Direct measurement of CTDI on helical CT scans.

Purpose: Medical physics computed tomography (CT) practice involves measurements to determine CTDI on representative clinical CT protocols. In current practice the majority of CT exams employ helical scans. To determine CTDI for a helical scan, one measures CTDI with an axial scan, then divides by the pitch.

Half Century Since SIDS: A Reappraisal of Terminology.

After a sudden infant death, parents and caregivers need accurate and open communication about why their infant died. Communicating tragic news about a child's death to families and caregivers is difficult. Shared and consistent terminology is essential for pediatricians, other physicians, and nonphysician clinicians to improve communication with families and among themselves.

"Effect of very dense artifacts on Hologic and general electric bone densitometry results".

Unlabelled: Very dense artifacts confound bone density measurement. Hologic and GE densitometers exclude artifact density and GE also excludes associated area. Consequently, BMD is decreased with Hologic software.

Work-Life Balance, Burnout, and Physician Wellness.

Work-life balance, burnout, and physician wellness have become an important focus over the last 20 years in the field of medicine. Significant work design and cultural changes are to blame for these newly recognized aspects of a physician's career and life as a whole. Unique aspects of the work environment in the United States not only contribute to these issues in the field of medicine, but also affect the US workforce at large.

Gadoxetate Disodium enhanced spectral dual-energy CT for evaluation of cholangiocarcinoma: Preliminary data.

Purpose: Evaluate Gadoxetate Disodium enhanced dual-energy CT for visualization of perihilar cholangiocarcinoma by exploiting the hepatobiliary uptake of Gadoxetate Disodium and viewing images at the k-edge of gadolinium on the spectrum of simulated monoenergetic energies available with Dual Energy CT.

Material And Methods: In this prospective, IRB-approved study in patients with suspected cholangiocarcinoma, subjects who underwent a clinically indicated Gadoxetate Disodium liver MRI were immediately scanned without further IV contrast administration using rapid kVp-switching dual energy CT (rsDECT). Initial Gadoxetate Disodium dose was the FDA approved clinical dose, 0.

High-ratio grid considerations in mobile chest radiography.

Purpose: Grids are often not used in mobile chest radiography, and when used, they have a low ratio and are often inaccurately aligned. Recently, a mobile radiography automatic grid alignment system (MRAGA) was developed that accurately and automatically aligns the focal spot with the grid. The objective of this study is to investigate high-ratio grid tradeoffs in mobile chest radiography at fixed patient dose when the focal spot lies on the focal axis of the grid.

SU-E-I-53: Optimal KVp for Image Quality and Noise in Iodine Contrast in Head CTA.

Purpose: For brain CT perfusion it is well established that 80 kVp is optimal. Although neuro-CT angiography is somewhat similar, emphasis is on the detection of aneurysms and related vascular pathologies throughout the brain. Thus it is necessary to visualize small and large blood vessels with contrast material, as well as form multi-planar views and 3D images, so image quality and noise in addition to contrast are important for thin slices.

Atypical presentation of a mediastinal mass in an adolescent: Critical care considerations.

Objective: To describe the clinical course and treatment of a large mediastinal mass with unusual presentation and critical lower airway compression in an adolescent.

Design: Case report.

Setting: Pediatric intensive care unit in a tertiary care, academic children's hospital.

Anniversary paper: AAPM Education Council: looking back or looking forward.

As we celebrate the 50th year of the American Association of Physicists in Medicine (AAPM), what better time to look back at our development as well as to look forward to the opportunities that lie ahead. Here the authors will review some of the achievements of the Education Council and show how the activities are helping to shape the future educational goals and opportunities of the AAPM and the medical physics profession. Much of the work of the Education Council is carried out by the various committees and subcommittees that make up the Council or have a liaison relationship with the Council.

Black hole artifacts-a new potential pitfall for DXA accuracy?

Certain types of metallic objects apparently have high attenuation (a white image) on dual-energy X-ray absorptiometry (DXA) scan images, but instead show up as black (black hole artifacts). When small, these artifacts may easily be missed on visual inspection. We hypothesized that such "black hole" artifacts could have a significant effect on bone mineral density (BMD) results.

The effect of common artifacts lateral to the spine on bone mineral density in the lumbar spine.

Artifacts such as surgical clips, gallstones, and kidney stones are often present in the soft tissue stripe lateral to vertebral bodies. Using cadaveric specimens, we placed bra wires, gallbladder clips, a large gallstone, a calcium carbonate or a calcium citrate pill lateral to L1, or a large or small calcium-containing kidney stone lateral to L3 and compared the mean bone mineral density (BMD) of individual vertebral bodies and L1-L4 with and without the soft tissue artifact. The specimens used had high BMD (L1-L4 BMD=1.

Case report of a patient with primary central nervous system lymphoma treated with radioimmunotherapy.

Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma arising within and confined to the central nervous system and, unlike other primary brain tumors, is very responsive to treatment. Aggressive management can lead to prolonged remissions or cures. However, the prognosis at relapse is generally poor with limited therapeutic options; clearly, new strategies are needed for these patients.

AAPM Task Group 108: PET and PET/CT shielding requirements.

The shielding of positron emission tomography (PET) and PET/CT (computed tomography) facilities presents special challenges. The 0.511 MeV annihilation photons associated with positron decay are much higher energy than other diagnostic radiations.

Gated SPECT perfusion imaging for the simultaneous assessment of myocardial perfusion and ventricular function in the BARI 2D trial: an initial report from the Nuclear Core Laboratory.

Background: The BARI 2D (Bypass Angioplasty Revascularization Investigation 2 Diabetes) trial, a National Heart, Lung, and Blood Institute-sponsored study in type 2 diabetic patients with coronary artery disease, completed patient recruitment in March 2005. This trial had a nuclear substudy in addition to many other substudies.

Methods And Results: After patient enrollment, adenosine gated single photon emission computed tomography perfusion imaging is performed at years 1 and 3.

Patient self-attenuation and technologist dose in positron emission tomography.

Positron emission tomography (PET), with 511-keV radiation and long patient-uptake times, presents unique radiation safety concerns. This two-part study considers aspects of PET radiation safety as they relate to PET suite design, dose to the public, and technologist occupational dose. In the first part of the study, the self-attenuation of radiation by patients' bodies was quantified.

Quantitative SPECT imaging: a review and recommendations by the Focus Committee of the Society of Nuclear Medicine Computer and Instrumentation Council.

This article is a review of the physics principles, instrumentation and reconstruction methods behind SPECT imaging. Particular attention is paid to the mechanisms that can significantly affect the accuracy of a SPECT image. We describe instrumentation advances and reconstruction methods used to correct images to improve image quality and produce quantitative images.

Quantitation of SPECT performance: Report of Task Group 4, Nuclear Medicine Committee.

A comprehensive performance testing program is an essential ingredient of high-quality single-photon emission computed tomography (SPECT). Many of the procedures previously published are complicated, time consuming, or require a special testing environment. This Task Group developed a protocol for evaluating SPECT imaging systems that was simple, practical, required minimal test equipment, and could be performed in a few hours using processing software available on all nuclear medicine computers.

Pharmacokinetics, immune response, and biodistribution of iodine-131-labeled chimeric mouse/human IgG1,k 17-1A monoclonal antibody.

Pharmacokinetics, immunogenicity, and biodistribution of a 131I-labeled mouse/human chimeric monoclonal antibody (C-17-1A) was studied in six metastatic colon cancer patients. Pharmacokinetics obtained from serum radioactivity or chimera concentration were identical after 5 mCi of 131I-C-17-1A with mean alpha half-lives of 17.6 +/- 2.