A novel method to evaluate gamma camera rotational uniformity and sensitivity variation

Kappadath, S.C., Erwin, W.D. and Wendt, R.E., III (2009), A novel method to evaluate gamma camera rotational uniformity and sensitivity variation. Med. Phys., 36: 1947-1955. https://doi.org/10.1118/1.3125642https://openworks.mdanderson.org/mdacc_imgphys_pubs/1007/thumbnail.jp

Observed intercamera variability in clinically relevantperformance characteristics for Siemens Symbia gammacameras

This is the peer reviewed version of the following article: Kappadath SC, Erwin WD, Wendt RE 3rd. Observed inter-camera variability of clinically relevant performance characteristics for Siemens Symbia gamma cameras. J Appl Clin Med Phys. 2006;7(4):74-80. Published 2006 Nov 28., which has been published in final form at doi:10.1120/jacmp.v7i4.2376. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.https://openworks.mdanderson.org/mdacc_imgphys_pubs/1009/thumbnail.jp

Optimal 57Co Flood Source Activity and Acquisition Time for Lymphoscintigraphy Localization Images

Martha V. Mar, Renee L. Dickinson, William D. Erwin, Richard E. Wendt. Optimal 57Co Flood Source Activity and Acquisition Time for Lymphoscintigraphy Localization Images. Journal of Nuclear Medicine Technology Jun 2008, 36 (2) 82-87; DOI: 10.2967/jnmt.107.047043https://openworks.mdanderson.org/mdacc_imgphys_pubs/1008/thumbnail.jp

A preclinical investigation of the saturation and dosimetry of 153Sm-DOTMP as a bone-seeking radiopharmaceutical

Simón J, Frank RK, Crump DK, Erwin WD, Ueno NT, Wendt RE. A preclinical investigation of the saturation and dosimetry of 153Sm-DOTMP as a bone-seeking radiopharmaceutical. Nuclear Medicine and Biology. 2012/08/01/ 2012;39(6):770-776. doi:https://doi.org/10.1016/j.nucmedbio.2011.12.015https://openworks.mdanderson.org/mdacc_imgphys_pubs/1006/thumbnail.jp

Hybrid Modality Fusion of Planar Scintigrams and CT Topograms to Localize Sentinel Lymph Nodes in Breast Lymphoscintigraphy: Technical Description and Phantom Studies

Lymphoscintigraphy is a nuclear medicine procedure that is used to detect sentinel lymph nodes (SLNs). This project sought to investigate fusion of planar scintigrams with CT topograms as a means of improving the anatomic reference for the SLN localization. Heretofore, the most common lymphoscintigraphy localization method has been backlighting with a 57Co sheet source. Currently, the most precise method of localization through hybrid SPECT/CT increases the patient absorbed dose by a factor of 34 to 585 (depending on the specific CT technique factors) over the conventional 57Co backlighting. The new approach described herein also uses a SPECT/CT scanner, which provides mechanically aligned planar scintigram and CT topogram data sets, but only increases the dose by a factor of two over that from 57Co backlighting. Planar nuclear medicine image fusion with CT topograms has been proven feasible and offers a clinically suitable compromise between improved anatomic details and minimally increased radiation dose

Characterization of LP-Z Lipoprotein Particles and Quantification in Subjects with Liver Disease Using a Newly Developed NMR-Based Assay

Background: Lipoprotein particles with abnormal compositions, such as lipoprotein X (LP-X) and lipoprotein Z (LP-Z), have been described in cases of obstructive jaundice and cholestasis. The study objectives were to: (1) develop an NMR-based assay for quantification of plasma/serum LP-Z particles, (2) evaluate the assay performance, (3) isolate LP-Z particles and characterize them by lipidomic and proteomic analysis, and (4) quantify LP-Z in subjects with various liver diseases. Methods: Assay performance was assessed for linearity, sensitivity, and precision. Mass spectroscopy was used to characterize the protein and lipid content of isolated LP-Z particles. Results: The assay showed good linearity and precision (2.5-6.3%). Lipid analyses revealed that LP-Z particles exhibit lower cholesteryl esters and higher free cholesterol, bile acids, acylcarnitines, diacylglycerides, dihexosylceramides, lysophosphatidylcholines, phosphatidylcholines, triacylglycerides, and fatty acids than low-density lipoprotein (LDL) particles. A proteomic analysis revealed that LP-Z have one copy of apolipoprotein B per particle such as LDL, but less apolipoprotein (apo)A-I, apoC3, apoA-IV and apoC2 and more complement C3. LP-Z were not detected in healthy volunteers or subjects with primary biliary cholangitis, primary sclerosing cholangitis, autoimmune hepatitis, or type 2 diabetes. LP-Z were detected in some, but not all, subjects with hypertriglyceridemia, and were high in some subjects with alcoholic liver disease. Conclusions: LP-Z differ significantly in their lipid and protein content from LDL. Further studies are needed to fully understand the pathophysiological reason for the enhanced presence of LP-Z particles in patients with cholestasis and alcoholic liver disease

Impact of Experience Corps® Participation on Children’s Academic Achievement and School Behavior

This article reports on the impact of the Experience Corps® (EC) Baltimore program, an intergenerational, school-based program aimed at improving academic achievement and reducing disruptive school behavior in urban, elementary school students in Kindergarten through third grade (K-3). Teams of adult volunteers aged 60 and older were placed in public schools, serving 15 h or more per week, to perform meaningful and important roles to improve the educational outcomes of children and the health and well-being of volunteers. Findings indicate no significant impact of the EC program on standardized reading or mathematical achievement test scores among children in grades 1–3 exposed to the program. K-1st grade students in EC schools had fewer principal office referrals compared to K-1st grade students in matched control schools during their second year in the EC program; second graders in EC schools had fewer suspensions and expulsions than second graders in non-EC schools during their first year in the EC program. In general, both boys and girls appeared to benefit from the EC program in school behavior. The results suggest that a volunteer engagement program for older adults can be modestly effective for improving selective aspects of classroom behavior among elementary school students in under-resourced, urban schools, but there were no significant improvements in academic achievement. More work is needed to identify individual- and school-level factors that may help account for these results

Atmospheric Escape Processes and Planetary Atmospheric Evolution

The habitability of the surface of any planet is determined by a complex evolution of its interior, surface, and atmosphere. The electromagnetic and particle radiation of stars drive thermal, chemical and physical alteration of planetary atmospheres, including escape. Many known extrasolar planets experience vastly different stellar environments than those in our Solar system: it is crucial to understand the broad range of processes that lead to atmospheric escape and evolution under a wide range of conditions if we are to assess the habitability of worlds around other stars. One problem encountered between the planetary and the astrophysics communities is a lack of common language for describing escape processes. Each community has customary approximations that may be questioned by the other, such as the hypothesis of H-dominated thermosphere for astrophysicists, or the Sun-like nature of the stars for planetary scientists. Since exoplanets are becoming one of the main targets for the detection of life, a common set of definitions and hypotheses are required. We review the different escape mechanisms proposed for the evolution of planetary and exoplanetary atmospheres. We propose a common definition for the different escape mechanisms, and we show the important parameters to take into account when evaluating the escape at a planet in time. We show that the paradigm of the magnetic field as an atmospheric shield should be changed and that recent work on the history of Xenon in Earth's atmosphere gives an elegant explanation to its enrichment in heavier isotopes: the so-called Xenon paradox