10:L55-L58.
[9] Guimaraes AR, Baker JR, Jenkins BG, Lee PL, Weisskoff RM, Rosen BR, Gonzalez RG. Echo-planar chemical shift imaging. Magn Reson Med 1999; 41(5):877-822.
[10] Adalsteinsson E, Irarrazabal P, Topp S, Meyer C, Macovski A, Spielman DM. Volumetric spectroscopic imaging with spiral-based k-space trajectories. Magn Reson Med 1998; 39:889-898.
[11] Posse S, Tedeschi G, Risinger R, Ogg R, Bihan DL. High speed 1H spectroscopic imaging in human brain by echo planar spatial-spectral encoding. Magn Reson Med 1995; 33(1):34-40.
[12] Mansfield P. Spatial mapping of the chemical shift in NMR. Magn Reson Med 1984; 1:370-386.
[13] Posse S, DeCarli C, Le Bihan D. Three-dimensional echo-planar MR spectroscopic imaging at short echo times in the human brain. Radiology 1994; 192:733-738.
[14] Webb P, Spielman D, Macovski A. A fast spectroscopic imaging method using a blipped phase encode gradient. Magn Reson Med 1989; 12:306-315.
[15] Matsui S, Sekihara K, Kohno H. Spatially resolved NMR spectroscopy using phase-modulated spin-echo trains. J Magn Reson 1986; 67:476-490.
[16] Dydak U, Weiger M, Pruessmann KP, Meier D, Boesiger P. Sensitivity-encoded spectroscopic imaging. Magn Reson Med 2001; 46(4):713-722
[17] Dydak U, Pruessmann KP, Weiger M, Tsao J, Meier D, Boesiger P. Parallel spectroscopic imaging with spin-echo trains. Magn Reson Med 2003; 50(1):196-200.
[18] Pruessmsnn KP. Encoding and reconstruction in parallel MRI. NMR Biomed 2006; 19:288-299.
[19] Pruessmann KP, Weiger M, Scheidegger MB, Boesiger P. SENSE: sensitivity encoding for fast MRI. Magn Reson Med 1999; 42:952-962.
[20] Lin FH, Tsai SY, Otazo R, Caprihan A, Wald LL, Belliveau JW, Posse S. Sensitivity-encoded (SENSE) proton echo-planar spectroscopic imaging (PEPSI) in human brain. Magn Reson Med 2007; 57:249-257.
[21] Griswold MA, Jakob PM, Heidemann RM, Nittka M, Jellus V, Wang J, Kiefer B, Haase A. Generalized autocalibrating partially parallel acquisitions (GRAPPA). Magn Reson Med 2002; 47(6):1202-1210.
[22] Tsai SY, Otazo R, Posse S, Lin YR, Chung HW, Wald LL, Wiggins GC, and Lin FH. Accelerated proton echo planar spectroscopic imaging (PEPSI) using GRAPPA with a 32-channel phased-array coil. Magn Reson Med 2008; 59:989-998.
[23] Lin FH, Wald LL, Alhfors SP, hamalainen MS, Kwong KK, Belliveau JW. Dynamic magnetic resonance inverse imaging of human brain function. Magn Reson Med 2006; 56(4):787-802.
[24] Lin FH, Witzel T, Mandeville JB, Polimeni JR, Zeffiro TA, Grave DN, Wiggins G, Wald LL, Belliveau JW. Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual processing. Neuroimage 2008; 42(1):230-247.
[25] Lin FH, Witzel T, Zeffiro TA, Belliveau JW. Linear constraint minimum variance beamformer functional magnetic resonance inverse imaging. Neuroimage 2008; 43(2):297-311.
[26] Lin FH, Witzel T, Chang WT, Tsai WK, Wang YH, Kuo WJ, Belliveau JW. K-space reconstruction of magnetic resonance inverse imaging (K-InI) of human visuomotor systems. Neuroimage 2010; 49(4):3086-3098.
[27] Mansfield P, Doyle M. Chemical shift imaging: a hybrid approach. Magn Reson Med 1987; 5:255-261.
[28] Haase A, Frahm J, Hanicke W, Matthaei D. 1H NMR chemical shift selective (CHESS) imaging. Phys Med Biol 1985; 30(4):341-344.
[29] Frahm J, Haase A, Hanicke W, Matthaei D, Bomsdorf H, Helzel T. Chemical shift selective MR imaging using a whole-body magnet. Radiology 1985; 156(2):441-444.
[30] Haase A, Frahm J. Multiple chemical-shift-selective NMR imaging using simulated echoes. Magn Reson Med 1985; 64:94-102.
[31] Connelly A, Counsell C, Lohman JA, Ordidge RJ. Outer volume suppressed image related in vivo spectroscopy (OSIRIS), a high-sensitivity localization technique. J Magn Reson 1988; 78:519-525.
[32] Jackson J, Meyer C, Nishimura D, Macovski A. Selection of a convolution function for Fourier inversion using gridding. IEEE Transaction on Medical Imaging 1991; 10(3):473-478.
[33] de Graaf RA. In vivo NMR spectroscopy: Principles and techniques: JOHN WILEY &; SONS; 1998.
[34] Willig-Onwuachi JD, Yeh EN, Grant AK, Ohliger MA, McKenzie CA, Sodickson DK. Phase-constrained parallel MR image reconstruction. J Magn Reson 2005; 176:187-198.
[35] Bydder M, Robson MD. Partial Fourier partially parallel imaging. Magn Reson Med 2005; 53:1393-1401.
[36] Lew C, Pineda AR, Clayton D, Spielman D, Chan F, Bammer R. SENSE phase-constrained magnitude reconstruction with iterative phase refinement. Magn Reson Med 2007; 58(5):910-921.
[37] de Graaf RA, Bovee WM. Improved quantification of in vivo 1H NMR spectra by optimization of signal acquisition and processing and by incorporation of prior knowledge into the spectral fitting. Magn Reson Med 1990; 15:305-319.
[38] Provencher SW. Estimation of metabolite concentrations from localized in vivo proton NMR spectra. Magn Reson Med 1993; 30:672-679.
[39] Cavassila S, Deval S, Huegen C, van Ormondt D, Graveron-Demilly D. Cramer-Rao bound expressions for parametric estimation of overlapping peaks: influence of prior knowledge. J Magn Reson 2000; 143:311-320.
[40] Cavassila S, Deval S, Huegen C, van Ormondt D, Graveron-Demilly D. Cramer-Rao bounds: an evaluation tool for quantitation. NMR Biomed 2001; 14:278-283.
[41] Ratiney H, Coenradie Y, Cavassila S, van Ormondt D, Graveron-Demilly D. Time-domain quantitation of 1H short echo-time signals: background accommodation. Magma 2004; 16:284–296.
[42] Golman K, Ardenkjaer-Larsen JH, Petersson JS, Mansson S, Leunbach I. Molecular imaging with endogenous substances. Proc Natl Acad Sci USA 2003; 100:10435–10439.
[43] Golman K, in’t Zandt R, Thaning M. Real-time metabolic imaging. Proc Natl Acad Sci USA 2006; 103(30):11270-11275.
[44] Sanchez-Gonzalez J, Tsao J, Dydak U, Desco M, Boesiger P, Pruessmsnn KP. Minimum-norm reconstruction for sensitivity-encoded magnetic resonance spectroscopic imaging. Magn Reson Med 2006; 55:287-295.