Wayne O. Carter
Pfizer
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Publication
Featured researches published by Wayne O. Carter.
Journal of Magnetic Resonance Imaging | 2001
Karl Turetschek; T. P. Roberts; Eugenia Floyd; Anda Preda; Viktor Novikov; David M. Shames; Wayne O. Carter; Robert C. Brasch
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 (KPS) 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 (KPS) 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.
Journal of Magnetic Resonance Imaging | 2001
Karl Turetschek; Eugenia Floyd; Thomas H. Helbich; T. P. Roberts; David M. Shames; Michael F. Wendland; Wayne O. Carter; Robert C. Brasch
A new contrast medium, MS‐325, was compared to albumin‐(Gd‐DTPA)30 in 18 chemically induced rat breast tumors based on quantitative estimates of microvascular permeability (KPS) and fractional plasma volume (fPV) using a two‐compartment bidirectional model. No significant correlation was found between MS‐325‐enhanced microvascular assays with either tumor grade or with microvascular counts (MVCs). In comparison, the correlation coefficient between KPS and histologic tumor grade using albumin‐(Gd‐DTPA)30 (r = .58) was statistically significant (P < .01). Also, using albumin‐(Gd‐DTPA)30, a significant correlation (r = .55, P < .05) was observed between the KPS and MVC, a biomarker of angiogenesis. Correlations between fPV and MVC were not statistically significant for either contrast medium. In conclusion, using MS‐325, no significant correlations between the MR‐estimated permeability values or plasma volumes were observed in experimental breast tumors with either the histologic tumor grade or MVC. This analysis confirms our previous determination that capillary permeability estimates, using a prototype large molecular contrast medium, albumin‐(Gd‐DTPA)30, correlate significantly with both histologic tumor grade and MVC. J. Magn. Reson. Imaging 2001;14:237–242.
Magnetic Resonance in Medicine | 2001
Karl Turetschek; Eugenia Floyd; David M. Shames; Timothy P.L. Roberts; Anda Preda; Viktor Novikov; Claire Corot; Wayne O. Carter; Robert C. Brasch
The diagnostic potential of a new rapid clearance blood pool contrast medium (P792; MW = 6.47 kDa) for the MR assessment of microvessel characteristics was assessed in 42 chemically‐induced breast tumors, with comparisons to albumin‐(Gd‐DTPA). Microvessel characteristics, including the transendothelial permeability (KPS) and the fractional blood volume (fPV), were estimated by using dynamic MR data fit to a bidirectional two‐compartment model. The MR‐derived estimates for KPS and fPV using each contrast agent were compared, and assays using each contrast agent were correlated to the histologic tumor grade (SBR score) and the microvascular density (MVD) counts. Using P792‐enhanced data, neither KPS nor fPV showed a statistically significant correlation with the tumor grade or the MVD (P > .05). Conversely, using albumin‐(GdDTPA)30, KPS values correlated significantly with the histologic tumor grade (r = .55; P < .0005) and the MVD (r = .34, P < .05), whereas no correlation was established for fPV. In conclusion, based on P792 data no correlation between tumor microvascular characteristics and histologic markers (SBR score or MVD) was found in this breast tumor model. Our analysis suggests that contrast media of relatively large (on the order of 90 kDa) molecular size, such as albumin‐(GdDTPA)30, are more accurate for the characterization of tumor microvessels. Magn Reson Med 45:880–886, 2001.
Investigative Radiology | 2005
Anda Preda; Karl Turetschek; Heike Daldrup; Eugenia Floyd; Viktor Novikov; David M. Shames; Timothy P.L. Roberts; Wayne O. Carter; Robert C. Brasch
Objectives:The objectives of this study were to determine if magnetic resonance (MR) estimates of quantitative tissue microvascular characteristics from regions of interest (ROI) limited to the tumor periphery provided a better correlation with tumor histologic grade than ROI defined for the whole tumor in cross-section. Methods:A metaanalysis was based on 98 quantitative MR image breast tumor characterizations acquired in 3 separate experimental studies using identical methods for tumor induction and contrast enhancement. Results:The endothelial transfer coefficient (KPS) of albumin (Gd-DTPA)30 from the tumor periphery correlated (r = 0.784) significantly more strongly (P < 0.001) with the pathologic tumor grade than KPS derived from the whole tumor (r = 0.604). KPS estimates, either from the tumor periphery or from the whole tumor, correlated significantly more strongly with histologic grade (P < 0.01) than MR image estimates of fractional plasma volume (fPV) from either tumor periphery (r = 0.368) or whole tumor (r = 0.323). Conclusions:KPS estimates from the tumor periphery were the best of these measurable MR image microvascular characteristics for predicting the histologic grade.
Journal of Magnetic Resonance Imaging | 2003
Kenneth R. Maravilla; Yunyu Cao; Julia R. Heiman; Patricia A. Garland; Barry T. Peterson; Wayne O. Carter; Robert M. Weisskoff
To determine if a similar sexual arousal response in normal, healthy women could be obtained and monitored by serial magnetic resonance (MR) imaging at two separate sessions.
Radiology | 2006
Peter R. Kornaat; Johan L. Bloem; Ruth Y. T. Ceulemans; Naghmeh Riyazi; Frits R. Rosendaal; Rob G. H. H. Nelissen; Wayne O. Carter; Marie-Pierre Hellio Le Graverand; Margreet Kloppenburg
Skeletal Radiology | 2005
Peter R. Kornaat; Ruth Y. T. Ceulemans; Herman M. Kroon; Naghmeh Riyazi; Margreet Kloppenburg; Wayne O. Carter; Thasia Woodworth; Johan L. Bloem
European Journal of Nuclear Medicine and Molecular Imaging | 2003
Karl Turetschek; Anda Preda; Eugenia Floyd; David M. Shames; Viktor Novikov; Timothy P.L. Roberts; Jeanette Marjorie Wood; Yanjun Fu; Wayne O. Carter; Robert C. Brasch
Academic Radiology | 2002
Karl Turetschek; Anda Preda; Eugenia Floyd; David M. Shames; Viktor Novikov; Timothy P.L. Roberts; Jeanette Marjorie Wood; Yanjun Fu; Wayne O. Carter; Robert C. Brasch
European Radiology | 2005
Anda Preda; Viktor Novikov; Martina Möglich; Eugenia Floyd; Karl Turetschek; David M. Shames; T. P. Roberts; Claire Corot; Wayne O. Carter; Robert C. Brasch