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Laissy J. Editorial for “Comparison of Three Ultrasmall, Superparamagnetic Iron Oxide Nanoparticles for Magnetic Resonance Imaging at 3.0 T”. J Magn Reson Imaging 2022; 57:1830-1831. [PMID: 36269569 DOI: 10.1002/jmri.28452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 09/01/2022] [Indexed: 11/11/2022] Open
Affiliation(s)
- Jean‐Pierre Laissy
- Department of Radiology Hôpital Bichat AP‐HP Paris Cedex France
- Department of Radiology Hôpital Lariboisière APHP Paris France
- INSERM U1148 France
- DHU FIRE, University de Paris France
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Li R, Jin S, Wu T, Zang X, Li M, Li J. Usefulness of silent magnetic resonance angiography (MRA) for the diagnosis of atherosclerosis of the internal carotid artery siphon in comparison with time-of-flight MRA. Eur J Med Res 2022; 27:44. [PMID: 35314001 PMCID: PMC8935786 DOI: 10.1186/s40001-022-00673-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 03/07/2022] [Indexed: 11/10/2022] Open
Abstract
Background and purpose Flow visualization in 3D time-of-flight MRA (3D-TOF MRA) may be limited for internal carotid artery siphon owing to turbulent artifact. The purpose of this study was to compare the usefulness of Silent MRA and 3D-TOF MRA to assess atherosclerosis of the internal carotid artery siphon. Material and methods A total of 106 patients with suspected cerebrovascular disease were included. All patients were scanned with Silent MRA and 3D-TOF MRA sequences and also underwent DSA examination. Two observers independently assessed the TOF MRA and Silent MRA images of atherosclerosis of the internal carotid artery siphon. The diagnostic efficacy of two MRA methods in evaluating atherosclerosis of the carotid siphon was performed by using receiver operating characteristic (ROC) curve analysis. Interobserver reliability was also assessed using weighted kappa statistics. Results Image of Silent MRA sequence had higher subjective evaluation scores and significantly high CNR between the carotid siphon and the background tissues than the image of 3D-TOF MRA sequence (P < 0.05). The AUC was 0.928 (95% CI 0.909–0.986) for Silent MRA, which was significantly higher than that of 3D-TOF MRA (0.671, 95% CI 0.610–0.801, P < 0.05). Silent MRA had high sensitivity, specificity and accuracy than 3D-TOF MRA for visualization of the carotid siphon. Conclusions Silent MRA as a new angiographic modality is superior to 3D-TOF MRA for visualization of the carotid siphon, and maybe an alternative to 3D-TOF MRA in the diagnosis of atherosclerosis of the carotid siphon.
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Affiliation(s)
- Rui Li
- Department of Medical Imaging, Tianjin Huanhu Hospital, 6 Jizhao Road, Tianjin, 300350, China.,Department of Medical Imaging, Affiliated Huanhu Hospital of Nankai University, 6 Jizhao Road, Tianjin, 300350, China
| | - Song Jin
- Department of Medical Imaging, Tianjin Huanhu Hospital, 6 Jizhao Road, Tianjin, 300350, China.,Department of Medical Imaging, Affiliated Huanhu Hospital of Nankai University, 6 Jizhao Road, Tianjin, 300350, China
| | - Tao Wu
- GE Healthcare MR Enhanced Application Team, 1 Tongji South Road, Beijing, 100176, China
| | - Xiao Zang
- Department of Radiology, The First Medical Center of PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Meng Li
- Department of Radiology, The First Medical Center of PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Jinfeng Li
- Department of Radiology, The First Medical Center of PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
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Iv M, Choudhri O, Dodd RL, Vasanawala SS, Alley MT, Moseley M, Holdsworth SJ, Grant G, Cheshier S, Yeom KW. High-resolution 3D volumetric contrast-enhanced MR angiography with a blood pool agent (ferumoxytol) for diagnostic evaluation of pediatric brain arteriovenous malformations. J Neurosurg Pediatr 2018; 22:251-260. [PMID: 29882734 DOI: 10.3171/2018.3.peds17723] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Patients with brain arteriovenous malformations (AVMs) often require repeat imaging with MRI or MR angiography (MRA), CT angiography (CTA), and digital subtraction angiography (DSA). The ideal imaging modality provides excellent vascular visualization without incurring added risks, such as radiation exposure. The purpose of this study is to evaluate the performance of ferumoxytol-enhanced MRA using a high-resolution 3D volumetric sequence (fe-SPGR) for visualizing and grading pediatric brain AVMs in comparison with CTA and DSA, which is the current imaging gold standard. METHODS In this retrospective cohort study, 21 patients with AVMs evaluated by fe-SPGR, CTA, and DSA between April 2014 and August 2017 were included. Two experienced raters graded AVMs using Spetzler-Martin criteria on all imaging studies. Lesion conspicuity (LC) and diagnostic confidence (DC) were assessed using a 5-point Likert scale, and interrater agreement was determined. The Kruskal-Wallis test was performed to assess the raters' grades and scores of LC and DC, with subsequent post hoc pairwise comparisons to assess for statistically significant differences between pairs of groups at p < 0.05. RESULTS Assigned Spetzler-Martin grades for AVMs on DSA, fe-SPGR, and CTA were not significantly different (p = 0.991). LC and DC scores were higher with fe-SPGR than with CTA (p < 0.05). A significant difference in LC scores was found between CTA and fe-SPGR (p < 0.001) and CTA and DSA (p < 0.001) but not between fe-SPGR and DSA (p = 0.146). A significant difference in DC scores was found among DSA, fe-SPGR, and CTA (p < 0.001) and between all pairs of the groups (p < 0.05). Interrater agreement was good to very good for all image groups (κ = 0.77-1.0, p < 0.001). CONCLUSIONS Fe-SPGR performed robustly in the diagnostic evaluation of brain AVMs, with improved visual depiction of AVMs compared with CTA and comparable Spetzler-Martin grading relative to CTA and DSA.
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Affiliation(s)
- Michael Iv
- 1Department of Radiology, Stanford University Medical Center, Stanford
| | - Omar Choudhri
- 1Department of Radiology, Stanford University Medical Center, Stanford
| | - Robert L Dodd
- 1Department of Radiology, Stanford University Medical Center, Stanford
| | - Shreyas S Vasanawala
- 1Department of Radiology, Stanford University Medical Center, Stanford.,2Department of Radiology, Lucile Packard Children's Hospital, Palo Alto
| | - Marcus T Alley
- 3Richard M. Lucas Center for Imaging, Stanford University, Stanford; and
| | - Michael Moseley
- 3Richard M. Lucas Center for Imaging, Stanford University, Stanford; and
| | | | - Gerald Grant
- 4Division of Pediatric Neurosurgery, Lucile Packard Children's Hospital, Palo Alto, California
| | - Samuel Cheshier
- 4Division of Pediatric Neurosurgery, Lucile Packard Children's Hospital, Palo Alto, California
| | - Kristen W Yeom
- 2Department of Radiology, Lucile Packard Children's Hospital, Palo Alto
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Antonelli A, Pacifico S, Sfara C, Tamma M, Magnani M. Ferucarbotran-loaded red blood cells as long circulating MRI contrast agents: first in vivo results in mice. Nanomedicine (Lond) 2018; 13:675-687. [PMID: 29488423 DOI: 10.2217/nnm-2017-0339] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
AIM The encapsulation of superparamagnetic iron oxide contrast agents in red blood cells (RBCs) could overcome their rapid removal by reticulo-endothelial system improving their stability in blood circulation. MATERIALS & METHODS Murine ferucarbotran-loaded RBCs were tested in vivo as new contrasting agents in MRI application. RESULTS A superior visualization of organs and cerebral vessels was evidenced in ferucarbotran-loaded RBCs-treated mice compared with the controls. The signal enhancement lasted for days, while the contrast from bulk ferucarbotran disappeared after few minutes. CONCLUSION Ferucarbotran-loaded RBCs showed to improve diagnostic imaging and their use may extend the time frame for MRI and magnetic resonance angiography since to date the time frame for data acquisition has been limited to the first pass.
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Affiliation(s)
- Antonella Antonelli
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Via Saffi 2, 61029 Urbino (PU) 61029, Italy
| | - Severina Pacifico
- Department Environmental, Biological & Pharmaceutical Sciences & Technologies, Second University of Napoli, Via Vivaldi 43, Caserta 81100, Italy
| | - Carla Sfara
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Via Saffi 2, 61029 Urbino (PU) 61029, Italy
| | - Marialuisa Tamma
- Center of Biotechnologies Antonio Cardarelli Hospital, Via A Cardarelli 9, Napoli 80131, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Via Saffi 2, 61029 Urbino (PU) 61029, Italy
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Chiribiri A, Morton G, Nagel E. Gadofosveset injection for magnetic resonance angiography. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/iim.10.39] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Persigehl T, Bieker R, Matuszewski L, Wall A, Kessler T, Kooijman H, Meier N, Ebert W, Berdel WE, Heindel W, Mesters RM, Bremer C. Antiangiogenic Tumor Treatment: Early Noninvasive Monitoring with USPIO-enhanced MR Imaging in Mice. Radiology 2007; 244:449-56. [PMID: 17562810 DOI: 10.1148/radiol.2442060371] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively investigate steady-state blood volume measurements for early quantitative monitoring of antiangiogenic treatment with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS The institutional animal care committee approved all experiments. HT-1080 fibrosarcoma-bearing nude mice were injected with a thrombogenic vascular targeting agent (VTA) (11 nude mice, 20 tumors) or saline (12 nude mice, 20 tumors). USPIO-enhanced (SH U 555C) MR imaging was performed after the VTA was administered. USPIO-induced changes in tissue R2* (DeltaR2*) were measured with a T2-weighted dual-echo echo-planar imaging sequence, and the vascular volume fraction (VVF) was calculated. Parametric DeltaR2* maps were analyzed with respect to tumor perfusion patterns. Correlative histologic analysis was performed for grading of tissue thrombosis, and tissue perfusion was quantified with fluorescent microbeads. Unpaired Student t test and Spearman nonparametric correlation coefficient were used for statistical analysis. RESULTS The DeltaR2* values were significantly (P < .001) reduced shortly after treatment initiation (mean DeltaR2*, 0.017 msec(-1) +/- 0.0014 [standard error] in control animals vs 0.005 msec(-1) +/- 0.0007 in animals that received VTA), which was also reflected by a decrease in the VVF (2.47% +/- 0.18 vs 0.41% +/- 0.48, P < .001). Histologic analysis revealed various degrees of tumor thrombosis after VTA treatment that correlated inversely with the DeltaR2* values (r = -0.83). Moreover, tumor perfusion measurements corroborated the MR results, indicating a significant reduction in tissue perfusion after VTA treatment (mean tissue fluorescence, 570.4 arbitrary units [au] per gram +/- 27 vs 161.7 au/g +/- 17; P < .05). CONCLUSION USPIO-enhanced MR imaging enables early monitoring of antiangiogenic treatment of tumors.
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Affiliation(s)
- Thorsten Persigehl
- Department of Clinical Radiology, University Hospital Muenster, Albert-Schweitzer-Str 33, D-48129 Muenster, Germany
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Ayyagari AL, Zhang X, Ghaghada KB, Annapragada A, Hu X, Bellamkonda RV. Long-circulating liposomal contrast agents for magnetic resonance imaging. Magn Reson Med 2006; 55:1023-9. [PMID: 16586449 DOI: 10.1002/mrm.20846] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Contrast-enhanced magnetic resonance imaging (CE-MRI) is a dynamic technique for imaging vasculature. However, the currently used gadolinium (Gd) chelates, such as Gd-DTPA, restrict the time window for image acquisition due to their rapid elimination from blood and their rapid diffusion into the extravascular space, which prevents their use in steady-state imaging, particularly for MR angiography (MRA). The goal of this study was to prepare long-circulating polyethylene glycol-bearing ((PEG)ylated) liposomes encapsulating Gd chelate, and characterize and demonstrate their utility for MRA. The liposomes were prepared by hydrating a mixture of lipids with gadodiamide (Omniscan). The liposomes were sized down to around 100 nm by extruder and exhaustively dialysed to remove the unencapsulated gadodiamide. The Gd liposomes exhibited a significant sustained (>4 hr) contrast enhancement of the vasculature with improved spatial details in a rat model with little leakage relative to Gd-DTPA controls as shown by MRI. We suggest that such long-circulating liposomal formulations allow for high spatial resolution imaging without the confounding effects of clearance and extravascular diffusion of the agent complicating the data and image analysis.
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Affiliation(s)
- Ananta Laxmi Ayyagari
- WHC Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, Georgia 30332-0535, USA
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Tombach B, Reimer P, Bremer C, Allkemper T, Engelhardt M, Mahler M, Ebert W, Heindel W. First-pass and equilibrium-MRA of the aortoiliac region with a superparamagnetic iron oxide blood pool MR contrast agent (SH U 555 C): results of a human pilot study. NMR IN BIOMEDICINE 2004; 17:500-506. [PMID: 15523717 DOI: 10.1002/nbm.906] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The purpose of this study was to study different doses for first-pass and equilibrium phase MRA of aortoiliac vessels with a superparamagnetic iron oxide (SPIO) intravascular MR contrast agent (SH U 555 C) after single i.v. bolus injection. Sixteen healthy volunteers were prospectively enrolled into this single-blind, placebo-controlled clinical trial. SHU 555 C was injected as an i.v. bolus at stepwise increased dose levels of 5, 10, 20 and 40 micromol Fe/kg bodyweight (b.w.) corresponding to injection volumes of 0.01, 0.02, 0.04 and 0.08 ml/kg b.w. Serial high-resolution three-dimensional MRA of the aortoiliac vessels was acquired during first-pass and equilibrium, at 6 min intervals up to 42 min after contrast application using a breath-hold three-dimensional FLASH sequence on a 1.5 T scanner. Intravascular enhancement was calculated within the abdominal aorta and the inferior vena cava and a statistical analysis for significant differences in vessel enhancement was performed during the bolus and equilibrium phases. The visibility of vessels was ranked and effects of potential artifacts on image quality were graded for each time point and dose group. SH U 555 C showed a dose-dependent intravascular enhancement during the observation period (42 min). The highest dose of 40 micromol Fe/kg b.w. revealed the highest image quality during first-pass and equilibrium phases. The intravascular enhancement in the aorta increased dose-dependently from 5 to 40 micromol kg b.w. during first-pass and equilibrium phases (p<0.05). Intravascular signal inhomogeneities were observed at lower doses and decreased with increasing doses. First-pass MRA was diagnostic at doses of 10, 20 and 40 micromol Fe/kg b.w. For equilibrium MRA, a dose of 40 micromol Fe/kg b.w. was considered to be diagnostic. SH U 555 C proved to be a contrast agent with a high T1-effect suitable for both first-pass MRA comparable to gadolinium-enhanced MRA and high resolution equilibrium MRA up to 42 min post-injection (p.i.).
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Affiliation(s)
- Bernd Tombach
- Department of Clinical Radiology, Westfalian Wilhelms-University of Muenster, Muenster, Germany.
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Herborn CU, Schmidt M, Bruder O, Nagel E, Shamsi K, Barkhausen J. MR Coronary Angiography with SH L 643 A: Initial Experience in Patients with Coronary Artery Disease. Radiology 2004; 233:567-73. [PMID: 15358848 DOI: 10.1148/radiol.2332031545] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively assess the accuracy of breath-hold three-dimensional magnetic resonance (MR) coronary angiography with the gadolinium-based intravascular contrast agent SH L 643 A in patients with coronary artery disease. MATERIALS AND METHODS Twelve patients (seven men, five women; age range, 46-78 years; mean age, 61.3 years) with angiographically proved coronary artery disease (luminal narrowing >50%) underwent breath-hold three-dimensional MR coronary angiography before and after injection of SH L 643 A (0.1 mmol gadolinium per kilogram body weight). For all MR examinations, signal-to-noise ratio and contrast-to-noise ratio were measured. Image quality was assessed with a four-point scale. Conventional angiograms and MR angiograms were evaluated for depiction of the left main, proximal and middle left anterior descending, proximal left circumflex, and proximal and middle right coronary artery segments in a blinded fashion by two experienced readers in consensus. Results of this evaluation were compared by using a paired Student t test. P < .05 was considered to indicate a statistically significant difference. RESULTS For the 72 coronary artery segments, the contrast-to-noise ratio significantly improved after administration of SH L 643 A, compared with the prior ratio (9.8 +/- 5.1 [standard deviation] vs 23.0 +/- 8.7; P < .01), whereas the difference in signal-to-noise ratio did not reach statistical significance (25.2 +/- 11.4 vs 29.5 +/- 9.8; P > .3). Image quality significantly improved from a mean of 2.0 +/- 0.9 for nonenhanced images to 2.9 +/- 0.9 (P < .03) for contrast material-enhanced images. The proportion of segments for which images were nondiagnostic decreased from 38% to 10% with application of SH L 643 A. Overall sensitivity and specificity of contrast-enhanced MR coronary angiography for detection of coronary artery disease were 80% and 93%, respectively, and accuracy was 87%. CONCLUSION Use of SH L 643 A improves detection of coronary artery disease at three-dimensional MR coronary angiography.
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Affiliation(s)
- Christoph U Herborn
- Department of Diagnostic and Interventional Radiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany
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Bjørnerud A, Johansson L. The utility of superparamagnetic contrast agents in MRI: theoretical consideration and applications in the cardiovascular system. NMR IN BIOMEDICINE 2004; 17:465-477. [PMID: 15526351 DOI: 10.1002/nbm.904] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This review will discuss the in vivo physical chemical relaxation properties of superparamagnetic iron oxide particles. Various parameters such as size, magnetization, compartmentalization and water exchange effects and how these alter the behavior of the iron oxide particles in an in vitro vs an in vivo situation with special reference to the cardiovascular system will be exemplified. Furthermore, applications using iron oxide particles for vascular, perfusion and viability imaging as well as assessment of the inflammatory status of a given tissue will be discussed.
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Affiliation(s)
- Atle Bjørnerud
- Department of Radiology, Rikshospitalet University Hospital, N-0027 Oslo, Norway.
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Graff BA, Vangberg L, Rofstad EK. Quantitative assessment of uptake and distribution of iron oxide particles (NC100150) in human melanoma xenografts by contrast-enhanced MRI. Magn Reson Med 2004; 51:727-35. [PMID: 15065245 DOI: 10.1002/mrm.20028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The intratumor heterogeneity in uptake of iron oxide particles (NC100150) in human melanoma xenografts was studied by MRI and the uptake was related to the blood volume fraction, BV, and the permeability surface area product, PS, in an attempt to identify transport barriers limiting the delivery of large macromolecular therapeutic agents to tumors. Dynamic MRI was performed by using spoiled gradient recalled sequences and the extravascular uptake of NC100150, BV, and PS were calculated for each tumor voxel by using a two-compartment tissue model. The uptake of NC100150 and BV were low in the tumor center and increased gradually towards the tumor periphery, whereas there was no radial gradient in PS. Significant correlations were found between the voxel values of the parameters. Thus, PS was inversely correlated to BV, and this correlation was stronger in the center than in the periphery of the tumors. The uptake of NC100150 was positively correlated to PS and this correlation was strong in the tumor periphery, where the blood perfusion is high, and weak in the tumor center, where the blood perfusion is low. In contrast, the uptake of NC100150 was not correlated to BV in any tumor region. These observations suggest that the extravascular uptake of NC100150 was limited primarily by the microvascular permeability in the tumor periphery and primarily by the blood perfusion in the tumor center.
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Affiliation(s)
- Bjørn A Graff
- Department of Biophysics, The Norwegian Radium Hospital, Montebello, Oslo, Norway
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Herborn CU, Barkhausen J, Paetsch I, Hunold P, Mahler M, Shamsi K, Nagel E. Coronary arteries: contrast-enhanced MR imaging with SH L 643A--experience in 12 volunteers. Radiology 2003; 229:217-23. [PMID: 12944598 DOI: 10.1148/radiol.2291021033] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess SH L 643A for three-dimensional breath-hold and respiratory-gated magnetic resonance (MR) imaging in the depiction of coronary arteries. MATERIALS AND METHODS Twelve healthy male volunteers underwent either three-dimensional breath-hold (n = 6) or respiratory-gated (n = 6) coronary MR angiography before and after intravenous injection of 0.1 mmol SH L 643A per kilogram of body weight. For nonenhanced and contrast material-enhanced examinations, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements were obtained. Image quality was assessed in consensus with a five-point scale. Statistical analysis of nonenhanced and contrast-enhanced images was based on a two-tailed paired Student t test. A P value at the.05 significance level was used. RESULTS Overall statistically significant improvement in CNR was observed after administration of SH L 643A compared with that on nonenhanced images (8.7 +/- 5.3 [SD] vs 23.6 +/- 7.2, P <.01). While SNR of contrast-enhanced images showed improvement over that of nonenhanced images, the difference was not statistically significant (25.4 +/- 0.8 vs 30.2 +/- 16.8, P >.2). Image quality improved from a mean of 3.1 +/- 0.8 for nonenhanced images to 4.0 +/- 0.8 (P <.01) for contrast-enhanced images. CONCLUSION SH L 643A causes significant improvement of the blood-myocardium contrast enhancement at coronary MR angiography compared with that with nonenhanced sequences.
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Affiliation(s)
- Christoph U Herborn
- Department of Diagnostic and Interventional Radiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany
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Lei T, Udupa JK, Odhner D, Nyúl LG, Saha PK. 3DVIEWNIX-AVS: a software package for the separate visualization of arteries and veins in CE-MRA images. Comput Med Imaging Graph 2003; 27:351-62. [PMID: 12821028 DOI: 10.1016/s0895-6111(03)00029-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Our earlier study developed a computerized method, based on fuzzy connected object delineation principles and algorithms, for artery and vein separation in contrast enhanced Magnetic Resonance Angiography (CE-MRA) images. This paper reports its current development-a software package-for routine clinical use. The software package, termed 3DVIEWNIX-AVS, consists of the following major operational parts: (1) converting data from DICOM3 to 3DVIEWNIX format, (2) previewing slices and creating VOI and MIP Shell, (3) segmenting vessel, (4) separating artery and vein, (5) shell rendering vascular structures and creating animations. This package has been applied to EPIX Medical Inc's CE-MRA data (AngioMark MS-325). One hundred and thirty-five original CE-MRA data sets (of 52 patients) from 6 hospitals have been processed. In all case studies, unified parameter settings produce correct artery-vein separation. The current package is running on a Pentium PC under Linux and the total computation time per study is about 3 min. The strengths of this software package are (1) minimal user interaction, (2) minimal anatomic knowledge requirements on human vascular system, (3) clinically required speed, (4) free entry to any operational stages, (5) reproducible, reliable, high quality of results, and (6) cost effective computer implementation. To date, it seems to be the only software package (using an image processing approach) available for artery and vein separation of the human vascular system for routine use in a clinical setting.
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Affiliation(s)
- Tianhu Lei
- Medical Image Processing Group, Department of Radiology, University of Pennsylvania, 4th floor, Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021, USA
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Wikström J, Wasser MN, Pattynama PMT, Bonomo L, Hamm B, Del Maschio A, Knopp MV, Marchal G, Barentsz JO, Oudkerk M, Hentrich HR, Daprà M, Kirchin MA, Shen N, Spinazzi A, Ahlström H. Gadobenate dimeglumine-enhanced magnetic resonance angiography of the pelvic arteries. Invest Radiol 2003; 38:504-15. [PMID: 12874517 DOI: 10.1097/01.rli.0000074585.46615.2e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate 4 doses of gadobenate dimeglumine (Gd-BOPTA) for contrast-enhanced magnetic resonance angiography (CE-MRA) of the pelvic arteries and to compare CE-MRA with unenhanced time-of-flight MRA (2D-TOF-MRA). METHODS A multicenter Phase II dose-finding study was performed in 136 patients with Gd-BOPTA doses of 0.025, 0.05, 0.1, and 0.2 mmol/kg bodyweight. Evaluation of CE-MRA images and comparison with 2D-TOF-MRA images was performed onsite and by 2 blinded offsite reviewers in terms of subjective image quality, number of lesions detected, and confidence in lesion characterization. RESULTS Significant (P < 0.05) improvements over unenhanced findings were observed for CE-MRA at all dose levels. For reviewer 1 and the onsite investigators, the overall image quality increased up to a dose of 0.1 mmol/kg and then plateaued. For reviewer 2, increased image quality was noted up to a dose of 0.2 mmol/kg. Significant (P < 0.005) increases in diagnostic confidence on CE-MRA versus unenhanced MRA was observed for all dose groups by reviewer 1 and the onsite investigators and for the 0.1 and 0.2 mmol/kg dose groups by reviewer 2. No serious adverse events were recorded that were attributable to the study drug and no trends in laboratory parameters, vital signs, or electrocardiogram recordings were observed. CONCLUSIONS Gadobenate dimeglumine-enhanced MRA is safe and significantly more effective than unenhanced 2D-TOF-MRA for imaging the pelvic arteries. A dose of 0.1 mmol/kg appears the most appropriate dose for subsequent Phase III clinical evaluation.
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Affiliation(s)
- Johan Wikström
- Department of Diagnostic Radiology, Uppsala University Hospital, Uppsala, Sweden.
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Svensson J. Contrast-enhanced magnetic resonance angiography: development and optimization of techniques for paramagnetic and hyperpolarized contrast media. Acta Radiol 2003; 429:1-30. [PMID: 12757468 DOI: 10.1034/j.1600-0455.44.s.429.1.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Contrast-enhanced magnetic resonance angiography (CE-MRA) is a diagnostic method for imaging of vascular structures based on nuclear magnetic resonance. Vascular enhancement is achieved by injection of a contrast medium (CM). Studies were performed using two different types of CM: conventional paramagnetic CM, and a new type of CM based on hyperpolarized (HP) nuclei. The effects of varying CM concentration with time during image acquisition were studied by means of computer simulations using two different models. It was shown that a rapid concentration variation during encoding of the central parts of k-space could result in signal loss and severe image artifacts. The results were confirmed qualitatively with phantom experiments. A postprocessing method was developed to address problems with simultaneous enhancement of arteries and veins in CE-MRA of the lower extremities. The method was based on the difference in flow-induced phase in the two vessel types. Evaluation of the method was performed with flow phantom measurements and with CE-MRA in two volunteers using standard pulse sequences. The flow-induced phase in the vessels of interest was sufficient to distinguish arteries from veins in the superior-inferior direction. Using this method, the venous enhancement could be extinguished. The possibility of using HP nuclei as CM for CE-MRA was evaluated. Signal expressions for a flow of HP CM imaged with a gradient echo sequence were derived. These signal expressions were confirmed in phantom experiments using HP 129Xe dissolved in ethanol. Studies were also performed with a new CM based on HP 13C. The CM had very long relaxation times (T1, in vivo/T2, in vivo approximately 38/1.3 s). The long relaxation times were utilized in imaging with a fully balanced steady-state free precession pulse sequence (trueFISP), where the optimal flip angle was found to be 180 degrees. CE-MRA with the 13C-based CM in rats resulted in images with high vascular SNR (approximately 500). CE-MRA is a useful clinical tool for diagnosing vascular disease. With the development of new contrast media, based on hyperpolarized nuclei for example, there is a potential for further improvement in the signal levels that can be achieved, enabling a standard of imaging of vessels that is not possible today.
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Affiliation(s)
- Jonas Svensson
- Department of Radiation Physics, Institute of Radiology and Physiology, Malmö, Malmö University Hospital, Lund University, SE-205 02 Malmö, Sweden
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16
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Michel SCA, Keller TM, Fröhlich JM, Fink D, Caduff R, Seifert B, Marincek B, Kubik-Huch RA. Preoperative breast cancer staging: MR imaging of the axilla with ultrasmall superparamagnetic iron oxide enhancement. Radiology 2002; 225:527-36. [PMID: 12409591 DOI: 10.1148/radiol.2252011605] [Citation(s) in RCA: 165] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate magnetic resonance (MR) imaging with ultrasmall superparamagnetic iron oxide (USPIO) enhancement for preoperative axillary lymph node staging in patients with breast cancer by using histopathologic findings as the standard of reference. MATERIALS AND METHODS MR imaging was performed with a 1.5-T system within 24-36 hours after the start of intravenous slow-drip infusion of USPIO in 20 patients with breast cancer who were scheduled for surgery, followed by gadolinium-enhanced MR imaging. Lymph nodes were staged prospectively by using newly established criteria, and results were correlated with histologic findings. RESULTS In two patients, preoperative findings led to a change in therapeutic approach, and neoadjuvant chemotherapy was given; both patients were excluded from statistical analysis. Results of axillary staging with USPIO-enhanced MR imaging were true-positive in nine, true-negative in seven, false-positive in zero, and false-negative in two of 18 patients (sensitivity, 82%; specificity, 100%; positive predictive value, 100%; second reader, kappa = 1.0). Four hundred five lymph nodes were detected with MR imaging. For first and second readers, respectively, lymph node-based sensitivity was 83% and 73% and specificity was 96% and 97% (kappa = 0.68). USPIO as the intravascular contrast agent could not replace gadolinium for assessment of the primary tumor; however, no clinically relevant interaction was seen. Thus, an integrated imaging approach was feasible in all patients. CONCLUSION USPIO-enhanced MR imaging has the potential to become an adjunct to conventional MR imaging of the breast for preoperative assessment of axillary lymph nodes in patients with breast cancer.
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Affiliation(s)
- Sven C A Michel
- Institute of Diagnostic Radiology, University Hospital Zurich, Switzerland
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17
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Canet Soulas EP, Marchand B, Casali C, Corot C, Douek P, Revel D. Evaluation of MR contrast agents with high relaxivity and reduced interstitial diffusion for contrast material-enhanced MRA and myocardial perfusion studies. Acad Radiol 2002; 9 Suppl 1:S88-91. [PMID: 12019906 DOI: 10.1016/s1076-6332(03)80407-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Wagner S, Schnorr J, Pilgrimm H, Hamm B, Taupitz M. Monomer-coated very small superparamagnetic iron oxide particles as contrast medium for magnetic resonance imaging: preclinical in vivo characterization. Invest Radiol 2002; 37:167-77. [PMID: 11923639 DOI: 10.1097/00004424-200204000-00002] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RATIONALE AND OBJECTIVES Preclinical in-vivo characterization of a newly developed MR contrast medium consisting of very small superparamagnetic iron oxide particles (VSOP) coated with citrate (VSOP-C184). METHODS VSOP-C184 (core diameter: 4 nm; total diameter: 8.6 nm; relaxivities in water at 0.94 T (T1) 20.1 and (T2) 37.1 l/[mmol*sec]) was investigated to determine its pharmacokinetics, efficacy, acute single dose toxicity, repeated dose toxicity, and genotoxicity. RESULTS The plasma elimination half-life at 0.045 mmol Fe/kg was 21.3 +/- 5.5 minutes in rats and 36.1 +/- 4.2 minutes in pigs, resulting in a T1-relaxation time of plasma of < 100 milliseconds for 30 minutes in pigs. The particles are mainly cleared via the phagocytosing system of the liver. MR angiography at a dose of 0.045 mmol Fe/kg shows an excellent depiction of the thoracic and abdominal vasculature in rats and of the coronary arteries in pigs. The LD50 in mice is > 17.9 mmol Fe/kg. A good tolerance and safety profile was found. CONCLUSIONS The experiments indicate, that VSOP-C184 may be a well tolerated and safe contrast medium for MR imaging that can be effectively used for MR angiography including visualization of the coronary arteries.
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Affiliation(s)
- Susanne Wagner
- Department of Radiology, Charité, Medizinische Fakultät der Humboldt-Universität zu Berlin, Berlin, Germany
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19
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Svensson J, Leander P, Maki JH, Stahlberg F, Olsson LE. Separation of arteries and veins using flow-induced phase effects in contrast-enhanced MRA of the lower extremities. Magn Reson Imaging 2002; 20:49-57. [PMID: 11973029 DOI: 10.1016/s0730-725x(02)00479-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
In 3-D contrast-enhanced magnetic resonance (MR) angiography of the lower extremities the goal is most often to enhance arterial structures while keeping veins and surrounding tissue unenhanced. Imaging during steady-state concentration of a blood pool agent or during poor timing of an extra-cellular contrast medium may result in simultaneous venous enhancement, making interpretation of the angiogram difficult. The aim of this study was to develop a post-processing method to separate the arteries from the veins in standard contrast-enhanced MR angiograms. The method was based on the different accumulation of flow-induced phase in the arteries and veins of the lower extremities. The method was tested in both phantom experiments and volunteers undergoing 3-D contrast-enhanced MR angiography using both an extra-cellular contrast medium and a blood pool agent. In the phantom studies, opposite directional flow was successfully separated at mean flow velocities as low as 9 cm/s. In the volunteer studies, the larger veins were successfully extinguished while the larger arteries were left unaffected. In smaller vessels with low flow velocities the separation was less successful. This was most apparent in vessels not oriented superior-inferior. The method developed here is promising for separating arteries from veins in contrast-enhanced MR angiography although the results could be further improved by either a different pulse sequence design or combining this method with other segmentation methods.
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Affiliation(s)
- Jonas Svensson
- Department of Radiation Physics, Malmö University Hospital, SE-205 02, Malmö, Sweden
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20
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Zheng J, Carr J, Harris K, Saker MB, Cavagna FM, Maggioni F, Laub G, Li D, Finn JP. Three-dimensional MR pulmonary perfusion imaging and angiography with an injection of a new blood pool contrast agent B-22956/1. J Magn Reson Imaging 2001; 14:425-32. [PMID: 11599067 DOI: 10.1002/jmri.1203] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Initial evaluation of a new blood pool agent, B-22956/1, for pulmonary imaging was performed in five domestic pigs with artificial embolism. Pre-embolism 3D pulmonary perfusion images were first acquired by injecting an extravascular agent, gadoteridol. The pulmonary arteries of the pigs were then occluded by the artificial emboli. Post-embolism perfusion scans were subsequently performed by injecting B-22956/1. Additional post-embolism high-spatial-resolution angiograms were also acquired. Parenchyma perfusion deficits were well depicted in the post-embolism perfusion maps. The post-embolism angiography clearly revealed the location and extent of the filling defects in the pulmonary vessels. Signal intensities of perfusion maps on the normal parenchyma were significantly improved (30%) by using B-22956/1, in comparison with perfusion images using gadoteridol (P < 0.01). Many pulmonary angiograms with approximately equal contrast could be obtained even at 22 minutes after the injection of B-22956/1. Our initial results indicate that blood pool agent B-22956/1 may provide opportunities for whole-lung-coverage perfusion mapping and additional high-resolution target angiograms after a single injection.
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Affiliation(s)
- J Zheng
- Mallinkcrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kings Highway, St. Louis, MO 63110, USA.
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21
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Lei T, Udupa JK, Saha PK, Odhner D. Artery-vein separation via MRA--an image processing approach. IEEE TRANSACTIONS ON MEDICAL IMAGING 2001; 20:689-703. [PMID: 11513021 DOI: 10.1109/42.938238] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This paper presents a near-automatic process for separating vessels from background and other clutter as well as for separating arteries and veins in contrast-enhanced magnetic resonance angiographic (CE-MRA) image data, and an optimal method for three-dimensional visualization of vascular structures. The separation process utilizes fuzzy connected object delineation principles and algorithms. The first step of this separation process is the segmentation of the entire vessel structure from the background and other clutter via absolute fuzzy connectedness. The second step is to separate artery from vein within this entire vessel structure via iterative relative fuzzy connectedness. After seed voxels are specified inside artery and vein in the CE-MRA image, the small regions of the bigger aspects of artery and vein are separated in the initial iterations, and further detailed aspects of artery and vein are included in later iterations. At each iteration, the artery and vein compete among themselves to grab membership of each voxel in the vessel structure based on the relative strength of connectedness of the voxel in the artery and vein. This approach has been implemented in a software package for routine use in a clinical setting and tested on 133 CE-MRA studies of the pelvic region and two studies of the carotid system from six different hospitals. In all studies, unified parameter settings produced correct artery-vein separation. When compared with manual segmentation/separation, our algorithms were able to separate higher order branches, and therefore produced vastly more details in the segmented vascular structure. The total operator and computer time taken per study is on the average about 4.5 min. To date, this technique seems to be the only image processing approach that can be routinely applied for artery and vein separation.
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Affiliation(s)
- T Lei
- Department of Radiology, University of Pennsylvania, Philadelphia 19104, USA
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22
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Turetschek K, Roberts TP, Floyd E, Preda A, Novikov V, Shames DM, Carter WO, Brasch RC. Tumor microvascular characterization using ultrasmall superparamagnetic iron oxide particles (USPIO) in an experimental breast cancer model. J Magn Reson Imaging 2001; 13:882-8. [PMID: 11382948 DOI: 10.1002/jmri.1126] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The diagnostic potential of ultrasmall superparamagnetic iron oxide particles (USPIO) for quantitative tumor microvessel characterization was assessed by kinetic analysis of dynamic magnetic resonance imaging (MRI) in a rodent breast cancer model. Microvascular characteristics (transendothelial permeability (K(PS)) and fractional plasma volume (fPV)) were estimated in 32 female Sprague Dawley rats, bearing breast tumors of varying malignancy. These values were compared to a prototype macromolecular contrast medium standard, albumin-(GdDTPA)(30). Transendothelial permeability (K(PS)) correlated significantly (P < 0.05) with the tumor grade (Scarff-Bloom-Richardson (SBR) score) for the USPIO (r = 0.36), as well as for the reference macromolecule, albumin-(GdDTPA)(30) (r = 0.54). Estimates for the fPV did not show a statistically significant correlation with the tumor grade for either contrast medium. In conclusion, USPIO-enhanced MRI data were capable to characterize tumor microvessel properties in this breast cancer model: microvascular permeability (determined using USPIO) correlated significantly with tumor grade. Thus, quantitative estimation of microvascular characteristics in tumors could provide a surrogate of new vessel formation (angiogenesis) and thus a further important clinical indication for USPIO, in addition to MR angiography. J. Magn. Reson. Imaging 2001;13:882-888.
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Affiliation(s)
- K Turetschek
- Center for Pharmaceutical and Molecular Imaging, Department of Radiology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628, USA
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23
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Bremerich J, Colet JM, Giovenzana GB, Aime S, Scheffler K, Laurent S, Bongartz G, Muller RN. Slow clearance gadolinium-based extracellular and intravascular contrast media for three-dimensional MR angiography. J Magn Reson Imaging 2001; 13:588-93. [PMID: 11276103 DOI: 10.1002/jmri.1082] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The objective of this study was to assess two new slow-clearance contrast media with extracellular and intravascular distribution for magnetic resonance angiography (MRA). Extracellular Gd-DTPA-BC(2)glucA and intravascular Gd(DO3A)(3)-lys(16) were developed within the European Biomed2 MACE Program and compared with two reference compounds, intravascular CMD-A2-Gd-DOTA and extracellular GdDOTA, in 12 rats. Pre- and post-contrast three-dimensional MR (TR/TE = 5 msec/2.2 msec; isotropic voxel size 0.86 mm(3)) was acquired for 2 hours. Signal-to-noise enhancement (DeltaSNR) was calculated. Two minutes after injection, all contrast media provided strong vascular signal enhancement. The DeltaSNR for Gd-DTPA-BC(2)glucA, Gd(DO3A)(3)-lys(16), CMD-A2-Gd-DOTA, and GdDOTA were 13.0 +/- 1.8, 25.0 +/- 3.2, 25.0 +/- 4.0, and 18.0 +/- 3.4, respectively. Gd-DTPA-BC(2)glucA, Gd(DO3A)(3)-lys(16), and CMD-A2-Gd-DOTA cleared slowly from the circulation, whereas GdDOTA cleared rapidly. Vascular DeltaSNR at 2 hours were 2.9 +/- 0.6, 25.0 +/- 3.2, 25.0 +/- 4.0, and 0.4 +/- 1.0. Gd(DO3A)(3)-lys(16) provided strong vascular and minor background enhancement, and thus may be useful for MRA or perfusion imaging. Gd-DTPA-BC(2)glucA produces persistent enhancement of extracellular water, and thus may allow quantification of extracellular distribution volume and assessment of myocardial viability.
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Affiliation(s)
- J Bremerich
- Department of Radiology, University Hospital, Basel, Switzerland.
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24
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Li D, Zheng J, Weinmann HJ. Contrast-enhanced MR imaging of coronary arteries: comparison of intra- and extravascular contrast agents in swine. Radiology 2001; 218:670-8. [PMID: 11230638 DOI: 10.1148/radiology.218.3.r01mr03670] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare the efficacy of an intravascular contrast agent, gadomer-17, in improving magnetic resonance (MR) imaging of coronary arteries with that of an extravascular agent, gadopentetate dimeglumine, in pigs. MATERIALS AND METHODS Eight pigs underwent imaging after three injections: 0.20 mmol of gadopentetate dimeglumine per kilogram of body weight and 0.05 and 0.10 mmol/kg gadomer-17. Coronary images were acquired repeatedly after each injection by using an inversion-recovery-prepared segmented three-dimensional sequence with either breath holding (n = 4) or respiratory gating (n = 4). Coronary artery-to-myocardium contrast-to-noise ratios (CNRs) were compared between injections. RESULTS At breath-hold imaging, substantial CNR improvement over precontrast images was observed in images acquired during the first pass of gadopentetate dimeglumine in coronary arteries and up to 6 and 10 minutes after 0.05 and 0.10 mmol/kg of gadomer-17 injections, respectively. The CNR with 0.10 mmol/kg of gadomer-17 was 20% (P <.05) higher than that with gadopentetate dimeglumine at first-pass imaging. At respiratory-gated imaging, significant CNR improvement (P <.05) over precontrast images was observed in images acquired up to 10, 30, and 50 minutes after gadopentetate dimeglumine and both gadomer-17 injections, respectively. The CNR on the first images obtained after 0.10 mmol/kg gadomer-17 injection was 168% (P <.05) higher than that on the images obtained after gadopentetate dimeglumine injection. CONCLUSION Gadomer-17 provided greater and more persistent CNR improvements than did gadopentetate dimeglumine; further evaluation of its utility for coronary imaging in humans is warranted.
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Affiliation(s)
- D Li
- Department of Radiology, Northwestern University Medical School, 448 E Ontario St, Ste 700, Chicago, IL 60611, USA.
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25
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Turetschek K, Huber S, Floyd E, Helbich T, Roberts TP, Shames DM, Tarlo KS, Wendland MF, Brasch RC. MR imaging characterization of microvessels in experimental breast tumors by using a particulate contrast agent with histopathologic correlation. Radiology 2001; 218:562-9. [PMID: 11161179 DOI: 10.1148/radiology.218.2.r01fe37562] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To define the diagnostic potential of magnetic resonance (MR) imaging enhanced with ultrasmall superparamagnetic iron oxide (USPIO) particles for the quantitative characterization of tumor microvasculature. MATERIALS AND METHODS NC100150 injection, a USPIO in clinical trials, and albumin-(Gd-DTPA)(30) were compared at MR imaging on sequential days in the same 19 rats with mammary tumors. Kinetic analysis of dynamic T1-weighted three-dimensional spoiled gradient-recalled imaging data with a two-compartment bidirectional model yielded MR imaging estimates of microvascular permeability (K(PS)) and fractional plasma volume (fPV) for each contrast medium. RESULTS Strongly positive and significant correlations were observed between MR imaging-derived K(PS )estimates and histologic tumor grade with either the soluble albumin-(Gd-DTPA)(30) (r = 0.88; P <.001) or larger particulate USPIO (r = 0.82; P <.001). A significant correlation (P <.05) was observed with each contrast medium between K(PS) and the histologic microvascular density (MVD), an angiogenesis indicator. Despite the considerable difference in molecule and particle sizes, no significant difference was observed in the MR imaging-derived mean permeability values generated with the two contrast media. CONCLUSION USPIO, a macromolecular particulate MR imaging contrast agent, can be applied successfully to characterize tumor microvessels in animals. USPIO-derived K(PS) correlated strongly with histopathologic tumor grade, MVD, and K(PS) values derived by using albumin-(Gd-DTPA)(30) in the same tumors.
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Affiliation(s)
- K Turetschek
- Center for Pharmaceutical and Molecular Imaging, Department of Radiology, University of California, San Francisco, Box 0628, 505 Parnassus Ave, San Francisco, CA 94143-0628, USA
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26
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Taupitz M, Schnorr J, Abramjuk C, Wagner S, Pilgrimm H, Hünigen H, Hamm B. New generation of monomer-stabilized very small superparamagnetic iron oxide particles (VSOP) as contrast medium for MR angiography: preclinical results in rats and rabbits. J Magn Reson Imaging 2000; 12:905-11. [PMID: 11105029 DOI: 10.1002/1522-2586(200012)12:6<905::aid-jmri14>3.0.co;2-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The purpose of this study was to evaluate the signal enhancement characteristics of very small superparamagnetic iron oxide particles (VSOP)-C63, a new monomer-coated, iron oxide-based magnetic resonance (MR) blood pool contrast medium with a very small particle size and optimized physical properties. Equilibrium MR angiography (MRA) of rats (thoracic and abdominal vessels) was performed at 1.5 T with a three-dimensional gradient-recalled echo (3D GRE) technique (TR/TE 6.6/2.3 msec, flip angle 25 degrees ) before and after (every 3-5 minutes up to 50 minutes) i.v. injection of VSOP-C63 [dosages: 15, 30, 45, 60, 75, and 90 micromol Fe/kg; diameter: 8 nm; relaxivities at 0.47 T: R1 = 30 l/(mmol * s); R2 = 39 l/(mmol * s)]. First-pass MRA images (3D-GRE, TR/TE 4.5/1.7 msec, flip angle 25 degrees ) were obtained with 45 micromol Fe/kg VSOP-C63 in comparison with 0.2 mmol Gd/kg of gadolinium diethylene triamine pentaacetic acid (Gd DTPA; before and every 5 seconds p.i.). MRA (3D GRE, TR/TE 4.5/1.7 msec, flip angle 25 degrees) of coronary vessels in rabbits was performed after i.v. injection of 45 micromol Fe/kg of VSOP-C63. In rats maximal S/N ratio in thoracic and abdominal arteries directly after i.v. injection of VSOP-C63 was 25 +/- 1, 43 +/- 2, 49 +/- 4, 57 +/- 3, 64 +/- 3, and 63 +/- 3 for the different dosages. Blood half-life was dose dependent (15 +/- 2, 20 +/- 3, 29 +/- 6, 37 +/- 5, 61 +/- 16, and 86 +/- 21 minutes). At a dose of 30 micromol Fe/kg even small intrarenal arteries were sharply delineated. First-pass MRA showed no significant difference in the S/N ratio between Gd-DTPA (71.5 +/- 11.5) and VSOP-C63 (65.1 +/- 18. 3). The proximal segments of the coronary arteries in rabbits were clearly depicted at a dose of 45 micromol Fe/kg. The monomer-coated, iron oxide-based contrast medium VSOP-C63 exhibits favorable properties as a blood pool agent for both equilibrium and first-pass MRA. J. Magn. Reson. Imaging 2000;12:905-911.
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Affiliation(s)
- M Taupitz
- Department of Radiology, Charité, Medizinische Fakultät, Humboldt-Universität zu Berlin, 10098 Berlin, Germany
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Abstract
Currently available magnetic resonance (MR) contrast agents are not confined to the intravascular space because of their small molecular size. These agents produce peak vascular enhancement for only a short period. Conversely, blood pool agents have longer intravascular residence time and higher relaxivity. Therefore these agents provide MR angiography with flexibility, versatility, and accuracy. With blood pool agents, the timing of contrast injection becomes less significant because the optimal imaging window is in tens of minutes rather than seconds. In addition, larger anatomic regions can be imaged optimally. Preliminary evidence appears to support the notion that blood pool agents may play a diagnostic role in coronary, peripheral, and pulmonary angiography. Besides their ability to increase vascular contrast, blood pool agents provide physiologic information, including rate of entry, rate of accumulation, and rate of elimination. MR imaging with blood pool agents also have proven to be of significant value in the assessments of myocardial perfusion and microvascular permeability. In anticipation of broad clinical use, blood pool agents are currently being evaluated in human trails. Examples include gadolinium-chelate that binds in vivo to albumin to form blood pool agents and ultrasmall superparamagnetic iron oxide particles. This review discusses the applications of MR blood pool agents in the cardiovascular system. J. Magn. Reson. Imaging 2000;12:890-898.
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Affiliation(s)
- M Saeed
- Department of Radiology, University of California, San Francisco, California 94143, USA.
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Bremerich J, Roberts TP, Wendland MF, Wyttenbach R, Arheden H, Reddy GP, Shafaghi N, Higgins CB, Saeed M. Three-dimensional MR imaging of pulmonary vessels and parenchyma with NC100150 injection (Clariscan). J Magn Reson Imaging 2000; 11:622-8. [PMID: 10862061 DOI: 10.1002/1522-2586(200006)11:6<622::aid-jmri8>3.0.co;2-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The influence of increasing doses of NC100150 Injection (Clariscantrade mark) and echo times on visualization of pulmonary vessels and parenchyma was evaluated. The effects of 0.5, 1, 2, 4, and 8 mg Fe/kg NC100150 Injection and echo times (TE) of 1.1, 1.8, 2. 2, and 4.3 msec were determined in six dogs using breath-hold three-dimensional (3D) spoiled gradient-echo magnetic resonance (MR) sequence. At 2 mg Fe/kg and TE of 1.1 msec, the signal-to-noise ratio of the central pulmonary arteries and parenchyma was significantly increased (5.3 +/- 2.2 to 50.3 +/- 2.4) and (2.2 +/- 0. 9 to 6.4 +/- 1.1), respectively. Using the TE of 1.1 msec, signal intensity in the main arteries continued to increase with increasing dose. Moreover, the enhancement of pulmonary parenchyma and microvasculature had a positive dose response. 3D MR imaging with ultrashort echo time and 2 mg Fe/kg NC100150 Injection produces angiograms with strong vascular contrast and allows qualitative assessment of pulmonary parenchyma and microvasculature.
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Affiliation(s)
- J Bremerich
- Department of Radiology, University of California San Francisco, San Francisco, California 94143-0628, USA
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29
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Saeed M, Wendland MF, Watzinger N, Akbari H, Higgins CB. MR contrast media for myocardial viability, microvascular integrity and perfusion. Eur J Radiol 2000; 34:179-95. [PMID: 10927160 DOI: 10.1016/s0720-048x(00)00198-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cardiovascular imaging requires an appreciation of rapidly evolving MR imaging sequences as well as careful utilization of intravascular, extracellular and intracellular MR contrast media. At the present time, clinical studies are restricted to the use of extracellular MR contrast media. MR imaging has the potential to noninvasively measure multiple parameters of the cardiovascular system in a single imaging session. Recent advances in fast and ultrafast MR imaging have considerably enhanced the capability of this technique, beyond the assessment of left ventricular wall motion and morphology into visualization of the coronary arteries and measurement of blood flow. During the course of the last several years, multiple strategies for imaging viable myocardium have been developed and validated using MR contrast media. Contrast enhanced dynamic MR imaging provides information regarding microvascular integrity and perfusion. Because these information can be provided noninvasively by MR imaging, repeated measurements can be performed in longitudinal studies to monitor the progression or regression of myocardial injury. Similar studies are needed to examine the effects of newly developed cardioprotective therapeutics. Development of suitable intravascular MR contrast medium may be essential for visualization of the coronary arteries and interventional therapies. MR imaging may emerge as one-stop-shop for evaluating the heart and coronary system. This capability will make MR imaging cost-effective in the first decade of this millennium.
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Affiliation(s)
- M Saeed
- Department of Radiology, University of California, Box 0628, 505 Parnassus Ave, San Francisco, CA 94143, USA.
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Clarke SE, Weinmann HJ, Dai E, Lucas AR, Rutt BK. Comparison of two blood pool contrast agents for 0.5-T MR angiography: experimental study in rabbits. Radiology 2000; 214:787-94. [PMID: 10715047 DOI: 10.1148/radiology.214.3.r00mr25787] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate two experimental blood pool agents for potential use in equilibrium phase abdominal magnetic resonance (MR) angiography. MATERIALS AND METHODS MR imaging at 0.5 T was performed in 37 rabbits before and after intravenous injection of a gadolinium-based blood pool contrast agent (SH L 643 A), superparamagnetic iron oxide blood pool agent (SH U 555 C), or gadopentetate dimeglumine. T1-weighted fast spoiled gradient-echo images from the renal arteries to below the iliac bifurcation were obtained. The aorta-to-tissue signal difference-to-noise ratio (SDNR) was measured over time. RESULTS Both blood pool agents yielded excellent demonstration of the rabbit abdominal aorta. At a dose of 0.1 mmol/kg, both provided a statistically significant increase in aorta-to-tissue SDNR in comparison with that achieved with gadopentetate dimeglumine (200% increase for SH L 643 A, 95% increase for SH U 555 C; P < .05). A 0.1 mmol/kg dose of SH L 643 A provided a 24% increase in SDNR relative to the increase with a 0.37 mmol/kg dose of gadopentetate dimeglumine. Time-dependent enhancement properties of the blood pool agents differed due to differences in elimination method. CONCLUSION Both blood pool agents were found to be promising contrast agents for 0.5-T MR angiography; however, their clinical applicability warrants further investigation. The gadolinium-based agent had several advantages over the iron oxide compound, including less T2* dephasing, lack of susceptibility artifacts, and fast renal elimination.
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Affiliation(s)
- S E Clarke
- Robarts Research Institute, Imaging Research Laboratories, London, Ontario, Canada
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Marchand B, Douek PC, Benderbous S, Corot C, Canet E. Pilot MR evaluation of pharmacokinetics and relaxivity of specific blood pool agents for MR angiography. Invest Radiol 2000; 35:41-9. [PMID: 10639035 DOI: 10.1097/00004424-200001000-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate the use of two new blood pool contrast agents (P760, P775) compared with a low-molecular-weight gadolinium chelate in MR angiography. METHODS The r1 efficiency of P760 was evaluated in vitro at 1.5 T; 3D abdominal contrast-enhanced MR angiography with qualitative analysis was compared in four rabbits after injection of incremental doses of P760 and in one rabbit after Gd-DOTA. A dynamic MR study was performed using a 2D T1-weighted turbo-flash MR sequence after injection of P760, P775, and Gd-DOTA. Each compound was tested at equivalent doses in three rabbits to assess r1 efficiency. Quantitative analysis of signal intensity in the aorta, the inferior vena cava, the renal cortex, and the medulla was performed. RESULTS In vitro, the r1 efficiency of P760 was 23.3 mmol(-1) x L x sec(-1) at 1.5 T. Injection of a dose of P760 10 times less than Gd-DOTA allowed similar vessel visualization. The signal intensity peak and first-pass contrast kinetics in the aorta and the inferior vena cava were similar with the three products. Compared with P760 and Gd-DOTA, P775 allowed a greater renal cortex signal intensity at the first pass and a faster decrease on delayed images. CONCLUSIONS The superior r1 efficiency of P760 and P775 was confirmed in vitro and in vivo at 1.5 T compared with Gd-DOTA, and P775 proved to be a rapid-clearance blood pool agent.
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Wagenseil JE, Johansson LO, Lorenz CH. Characterization of t1 relaxation and blood-myocardial contrast enhancement of NC100150 injection in cardiac MRI. J Magn Reson Imaging 1999; 10:784-9. [PMID: 10548789 DOI: 10.1002/(sici)1522-2586(199911)10:5<784::aid-jmri24>3.0.co;2-a] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A new ultrasmall superparamagnetic iron oxide (Clariscan; NC100150 Injection) was studied in domestic farm pigs. The T1 effects were characterized for blood and myocardium and the blood-myocardial contrast was measured in T1-weighted cine images. The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured at baseline and contrast doses of 1 and 5 mg Fe/kg body weight (bw) at end diastole and late systole. The T1 values for blood and myocardium were reduced by 97 and 43%, respectively, from baseline to 5 mg Fe/kg bw. The CNR was significantly improved with contrast at end diastole and late systole. The maximum improvement shown was 202% at 5 mg Fe/kg bw in late systole. The percent SNR enhancement was significantly higher in blood than myocardium at late systole. NC100150 Injection is an effective T1 shortening agent and can be used to improve blood-myocardial contrast in cine images of the heart. J. Magn. Reson. Imaging 1999;10:784-789.
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Affiliation(s)
- J E Wagenseil
- Center for Cardiovascular MR, Cardiovascular Division, Barnes-Jewish Hospital at Washington University Medical Center, St. Louis, Missouri 63110, USA
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Abstract
This review explores the present status of contrast media available for myocardial perfusion studies, the magnetic resonance (MR) sequences adapted to multi-slice first-pass acquisitions, and the issue of myocardial perfusion quantification. To date, only low molecular weight paramagnetic gadolinium chelates have been used in clinical protocols for myocardial perfusion. With the availability of fast MR acquisition techniques to follow the first-pass distribution of the contrast agent in the myocardium, the bolus tracking technique represents the more widely used protocol in MR perfusion studies. On T1-weighted imaging, the ischemic zone appears with a delayed and lower signal enhancement compared with normally perfused myocardium. Visual analysis of the image series can be greatly improved by image post-processing to obtain relative myocardial perfusion maps. With an intravascular tracer, myocardial kinetics are in theory easier to analyze in terms of perfusion. In experimental studies, different intravascular or blood pool MR contrast agents have been tested to measure quantitative perfusion parameters. If a simple flow-limited kinetic model is developed with MR contrast agents, one important clinical application will be the evaluation of the functional consequence of coronary stenoses, ie, non-invasive evaluation of the coronary reserve.
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Affiliation(s)
- E P Canet
- Laboratoire CREATIS, UMR CNRS 5515, Hôpital Cardiologique, and INSA, 69394 Lyon, France
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Bremer C, Allkemper T, Baermig J, Reimer P. RES-specific imaging of the liver and spleen with iron oxide particles designed for blood pool MR-angiography. J Magn Reson Imaging 1999; 10:461-7. [PMID: 10508309 DOI: 10.1002/(sici)1522-2586(199909)10:3<461::aid-jmri30>3.0.co;2-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The purpose of this study was to determine the dependency of liver- and spleen-enhancement on particle size and dose of bolus-injectable iron oxides designed for blood-pool MR-angiography (MRA). The superparamagnetic iron oxide SHU 555 A [particle size 65 nm (group 1)] and three derivatives designed for blood-pool MRA (groups 2-4) with smaller hydrodynamic diameters (46/33/21 nm) were i.v. injected in New Zealand White rabbits at doses of 10, 20, or 40 micromol Fe/kg bw. MRI was performed before, 2, and 24 hours after contrast application using T1-weighted SE and T2-weighted TSE sequences. In addition splenic tissue was harvested post mortem and scanned ex vivo. All iron oxides significantly decreased the SI of liver and spleen in T1- and T2-weighted images at 2 and 24 hours after application of contrast media (P < 0.01). The signal intensity was inversely related to the dose applied. Decreasing particle size resulted in a lower signal enhancement in liver and spleen. However, ultra-small superparamagnetic iron oxides suited for blood-pool MRA (USPIOs, group 4) still revealed a significant signal enhancement in the liver and spleen even 24 hours after contrast application (< - 60%, 40 micromol Fe/kg bw). They might thus be used for comprehensive abdominal studies including contrast enhanced MR-angiography and RES-specific imaging.
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Affiliation(s)
- C Bremer
- Department of Clinical Radiology, Westfaelische Wilhelms-Universitaet Muenster, Albert-Schweitzer-Strasse 33, D-48129 Muenster, Germany.
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Enhanced Artery Visualization in Blood Pool MRA: Results in the Peripheral Vasculature. ACTA ACUST UNITED AC 1999. [DOI: 10.1007/3-540-48714-x_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Ladd DL, Hollister R, Peng X, Wei D, Wu G, Delecki D, Snow RA, Toner JL, Kellar K, Eck J, Desai VC, Raymond G, Kinter LB, Desser TS, Rubin DL. Polymeric gadolinium chelate magnetic resonance imaging contrast agents: design, synthesis, and properties. Bioconjug Chem 1999; 10:361-70. [PMID: 10346865 DOI: 10.1021/bc980086+] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have synthesized and evaluated five series of polymeric gadolinium chelates which are of interest as potential MRI blood pool contrast agents. The polymers were designed so that important physical properties including molecular weight, relaxivity, metal content, viscosity, and chelate stability could be varied. We have shown that, by selecting polymers of the appropriate MW, extended blood pool retention can be achieved. In addition, relaxivity can be manipulated by changing the polymer rigidity, metal content affected by monomer selection, viscosity by polymer shape, and chelate stability by chelator selection.
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Affiliation(s)
- D L Ladd
- Torsten Almén Research Center, Nycomed Amersham Imaging, 466 Devon Park Drive, Wayne, Pennsylvania 19087, USA.
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