Hyperpolarized Nuclei for NMR Imaging and Spectroscopy - Lunds ...

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x 3.6 Vascular imaging of a 13 C-based imaging agent . . . . . . . . . . . . . . . . . . . . . 31 3.6.1 In vitro investigations — sequence optimization . . . . . . . . . . . . 31 3.6.2 In vivo trueFISP imaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3.7 Measurements of regional pulmonary ventilation . . . . . . . . . . . . . . . . . . . 32 3.7.1 The ventilation model and measurement procedure. . . . . . . . . . 32 3.7.2 Detection of vertical ventilation gradients . . . . . . . . . . . . . . . . . . 33 3.8 Diffusion capacity and perfusion of the rat lung . . . . . . . . . . . . . . . . . . . . 33 3.8.1 The alveolar diffusion model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3.8.2 Measurement procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4.1 Investigation of dissolved 129 Xe for MRA applications (Paper I). . . . . . . 36 4.2 Vascular imaging of a 13 C-based imaging agent (Paper II). . . . . . . . . . . . 37 4.3 Measurements of regional pulmonary ventilation (Paper III) . . . . . . . . . 38 4.4 Vertical gradients of pulmonary ventilation (Paper IV) . . . . . . . . . . . . . . 40 4.5 Diffusion capacity and perfusion of the rat lung (Paper V) . . . . . . . . . . . 41 5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 5.1 Echo-planar imaging of hyperpolarized imaging agents . . . . . . . . . . . . . . 43 5.2 Properties of the trueFISP sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 5.3 Hyperpolarized 3 He ventilation imaging in animals . . . . . . . . . . . . . . . . . 47 5.3.1 Aspects on T 1 relaxation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5.3.2 Pulse sequence considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5.4 Measurement of the uptake of 129 Xe in the lung . . . . . . . . . . . . . . . . . . . . 51 6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 7 Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 8 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
1 Introduction The phenomenon of nuclear magnetic resonance (NMR) was first detected in 1945 independently by Felix Bloch and Edward Purcell (Bloch et al. 1946, Purcell et al. 1946), who in 1952 were awarded the Nobel Prize for their achievements. The principle is based on the interaction of atomic nuclei with an external magnetic field. From its first applications within physics research, NMR spectroscopy rapidly evolved into an important tool within chemistry and biochemistry. After the introduction of NMR imaging (Lauterbur 1973), NMR techniques have gained widespread diagnostic use in medicine, where they are commonly referred to as magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Many atomic nuclei possess a magnetic moment and can hence be investigated by NMR, but the clinical use of MRI has to date been restricted to the proton ( 1 H) for reasons of sensitivity. Not only does 1 H have a higher sensitivity than any other nucleus (with the hypothetical exception of 3 H), it is also abundant in a very high concentration (about 80 M) in biological tissues. At any given magnetic field strength, the amplitude of the NMR signal is governed by the thermal equilibrium polarization of the nuclei. The amplitude of the NMR signal, and thus the achievable signal-to-noise ratio (SNR) in the corresponding image, increases with the strength of the magnetic field in which the experiment is performed. A different means to increase the NMR signal consists of enhancing the polarization by creating an artificial, non-equilibrium distribution of the nuclei: the “hyperpolarized” state. This state can be created in vivo employing dynamic nuclear polarization (DNP) techniques, such as the Overhauser effect (Overhauser 1953), in combination with a suitable contrast agent. Using this approach, signal enhancements of about 60 times the thermal equilibrium value have been reported at a low magnetic field of 0.01 T (Golman et al. 2000). Alternatively, the hyperpolarized state of a contrast agent can be created by an external device, followed by rapid administration of the agent to the subject to be imaged. Examples of the latter approach include hyperpolarization of the noble gases 129 Xe (Albert et al. 1994) and 3 He (Middleton et al. 1995) using optical pumping, and hyperpolarization of 13 C, by either parahydrogen-induced hyperpolarization (Golman et al. 2001) or DNP hyperpolarization (Golman et al. 2002). 1
Page 1: ��
Page 4 and 5: DOKUMENTDATABLAD enl SIS 61 41 21 O
Page 6 and 7: Doctoral Dissertation Department of
Page 9 and 10: Abstract Based on the principle of
Page 11 and 12: Original papers This thesis is base
Page 13: Table of Contents 1 Introduction .
Page 17 and 18: By using hyperpolarized imaging age
Page 19 and 20: vector addition of all the magnetic
Page 21 and 22: illustrates the difference between
Page 23 and 24: pumping process (Colegrove and Fran
Page 25 and 26: thetic effects, and has been used a
Page 27 and 28: 1 T 1,O2 p = ξ O2 [11] where ξ Xe
Page 29 and 30: 1 2 2 −6 ∝ γC γHrτ c. [17] T
Page 31 and 32: and thus breaks down at very low fr
Page 33 and 34: 230 mT, e.g., Tseng et al. 1998, Du
Page 35 and 36: lation-perfusion ratio (V · A/Q ·
Page 37 and 38: after gas inhalation, due to the wa
Page 39 and 40: tion of an NMR signal from a small
Page 41 and 42: larized gas with air took place as
Page 43 and 44: Table 5. Parameters of the imaging
Page 45 and 46: The images were evaluated with resp
Page 47 and 48: partial pressure present within the
Page 49 and 50: 3.8.2 Measurement procedure The spe
Page 51 and 52: 4.2 Vascular imaging of a 13 C-base
Page 53 and 54: gions. In central lung areas, regio
Page 55 and 56: 4.5 Diffusion capacity and perfusio
Page 57 and 58: 5 Discussion In this thesis, three
Page 59 and 60: due to the increased demand on the
Page 61 and 62: 5.3 Hyperpolarized 3 He ventilation
Page 63 and 64: a theoretical T 1 of ∼38 min in t
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eath-holding periods during, e.g.,
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6 Conclusions The phantom study in
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8 References ABRAGAM A, GOLDMAN M.
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CHEN XJ, MÖLLER HE, CHAWLA MS, COF
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GIERADA DS, SAAM B, YABLONSKIY D, C
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KAUCZOR HU, HANKE A, VAN BEEK EJ. A
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OLSSON LE, MAGNUSSON P, DENINGER AJ
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TILTON RF, JR., KUNTZ ID, JR. Nucle
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Paper I
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formance of the gradient system, si
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S. MÅNSSON ET AL. Fig. 2. a-h) EPI
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though several technical issues rem
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Hyperpolarized 13 C MR angiography
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Introduction The most widespread te
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of the gradient moments prior to ea
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Methods Polarization procedure The
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secutive trueFISP images were acqui
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also to several other sources such
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low γ of 13 C reduces the sensitiv
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9. Chawla MS, Chen XJ, Möller HE,
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My 1 0.8 0.6 0.4 0.2 0 0 50 100 150
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Signal [a.u] 100 90 80 70 60 50 40
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a b Figure 5. Series of angiograms
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Paper III
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224 Deninger et al. FIG. 1. Sketch
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226 Deninger et al. FIG. 2. Coronal
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228 Deninger et al. FIG. 6. Histogr
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230 Deninger et al. FIG. 9. Monte C
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232 Deninger et al. 5. Gur D, Draye
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3 He MRI-based measurement of posit
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Introduction It is well known that
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3 He imaging All experiments were p
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coefficients b 1 and b 2, respectiv
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Using VI data after subtraction of
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To investigate whether the calculat
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14. Gur D, Drayer BP, Borovetz HS,
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Table 1. Gradient of VI [cm −1 ]
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Cycle 1 Cycle 2 Cycle 3 Cycle 4 2 s
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a Prone Ventilation index c Supine
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a Prone Supine 0 b 1 R 2 Prone Supi
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Paper V
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Abstract The ability to quantify pu
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lation and perfusion information by
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Applying the conditions at the inne
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where L is obtained from Eq. [8]. V
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After tracheal intubation, the anim
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Parametric analysis The fit of the
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in the LPS-treated group is consist
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3. Worsley DF, Palevsky HI, Alavi A
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enin activity in rats chronically e
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V-20 blood without Xe C a V a (t) L
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V-22 Error in estimated diffusion l
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V-24 NMR Ventilator repetition loop
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Figure 7. The peak amplitudes (circ
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