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Influence of blood/...
Influence of blood/tissue differences in contrast agent relaxivity on tracer based MR perfusion measurements
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- Morell, Arvid (author)
- Uppsala universitet,Radiologi
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- Lennmyr, Fredrik (author)
- Uppsala universitet,Anestesiologi och intensivvård
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- Jonsson, Ove (author)
- Uppsala universitet,Thoraxkirurgi
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- Tovedal, Thomas (author)
- Uppsala universitet,Anestesiologi och intensivvård
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- Pettersson, Jean (author)
- Uppsala universitet,Analytisk kemi
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- Bergquist, Jonas (author)
- Uppsala universitet,Analytisk kemi
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- Zemgulis, Vitas (author)
- Uppsala universitet,Thoraxkirurgi
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- Myrdal Einarsson, Gunnar (author)
- Uppsala universitet,Thoraxkirurgi
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- Thelin, Stefan (author)
- Uppsala universitet,Thoraxkirurgi
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- Ahlström, Håkan (author)
- Uppsala universitet,Radiologi
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- Bjørnerud, Atle (author)
- Uppsala universitet,Radiologi
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(creator_code:org_t)
- 2014-06-28
- 2015
- English.
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In: Magnetic Resonance Materials in Physics, Biology and Medicine. - : Springer Science and Business Media LLC. - 0968-5243 .- 1352-8661. ; 28:2, s. 135-147
- Related links:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
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- PURPOSE:Perfusion assessment by monitoring the transport of a tracer bolus depends critically on conversion of signal intensity into tracer concentration. Two main assumptions are generally applied for this conversion; (1) contrast agent relaxivity is identical in blood and tissue, (2) change in signal intensity depends only on the primary relaxation effect. The purpose of the study was to assess the validity and influence of these assumptions.MATERIALS AND METHODS:Blood and cerebral tissue relaxivities r1, r2, and r2* for gadodiamide were measured in four pigs at 1.5 T. Gadolinium concentration was determined by inductively coupled plasma atomic emission spectroscopy. Influence of the relaxivities, secondary relaxation effects and choice of singular value decomposition (SVD) regularization threshold was studied by simulations.RESULTS:In vivo relaxivities relative to blood concentration [in s-1 mM-1 for blood, gray matter (GM), white matter (WM)] were for r1 (2.614 ± 1.061, 0.010 ± 0.001, 0.004 ± 0.002), r2 (5.088 ± 0.952, 0.091 ± 0.008, 0.059 ± 0.014), and r2* (13.292 ± 3.928, 1.696 ± 0.157, 0.910 ± 0.139). Although substantial, by a nonparametric test for paired samples, the differences were not statistically significant. The GM to WM blood volume ratio was estimated to 2.6 ± 0.9 by r1, 1.6 ± 0.3 by r2, and 1.9 ± 0.2 by r2*. Secondary relaxation was found to reduce the tissue blood flow, as did the SVD regularization threshold.CONCLUSION:Contrast agent relaxivity is not identical in blood and tissue leading to substantial errors. Further errors are introduced by secondary relaxation effects and the SVD regularization.
Subject headings
- MEDICIN OCH HÄLSOVETENSKAP -- Klinisk medicin -- Radiologi och bildbehandling (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Clinical Medicine -- Radiology, Nuclear Medicine and Medical Imaging (hsv//eng)
- NATURVETENSKAP -- Kemi -- Analytisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Analytical Chemistry (hsv//eng)
Keyword
- MRI
- relaxivity
- contrast agent
- perfusion
- Radiologi
- Radiology
- Medical Radiophysics
- Medicinsk radiofysik
Publication and Content Type
- ref (subject category)
- art (subject category)
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- By the author/editor
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Morell, Arvid
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Lennmyr, Fredrik
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Jonsson, Ove
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Tovedal, Thomas
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Pettersson, Jean
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Bergquist, Jonas
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show more...
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Zemgulis, Vitas
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Myrdal Einarsson ...
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Thelin, Stefan
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Ahlström, Håkan
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Bjørnerud, Atle
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show less...
- About the subject
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- MEDICAL AND HEALTH SCIENCES
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MEDICAL AND HEAL ...
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and Clinical Medicin ...
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and Radiology Nuclea ...
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- NATURAL SCIENCES
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NATURAL SCIENCES
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and Chemical Science ...
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and Analytical Chemi ...
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Magnetic Resonan ...
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Uppsala University