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Stecker IR, Bdaiwi AS, Niedbalski PJ, Chatterjee N, Hossain MM, Cleveland ZI. Impact of undersampling on preclinical lung T 2* mapping with 3D radial UTE MRI at 7 T. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 365:107741. [PMID: 39089222 PMCID: PMC11357708 DOI: 10.1016/j.jmr.2024.107741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 06/28/2024] [Accepted: 07/11/2024] [Indexed: 08/03/2024]
Abstract
Lung diseases are almost invariably heterogeneous and progressive, making it imperative to capture temporally and spatially explicit information to understand the disease initiation and progression. Imaging the lung with MRI-particularly in the preclinical setting-has historically been challenging because of relatively low lung tissue density, rapid cardiac and respiratory motion, and rapid transverse (T2*) relaxation. These limitations can largely be mitigated using ultrashort-echo-time (UTE) sequences, which are intrinsically robust to motion and avoid significant T2* decay. A significant disadvantage of common radial UTE sequences is that they require inefficient, center-out k-space sampling, resulting in long acquisition times relative to conventional Cartesian sequences. Therefore, pulmonary images acquired with radial UTE are often undersampled to reduce acquisition time. However, undersampling reduces image SNR, introduces image artifacts, and degrades true image resolution. The level of undersampling is further increased if offline gating techniques like retrospective gating are employed, because only a portion (∼40-50%) of the data is used in the final image reconstruction. Here, we explore the impact of undersampling on SNR and T2* mapping in mouse lung imaging using simulation and in-vivo data. Increased scatter in both metrics was noticeable at around 50% sampling. Parenchymal apparent SNR only decreased slightly (average decrease ∼ 1.4) with as little as 10% sampling. Apparent T2* remained similar across undersampling levels, but it became significantly increased (p < 0.05) below 80% sampling. These trends suggest that undersampling can generate quantifiable, but moderate changes in the apparent value of T2*. Moreover, these approaches to assess the impact of undersampling are straightforward to implement and can readily be expanded to assess the quantitative impact of other MR acquisition and reconstruction parameters.
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Affiliation(s)
- Ian R Stecker
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Abdullah S Bdaiwi
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Peter J Niedbalski
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Neelakshi Chatterjee
- Division of Biostatistics and Bioinformatics, Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, OH, United States; Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Md M Hossain
- Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States
| | - Zackary I Cleveland
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States; Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.
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Rotkopf LT, Buschle LR, Schlemmer HP, Ziener CH. Influence of diffusion on transverse relaxation rates and phases of an ensemble of magnetic spheres. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 341:107259. [PMID: 35779309 DOI: 10.1016/j.jmr.2022.107259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 05/30/2022] [Accepted: 06/19/2022] [Indexed: 06/15/2023]
Abstract
In quantitative susceptibility mapping, the tissue susceptibility is determined from the magnitude and phase of the gradient echo signal, which is influenced by the interplay of complex susceptibility and diffusion effect. Herein, we analytically analyze the influence of diffusion on magnitude and phase images generated by randomly arranged magnetic spheres as a model of intracerebral iron depositions. We demonstrate that both gradient and spin echo relaxation rate constants have a strong and nonlinear dependence on diffusion strength and give empirical formulas for magnitude and phase. This may be used in the future to improve QSM processing methods. In addition, we show that, in theory, combined acquisitions of gradient and spin echo can be used to determine the dimension of the magnetic spheres and the diffusion strength.
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Affiliation(s)
- L T Rotkopf
- Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld 220, 69120 Heidelberg, Germany; Medical Faculty, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - L R Buschle
- Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld 220, 69120 Heidelberg, Germany
| | - H-P Schlemmer
- Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld 220, 69120 Heidelberg, Germany
| | - C H Ziener
- Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld 220, 69120 Heidelberg, Germany.
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Rotkopf LT, Kampf T, Triphan SMF, Schlemmer HP, Ziener CH. Influence of flow and susceptibility effects on spin dephasing in lung tissue. Med Phys 2022; 49:5981-5992. [PMID: 35638106 DOI: 10.1002/mp.15784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 05/17/2022] [Accepted: 05/21/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Magnetic resonance imaging (MRI) of the lung can be used for diagnosis and monitoring of interstitial lung disease. Biophysical models of alveolar lung tissue are needed to understand the complex interplay of susceptibility, diffusion, and flow effects, and their influence on magnetic resonance (MR) spin dephasing. METHODS In this work, we present a method for modeling the signal decay of lung tissue by utilizing a two-compartment model, which considers the different spin dephasing mechanisms in the alveolar vasculature and interstitial tissue. This allows calculating the magnetization dynamics and the MR lineshape, which can be measured noninvasively using clinical MR scanners. RESULTS The accuracy of the method was evaluated using finite element simulations and the experimentally measured lineshapes of a healthy volunteer. In this comparison, the model performs well, indicating that the relevant spin dephasing mechanisms are correctly taken into account. CONCLUSIONS The proposed method can be used to estimate the influence of blood flow and alveolar geometry on the MR lineshape of lung tissue.
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Affiliation(s)
- Lukas T Rotkopf
- Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld, Heidelberg, Germany.,Medical Faculty, Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Thomas Kampf
- Department of Neuroradiology, Würzburg University Hospital, Würzburg, Germany.,Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany
| | - Simon M F Triphan
- Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany
| | - Heinz-Peter Schlemmer
- Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld, Heidelberg, Germany
| | - Christian H Ziener
- Department of Radiology, German Cancer Research Center, Im Neuenheimer Feld, Heidelberg, Germany
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Hahn AD, Malkus A, Kammerman J, Higano N, Walkup LL, Woods J, Fain SB. Effects of neonatal lung abnormalities on parenchymal R 2 * estimates. J Magn Reson Imaging 2021; 53:1853-1861. [PMID: 33404085 DOI: 10.1002/jmri.27487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 11/09/2022] Open
Abstract
Infants admitted to the neonatal intensive care unit (NICU) often suffer from multifaceted pulmonary morbidities that are not well understood. Ultrashort echo time (UTE) magnetic resonance imaging (MRI) is a promising technique for pulmonary imaging in this population without requiring exposure to ionizing radiation. The aims of this study were to investigate the effect of neonatal pulmonary disease on R2 * and tissue density and to utilize numerical simulations to evaluate the effect of different alveolar structures on predicted R2 *.This was a prospective study, in which 17 neonatal human subjects (five control, seven with bronchopulmonary dysplasia [BPD], five with congenital diaphragmatic hernia [CDH]) were enrolled. Twelve subjects were male and five were female, with postmenstrual age (PMA) at MRI of 39.7 ± 4.7 weeks. A 1.5T/multiecho three-dimensional UTE MRI was used. Pulmonary R2 * and tissue density were compared across disease groups over the whole lung and regionally. A spherical shell alveolar model was used to predict the expected R2 * over a range of tissue densities and tissue susceptibilities. Tests for significantly different mean R2 * and tissue densities across disease groups were evaluated using analysis of variance, with subsequent pairwise group comparisons performed using t tests. Lung tissue density was lower in the ipsilateral lung in CDH compared to both controls and BPD patients (both p < 0.05), while only the contralateral lung in CDH (CDHc) had higher whole-lung R2 * than both controls and BPD (both p < 0.05). R2 * differences were significant between controls and CDHc within all tissue density ranges (all p < 0.05) with the exception of the 80%-90% range (p = 0.17). Simulations predicted an inverse relationship between alveolar tissue density and R2 * that matches empirical human data. Alveolar wall thickness had no effect on R2 * independent of density (p = 1). The inverse relationship between R2 * and tissue density is influenced by the presence of disease globally and regionally in neonates with BPD and CDH in the NICU. LEVEL OF EVIDENCE: 2. TECHNICAL EFFICACY STAGE: 2.
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Affiliation(s)
- Andrew D Hahn
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Annelise Malkus
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Jeffery Kammerman
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Nara Higano
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Laura L Walkup
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jason Woods
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Sean B Fain
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA
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Kammerman J, Hahn AD, Cadman RV, Malkus A, Mummy D, Fain SB. Transverse relaxation rates of pulmonary dissolved-phase Hyperpolarized 129 Xe as a biomarker of lung injury in idiopathic pulmonary fibrosis. Magn Reson Med 2020; 84:1857-1867. [PMID: 32162357 DOI: 10.1002/mrm.28246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 02/12/2020] [Accepted: 02/12/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE The MR properties (chemical shifts and R 2 ∗ decay rates) of dissolved-phase hyperpolarized (HP) 129 Xe are confounded by the large magnetic field inhomogeneity present in the lung. This work improves measurements of these properties using a model-based image reconstruction to characterize the R 2 ∗ decay rates of dissolved-phase HP 129 Xe in healthy subjects and patients with idiopathic pulmonary fibrosis (IPF). METHODS Whole-lung MRS and 3D radial MRI with four gradient echoes were performed after inhalation of HP 129 Xe in healthy subjects and patients with IPF. A model-based image reconstruction formulated as a regularized optimization problem was solved iteratively to measure regional signal intensity in the gas, barrier, and red blood cell (RBC) compartments, while simultaneously measuring their chemical shifts and R 2 ∗ decay rates. RESULTS The estimation of spectral properties reduced artifacts in images of HP 129 Xe in the gas, barrier, and RBC compartments and improved image SNR by over 20%. R 2 ∗ decay rates of the RBC and barrier compartments were lower in patients with IPF compared to healthy subjects (P < 0.001 and P = 0.005, respectively) and correlated to DLCO (R = 0.71 and 0.64, respectively). Chemical shift of the RBC component measured with whole-lung spectroscopy was significantly different between IPF and normal subjects (P = 0.022). CONCLUSION Estimates for R 2 ∗ in both barrier and RBC dissolved-phase HP 129 Xe compartments using a regional signal model improved image quality for dissolved-phase images and provided additional biomarkers of lung injury in IPF.
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Affiliation(s)
- Jeff Kammerman
- Department of Medical Physics, Univsersity of Wisconsin, Madison, Wisconsin
| | - Andrew D Hahn
- Department of Medical Physics, Univsersity of Wisconsin, Madison, Wisconsin
| | - Robert V Cadman
- Department of Medical Physics, Univsersity of Wisconsin, Madison, Wisconsin
| | - Annelise Malkus
- Department of Medical Physics, Univsersity of Wisconsin, Madison, Wisconsin
| | - David Mummy
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina.,Department of Radiology, Duke University Medical Center, Durham, North Carolina
| | - Sean B Fain
- Department of Medical Physics, Univsersity of Wisconsin, Madison, Wisconsin.,Department of Radiology, University of Wisconsin, Madison, Wisconsin.,Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin
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Ziener CH, Kampf T, Schlemmer HP, Buschle LR. Spin echoes: full numerical solution and breakdown of approximative solutions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:155101. [PMID: 30641507 DOI: 10.1088/1361-648x/aafe21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The spin echo signal from vessels in Krogh's capillary model as well in the random distribution vessel model are studied by numerically solving the Bloch-Torrey equation. A comparison is made with the Gaussian local phase approximation, the Gaussian phase approximation and the strong-collision approximation. Differences between the Gaussian local phase approximation and the Gaussian phase approximation are explained. In the intermediate diffusion regime, the full numerical solution shows oscillations which are absent in any of the approximate solutions. In the limit of large diffusion coefficients, where the approximations become exact, the signal shows a linear-exponential decay governed by a single parameter. The features of the exact numerical solution can be explained by an analytically solvable discrete two-level model. There is a one-to-one correspondence between the different diffusion regimes and the three cases of the damped harmonic oscillator.
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Affiliation(s)
- C H Ziener
- German Cancer Research Center DKFZ, E010 Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. University Hospital Heidelberg, Neuroradiology, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
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Dependence of the frequency distribution around a vessel on the voxel orientation. Magn Reson Imaging 2019; 57:259-270. [DOI: 10.1016/j.mri.2018.09.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 09/10/2018] [Accepted: 09/13/2018] [Indexed: 12/31/2022]
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Torres L, Kammerman J, Hahn AD, Zha W, Nagle SK, Johnson K, Sandbo N, Meyer K, Schiebler M, Fain SB. "Structure-Function Imaging of Lung Disease Using Ultrashort Echo Time MRI". Acad Radiol 2019; 26:431-441. [PMID: 30658930 DOI: 10.1016/j.acra.2018.12.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 12/19/2018] [Accepted: 12/21/2018] [Indexed: 12/14/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of this review is to acquaint the reader with recent advances in ultrashort echo time (UTE) magnetic resonance imaging (MRI) of the lung and its implications for pulmonary MRI when used in conjunction with functional MRI technique. MATERIALS AND METHODS We provide an overview of recent technical advances of UTE and explore the advantages of combined structure-function pulmonary imaging in the context of restrictive and obstructive pulmonary diseases such as idiopathic pulmonary fibrosis (IPF) and cystic fibrosis (CF). RESULTS UTE MRI clearly shows the lung parenchymal changes due to IPF and CF. The use of UTE MRI, in conjunction with established functional lung MRI in chronic lung diseases, will serve to mitigate the need for computed tomography in children. CONCLUSION Current limitations of UTE MRI include long scan times, poor delineation of thin-walled structures (e.g. cysts and reticulation) due to limited spatial resolution, low signal to noise ratio, and imperfect motion compensation. Despite these limitations, UTE MRI can now be considered as an alternative to multidetector computed tomography for the longitudinal follow-up of the morphological changes from lung diseases in neonates, children, and young adults, particularly as a complement to the unique functional capabilities of MRI.
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Buschle LR, Kurz FT, Kampf T, Schlemmer HP, Ziener CH. Spin dephasing around randomly distributed vessels. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 299:12-20. [PMID: 30529850 DOI: 10.1016/j.jmr.2018.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
We analyze the gradient echo signal in the presence of blood vessel networks. Both, diffusion and susceptibility effects are analytically emphasized within the Bloch-Torrey equation. Solving this equation, we present the first exact description of the local magnetization around a single vessel. This allows us to deduce the gradient echo signal of parallel vessels randomly distributed in a plane, which is valid for arbitrary mean vessel diameters in the range of physiological relevant blood volume fractions. Thus, the results are potentially relevant for gradient echo measurements of blood vessel networks with arbitrary vessel size.
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Affiliation(s)
- L R Buschle
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; Heidelberg University, Faculty of Physics and Astronomy, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany
| | - F T Kurz
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - T Kampf
- University of Würzburg, Department of Experimental Physics 5, Am Hubland, 97074 Würzburg, Germany; Würzburg University Hospital, Department of Neuroradiology, Josef-Schneider-Straße 11, 97080 Würzburg, Germany
| | - H P Schlemmer
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - C H Ziener
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
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Ziener CH, Kampf T, Kurz FT, Schlemmer HP, Buschle LR. Pseudo-diffusion effects in lung MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 299:1-11. [PMID: 30529849 DOI: 10.1016/j.jmr.2018.11.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
Magnetic resonance imaging of lung tissue is strongly influenced by susceptibility effects between spin-bearing water molecules and air-filled alveoli. The measured lineshape, however, also depends on the interplay between susceptibility effects and blood-flow around alveoli that can be approximated as pseudo-diffusion. Both effects are quantitatively described by the Bloch-Torrey-equation, which was so far only solved for dephasing on the alveolar surface. In this work, we extend this model to the whole range of physiological relevant air volume fractions. The results agree very well with in vivo measurements in human lung tissue.
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Affiliation(s)
- C H Ziener
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - T Kampf
- University of Würzburg, Department of Experimental Physics 5, Am Hubland, 97074 Würzburg, Germany; Würzburg University Hospital, Department of Neuroradiology, Josef-Schneider-Straße 11, 97080 Würzburg, Germany
| | - F T Kurz
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - H P Schlemmer
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - L R Buschle
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; Heidelberg University, Faculty of Physics and Astronomy, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
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Ziener CH, Kampf T, Schlemmer HP, Buschle LR. Spin dephasing in the Gaussian local phase approximation. J Chem Phys 2018; 149:244201. [DOI: 10.1063/1.5050065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- C. H. Ziener
- German Cancer Research Center-DKFZ, E010 Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - T. Kampf
- Department of Diagnostic and Interventional Neuroradiology, Würzburg University Hospital, Josef-Schneider-Straße 11, 97080 Würzburg, Germany
- Department of Experimental Physics 5, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - H.-P. Schlemmer
- German Cancer Research Center-DKFZ, E010 Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - L. R. Buschle
- German Cancer Research Center-DKFZ, E010 Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
- Faculty of Physics and Astronomy, Heidelberg University, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany
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Vessel radius mapping in an extended model of transverse relaxation. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2018; 31:531-551. [DOI: 10.1007/s10334-018-0677-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 01/14/2018] [Accepted: 01/15/2018] [Indexed: 10/18/2022]
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