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

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Bergin et al. 1993). In 1994, the first MR images using hyperpolarized gas were demonstrated, showing excised mouse lungs filled with 129 Xe (Albert et al. 1994). The first 3 He images depicting the lungs of a dead guinea pig were presented in 1995 (Middleton et al. 1995). These initial works were followed by the first human images using 3 He (Bachert et al. 1996, Ebert et al. 1996, MacFall et al. 1996) and 129 Xe (Albert et al. 1996, Mugler et al. 1997). For a review of the historical background of hyperpolarized lung imaging, see, e.g., Albert and Balamore 1998. In Figure 3, examples of lung images acquired with 1 H, 3 He, and 129 Xe are shown. a b c Figure 3. Lung MR images: 3D 1 H (a) and 3 He (b) images of a guinea pig, acquired at identical positions, and a 2D 129 Xe image of another guinea pig. (Images from our laboratory.) The diagnostic potential of hyperpolarized gas imaging was first demonstrated in studies revealing various ventilation defects in patients, where nonventilated regions were depicted as signal voids (Kauczor et al. 1996). Rapid dynamic imaging has also demonstrated the potential to detect abnormal breathing patterns caused by lung disease (Johnson et al. 1997, Gierada et al. 2000, Salerno et al. 2001a). Owing to the large diffusion coefficient of gases (especially 3 He), the image intensity will decrease in regions with elevated mobility of the gas (Chen et al. 1999a, Yablonskiy et al. 2002). By measuring the apparent diffusion coefficient (ADC), it is thus possible to gain information of pathological lung structure, e.g., in emphysematous lungs (Saam et al. 2000). From measurements of the T 1 relaxation time, it has further been possible to calculate the regional oxygen partial pressure pO 2 in the lungs based on the depolarizing effect of O 2 (see section 2.4.1) (Deninger et al. 1999, Möller et al. 2001, Deninger et al. 2002). The venti- 20
lation-perfusion ratio (V · A/Q · ) is highly relevant for the diagnosis of abnormal lung function (Guyton 1986). By combining 3 He ventilation imaging with 1 H perfusion imaging, initial attempts have been made to assess the V · A/Q · parameter in rats (Cremillieux et al. 1999) and in humans (Lipson et al. 2002). It has also been suggested to assess V · A/Q · indirectly via measurements of pO 2 using 3 He (Eberle 2002). Reviews of the potential clinical applications of 3 He lung imaging can be found, among others in papers by Salerno et al. 2001b, Kauczor et al. 2002. After the initial demonstration of human lung imaging with 129 Xe (Mugler et al. 1997), almost all work on humans has used 3 He, due to its higher sensitivity (see sections 2.3.1 and 2.5.1) and the current difficulties to polarize 129 Xe to as high levels as 3 He (∼20% vs. ∼40%, (Möller et al. 2002)). Efforts to quantify parameters of the lung (e.g., ADC and transverse relaxation time T 2*) with 129 Xe have to date been made in animal experiments (Chen et al. 1999a, Chen et al. 1999b). Many aspects of the use of hyperpolarized gases in the lungs are discussed in a review article by Möller et al. 2002. 2.6.2 Hyperpolarized gases in other organs Owing to its solubility in blood and tissues, inhaled 129 Xe is distributed throughout the body, and can thus be used for applications other than lung imaging (Mugler et al. 1997). The resonance frequency of 129 Xe dissolved in liquids is ∼200 ppm higher than in the gas phase (Miller et al. 1981), and varies over a ∼20 ppm range in tissues in vivo (Sakai et al. 1996, Wagshul et al. 1996). An example of a hyperpolarized 129 Xe spectrum is shown in Figure 4. Because the resonance frequency of 129 Xe is sensitive to its local environment, numerous experiments involving spectroscopy or chemical shift imaging (CSI) have been presented, e.g., CSI of the chest and the brain (Swanson et al. 1997, Swanson et al. 1999), spectroscopy of tumors (Wolber et al. 2001), and probing of the pO 2 in blood (Wolber et al. 2000a). Using the large frequency shift between the gas-phase and the dissolved-phase 129 Xe, methods have been proposed to monitor the dynamics of 129 Xe when transported from the alveoli to the pulmonary blood (Ruppert et al. 2000a, Ruppert et al. 2000b), from which information about the diffusing capacity of the lung can be obtained. 21
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 and 14: Table of Contents 1 Introduction .
Page 15 and 16: 1 Introduction The phenomenon of nu
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: 230 mT, e.g., Tseng et al. 1998, Du
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
Page 65 and 66: eath-holding periods during, e.g.,
Page 67 and 68: 6 Conclusions The phantom study in
Page 69 and 70: 8 References ABRAGAM A, GOLDMAN M.
Page 71 and 72: CHEN XJ, MÖLLER HE, CHAWLA MS, COF
Page 73 and 74: GIERADA DS, SAAM B, YABLONSKIY D, C
Page 75 and 76: KAUCZOR HU, HANKE A, VAN BEEK EJ. A
Page 77 and 78: OLSSON LE, MAGNUSSON P, DENINGER AJ
Page 79 and 80: TILTON RF, JR., KUNTZ ID, JR. Nucle
Page 81: Paper I
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formance of the gradient system, si
Page 86 and 87:
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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