Motion suppression improves quantification of rat liver volume in vivo by magnetic resonance imaging

Cockman, Michael D.; Hayes, D. A.; Kuzmak, Barbara

doi:10.1002/mrm.1910300313

Cited by 9 publications

(4 citation statements)

References 4 publications

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“…Motion makes shimming and spatial localization very difficult (17,181, Moreover, water and fat suppression is insufficient and severe baseline distor- tions due to cardiac, respiratory, and peristaltic motions can occur. Figure 2 and Table 1 demonstrate the effects of gating on the performance of the NMR spectroscopy (STEAM) experiments.…”

Section: Performance Of Steam and Pressmentioning

confidence: 99%

Migration and Accumulation of Silicone in the Liver of Women with Silicone Gel‐Filled Breast Implants

Pfleiderer

Garrido

1995

Magnetic Resonance in Med

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1H NMR localized spectroscopy (STEAM), combined with echocardiography (ECG), respiratory gating, and water and fat suppression, was used to quantify silicone concentrations in the liver of women with silicone gel-filled breast implants. Localized spectroscopy was performed on 15 patients with silicone gel-filled breast prostheses and on eight volunteers with no implants. The 1H spectra in the liver of patients showed silicone resonances from 0.3 to -0.8 ppm, attributable to protons in the methyl groups of silicone. The presence of silicone in the liver could first be detected 3-4 years after breast prostheses implantation. No correlation between silicone concentrations and implantation times was observed. However, our results indicated that silicone concentrations may reflect implant integrity: detectable silicone concentrations in the liver appeared to be higher when the implants were ruptured than when the implants appeared intact. Moreover, new resonances in the range of -2.6 to -4 ppm were observed in most patients after long-term implantation. As these species increase with implantation time, the new resonances may reflect chemically changed silicone (paramagnetically shifted silicon complexes bound to iron) accumulated over time. The sensitivity of 1H NMR localized spectroscopy is sufficient to detect silicon concentrations as low as 0.20 mM. Results from one patient whose implants had been removed 14 months prior to the NMR examination showed no detectable silicone in the liver, indicating that it may have been excreted via bile or degraded to silica and high coordinated silicon complexes. Quantitative 1H localized spectroscopy of the liver in women with silicone gel-filled breast implants may provide valuable information concerning silicone accumulation and degradation in vivo, as well as about the kinetics of its elimination from the body after implant removal.

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Section: Performance Of Steam and Pressmentioning

confidence: 99%

Migration and Accumulation of Silicone in the Liver of Women with Silicone Gel‐Filled Breast Implants

Pfleiderer

Garrido

1995

Magnetic Resonance in Med

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“…Magnetic resonance imaging (MRI) is widely used in biology and clinical diagnosis and research to provide soft tissue anatomical and functional information noninvasively. It has been used to measure naïve rat liver volumes in vivo (2,18), and to study the effects of partial surgical hepatectomy to treat a variety of human liver diseases, and subsequent outcomes (1,5,19). There is also a suggestion that nuclear magnetic resonance relaxation times, which are related to the molecular and cellular environments of tissue water, may be sensitive to pathophysiologica l changes in regenerating (16) or transplanted (4) liver.…”

Section: Introductionmentioning

confidence: 99%

Longitudinal Magnetic Resonance Imaging Quantitation of Rat Liver Regeneration After Partial Hepatectomy

et al. 2002

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This report demonstrates the advantage s of using a noninvasive soft tissue imaging technique-magnetic resonance imaging (MRI)-to monitor liver regeneration after 70% partial hepatectomy in the rat in a longitudinal manner. Six animals were scanned prior to and on 6 subsequen t occasions up to 9 days after surgical removal of the median and left lateral lobes. Within the observed time frame liver volumes were restored to approximately 88% of presurgery values. The rate of regeneration was maximal at 1.5 days, which coincided with the maximum increase of Mitotic Index-a measure of cell proliferation, determined in a subsequen t study. Pre-and postpartial hepatectomy measurements remove two potentially confoundin g unknowns -the presurgery liver volume, and the amount of liver actually excised. 3D reconstruction s of the liver effectively illustrate the morphologica l changes associated with the procedure, and the regrowth of liver tissue.

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“…It has been applied successfully in mouse cardiac imaging, for instance to reduce flow artefacts (12,13), but leads to longer gradient pulses and TEs, compromising the signal, particularly at higher field strengths. Motion artefacts may also be reduced by multiple signal averaging (14) and image registration methods (15).…”

Section: Introductionmentioning

confidence: 99%

PROPELLER for motion‐robust imaging of in vivo mouse abdomen at 9.4 T

2010

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In vivo high-field MRI in the abdomen of small animals is technically challenging because of the small voxel sizes, short T(2) and physiological motion. In standard Cartesian sampling, respiratory and gastrointestinal motion can lead to ghosting artefacts. Although respiratory triggering and navigator echoes can either avoid or compensate for motion, they can lead to variable TRs, require invasive intubation and ventilation, or extend TEs. A self-navigated fast spin echo (FSE)-based periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) acquisition was implemented at 9.4 T to enable high-resolution in vivo MRI of mouse abdomen without the use of additional navigators or triggering. T(2)-weighted FSE-PROPELLER data were compared with single-shot FSE and multi-shot FSE data with and without triggering. Single-shot methods, although rapid and robust to motion, demonstrated strong blurring. Multi-shot FSE data showed better resolution, but suffered from marked blurring in the phase-encoding direction and motion in between shots, leading to ghosting artefacts. When respiratory triggering was used, motion artefacts were largely avoided. However, TRs and acquisition times were lengthened by up to approximately 20%. The PROPELLER data showed a 25% and 61% improvement in signal-to-noise ratio and contrast-to-noise ratio, respectively, compared with multi-shot FSE data, together with a 35% reduction in artefact power. A qualitative comparison between acquisition methods using diffusion-weighted imaging was performed. The results were similar, with the exception that respiratory triggering was unable to exclude major motion artefacts as a result of the sensitisation to motion by the diffusion gradients. The PROPELLER data were of consistently higher quality. Considerations specific to the use of PROPELLER at high field are discussed, including the selection of practical blade widths and the effects on contrast, resolution and artefacts.

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Motion suppression improves quantification of rat liver volume in vivo by magnetic resonance imaging

Cited by 9 publications

References 4 publications

Migration and Accumulation of Silicone in the Liver of Women with Silicone Gel‐Filled Breast Implants

Migration and Accumulation of Silicone in the Liver of Women with Silicone Gel‐Filled Breast Implants

Longitudinal Magnetic Resonance Imaging Quantitation of Rat Liver Regeneration After Partial Hepatectomy

PROPELLER for motion‐robust imaging of in vivo mouse abdomen at 9.4 T

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