Medicine and Health Sciences Commons^™

Volumetry Of Low-Contrast Liver Lesions With Ct: Investigation Of Estimation Uncertainties In A Phantom Study, Qin Li, Yongguang Liang, Qiao Huang, Min Zong, Benjamin Berman, Marios A. Gavrielides, Lawrence H. Schwartz, Binsheng Zhao, Nicholas Petrick

Food and Drug Administration Papers

Purpose: To evaluate the performance of lesion volumetry in hepatic CT as a function of various imaging acquisition parameters.

Methods: An anthropomorphic abdominal phantom with removable liver inserts was designed for this study. Two liver inserts, each containing 19 synthetic lesions with varying diameter (6–40 mm), shape, contrast (10–65 HU), and both homogenous and mixed-density were designed to have background and lesion CT values corresponding to arterial and portal-venous phase imaging, respectively. The two phantoms were scanned using two commercial CT scanners (GE 750 HD and Siemens Biograph mCT) across a set of imaging protocols (four slice thicknesses, …

Investigation Of Tattoo Pigments By Raman Spectroscopy, Betsy Jean Yakes, Tara Jade Michael, Marianita Perez-Gonzalez, Bhakti Petigara Harp

Food and Drug Administration Papers

As a result of the increase in the practice of tattooing, the US Food and Drug Administration has identified a need for improved analytical methods to detect the pigments and potential impurities in the inks. Raman spectroscopy allows for nondestructive identification of compounds and is commonly used in art, archaeology, and forensics; however, the technique has only limitedly been applied to the identification of tattoo pigments. In this study, approximately 30 inorganic, organometallic, and organic pigmentswere evaluated with Raman spectroscopy by using 532, 633, and 780-nmlasers. Individual optimization of the instrumental parameters was performed for each pigment in order to …

Bacterial Endotoxin Detection In Hyaluronic Acid-Based Medical Devices, Larissa F. Baeva, Srilekha Sarkar Das, Victoria M. Hitchins

Food and Drug Administration Papers

A simple and rapid method has been developed for testing bacterial endotoxin in hyaluronic acid (HA)-based medical devices. High-molecular-weight HA (HMW HA) in solution or HA-based medical devices was digested by the enzyme hyaluronidase to reduce solution viscosity by truncating the long chains of HA and to test for bacterial endotoxin. The bacterial endotoxin level was detected and measured by kinetic chromogenic Limulus Amebocyte Lysate (LAL) assay. The method was applied to two different ophthalmic viscosurgical devices (OVDs) and one dermal filler, and may easily be adapted to use with up to 3% HA solutions and other HA-based medical devices.

Pharmacokinetics And Distribution In Interstitial And Pulmonary Epithelial Lining Fluid Of Danofloxacin In Ruminant And Preruminant Calves, D. A. Mzyk, R. E. Baynes, K. M. Messenger, M. Martinez, G. W. Smith

Food and Drug Administration Papers

The objective of this study was to compare active drug concentrations in the plasma vs. different effector compartments including interstitial fluid (ISF) and pulmonary epithelial lining fluid (PELF) of healthy preruminating (3-week-old) and ruminating (6-month-old) calves. Eight calves in each age group were given a single subcutaneous (s.c.) dose (8 mg/kg) of danofloxacin. Plasma, ISF, and bronchoalveolar lavage (BAL) fluid were collected over 96 h and analyzed by high-pressure liquid chromatography. PELF concentrations were calculated by a urea dilution assay of the BAL fluids. Plasma protein binding was measured using a microcentrifugation system. For most preruminant and ruminant calves, the …