Publications by authors named "Tim J Wood"

Background: The non-prewhitening computational model observer with eye filter (NPWE) has been shown to reasonably predict human observer performance in general radiography and is an appropriate substitute when real clinical trials are not feasible. In this study, the NPWE model observer is used to detect specific tasks (circular designer nodules) ranging between 1 and 30 mm in diameter using chest and abdomen phantom images acquired across the diagnostic energy range (60-125 kVp) with and without an anti-scatter grid.

Purpose: The aim of this study was to derive tube voltage (kVp) settings that return maximal NPWE detectability (d') of designer nodules, for digital radiography (DR) chest and abdomen imaging.

View Article and Find Full Text PDF
Article Synopsis
  • Cone beam CT (CBCT) is essential for modern radiotherapy, but it can also result in high radiation doses to a large area of tissue, making dose optimization crucial.
  • A UK survey collected dose data from 63 radiotherapy centers, determining the cone beam dose index (CBDI) values for seven treatment sites and establishing national dose reference levels (DRLs) to ensure safety.
  • Significant differences were found in imaging systems and protocols, with centers that actively optimized imaging doses achieving better results, particularly in prostate versus gynecological treatments.
View Article and Find Full Text PDF

. Full-field digital mammography (FFDM) systems manufactured by Hologic that utilise either a 2D or linear anti-scatter grid have recently been installed in our clinic. The manufacturer advise that for matched dose, both grids deliver comparable image quality.

View Article and Find Full Text PDF

The aim of this study was to demonstrate the usefulness of large sample size patient dose audits for optimisation of CT automatic exposure control (AEC) settings, even when the investigation is limited to only three scanners at a single institution. Pre-optimisation patient dose audits of common CT examinations (n > 200 for each protocol) on three CT scanners (two Philips Brilliance and one Toshiba Aquilion) using radiology information system (RIS) data were conducted showing sub-optimal CT AEC performance on the Toshiba scanner. Based on these results, an optimisation exercise was carried out on the non-optimally performing scanner by phantom measurement and investigation of system configuration.

View Article and Find Full Text PDF

CT scans are an integral component of modern radiotherapy treatments, enabling the accurate localisation of the treatment target and organs-at-risk, and providing the tissue density information required for the calculation of dose in the treatment planning system. For these reasons, it is important to ensure exposures are optimised to give the required clinical image quality with doses that are as low as reasonably achievable. However, there is little guidance in the literature on dose levels in radiotherapy CT imaging either within the UK or internationally.

View Article and Find Full Text PDF

Effective detective quantum efficiency (eDQE) describes the resolution and noise properties of an imaging system along with scatter and primary transmission, all measured under clinically appropriate conditions. Effective dose efficiency (eDE) is the eDQE normalised to mean glandular dose and has been proposed as a useful metric for the optimisation of clinical imaging systems. The aim of this study was to develop a methodology for measuring eDQE and eDE on a Philips microdose mammography (MDM) L30 photon counting scanning system, and to compare performance with two conventional flat panel systems.

View Article and Find Full Text PDF

The use of computer simulated digital x-radiographs for optimisation purposes has become widespread in recent years. To make these optimisation investigations effective, it is vital simulated radiographs contain accurate anatomical and system noise. Computer algorithms that simulate radiographs based solely on the incident detector x-ray intensity ('dose') have been reported extensively in the literature.

View Article and Find Full Text PDF

The goal of most presentations is to engage audience participants. Effective presenters go beyond content expertise to connect with audiences through various techniques, formats, and presentation styles. Mayer's theory of multimedia learning, neurocognitive factors, and the assertion-evidence approach are essential elements that presenters can use if they have not had formal training in creating presentations.

View Article and Find Full Text PDF

Objective: The purpose of this study was to develop size-based radiotherapy kilovoltage cone beam CT (CBCT) protocols for the pelvis.

Methods: Image noise was measured in an elliptical phantom of varying size for a range of exposure factors. Based on a previously defined "small pelvis" reference patient and CBCT protocol, appropriate exposure factors for small, medium, large and extra-large patients were derived which approximate the image noise behaviour observed on a Philips CT scanner (Philips Medical Systems, Best, Netherlands) with automatic exposure control (AEC).

View Article and Find Full Text PDF

Synopsis of recent research by authors named "Tim J Wood"

  • - Tim J Wood's recent research focuses on optimizing imaging techniques and dose management in radiology and radiotherapy, ensuring that configurations maximize image quality while maintaining patient safety.
  • - His studies involve the evaluation of various imaging systems, including digital radiography (DR) and cone beam CT, with significant findings on factors that enhance detectability and reduce unnecessary radiation exposure.
  • - Notable works include a comparative analysis of digital mammography systems, assessment of dose indices for radiotherapy imaging, and the development of methods for accurate patient size considerations in protocol optimization, all contributing to improved clinical practices in medical imaging.

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionvjobs9q24ca5hednp9g59c5kp3o2lg6b): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once