The purpose of this study is to investigate the impacts of added filtration on the contrast-detail detectability of a digital X-ray imaging system for small animal studies. A digital X-ray imaging system specifically designed for small animal studies was used. This system is equipped with a micro X-ray source with a tungsten target and a beryllium window filtration and a CCD-based digital detec...

PURPOSE The Bayesian estimation algorithm improves the precision of bolus tracking perfusion imaging. However, this algorithm cannot directly calculate Tmax, the time scale widely used to identify ischemic penumbra, because Tmax is a non-physiological, artificial index that reflects the tracer arrival delay (TD) and other parameters. We calculated Tmax from the TD and mean transit time (MTT) ob...

The National Center for Asphalt Technology (NCAT) has undertaken a wide range of hot mix asphalt (HMA) related research projects. These projects have been funded by various agencies such as the National Cooperative Highway Research Program (NCHRP) of the Transportation Research Board, the Federal Highway Administration (FHWA), the Alabama Department of Transportation, the South Carolina Departm...

The National Center f’or Asphalt Trchnolofiy (NCAT) has just complctd two Nation;ll Coopwrrive HicThw:tv Rr<e:lrch Pq!ram (NtHR6) Projects: NCHRP 9-X. “Designing Stone Matrix Asphalt (SMA) Mixtures.” and NCHRP 9-9. “Reilnement of Superpave Gyratory Compaction Procedure.” Dr. Ray Brown. NCAT director. was the p r i n c i p a l invcsti:etor on both pmjects. The fint project on SMA represented ;I ...

Computerized neurocognitive assessment tools (NCATs) are increasingly used for baseline and post-concussion assessments. To date, NCATs have not demonstrated strong test-retest reliabilities. Most studies have used non-military populations and different methodologies, complicating the determination of the utility of NCATs in military populations. The test-retest reliability of four NCATs (Autom...

PURPOSE To investigate the efficacy of a second-generation prototype magnetic guidance system in complex vessel phantoms versus conventional navigation in simulated interventional radiology procedures and to analyze procedure and fluoroscopy times. MATERIALS AND METHODS The magnetic guidance system consists of two focused-field permanent magnets on each side of the body that create a 0.1-T na...

The European Commission recommends the CDMAM phantom as a tool to evaluate threshold contrast visibility in digital mammography [1, 2]. The use of the CDMAM phantom for that purpose has been proposed by Young [3] and other researchers. Recently, the phantom has been criticized because of poor reproducibility of the manufacturing process [4, 5], but it is still recommended by the European Commis...

PURPOSE To introduce the concept of dose-mass-based inverse optimization for radiotherapy applications. MATERIALS AND METHODS Mathematical derivation of the dose-mass-based formalism is presented. This mathematical representation is compared to the most commonly used dose-volume-based formulation used in inverse optimization. A simple example on digitally created phantom is presented. The pha...