Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex

Brasch, R. C.; Weinmann, HJ; Ge, Wesbey

doi:10.2214/ajr.142.3.625

Cited by 260 publications

(96 citation statements)

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“…The high SI areas seen on T1-weighted images in TO2 hamsters were considered to represent accumulation of Gd-DTPA in the matrix. [26][27][28][29][30] The enhanced areas seen on MRI in Bio 14.6 hamsters were reported to be consistent with fibrotic lesions, 27) and were also reported to be associated with inflammatory changes, including neovascularization, 28) enhanced vascular permeability, and edema. 31) Pooling of Gd-DTPA causes contrast enhancement and the enhanced areas seen in our TO2 hamsters were consistent with areas of progressive interstitial fibrosis revealed by histopathological examination from 8 weeks through to 29 weeks of age.…”

Section: Mri and Pathological Findingsmentioning

confidence: 99%

<b>Carvedilol Prevents Myocardial Fibrosis in Hamsters</b>

et al. 2006

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SUMMARYThe objective of the present study was to determine if carvedilol protects against myocardial degeneration and fibrotic change, and reduces mortality in TO2 hamsters.Carvedilol was administered intraperitoneally to 8 week-old TO2 hamsters for 21 weeks at a dose of 11 mg/kg/day. There were 15 TO2 hamsters in the carvedilol group (group C) and 10 in the untreated group (group N). The control group consisted of 11 Fb hamsters (group F). The mortality rate was determined from the number of surviving hamsters after 29 weeks. Myocardial fibrosis was evaluated by MRI and histopathological examination. EF and LVDd were determined by echocardiography at 8 and 29 weeks, while the MRI score was calculated at 29 weeks.Mortality, histopathological fibrosis, and MRI score were all lower in group C than in group N. Carvedilol had a protective effect against myocardial fibrosis and decreased the mortality rate in TO2 hamsters. ( 2-4) Following this, β-blocker therapy became used for the treatment of chronic heart failure.We previously performed MRI studies in a hamster model of cardiomyopathy (Bio 14.6 hamster) and found abnormal sites of enhancement as well as delayed enhancement. We proposed that the enhanced areas were regions of myocardial degeneration and fibrosis. 5) Carvedilol is a β-blocker that also has α-blocking and antioxidant effects, which have been shown to reduce the mortality rate of patients with moderate to severe chronic cardiac failure by 35% to 65%, in addition to also lowering the rehospitalization rate. 3,4) In the present study, we assessed the effects of carvedilol [6][7][8] in another hamster model of dilated cardiomyopathy, the BioFrom the

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Section: Mri and Pathological Findingsmentioning

confidence: 99%

<b>Carvedilol Prevents Myocardial Fibrosis in Hamsters</b>

et al. 2006

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“…Ordinarily, because every spin's precession frequency is proportional to the local magnetic field, the frequency spectrum I(ω) faithfully mirrors the spin density Diffusion is generally expected to contribute to blurring of images. For example, studies on paramagnetic contrast agents have shown that biological contours are blurred since contrast agents affect not only the tissue compartments to which they are confined but, through diffusive water exchange, also affect surrounding regions (7,8,9,10,11). Thus, one might expect that diffusion blurring should become prevalent in microscopic imaging, yet this may not necessarily be the case.…”

Section: Theorymentioning

confidence: 99%

“…The other diffusion domains considered below are three-dimensional with spherical boundaries, and for those the boundary conditions corresponding to [7] require that the radial component of the gradient of m ⊥ ( r, t) vanishes at the barrier.…”

Section: Theorymentioning

confidence: 99%

Edge enhancement by diffusion in microscopic magnetic resonance imaging

Pütz

Barsky

Schulten

1992

Journal of Magnetic Resonance (1969)

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In microscopic MRI (∼ 10 µm resolution), diffusion boundaries impermeable to water on a millisecond time scale distort the line shape function of the observed frequency spectra from the transverse magnetization in a manner similar to motional narrowing in MR spectroscopy. Reconstruction techniques developed for macroscopic imaging interpret these distortions as spatial deformations of objects. This distortion of frequency spectra is demonstrated for geometrically simple objects, and it is shown how in such cases the reconstructed images should be interpreted and how diffusioninduced distortions in frequency space may actually be exploited to enhance image contrast around compartmental boundaries. The distortions are properly described by Kubo's line shape function for which suitable numerical algorithms are provided.A parameter is introduced that provides an estimation of the extent of diffusioninduced distortions which can vary from an enhancement of image intensity near boundaries to, for extreme motional narrowing, a focusing of image intensity around compartment centers.

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“…2 Routine Gd-enhanced MR imaging plays a crucial role in the assessment of gliomas. 6 However, Gd-enhancement has limitations in that it identifies the presence of an abnormal blood-brain barrier, 7 rather than physiology, histology, genetic aberrations, or molecular events. With the advent of molecular and genetic treatment strategies aimed at gliomas, 3,4 more sophisticated radiologic methods are necessary to follow these tumors, including assessment of therapy and the detection of tumor progression.…”

mentioning

confidence: 99%

Apparent Diffusion Coefficient of Glial Neoplasms: Correlation with Fluorodeoxyglucose–Positron-Emission Tomography and Gadolinium-Enhanced MR Imaging

Holodny¹,

Makeyev²,

Beattie³

et al. 2010

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:Gd-enhancement provides essential information in the assessment of brain tumors. However, enhancement does not always correlate with histology or disease activity, especially in the setting of current therapies. Our aim was to compare FDG-PET scans to ADC maps and Gd-enhanced MR images in patients with glial neoplasms to assess whether DWI might offer information not available on routine MR imaging sequences and whether such findings have prognostic significance.

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Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex

Cited by 260 publications

References 0 publications

<b>Carvedilol Prevents Myocardial Fibrosis in Hamsters</b>

<b>Carvedilol Prevents Myocardial Fibrosis in Hamsters</b>

Edge enhancement by diffusion in microscopic magnetic resonance imaging

Apparent Diffusion Coefficient of Glial Neoplasms: Correlation with Fluorodeoxyglucose–Positron-Emission Tomography and Gadolinium-Enhanced MR Imaging

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