| Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy. | |
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MedLine Citation:
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PMID: 20508321 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s)(-1) in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized. |
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Authors:
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Peter J Haar; William C Broaddus; Zhi-jian Chen; Panos P Fatouros; George T Gillies; Frank D Corwin |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2010-05-28 |
Journal Detail:
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Title: Physics in medicine and biology Volume: 55 ISSN: 1361-6560 ISO Abbreviation: Phys Med Biol Publication Date: 2010 Jun |
Date Detail:
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Created Date: 2010-05-28 Completed Date: 2010-09-01 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 0401220 Medline TA: Phys Med Biol Country: England |
Other Details:
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Languages: eng Pagination: 3451-65 Citation Subset: IM |
Affiliation:
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Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Brain / cytology* Contrast Media / diagnostic use Convection* Extracellular Space / metabolism Gadolinium DTPA / diagnostic use* Magnetic Resonance Imaging* Male Rats Rats, Sprague-Dawley Spectrophotometry, Atomic* |
| Grant Support | |
ID/Acronym/Agency:
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1 F31 NS048813-01/NS/NINDS NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Contrast Media; 80529-93-7/Gadolinium DTPA |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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