Contrast-Specific Spherical Lesion Phantoms and Ancillary Analysis Software for the Objective Evaluation of Transrectal Ultrasound System Contrast Detectability.

Brachytherapy is an efficacious treatment option because of its benefits for patient recovery, dose localization and conformity, but these favorable outcomes can be ensured only if the transrectal ultrasound (TRUS) system is optimized for the specific application of ultrasound-guided prostate brachytherapy. The ability to delineate the prostate from surrounding tissue during TRUS-guided prostate brachytherapy is vital for treatment planning, and consequently, so is the contrast resolution. This study describes the development of task-specific contrast-detail phantoms with clinically relevant contrast and spherical target sizes for contrast-detail performance evaluation of TRUS systems used in the brachytherapy procedure.

Use of a novel anthropomorphic prostate simulator in a prostate brachytherapy transrectal ultrasound imaging workshop for medical physicists.

Purpose: Ultrasound imaging training is not required as part of radiation oncology training programs nor does any objective competency measure exist to independently assess performance. Physical simulation training can provide a structured approach to this training but only if suitably challenging training simulators exist. This study describes the design and preliminary evaluation of a simulation-based transrectal ultrasound (TRUS) imaging training workshop developed for medical physicists involved in low-dose-rate (LDR) prostate brachytherapy (PBT).

Development and Preliminary Evaluation of an Anthropomorphic Trans-rectal Ultrasound Prostate Brachytherapy Training Phantom.

The quality of the trans-rectal ultrasound (TRUS) image, and thus seed placement during the prostate brachytherapy (PBT) procedure, relies on the user's technical and clinical competency. Simulation-based medical education can provide a structured approach for the acquisition of clinical competencies, but the efficacy of the training relies on the fidelity of the training simulators. In this work, the design, development and preliminary evaluation of an anthropomorphic training phantom for TRUS PBT is described.

Perception of medical radiation risk in Ireland: Results of a public survey.

The Basic Safety Standards (BSS) directive 2013/59/EURATOM places a new emphasis on the practitioner and/or referrer to inform the patient of the benefits and risks associated with radiation dose. To communicate effectively, a prior knowledge of what a person comprehends is beneficial. The aim of this study was to evaluate the Irish public's current level of understanding of ionising radiation and its associated risks.

An investigation of the detection capability of pulsed wave duplex Doppler of low grade stenosis using ultrasound contrast agent microbubbles - An in-vitro study.

Objective: The objective of the study was to investigate whether clinically used ultrasonic contrast agents improved the accuracy of spectral Doppler ultrasound in the detection of low grade (<50%) renal artery stenosis. Low grade stenoses in the renal artery are notoriously difficult to reliably detect using Doppler ultrasound due to difficulties such as overlying fat and bowel gas.

Methods: A range of anatomically-realistic renal artery phantoms with varying low degrees of stenosis (0, 30 and 50%) were constructed and peak velocity data was measured from within the pre-stenotic and mid-stenotic regions in each phantom, for both unenhanced and contrast-enhanced spectral Doppler data acquisitions.

Investigation of the potential for sera from cattle persistently infected with bovine viral diarrhea virus to generate false-negative antibody ELISA results in pooled serum from seropositive and seronegative cattle.

We investigated the potential for viremic sera from cattle persistently infected with bovine viral diarrhea virus to create false-negative antibody results when testing pools of 10 sera by indirect or blocking ELISAs. Seronegative viremic sera ( n = 23) were each added to a series of artificially constructed pools containing various percentages (0-90%) of antibody-positive sera, and the resulting pools were assayed for antibody. In all 23 cases, a negative antibody result was obtained in the pool containing no seropositive sera.

A review of the recommendations governing quality assurance of ultrasound systems used for guidance in prostate brachytherapy.

Ultrasound guided brachytherapy for the treatment of prostate cancer has become a routine treatment option, due to many benefits including patient recovery and dose localisation [1]; however it is not clear whether the standards which govern the image quality for these systems are adequate. Upon review of the recommended standards for ultrasound systems used in prostate brachytherapy procedures, the recommended tests do not appear to be specific to the clinical application of ultrasound guided prostate brachytherapy. Rather they are generic and similar to those recommended for other clinical applications such as general abdominal scanning [2].

Sperm-Coating Beta-Defensin 126 Is a Dissociation-Resistant Dimer Produced by Epididymal Epithelium in the Bovine Reproductive Tract.

Beta-defensins are innate immune molecules, often described as antimicrobial peptides because of their bactericidal activity and are now known to have diverse additional functions, including cell signaling, chemoattraction, immunoregulation, and reproduction. In humans and primates, beta-defensin 126 has been shown to regulate the ability of sperm to swim through cervical mucus and to protect sperm from attack by the female immune system during transit toward the oviduct. Bovine beta-defensin 126 (BBD126) is the ortholog of human defensin 126, and computational analysis here revealed significant conservation between BBD126 and other mammalian orthologs at the N-terminus, although extensive sequence differences were detected at the C-terminus, implying possible species-specific roles for this beta-defensin in reproduction.

Use of a radio frequency shield during 1.5 and 3.0 Tesla magnetic resonance imaging: experimental evaluation.

Radiofrequency (RF) shields have been recently developed for the purpose of shielding portions of the patient's body during magnetic resonance imaging (MRI) examinations. We present an experimental evaluation of a commercially available RF shield in the MRI environment. All tests were performed on 1.

Assessment of three methods for detection of ultrasound artifacts.

Purpose: The purpose of this work is to measure the performance (sensitivity and specificity) of three different visually based methods of detecting ultrasound artifacts using dynamic clips obtained with a liquid phantom. It is important to detect the presence of these non uniformities as early as possible, so they can be assessed, tracked, and addressed well before clinical image quality is impacted.

Methods: A total of 28 transducers of varying models containing a single artificial artifact created by stretching thin filaments across the transducer face were prepared.

Four-year experience with a clinical ultrasound quality control program.

Ultrasound (US) quality control (QC) program data over a 4-year period from more than 45 scanners and more than 265 transducers were reviewed to optimize the program in terms of efficiency and effectiveness. Our program included evaluations of mechanical integrity, image uniformity, distance measurement accuracy and maximum depth of penetration (DOP). We computed failure rates and fraction of failures detected by each test.

Development of a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms.

Polyvinyl alcohol cryogel (PVA-C) is presented as a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms. Three different batches of 10% wt PVA-C containing (i) PVA-C alone, (ii) PVA-C with antibacterial agent and (iii) PVA-C with silicon carbide particles were produced, each with 1-6 freeze-thaw cycles. The resulting PVA-C samples were characterized acoustically (over a range 2.

Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom.

Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease.

Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography.

Evaluation of a low-cost liquid ultrasound test object for detection of transducer artefacts.

Routine quality control of ultrasound scanners and transducers is important for maintaining image quality. Our experience suggests that artefact and uniformity evaluation is the most effective single phantom test for detecting equipment problems. Current methods for assessing ultrasound images for artefacts have important limitations.

Development of a range of anatomically realistic renal artery flow phantoms.

Computer-aided modelling techniques were used to generate a range of anatomically realistic phantoms of the renal artery from medical images of a 64-slice CT data set acquired from a healthy volunteer. From these data, models of a normal healthy renal artery and diseased renal arteries with 30%, 50%, 70% and 85% stenoses were generated. Investment casting techniques and a low melting point alloy were used to create the vessels with varying degrees of stenosis.