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Eriksson, Rolf
Publications (4 of 4) Show all publications
Eriksson, R., Johansson, L., Bjerner, T., Karlsson, J. O. & Ahlström, H. (2006). Contrast enhancement of manganese-hydroxypropyl-tetraacetic acid, an MR contrast agent with potential for detecting differences in myocardial blood flow. Journal of Magnetic Resonance Imaging, 24(4), 858-863
Open this publication in new window or tab >>Contrast enhancement of manganese-hydroxypropyl-tetraacetic acid, an MR contrast agent with potential for detecting differences in myocardial blood flow
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2006 (English)In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 24, no 4, p. 858-863Article in journal (Refereed) Published
Abstract [en]

Purpose: To determine whether the contrast agent MnHPTA has potential for detecting differences in myocardial blood flow.

Materials and Methods: R1 in the myocardium was calculated from MR signal intensity measurements in 18 pigs after intravenous injection of 5, 15, or 25 mu mol MnHPTA/kg body weight. Measurements were made in each animal after administration at rest and during dobutamine-induced stress.

Results: A difference of approximately 0.1 see(-1) in the R1 increase between rest and stress still remained 31 minutes after administration of 25 mu mol MnHPTA/kg body weight. When two consecutive MnHPTA injections were performed, the second injection induced a lower R1 increase than the corresponding first injection.

Conclusion: MnHPTA at a dose of 25 mu mol/kg body weight (b.w.) has the potential to detect perfusion differences in myocardium. When two consecutive injections of MnHPTA were administered, the RI change after the second injection was affected by the earlier administration. Therefore, a protocol including more than one administration is not ideal for this contrast agent.

Keywords
manganese, magnetic resonance, myocardium, contrast agent, animal study
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-25041 (URN)10.1002/jmri.20718 (DOI)000240882000017 ()16958069 (PubMedID)
Available from: 2007-02-09 Created: 2007-02-09 Last updated: 2017-12-07Bibliographically approved
Hedström, E., Arheden, H., Eriksson, R., Johansson, L., Ahlström, H. & Bjerner, T. (2006). Importance of perfusion in myocardial viability studies using delayed contrast-enhanced magnetic resonance imaging. Journal of Magnetic Resonance Imaging, 24(1), 77-83
Open this publication in new window or tab >>Importance of perfusion in myocardial viability studies using delayed contrast-enhanced magnetic resonance imaging
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2006 (English)In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 24, no 1, p. 77-83Article in journal (Refereed) Published
Abstract [en]

PURPOSE: To investigate whether an extracellular gadolinium-(Gd)-based contrast agent (CA) enters nonperfused myocardium during acute coronary occlusion, and whether nonperfused myocardium presents as hyperintense in delayed contrast-enhanced (DE) MR images in the absence of CA in that region. MATERIALS AND METHODS: The left anterior descending coronary artery (LAD) was occluded for 200 minutes in six pigs. The longitudinal relaxation rate (R(1)) in blood, perfused myocardium, and nonperfused myocardium was repeatedly measured using a Look-Locker sequence before and during the first hour after administration of Gd-DTPA-BMA. RESULTS: While blood and perfused myocardium showed a major increase in R(1) after CA administration, nonperfused myocardium did not. R(1) in nonperfused myocardium was significantly lower than in blood and perfused myocardium during the first hour after CA administration. When the signal from perfused myocardium was nulled, demarcation of the hyperintense nonperfused myocardium was achieved in all of the study animals. CONCLUSION: Gd-DTPA-BMA does not enter ischemic myocardium within one hour after administration during acute coronary occlusion. The ischemic region with complete absence of CA still appears bright when the signal from perfused myocardium is nulled using inversion-recovery DE-MRI. This finding is important for understanding the basic pathophysiology of inversion-recovery viability imaging, as well as for imaging of acute coronary syndromes.

Keywords
Animals, Contrast Media/pharmacology, Coronary Disease/pathology, Coronary Vessels/pathology, Female, Gadolinium/pharmacology, Ischemia/pathology, Magnetic Resonance Imaging/*methods, Male, Myocardial Infarction/pathology, Myocardium/*pathology, Perfusion, Swine, Time Factors
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-25044 (URN)10.1002/jmri.20604 (DOI)000238894900010 ()16755547 (PubMedID)
Available from: 2007-02-09 Created: 2007-02-09 Last updated: 2017-12-07Bibliographically approved
Eriksson, R., Johansson, L., Bjerner, T. & Ahlström, H. (2004). Dobutamine-induced stress affects intracellular uptake of manganese: a quantitative magnetic resonance imaging study in pigs. Journal of Magnetic Resonance Imaging, 21(4), 360-364
Open this publication in new window or tab >>Dobutamine-induced stress affects intracellular uptake of manganese: a quantitative magnetic resonance imaging study in pigs
2004 (English)In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 21, no 4, p. 360-364Article in journal (Refereed) Published
Abstract [en]

PURPOSE:

To determine whether there are differences in increase in longitudinal relaxation rate (DeltaR1) in the myocardium between bolus administration of Mn(2+) ions during rest and during dobutamine-induced stress and, additionally, to determine whether there are differences in DeltaR1 between bolus injection and infusion of Mn(2+) ions during dobutamine-induced stress.

MATERIALS AND METHODS:

Pigs were divided into three groups with six pigs in each group. All animals received 15 mumol MnCl(2)/kg of body weight (b.w.) intravenously either as a bolus injection (groups 1 and 2) or as an infusion over one minute (group 3). The animals in groups 2 and 3 were subjected to dobutamine stress before injection of MnCl(2), while those in group 1 were not given dobutamine. T1 was quantified in the myocardium and left ventricular blood pool before contrast injection and repeatedly during a one-hour postinjection period.

RESULTS:

A significant difference in DeltaR1 between the groups with and the group without dobutamine stress was noted in the myocardium up to 45 minutes after contrast agent injection. No such significant difference was found between pigs that received the contrast agent as a bolus injection compared to infusion.

CONCLUSION:

Dobutamine stress increases uptake of manganese ions in the myocardium. This increase was independent of whether the contrast agent was administered as a bolus injection or as an infusion.

Keywords
dobutamine, manganese, magnetic resonance, myocardium, MEMRI
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-69878 (URN)10.1002/jmri.20279 (DOI)15779028 (PubMedID)
Available from: 2005-04-12 Created: 2005-04-12 Last updated: 2017-11-21Bibliographically approved
Eriksson, R., Johansson, L., Bjerner, T., Briley Saebo, K. & Ahlström, H. (2004). Uptake of MnCl2 and mangafodipir trisodium in the myocardium: a magnetic resonance imaging study in pigs. Journal of Magnetic Resonance Imaging, 19(5), 564-569
Open this publication in new window or tab >>Uptake of MnCl2 and mangafodipir trisodium in the myocardium: a magnetic resonance imaging study in pigs
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2004 (English)In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 19, no 5, p. 564-569Article in journal (Refereed) Published
Abstract [en]

PURPOSE:

To examine the changes in the longitudinal relaxation times (DeltaR1) induced in pig myocardium and blood following injections of 5, 10, and 15 micromol mangafodipir trisodium (Mn-DPDP) or MnCl2/kg of body weight (b.w.).

MATERIALS AND METHODS:

Twelve pigs were divided into two groups, one group receiving MnCl2 and the other receiving Mn-DPDP. Three consecutive doses of contrast agent (5, 10, and 15 micromol/kg of b.w.) were injected in each animal with a 40-minute time interval between each dose. Measurements of T1 in blood and myocardium were made 5, 15, 25, and 35 minutes after each injection. Additionally, relaxivity measurements in blood samples were performed.

RESULTS:

An increase in myocardial R1 was observed for both contrast agents at all concentration levels tested. This increase peaked 5 minutes after injection and then declined. An increase could still be detected 35 minutes after injection. The effect was larger when using MnCl2 than when using Mn-DPDP.

CONCLUSION:

The dissociation kinetics of Mn2+ from the DPDP ligand limits the relaxation increase of Mn-DPDP relative to that of MnCl2. On the other hand, the toxicity of MnCl2 may exclude it from clinical use.

Keywords
Animals, Contrast Media/administration & dosage/*pharmacokinetics, Edetic Acid/administration & dosage/*analogs & derivatives/blood/*pharmacokinetics, Female, Magnesium Chloride/administration & dosage/blood/*pharmacokinetics, Magnetic Resonance Imaging, Male, Models; Animal, Myocardium/*metabolism, Pyridoxal Phosphate/administration & dosage/*analogs & derivatives/blood/*pharmacokinetics, Research Support; Non-U.S. Gov't, Swine
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-72805 (URN)10.1002/jmri.20038 (DOI)15112305 (PubMedID)
Available from: 2005-09-26 Created: 2005-09-26 Last updated: 2017-12-14Bibliographically approved
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