Chemical exchange saturation transfer (CEST) and MR Z-spectroscopy in vivo: A review of theoretical approaches and methods

Physics in Medicine and Biology

Volumn 58, Issue 22, 2013, Pages

  Zaiss, Moritz ^a   Bachert, Peter ^a  

^a GERMAN CANCER RESEARCH CENTER DKFZ   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

LAKES; MAGNETIC RESONANCE IMAGING; METABOLITES; PHYSIOLOGICAL MODELS;

CHEMICAL EXCHANGE SATURATION TRANSFER; MACROMOLECULAR SYSTEMS; MAGNETIZATION TRANSFER; METABOLITE CONCENTRATIONS; NUCLEAR OVERHAUSER EFFECTS; PHYSIOLOGICAL PARAMETERS; RADIOFREQUENCY IRRADIATION; THEORETICAL TREATMENTS;

SATURATION MAGNETIZATION;

PROTON;

ARTIFACT; HUMAN; METHODOLOGY; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; REVIEW; THEORETICAL MODEL;

ARTIFACTS; HUMANS; MAGNETIC RESONANCE SPECTROSCOPY; MODELS, THEORETICAL; PROTONS;

EID: 84896336495     PISSN: 00319155     EISSN: 13616560     Source Type: Journal    
DOI: 10.1088/0031-9155/58/22/R221     Document Type: Review

References (146)

1. Abergel D and Palmer A G 2004 Approximate solutions of the Bloch-McConnell equations for two-site chemical exchange Chem. Phys. Chem. 5 787-93
2. Abergel D and Palmer A G 3rd 2005 A Markov model for relaxation and exchange in NMR spectroscopy J. Phys. Chem. B 109 4837-44 (Pubitemid 40407702)
3. Adler R S and Yeung H N 1993 Transient decay of longitudinal magnetization in heterogeneous spin systems under selective saturation: III. Solution by projection operators J. Magn. Reson. 104 321-30
4. Aime S, Calabi L, Biondi L, De Miranda M, Ghelli S, Paleari L, Rebaudengo C and Terreno E 2005 Iopamidol: exploring the potential use of a well-established x-ray contrast agent for MRI Magn. Reson. Med. 53 830-4 (Pubitemid 40478431)
5. Aime S, Delli Castelli D and Terreno E 2002 Novel pH-reporter MRI contrast agents Angew. Chem. 114 4510-2
6. Baguet E and Roby C 1997 Off-resonance irradiation effect in steady-state NMR saturation transfer J. Magn. Reson. 128 149-60 (Pubitemid 127452798)
7. Bar-Shir A et al 2013 Transforming thymidine into a magnetic resonance imaging probe for monitoring gene expression J. Am. Chem. Soc. 135 1617-24
8. Bloch F 1946 Nuclear induction Phys. Rev. 70 460
9. Butcher J C 1987 The Numerical Analysis Of Ordinary Differential Equations: Runge-Kutta and General Linear Methods (New York: Wiley-Interscience)
10. Cai K, Haris M, Singh A, Kogan F, Greenberg J H, Hariharan H, Detre J A and Reddy R 2012 Magnetic resonance imaging of glutamate Nature Med. 18 302-6
11. Chan K W Y, McMahon M T, Kato Y, Liu G, Bulte J W M, Bhujwalla Z M, Artemov D and van Zijl P C M 2012 Natural D-glucose as a biodegradable MRI contrast agent for detecting cancer Magn. Reson. Med. 68 1764-73
12. De Leon-Rodriguez L M, Lubag A J M, Malloy C R, Martinez G V, Gillies R J and Sherry AD 2009 Responsive MRI agents for sensing metabolism in vivo Acc. Chem. Res. 42 948-57
13. Desmond K L, Moosvi F and Stanisz G J 2013 Mapping of amide, amine, and aliphatic peaks in the CEST spectra of murine xenografts at 7 T Magn. Reson. Med. (Early view, doi:10.1002/mrm.24822)
14. Desmond K L and Stanisz G J 2012 Understanding quantitative pulsed CEST in the presence of MT Magn. Reson. Med. 67 979-90
15. Dixon W T, Hancu I, Ratnakar S J, Sherry A D, Lenkinski R E and Alsop D C 2010a A multislice gradient echo pulse sequence for CEST imaging Magn. Reson. Med. 63 253-6
16. Dixon W T, Ren J, Lubag A J M, Ratnakar J, Vinogradov E, Hancu I, Lenkinski R E and Sherry A D 2010b A concentration-independent method to measure exchange rates in PARACEST agents Magn. Reson. Med. 63 625-32
17. Dula A N, Arlinghaus L R, Dortch R D, Dewey B E, Whisenant J G, Ayers G D, Yankeelov T E and Smith S A 2012 Amide proton transfer imaging of the breast at 3 T: establishing reproducibility and possible feasibility assessing chemotherapy response Magn. Reson. Med. 70 216-24
18. Englander SW, Downer N W and Teitelbaum H 1972 Hydrogen exchange Annu. Rev. Biochem. 41 903-24
19. Forsen S and Hoffman R A 1963 Study of moderately rapid chemical exchange reactions by means of nuclear magnetic double resonance J. Chem. Phys. 39 2892-901
20. Friedman J I, McMahon M T, Stivers J T and Van Zijl P C M 2010 Indirect detection of labile solute proton spectra via the water signal using frequency-labeled exchange (FLEX) transfer J. Am. Chem. Soc. 132 1813-5
21. Garcia S, Chavez L, Lowery T J, Han S-I, Wemmer D E and Pines A 2007 Sensitivity enhancement by exchange mediated magnetization transfer of the xenon biosensor signal J. Magn. Reson. 184 72-77 (Pubitemid 46049044)
22. Gerigk L, Schmitt B, Stieltjes B, Röder F, Essig M, Bock M, Schlemmer H-P and Röthke M 2012 7 Tesla imaging of cerebral radiation necrosis after arteriovenous malformations treatment using amide proton transfer (APT) imaging J. Magn. Reson. Imaging 35 1207-9
23. Grad J and Bryant R G 1990 Nuclear magnetic cross-relaxation spectroscopy J. Magn. Reson. 90 1-8
24. Grunwald E, Jumper C F and Meiboom S 1962 Kinetics of proton transfer in methanol and the mechanism of the abnormal conductance of the hydrogen ion J. Am. Chem. Soc. 84 4664-71
25. Haneder S, Apprich S R, Schmitt B, Michaely H J, Schoenberg S O, Friedrich K M and Trattnig S 2012 Assessment of glycosaminoglycan content in intervertebral discs using chemical exchange saturation transfer at 3.0 Tesla: preliminary results in patients with low-back pain Eur. Radiol. 23 861-8
26. Haris M, Cai K, Singh A, Hariharan H and Reddy R 2011 In vivo mapping of brain myo-inositol NeuroImage 54 2079-85
27. Haris M, Nanga R P R, Singh A, Cai K, Kogan F, Hariharan H and Reddy R 2012a Exchange rates of creatine kinase metabolites: feasibility of imaging creatine by chemical exchange saturation transfer MRI NMR Biomed. 25 1305-9
28. Haris M, Singh A, Cai K, Nath K, Crescenzi R, Kogan F, Hariharan H and Reddy R 2013 MICEST: a potential tool for non-invasive detection of molecular changes in Alzheimer's disease J. Neurosci. Methods 212 87-93
29. Haris M et al 2012b Imaging of glutamate neurotransmitter alterations in Alzheimer's disease NMR Biomed. 26 386-91
30. Henkelman R M, Huang X, Xiang Q S, Stanisz G J, Swanson S D and Bronskill M J 1993 Quantitative interpretation of magnetization transfer Magn. Reson. Med. 29 759-66 (Pubitemid 23182857)
31. Henkelman R M, Stanisz G J and Graham S J 2001 Magnetization transfer in MRI: a review NMR Biomed. 14 57-64 (Pubitemid 32401348)
32. Hills B P, Cano C and Belton P S 1991 Proton NMR relaxation studies of aqueous polysaccharide systems Macromolecules 24 2944-50 (Pubitemid 21653230)
33. Jia G et al 2011 Amide proton transfer MR imaging of prostate cancer: a preliminary study J. Magn. Reson. Imaging 33 647-54
34. Jin T, Autio J, Obata T and Kim S 2011 Spin-locking versus chemical exchange saturation transfer MRI for investigating chemical exchange process between water and labile metabolite protons Magn. Reson. Med. 65 1448-60
35. Jin T and Kim S-G 2012 Quantitative chemical exchange sensitive MRI using irradiation with toggling inversion preparation Magn. Reson. Med. 68 1056-64
36. Jin T and Kim S-G 2013a In vivo saturation transfer imaging of nuclear Overhauser effect from aromatic and aliphatic protons: implication to APT quantification Proc. ISMRM 21st Annu. Meeting (Salt Lake City, UT,) 2528
37. Jin T and Kim S-G 2013b Off-resonance irradiation power to optimize the CEST sensitivity versus the exchange rate-specificity Proc. ISMRM 21st Annu. Meeting (Salt Lake City, UT,) 2550
38. Jin T, Wang P, Zong X and Kim S-G 2012a Magnetic resonance imaging of the amine-proton exchange (APEX) dependent contrast NeuroImage 59 1218-27
39. Jin T, Wang P, Zong X and Kim S-G 2012b MR imaging of the amide-proton transfer effect and the pH-insensitive nuclear Overhauser effect at 9.4 T Magn. Reson. Med. 69 760-70
40. Jones C K, Polders D, Hua J, Zhu H, Hoogduin H J, Zhou J, Luijten P and van Zijl P C M 2012 In vivo three-dimensional whole-brain pulsed steady-state chemical exchange saturation transfer at 7 T Magn. Reson. Med. 67 1579-89
41. Jones C K, Schlosser M J, van Zijl P C M, Pomper M G, Golay X and Zhou J 2006 Amide proton transfer imaging of human brain tumors at 3T Magn. Reson. Med. 56 585-92 (Pubitemid 44338877)
42. Jones C K et al 2013 Nuclear Overhauser enhancement (NOE) imaging in the human brain at 7 T NeuroImage 77 114-24
43. Kim M, Gillen J, Landman B A, Zhou J and van Zijl PCM 2009 Water saturation shift referencing (WASSR) for chemical exchange saturation transfer (CEST) experiments Magn. Reson. Med. 61 1441-50
44. Kogan F, Haris M, Singh A, Cai K, Debrosse C, Nanga R P R, Hariharan H and Reddy R 2013 Method for high-resolution imaging of creatine in vivo using chemical exchange saturation transfer Magn. Reson. Med. Early view, doi:10.1002/mrm.24641
45. Kreis R, Ernst T and Ross B D 1993 Absolute quantitation of water and metabolites in the human brain: II. Metabolite concentrations J. Magn. Reson. B 102 9-19
46. Krusche-Mandl I, Schmitt B, Zak L, Apprich S, Aldrian S, Juras V, Friedrich K M, Marlovits S, Weber M and Trattnig S 2012 Long-term results 8 years after autologous osteochondral transplantation: 7 T gagCEST and sodium magnetic resonance imaging with morphological and clinical correlation Osteoarthritis Cartilage 20 357-63
47. Lee J-S, Parasoglou P, Xia D, Jerschow A and Regatte R R 2013 Uniform magnetization transfer in chemical exchange saturation transfer magnetic resonance imaging Sci. Rep. 3 1707
48. Lee J-S, Regatte R R and Jerschow A 2012 Isolating chemical exchange saturation transfer contrast from magnetization transfer asymmetry under two-frequency rf irradiation J. Magn. Reson. 215 56-63
49. Li A X, Hudson R H E, Barrett J W, Jones C K, Pasternak S H and Bartha R 2008 Four-pool modeling of proton exchange processes in biological systems in the presence of MRI-paramagnetic chemical exchange saturation transfer (PARACEST) agents Magn. Reson. Med. 60 1197-206
50. Liepinsh E and Otting G 1996 Proton exchange rates from amino acid side chains-implications for image contrast Magn. Reson. Med. 35 30-42 (Pubitemid 26017917)
51. Ling W, Regatte R R, Navon G and Jerschow A 2008 Assessment of glycosaminoglycan concentration in vivo by chemical exchange-dependent saturation transfer (gagCEST) Proc. Natl Acad. Sci. USA 105 2266-70 (Pubitemid 351520501)
52. Liu D, Zhou J, Xue R, Zuo Z, An J and Wang D J J 2013c Quantitative characterization of nuclear overhauser enhancement and amide proton transfer effects in the human brain at 7 tesla Magn. Reson. Med. 70 1070-81
53. Liu G, Chan K W Y, Song X, Zhang J, Gilad A A, Bulte J W M, van Zijl P CM and McMahon M T 2013a Normalized Magnetization Ratio (NOMAR) filtering for creation of tissue selective contrast maps Magn. Reson. Med. 69 516-23
54. Liu G, Gilad A A, Bulte J W M, van Zijl P C M and McMahon M T 2010 High-throughput screening of chemical exchange saturation transfer MR contrast agents Contrast Media Mol. Imaging 5 162-70
55. Liu G, Song X, Chan K W Y and McMahon M T 2013b Nuts and bolts of chemical exchange saturation transfer MRI NMR Biomed. 26 810-28
56. Longo D, Colombo S, Dastrũ W, Poggi L, Tedoldi F, Terreno E, Uggeri F and Aime S 2009 CMR2009: 11.02: evaluating iopamidol as pH-responsive CEST agent at 3 and 7 T Contrast Media Mol. Imaging 4 294-5
57. Longo D L et al 2010 Iopamidol as a responsive MRI-chemical exchange saturation transfer contrast agent for pH mapping of kidneys: In vivo studies in mice at 7 T Magn. Reson. Med. 65 202-11
58. Look D C and Locker D R 1970 Time saving in measurement of NMR and EPR relaxation times Rev. Sci. Instrum. 41 250-1
59. Mangia S, De Martino F, Liimatainen T, Garwood M and Michaeli S 2011 Magnetization transfer using inversion recovery during off-resonance irradiation Magn. Reson. Imaging 29 1346-50
60. Mangia S, Liimatainen T, Garwood M and Michaeli S 2009 Rotating frame relaxation during adiabatic pulses versus conventional spin lock: simulations and experimental results at 4 T Magn. Reson. Imaging 27 1074-87
61. McConnell H M 1958 Reaction rates by nuclear magnetic resonance J. Chem. Phys. 28 430
62. McMahon M T, Gilad A A, Zhou J, Sun P Z, Bulte J W M and van Zijl P C M 2006 Quantifying exchange rates in chemical exchange saturation transfer agents using the saturation time and saturation power dependencies of the magnetization transfer effect on the magnetic resonance imaging signal (QUEST and QUESP): Ph calibration for poly-L-lysine and a starburst dendrimer Magn. Reson. Med. 55 836-47
63. McVicar N, Li A X, Suchý M, Hudson R H E, Menon R S and Bartha R 2012 Simultaneous in vivo pH and temperature mapping using a PARACEST-MRI contrast agent Magn. Reson. Med. 70 1016-25
64. Meldrum T, Bajaj V S, Wemmer D E and Pines A 2011 Band-selective chemical exchange saturation transfer imaging with hyperpolarized xenon-based molecular sensors J. Magn. Reson. 213 14-21
65. Meldrum T, Schröder L, Denger P, Wemmer D E and Pines A 2010 Xenon-based molecular sensors in lipid suspensions J. Magn. Reson. 205 242-6
66. Michaeli S, Sorce D J, Springer C S Jr, Ugurbil K and Garwood M 2006 T1ρ MRI contrast in the human brain: modulation of the longitudinal rotating frame relaxation shutter-speed during an adiabatic RF pulse J. Magn. Reson. 181 135-47 (Pubitemid 43866549)
67. Miloushev V Z and Palmer A G III 2005 R1ρ relaxation for two-site chemical exchange: general approximations and some exact solutions J. Magn. Reson. 177 221-7 (Pubitemid 41690885)
68. Morrison C and Mark Henkelman R 1995 A model for magnetization transfer in tissues Magn. Reson. Med. 33 475-82
69. Morrison C, Stanisz G and Henkelman R M 1995 Modeling magnetization transfer for biological-like systems using a semi-solid pool with a super-Lorentzian lineshape and dipolar reservoir J. Magn. Reson. B 108 103-13
70. Mulkern R V and Williams M L 1993 The general solution to the Bloch equation with constant rf and relaxation terms: application to saturation and slice selection Med. Phys. 20 5-13 (Pubitemid 23069852)
71. Murase K 2012 Behavior of the magnetization in spin-locking magnetic resonance imaging using numerical solutions to the time-dependent Bloch equations Phys. Med. Biol. 57 N481-92
72. Murase K and Tanki N 2011 Numerical solutions to the time-dependent Bloch equations revisited Magn. Reson. Imaging 29 126-31
73. Neuhaus D and Williamson M 1989 The NOE Effect in Structural and Conformational Analysis (New York: VCH) p 164
74. Op 't Eijnde B, Ursø B, Richter E A, Greenhaff P L and Hespel P 2001 Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization Diabetes 50 18-23 (Pubitemid 32047975)
75. Portnoy S and Stanisz G J 2007 Modeling pulsed magnetization transfer Magn. Reson. Med. 58 144-55 (Pubitemid 47229927)
76. Robinson T M, Sewell D A, Hultman E and Greenhaff PL 1999 Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle J. Appl. Physiol. 87 598-604 (Pubitemid 29374995)
77. Roeloffs V, Zaiss M and Bachert P 2013 An analytical approach towards pulsed-SL/CEST quantification Proc. 21st Annu. Meeting of ISMRM (Salt Lake City, UT,) 2546
78. Santyr G E, Fairbanks E J, Kelcz F and Sorenson J A 1994 Off-resonance spin locking for MR imaging Magn. Reson. Med. 32 43-51 (Pubitemid 24198554)
79. Scheidegger R, Vinogradov E and Alsop D C 2011 Amide proton transfer imaging with improved robustness to magnetic field inhomogeneity and magnetization transfer asymmetry using Saturation with Frequency Alternating RF Irradiation (SAFARI) Magn. Reson. Med. 66 1275-85
80. Schmitt B, Welsch G H, Zaiss M, Zbyn S, Goed S and Trattnig S 2012 T2 mapping and glycosaminoglycan-dependent chemical exchange saturation transfer (gagCEST) imaging of focal lesions in knee cartilage using 3 T MRI 20th Annu. ISMRM Scientific Meeting and Exhibition (Melbourne,) 0281
81. Schmitt B, Zaiß M, Zhou J and Bachert P 2011a Optimization of pulse train presaturation for CEST imaging in clinical scanners Magn. Reson. Med. 65 1620-9
82. Schmitt B, Zamecnik P, Zaiss M, Rerich E, Schuster L, Bachert P and Schlemmer H P 2011c A new contrast in MR mammography by means of chemical exchange saturation transfer (CEST) imaging at 3 Tesla: preliminary results RöFo 183 1030-6
83. Schmitt B, Zbýn S, Stelzeneder D, Jellus V, Paul D, Lauer L, Bachert P and Trattnig S 2011b Cartilage quality assessment by using glycosaminoglycan chemical exchange saturation transfer and (23)Na MR imaging at 7 T Radiology 260 257-64
84. Schröder L, Chavez L, Meldrum T, Smith M, Lowery T J, Wemmer D E and Pines A 2008a Molekulare Steuerelemente zur temperaturempfindlichen Depolarisierung in der kernmagnetischen Resonanz Angew. Chem. 120 4388-92
85. Schröder L, Lowery T J, Hilty C, Wemmer D E and Pines A 2006 Molecular imaging using a targeted magnetic resonance hyperpolarized biosensor Science 314 446-9 (Pubitemid 44628961)
86. Schröder L, Meldrum T, Smith M, Lowery T J, Wemmer D E and Pines A 2008b Temperature response of 129Xe depolarization transfer and its application for ultrasensitive NMR detection Phys. Rev. Lett. 100 9257603
87. Singh A, Cai K, Haris M, Hariharan H and Reddy R 2012 On B(1) inhomogeneity correction of in vivo human brain glutamate chemical exchange saturation transfer contrast at 7T Magn. Reson. Med. 69 818-24
88. Singh A, Haris M, Cai K, Kassey V B, Kogan F, Reddy D, Hariharan H and Reddy R 2011 Chemical exchange saturation transfer magnetic resonance imaging of human knee cartilage at 3 T and 7 T Magn. Reson. Med. 68 588-94
89. Sled J G and Pike G B 2000 Quantitative interpretation of magnetization transfer in spoiled gradient echo MRI sequences J. Magn. Reson. 145 24-36
90. Sloniec J, Schnurr M, Witte C, Resch-Genger U, Schröder L and Hennig A 2013 Biomembrane interactions of functionalized cryptophane-A: combined fluorescence and (129) Xe NMR studies of a bimodal contrast agent Chemistry 19 3110-8
91. Smith S A, Bulte J W M and van Zijl P C M 2009 Direct saturation MRI: theory and application to imaging brain iron Magn. Reson. Med. 62 384-93
92. Solomon I 1955 Relaxation processes in a system of two spins Phys. Rev. 99 559
93. Spence M M, Rubin S M, Dimitrov I E, Ruiz E J, Wemmer D E, Pines A, Yao S Q, Tian F and Schultz P G 2001 Functionalized xenon as a biosensor Proc. Natl Acad. Sci. 98 10654-7 (Pubitemid 32878676)
94. Stanisz G J, Odrobina E E, Pun J, Escaravage M, Graham S J, Bronskill M J and Henkelman R M 2005 T1, T2 relaxation and magnetization transfer in tissue at 3T Magn. Reson. Med. 54 507-12 (Pubitemid 41233744)
95. Steenge G R, Lambourne J, Casey A, Macdonald I A and Greenhaff P L 1998 Stimulatory effect of insulin on creatine accumulation in human skeletal muscle Am. J. Physiol. 275 E974-9
96. Stevens T K, Palaniappan K K, Ramirez R M, Francis M B, Wemmer D E and Pines A 2012 HyperCEST detection of a 129Xe-based contrast agent composed of cryptophane-A molecular cages on a bacteriophage scaffold Magn. Reson. Med. 69 1245-52
97. Sun P Z 2012 Simplified quantification of labile proton concentration-weighted chemical exchange rate (k(ws)) with RF saturation time dependent ratiometric analysis (QUESTRA): normalization of relaxation and RF irradiation spillover effects for improved quantitative chemical exchange saturation transfer (CEST) MRI Magn. Reson. Med. 67 936-42
98. Sun P Z, Farrar C T and Sorensen A G 2007a Correction for artifacts induced by B(0) and B(1) field inhomogeneities in pH-sensitive chemical exchange saturation transfer (CEST) imaging Magn. Reson. Med. 58 1207-15 (Pubitemid 350234207)
99. Sun P Z, Murata Y, Lu J, Wang X, Lo E H and Sorensen A G 2008 Relaxation-compensated fast multislice amide proton transfer (APT) imaging of acute ischemic stroke Magn. Reson. Med. 59 1175-82 (Pubitemid 351590532)
100. Sun P Z and Sorensen AG 2008 Imaging pH using the chemical exchange saturation transfer (CEST) MRI: Correction of concomitant RF irradiation effects to quantify CEST MRI for chemical exchange rate and pH Magn. Reson. Med. 60 390-7
101. Sun P Z, van Zijl P C M and Zhou J 2005a Optimization of the irradiation power in chemical exchange dependent saturation transfer experiments J. Magn. Reson. 175 193-200 (Pubitemid 40891674)
102. Sun P Z, Wang E, Cheung J S, Zhang X, Benner T and Sorensen A G 2011 Simulation and optimization of pulsed radio frequency irradiation scheme for chemical exchange saturation transfer (CEST) MRI-demonstration of pH-weighted pulsed-amide proton CEST MRI in an animal model of acute cerebral ischemia Magn. Reson. Med. 66 1042-8
103. Sun P Z, Zhou J, Huang J and van Zijl P 2007b Simplified quantitative description of amide proton transfer (APT) imaging during acute ischemia Magn. Reson. Med. 57 405-10 (Pubitemid 46214544)
104. Sun P Z, Zhou J, Sun W, Huang J and Zijl van P C M 2005b Suppression of lipid artifacts in amide proton transfer imaging Magn. Reson. Med. 54 222-5 (Pubitemid 40898418)
105. Tee Y K, Khrapitchev A A, Sibson N R, Payne S J and Chappell M A 2012 Evaluating the use of a continuous approximation for model-based quantification of pulsed chemical exchange saturation transfer (CEST) J. Magn. Reson. 222 88-95
106. Terreno E, Barge A, Beltrami L, Cravotto G, Castelli D D, Fedeli F, Jebasingh B and Aime S 2008 Highly shifted LIPOCEST agents based on the encapsulation of neutral polynuclear paramagnetic shift reagents Chem. Commun. 7 600-2
107. Terreno E, Cabella C, Carrera C, Delli Castelli D, Mazzon R, Rollet S, Stancanello J, Visigalli M and Aime S 2007 From spherical to osmotically shrunken paramagnetic liposomes: an improved generation of LIPOCEST MRI agents with highly shifted water protons Angew. Chem., Int. Edn Engl. 46 966-8 (Pubitemid 46192059)
108. Terreno E, Castelli D D and Aime S 2010 Encoding the frequency dependence in MRI contrast media: the emerging class of CEST agents Contrast Media Mol. Imaging 5 78-98
109. Togao O, Takashi Y, Jochen K, Akio H, Koji Y, Kazufumi K, Yuriko S, Koji S, Masaya Takahashi and Hiroshi H 2012 Effect of saturation pulse length on parallel transmission based amide proton transfer (APT) imaging of different brain tumor types Proc. 20th Annu. Meeting of ISMRM (Melbourne,) 0743
110. Trott O, Abergel D and Palmer A G 2003 An average-magnetization analysis of R 1ρ relaxation outside of the fast exchange limit Mol. Phys. 101 753-63
111. Trott O and Palmer A G 2002 R1[ρ] relaxation outside of the fast-exchange limit J. Magn. Reson. 154 157-60
112. Trott O and Palmer A G 3rd 2004 Theoretical study of R(1ρ) rotating-frame and R2 free-precession relaxation in the presence of n-site chemical exchange J. Magn. Reson. 170 104-12
113. Van Zijl P C M and Yadav N N 2011 Chemical exchange saturation transfer (CEST): What is in a name and what isn't? Magn. Reson. Med. 65 927-48
114. Van Zijl P C M, Zhou J, Mori N, Payen J-F, Wilson D and Mori S 2003 Mechanism of magnetization transfer during on-resonance water saturation. A new approach to detect mobile proteins, peptides, and lipids Magn. Reson. Med. 49 440-9 (Pubitemid 36262811)
115. Vinogradov E, Sherry A D and Lenkinski R E 2013 CEST: from basic principles to applications, challenges and opportunities J. Magn. Reson. 229 155-72
116. Vinogradov E, Soesbe T C, Balschi J A, Sherry A D and Lenkinski R E 2012 pCEST: positive contrast using chemical exchange saturation transfer J. Magn. Reson. 215 64-73
117. Ward K, Aletras A and Balaban R 2000 A new class of contrast agents for MRI based on proton chemical exchange dependent saturation transfer (CEST) J. Magn. Reson. 143 79-87
118. Woessner D E, Zhang S, Merritt M E and Sherry A D 2005 Numerical solution of the Bloch equations provides insights into the optimum design of PARACEST agents for MRI Magn. Reson. Med. 53 790-9 (Pubitemid 40478426)
119. Wolff S D and Balaban R S 1990 NMR imaging of labile proton exchange J. Magn. Reson. 86 164-9
120. Woods M, Woessner D E and Sherry A D 2006 Paramagnetic lanthanide complexes as PARACEST agents for medical imaging Chem. Soc. Rev. 35 500-11 (Pubitemid 43815284)
121. Wu R, Liu C-M, Liu P K and Sun P Z 2012 Improved measurement of labile proton concentration-weighted chemical exchange rate (k(ws)) with experimental factor-compensated and T(1)-normalized quantitative chemical exchange saturation transfer (CEST) MRI Contrast Media Mol. Imaging 7 384-9
122. Xu J, Yadav N N, Bar-Shir A, Jones C K, Chan K W Y, Zhang J, Walczak P, McMahon M T and van Zijl P C M 2013a Variable delay multi-pulse train for fast chemical exchange saturation transfer and relayed-nuclear overhauser enhancement MRI Magn. Reson. Med. (Early view, doi:10.1002/mrm.24850)
123. Xu X, Lee J-S and Jerschow A 2013b Ultrafast scanning of exchangeable sites by NMR spectroscopy Angew. Chem. Int. Edn Engl. 52 8281-4
124. Yadav N N, Jones C K, Hua J, Xu J and van Zijl P C M 2013 Imaging of endogenous exchangeable proton signals in the human brain using frequency labeled exchange transfer imaging Magn. Reson. Med. 69 966-73
125. Yadav N N, Jones C K, Xu J, Bar-Shir A, Gilad A A, McMahon M T and van Zijl P C M 2012 Detection of rapidly exchanging compounds using on-resonance frequency-labeled exchange (FLEX) transfer Magn. Reson. Med. 68 1048-55
126. Yeung H N, Adler R S and Swanson S D 1994 Transient decay of longitudinal magnetization in heterogeneous spin systems under selective saturation: IV. Reformulation of the spin-bath-model equations by the Redfield-Provotorov theory J. Magn. Reson. 106 37-45
127. Yeung H N and Swanson S D 1992 Transient decay of longitudinal magnetization in heterogeneous spin systems under selective saturation J. Magn. Reson. 99 466-79
128. Yuan J, Zhou J, Ahuja A T and Wang Y-X J 2012 MR chemical exchange imaging with spin-lock technique (CESL): a theoretical analysis of the Z-spectrum using a two-pool R(1ρ) relaxation model beyond the fast-exchange limit Phys. Med. Biol. 57 8185-200
129. Zaiss M and Bachert P 2012a Exchange-dependent relaxation in the rotating frame for slow and intermediate exchange - modeling off-resonant spin-lock and chemical exchange saturation transfer NMR Biomed. 26 507-18
130. Zaiss M and Bachert P 2012b Equivalence of spin-lock and magnetization transfer NMR experiments arXiv: 1203.2067v1
131. Zaiss M, Xu J, Goerke S, Khan I S, Singer R J, Gore J C, Gochberg D F and Bachert P 2013a Inverse Z-spectrum analysis for MT- and spillover-corrected and T1-compensated steady-state pulsed CEST-MRI-application to pH-weighted MRI of acute stroke arXiv:1302.6605v2
132. Zaiss M, Kunz P, Goerke S, Radbruch A and Bachert P 2013b MR imaging of protein folding in vitro employing Nuclear-Overhauser-mediated saturation transfer NMR Biomed. (Early view, doi:10.1002/nbm.3021)
133. Zaiss M, Schmitt B and Bachert P 2011 Quantitative separation of CEST effect from magnetization transfer and spillover effects by Lorentzian-line-fit analysis of z-spectra J. Magn. Reson. 211 149-55
134. Zaiss M, Schnurr M and Bachert P 2012 Analytical solution for the depolarization of hyperpolarized nuclei by chemical exchange saturation transfer between free and encapsulated xenon (HyperCEST) J. Chem. Phys. 136 144106
135. Zhang S, Merritt M, Woessner D E, Lenkinski R E and Sherry A D 2003 PARACEST agents: modulating MRI contrast via water proton exchange Acc. Chem. Res. 36 783-90
136. Zhang S, Winter P, Wu K and Sherry A D 2001 A novel europium(III)-based MRI contrast agent J. Am. Chem. Soc. 123 1517-8 (Pubitemid 32167350)
137. Zhao J M, Har-el Y, McMahon M T, Zhou J, Sherry A D, Sgouros G, Bulte J W M and van Zijl P C M 2008 Size-induced enhancement of chemical exchange saturation transfer (CEST) contrast in liposomes J. Am. Chem. Soc. 130 5178-84 (Pubitemid 351537078)
138. Zhou J 2011 Amide proton transfer imaging of the human brain Methods Mol. Biol. 711 227-37
139. Zhou J, Payen J-F, Wilson D A, Traystman R J and van Zijl P C M 2003 Using the amide proton signals of intracellular proteins and peptides to detect pH effects in MRI Nature Med. 9 1085-90 (Pubitemid 37021791)
140. Zhou J and van Zijl P C M 2006 Chemical exchange saturation transfer imaging and spectroscopy Prog. Nucl. Magn. Reson. Spectrosc. 48 109-36
141. Zhou J, Wilson D A, Sun P Z, Klaus J A and van Zijl P C M 2004 Quantitative description of proton exchange processes between water and endogenous and exogenous agents for WEX, CEST, and APT experiments Magn. Reson. Med. 51 945-52 (Pubitemid 38580606)
142. Zhou J, Yan K and Zhu H 2012 A simple model for understanding the origin of the amide proton transfer MRI signal in tissue Appl. Magn. Reson. 42 393-402
143. Zhou J et al 2011 Differentiation between glioma and radiation necrosis using molecular magnetic resonance imaging of endogenous proteins and peptides Nature Med. 17 130-4
144. Zu Z, Janve V A, Li K, Does M D, Gore J C and Gochberg D F 2011a Multi-angle ratiometric approach to measure chemical exchange in amide proton transfer imaging Magn. Reson. Med. 68 711-9
145. Zu Z, Janve V A, Xu J, Does M D, Gore J C and Gochberg D F 2012 A new method for detecting exchanging amide protons using chemical exchange rotation transfer Magn. Reson. Med. 69 637-47
146. Zu Z, Li K, Janve V A, Does M D and Gochberg D F 2011b Optimizing pulsed-chemical exchange saturation transfer imaging sequences Magn. Reson. Med. 66 1100-8