Apparent Diffusion Coefficients in Spinal Cord Transplants and Surrounding White Matter Correlate With Degree of Axonal Dieback After Injury in Rats

Abstract Background: Diffusion and perfusion MRI can invasively define physical properties and angiogenic features of tumors, and guide the individual treatment. The purpose of this study was to investigate whether the diffusion and perfusion MRI parameters of primary central nervous system lymphomas (PCNSLs) are related to the tumor locations.Methods: We retrospectively reviewed the diffusion, perfusion, and conventional MRI of 68 patients with PCNSLs at different locations (group 1: cortical gray matter, group 2: white matter, group 3: deep gray matter). Relative maximum cerebral blood volume (rCBVmax) from perfusion MRI, minimum apparent diffusion coefficients (ADCmin) from DWI of each group were calculated and compared by one-way ANOVA test. In addition, we compared the mean apparent diffusion coefficients (ADCmean) in three different regions of control group.Results: The rCBVmax of PCNSLs yielded the lowest value in the white matter group, and the highest value in the cortical gray matter group (P < 0.001). However, the ADCmin of each subgroup was not statistically different. The ADCmean of each subgroup in control group was not statistically different.Conclusion: Our study confirms that rCBVmax of PCNSLs are related to the tumor location, and provide simple but effective information for guiding the clinical practice of PCNSLs.

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Increased Apparent Diffusion Coefficients on MRI Linked with Matrix Metalloproteinases and Edema in White Matter after Bilateral Carotid Artery Occlusion in Rats

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2008.121 ◽

2008 ◽

Vol 29 (2) ◽

pp. 308-316 ◽

Cited By ~ 41

Author(s):

Rohit Sood ◽

Yi Yang ◽

Saeid Taheri ◽

Eduardo Candelario-Jalil ◽

Eduardo Y Estrada ◽

...

Keyword(s):

White Matter ◽

Matrix Metalloproteinases ◽

Carotid Artery ◽

Diffusion Coefficients ◽

Artery Occlusion ◽

Carotid Artery Occlusion ◽

Apparent Diffusion Coefficients ◽

Bilateral Carotid ◽

Apparent Diffusion

White matter (WM) injury after bilateral common carotid artery occlusion (BCAO) in rat is associated with disruption of the blood—brain barrier (BBB) by matrix metalloproteinases (MMPs). We hypothesized that WM injury as seen on magnetic resonance imaging (MRI) would correlate with regions of increased MMP activity. MRI was performed 3 days after BCAO surgery in rats. Apparent diffusion coefficients (ADC) were calculated and vascular permeability was quantified by the multiple-time graphical analysis (MTGA) method, using gadolinium-diethylenetriamine pentaacid (Gd-DTPA). After MRI, one group of animals had BBB permeability measured in the WM with 14C-sucrose, and another had Evans blue (EB) injected for fluorescent microscopy for MMP-2, MMP-9, tight junction proteins (TJPs), and in situ zymography. We found that ADC values were increased in WM in BCAO rats compared with controls ( P< 0.05). WM with increased ADC had leakage of EB. MMP-2 and MMP-9 activity on in situ zymograms corresponded with leakage of EB. Although increased permeability to EB could be visualized, permeability quantification with 14C-sucrose and Gd-DTPA failed to show increases and TJPs were intact. We propose that increased ADC, which is a marker of vasogenic edema, is related to activity of MMP-2 and MMP-9. MRI provides unique information that can be used to guide tissue studies of WM injury.

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