Lung parenchyma: magnetic susceptibility in MR imaging.

Bergin, Colleen J.; Glover, Gary H.; Pauly, John M.

doi:10.1148/radiology.180.3.1871305

Cited by 152 publications

(100 citation statements)

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“…This decrease is due to the diffusion of the tissue protons in the field gradients created by the differences in the susceptibilities of the tissue and the capillary vascular space. Furthermore, susceptibility-based imaging of lung parenchyma using paired symmetricasymmetric spin echo has been reported (25,26). Since these studies rely on reporting changes in the T2 (or phase) of the protons of the surrounding tissues, their application is severely restricted in the lungs, where the proton concentration is low.…”

Section: Discussionmentioning

confidence: 99%

Indirect detection of lung perfusion using susceptibility‐based hyperpolarized gas imaging

Dimitrov

Insko

Rizi

et al. 2005

Magnetic Resonance Imaging

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Purpose:To address the problem of inadequate signal-tonoise ratio (SNR) encountered in lung perfusion magnetic resonance imaging (MRI) by developing an indirect detection based on the strong hyperpolarized (HP) gas signal. Materials and Methods:Our model is based on detecting the effects of gadolinium (Gd) flowing through lung capillaries by recording the phase of the nearby alveolar HP gas. In a HP gas 3 He phantom we imaged gas phases before and after removing tubes containing paramagnetic solution away from the phantom. We also imaged HP gas phases in pig lungs before and after injection of Gd. Finally, parenchymal spin phase in excised lungs was measured as a function of Gd concentration. Results:In the phantom, the differential phase map displayed a pattern characteristic of a susceptibility-induced dipole field, showing the possibility of an indirect detection. In vivo, the differential phase map showed homogeneous appearance, as expected for uniform perfusion in healthy lungs. Ex vivo, the parenchymal spin phases were shown to depend linearly on Gd concentration. Conclusion:Our method should allow indirect perfusion (Q) and direct ventilation (V) to be assessed simultaneously, thus allowing for diagnosis of V/Q mismatches. The linear dependency of parenchymal spin phase vs. Gd concentration may allow for quantification of lung perfusion.

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Section: Discussionmentioning

confidence: 99%

Indirect detection of lung perfusion using susceptibility‐based hyperpolarized gas imaging

Dimitrov

Insko

Rizi

et al. 2005

Magnetic Resonance Imaging

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“…Since UTE-MRI of the lung was first demonstrated in the early 1990s on a 1.5 T system (28), most of the subsequent studies have been performed on animal MR systems at higher field strengths (14,15,18,22). Only recently, investigators performed UTE-MRI of the lung in animal models using clinical systems at 3.0 T (16,17).…”

Section: Te=01 Ms Te=21 Msmentioning

confidence: 99%

Ultrashort echo time MRI of pulmonary water content: assessment in a sponge phantom at 1.5 and 3.0 Tesla

Molinari¹,

Madhuranthakam²,

Lenkinski³

et al. 2013

Diagn Interv Radiol

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ORIGINAL ARTICLE PURPOSE We aimed to develop a predictive model for lung water content using ultrashort echo time (UTE) magnetic resonance imaging (MRI) and a sponge phantom. MATERIALS AND METHODSImage quality was preliminarily optimized, and the signalto-noise ratio (SNR) of UTE was compared with that obtained from a three-dimensional fast gradient echo (FGRE) sequence. Four predetermined volumes of water (3.5, 3.0, 2.5, and 2.0 mL) were soaked in cellulose foam sponges 1.8 cm 3 in size and were imaged with UTE-MRI at 1.5 and 3.0 Tesla (T). A multiple echo time experiment (range, 0.1-9.6 ms) was conducted, and the T2 signal decay curve was determined at each volume of water. A three-parameter equation was fitted to the measured signal, allowing for the calculation of proton density and T2*. The calculation error of proton density was determined as a function of echo time. The constants that allowed for the determination of unknown volumes of water from the measured proton density were calculated using linear regression. RESULTS UTE-MRI provided excellent image quality for the four phantoms and showed a higher SNR, compared to that of FGRE. Proton density decreased proportionally with the decreases in both lung water and field strength (from 3.5 to 2.0 mL; proton density range at 1.5 T, 30.5-17.3; at 3.0 T, 84.2-41.5). Minimum echo time less than 0.6 ms at 1.5 T and 1 ms at 3.0 T maintained calculation errors for proton density within the range of 0%-10%. The slopes of the lines for determining the unknown volumes of water with UTE-MRI were 0.12±0.003 at 1.5 T and 0.05±0.002 at 3.0 T (P < 0.0001). CONCLUSIONIn a sponge phantom imaged at 1.5 and 3.0 T, unknown volumes of water can be predicted with high accuracy using UTE-MRI.

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“…Recently, it was also shown that HASTE-MRI of the lungs is also feasible at 3 Tesla (T), and that a higher lesion contrast of nodules and infiltrates is observed at 3T when compared with 1.5T (13). For the lungs, however, susceptibility increases at higher field strength, which may degrade the image quality and thus reduce the effectiveness of lung MRI (14).…”

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confidence: 99%

Half‐fourier‐acquisition single‐shot turbo spin‐echo (HASTE) MRI of the lung at 3 Tesla using parallel imaging with 32‐receiver channel technology

Henzler

Dietrich

Krissak

et al. 2009

Magnetic Resonance Imaging

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Purpose:To assess the feasibility of half-Fourier-acquisition single-shot turbo spin-echo (HASTE) of the lung at 3 Tesla (T) using parallel imaging with a prototype of a 32-channel torso array coil, and to determine the optimum acceleration factor for the delineation of intrapulmonary anatomy. Materials and Methods:Nine volunteers were examined on a 32-channel 3T MRI system using a prototype 32-channeltorso-array-coil. HASTE-MRI of the lung was acquired at both, end-inspiratory and end-expiratory breathhold with parallel imaging (Generalized autocalibrating partially parallel acquisitions ϭ GRAPPA) using acceleration factors ranging between R ϭ 1 (TE ϭ 42 ms) and R ϭ 6 (TE ϭ 16 ms). The image quality of intrapulmonary anatomy and subjectively perceived noise level was analyzed by two radiologists in consensus. In addition quantitative measurements of the signalto-noise ratio (SNR) of HASTE with different acceleration factors were assessed in phantom measurements. Results:Using an acceleration factor of R ϭ 4 image blurring was substantially reduced compared with lower acceleration factors resulting in sharp delineation of intrapulmonary structures in expiratory scans. For inspiratory scans an acceleration factor of 2 provided the best image quality. Expiratory scans had a higher subjectively perceived SNR than inspiratory scans. Conclusion:Using optimized multi-element coil geometry HASTE-MRI of the lung is feasible at 3T with acceleration factors up to 4. Compared with nonaccelerated acquisitions, shorter echo times and reduced image blurring are achieved. Expiratory scanning may be favorable to compensate for susceptibility associated signal loss at 3T.

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Lung parenchyma: magnetic susceptibility in MR imaging.

Cited by 152 publications

References 0 publications

Indirect detection of lung perfusion using susceptibility‐based hyperpolarized gas imaging

Indirect detection of lung perfusion using susceptibility‐based hyperpolarized gas imaging

Ultrashort echo time MRI of pulmonary water content: assessment in a sponge phantom at 1.5 and 3.0 Tesla

Half‐fourier‐acquisition single‐shot turbo spin‐echo (HASTE) MRI of the lung at 3 Tesla using parallel imaging with 32‐receiver channel technology

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