Accuracy and calibration of integrated radiation output indicators in diagnostic radiology: A report of the AAPM Imaging Physics Committee Task Group 190.

Due to the proliferation of disciplines employing fluoroscopy as their primary imaging tool and the prolonged extensive use of fluoroscopy in interventional and cardiovascular angiography procedures, "dose-area-product" (DAP) meters were installed to monitor and record the radiation dose delivered to patients. In some cases, the radiation dose or the output value is calculated, rather than measured, using the pertinent radiological parameters and geometrical information. The AAPM Task Group 190 (TG-190) was established to evaluate the accuracy of the DAP meter in 2008.

An investigation into factors affecting the precision of CT radiation dose profile width measurements using radiochromic films.

Purpose: To investigate the impact of x-ray beam energy, exposure intensity, and flat-bed scanner uniformity and spatial resolution on the precision of computed tomography (CT) beam width measurements using Gafchromic XR-QA2 film and an off-the-shelf document scanner.

Methods: Small strips of Gafchromic film were placed at isocenter in a CT scanner and exposed at various x-ray beam energies (80-140 kVp), exposure levels (50-400 mA s), and nominal beam widths (1.25, 5, and 10 mm).

Diagnostic ionizing radiation exposure in premature patients.

Objective: Concern regarding the magnitude and consequences of diagnostic radiation exposure in premature infants in neonatal intensive care units (NICUs) has increased as survival of premature infants has improved. Radiation exposure is not often rigorously monitored in NICU patients. The purpose of this observational study was to quantify the amount of ionizing radiation exposure in infants <33 weeks gestational age and to identify the indications for diagnostic imaging.

Quantitative evaluation of light scattering intensities of the crystalline lens for radiation related minimal change in interventional radiologists: a cross-sectional pilot study.

To evaluate low-dose X-ray radiation effects on the eye by measuring the amount of light scattering in specific regions of the lens, we compared exposed subjects (interventional radiologists) with unexposed subjects (employees of medical service companies), as a pilot study. According to numerous exclusionary rules, subjects with confounding variables contributing to cataract formation were excluded. Left eye examinations were performed on 68 exposed subjects and 171 unexposed subjects.

Comparison of topogram-based body size indices for CT dose consideration and scan protocol optimization.

Purpose: To retrospectively compare different topogram-based patient body size indices and to determine the optimal topogram-based body size index as a basis for body computed tomography (CT) dose consideration and scan protocol optimization.

Methods: Forty-three routine thorax and abdomen CT scans are studied retrospectively, with patient ages ranging from 18 to 67 yr. The individual patient's water-equivalent diameter (D(w)) of the scanned body region is computed from CT DICOM images as the "gold standard," after first converting from Hounsfield units values to μa values, where μ is the normalized tissue attenuation coefficient and a is the area per pixel.

Role of postmarketing surveillance in contemporary medicine.

Contemporary medicine is a large and complex system involving many participants, all of whom play a critical role in managing the risks intrinsic to medical product use. Despite the robust premarket review and approval process of the U.S.

Challenges, successes and hopes in the development of novel TB therapeutics.

Despite efficacious drugs for treatment, TB continues to affect enormous numbers of patients throughout the world. Failure to control TB may be related to the biological characteristics of Mycobacterium tuberculosis, the nature of susceptible hosts often impoverished and poorly supported by healthcare infrastructure and the complex treatment regimens that must be used. Challenges to anti-TB drug development include the organism's slow replication, the ability of M.

Increased radiation dose to overweight and obese patients from radiographic examinations.

Purpose: To estimate the increase in effective radiation dose from diagnostic x-rays for overweight and obese adult patients, as compared with the effective dose for lean reference phantoms.

Materials And Methods: Relative effective radiation doses (E/E(0)) for the acquisition of chest and abdominal radiographs were calculated by using Monte Carlo computer simulations of effective doses delivered to adult phantoms with (E) and without (E(0)) subcutaneous adipose tissue added to the torso for five fat distributions. Total (anterior plus posterior) fat thicknesses ranged from 0 to 38 cm.

Digital mammographic artifacts on full-field systems: what are they and how do I fix them?

The recent introduction of digital mammography represents a significant technologic advance in breast imaging. However, many radiologists and technologists are unfamiliar with artifacts that are commonly seen with this modality, and recognizing these artifacts is critical for optimizing image quality. Commonly encountered artifacts include patient-related artifacts (motion artifact, antiperspirant artifact, thin breast artifact), hardware-related artifacts (field inhomogeneity, detector-associated artifacts, collimator misalignment, underexposure, grid lines, grid misplacement, vibration artifact), and software processing artifacts ("breast-within-a-breast" artifact, vertical processing bars, loss of edge, high-density artifacts).

Developing new drugs for the treatment of drug-resistant tuberculosis: a regulatory perspective.

Simplifying and shortening treatment for drug-sensitive tuberculosis and providing new treatment options for drug-resistant tuberculosis constitute two principal goals in the development of novel drugs for tuberculosis. Demonstration of clinical efficacy in drug-sensitive tuberculosis is challenging, given high success rates for existing regimens, concerns about substituting an investigational agent for the most effective agents in a regimen and difficulties in determining the effect size of the components of a combination regimen. Large and prolonged studies would be needed either to show superiority over existing regimens or statistically defensible non-inferiority compared to existing regimens.

Economic issues with follow-on protein products.

The economic effects of the possible introduction of 'follow-on' protein products have been the subject of recent debate. Here, we aim to explore the economic issues surrounding this debate using three measures: total sales, product complexity and patent expiry. Our analysis shows that the sales of therapeutic protein products are concentrated in a relatively small number of branded products, which may be the most attractive targets for follow-on development.

Single parents of children with chronic illness: an understudied phenomenon.

Objective: To examine the chronic illness literature and evaluate the impact on single parenting and children and adolescents with chronic illness.

Methods: We conducted literature reviews of relevant research pertaining to single-parent families on PubMed, Medline, and PsychINFO and also surveyed pertinent book chapters and all of the articles from the Journal of Pediatric Psychology since 1987 for articles, specifically examining the potential associations of single (lone) parenting versus two-parent households on children's psychosocial functioning and the impact of the child's illness on caregiver functioning.

Results: While the literature has examined and discussed the stressors associated with parenting a child with an illness, including the impact of illness on finances, family roles, and caregiver burden, few studies have examined single parents of children and adolescents with chronic illnesses and related stressors stemming from being a lone caregiver.

The FDA's assessment of follow-on protein products: a historical perspective.

The scientific and regulatory issues that are associated with the possible introduction of 'follow-on' versions of protein drug products are the topic of considerable debate at present. Because of the differences between protein drug products and small-molecule drugs, the development of follow-on versions of protein products presents more complex scientific challenges than those presented by the development of generic versions of small-molecule drugs. Here, with a view to illustrating the Food and Drug Administration's (FDA's) scientific reasoning and experience in this area, we discuss past examples of the FDA's actions involving the evaluation of various types of follow-on and second-generation protein products and within-product manufacturing changes.