Differentiation of chronic lesions after stroke in stroke‐prone spontaneously hypertensive rats using diffusion weighted MRI

Takahashi, Masaya; Fritz‐Zieroth, Bernhard; Chikugo, Takaaki; Ogawa, Hiroshi

doi:10.1002/mrm.1910300411

Cited by 39 publications

(16 citation statements)

References 13 publications

(2 reference statements)

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“…After an initial rapid decline, the ADC appears to return to normal and then increases above baseline at 1.5-2 days in animal models of focal ischemia (111, and a similar trend has been observed in humans (12). This suggests that measurement of ADC values may, in combination with T, and T, measurements, provide an indication of the age of a subacute to chronic stroke lesion (13). The greatest potential clinical application of DWI, however, is the evaluation of hyperacute stroke when possible therapies can be administered.…”

Section: Introductionsupporting

confidence: 53%

Navigated Diffusion Imaging of Normal and Ischemic Human Brain

Crespigny¹,

Marks²,

Enzmann³

et al. 1995

Magnetic Resonance in Med

161

100

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The principal barrier to clinical application of diffusion-weighted MR imaging is the severe image degradation caused by patient motion. One way to compensate for motion effects is the use of a "navigator echo" phase correction scheme. In this work, a modification of this technique is introduced, in which the phase correction step is performed in the frequency domain (i.e., after the readout Fourier transform). This significantly improves the robustness of the navigator echo approach and, when combined with cardiac gating, allows diagnostic quality diffusion-weighted images of the brain to be routinely obtained on standard clinical scanner hardware. The technique was evaluated in phantom studies and in 23 humans (3 normal volunteers and 20 patients). Diffusion anisotropy and apparent diffusion coefficient maps were generated from the image data and showed decreased apparent diffusion in acute stroke lesions and, in several cases, increased apparent diffusion in chronic stroke lesions.

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Section: Introductionsupporting

confidence: 53%

Navigated Diffusion Imaging of Normal and Ischemic Human Brain

Crespigny¹,

Marks²,

Enzmann³

et al. 1995

Magnetic Resonance in Med

161

100

View full text Add to dashboard Cite

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“…This very significant ADC reduction in ischemic tissue appears as regional high signal intensity in DWI. Over the last 5 years, a number of studies have reported consistent observations that there is close correlation between ADC reduction and the degree of ischemic injury (4,25,28,30,35,43,45,49,52,65,70,(80)(81)(82)(83). The regional ADC values and the resulting contrast in DWI provide a noninvasive tool for monitoring the time evolution and spatial expansion of ischemic lesions.…”

mentioning

confidence: 92%

“…Various investigations based on MCA occlusion techniques such as electrocauterization and the catheter-guided thread were performed in rats, cats and rabbits, and all this work supported the original observation by MOSELEY et al (51,53). Quantitative evaluation of the apparent diffusion coefficient (ADC) in animal models clearly demonstrated that ADC in the subacute and acute ischemic brain falls by typically 30-60% in the first hours, irrespective of species (25,30,49,52,70). This very significant ADC reduction in ischemic tissue appears as regional high signal intensity in DWI.…”

mentioning

confidence: 99%

Diffusion-weighted MR imaging of acute cerebral ischemia

Chen

Hindmarsh

1998

Acta Radiol

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Diffusion-weighted MR imaging has been used in studies on experimental animal models and on patients with acute cerebral ischemia. Compared with CT and conventional MR techniques, diffusion-weighted imaging can provide earlier and more precise detection of the location and the extent of an ischemic lesion during the critical first few hours after the onset of stroke. Quantitative apparent diffusion coefficient (ADC) mapping of the brain water can also be carried out by recording a series of diffusion-weighted images with different amplitudes of the displacement encoding gradients. ADC maps can provide important information about the extra- and intracellular water homeostasis. ADC reduction of the tissue water is one of the early signals of the pathophysiological cascade resulting from ischemic tissue injury. Diffusion MR imaging has become a valuable tool in stroke research. It may also prove a valuable tool in monitoring the efficiency of therapeutic effects in stroke patients. It is our intention to provide an overview of the recent development in this area with emphasis on the diffusion-weighted MR techniques, and to discuss the possible underlying biophysical mechanisms responsible for the contrast of diffusion-weighted imaging.

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“…Takahashi et al [53] found an increase in ADC with a rat stroke model in the chronic stage was related to the presence of gliosis. In this study at 1 day post-injection, there was a trend toward increased %DWI in the ipsilateral posterior hippocampus, followed by decreased %DWI after 1 week post-injection, though the change only reached significance for the ADC measurements at the 28 day time point.…”

Section: Diffusion-weighted Imagingmentioning

confidence: 99%

Metabolic and pathological effects of temporal lobe epilepsy in rat brain detected by proton spectroscopy and imaging

et al. 1997

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The goal of these experiments was to test the hypothesis that in an animal model of temporal lobe epilepsy (TLE), magnetic resonance spectroscopic measurement of N-acetylaspartate (NAA) and other metabolites, together with magnetic resonance imaging, provides a sensitive in vivo method to localize and monitor the progression of neuronal cell death and gliosis. Seizures were induced in rats by unilateral hippocampal injection of kainate. Magnetic resonance measurements were made from 1 to 84 days using proton spectroscopic imaging ( 1 H-MRSI), T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI). The results were compared with findings on histological sections. Decreased NAA and creatine levels and increased apparent diffusion coefficient of water were found in the ipsilateral hippocampus after 14 days where neuronal loss and gliosis were observed. In the contralateral hippocampus a significant increase of choline level was observed. These results suggest that 1 H-MRSI is a useful in vivo method for localizing neuronal loss and may also indicate additional pathological and metabolic alterations. In addition, DWI may be a useful method for in vivo detection of tissue alterations due to TLE.

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Differentiation of chronic lesions after stroke in stroke‐prone spontaneously hypertensive rats using diffusion weighted MRI

Cited by 39 publications

References 13 publications

Navigated Diffusion Imaging of Normal and Ischemic Human Brain

Navigated Diffusion Imaging of Normal and Ischemic Human Brain

Diffusion-weighted MR imaging of acute cerebral ischemia

Metabolic and pathological effects of temporal lobe epilepsy in rat brain detected by proton spectroscopy and imaging

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