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Biomedical subjects

K Faulkner

Publications and source records attributed to K Faulkner.

At least 37 records · Page 2Linked to original sources
PubMed2003

Software for the estimation of foetal radiation dose to patients and staff in diagnostic radiology.

Occasionally, it is clinically necessary to perform a radiological examination(s) on a woman who is known to be pregnant or an examination is performed on a woman who subsequently discovers that she was pregnant at the time. In radiological examinations, especially of the lower abdomen and pelvis area, the foetus is directly irradiated. It is therefore important to be able to determine the absorbed dose to the foetus in diagnostic radiology for pregnant patients as well as the foetal dose from occupational exposure of the pregnant worker. The determination of the absorbed dose to the unborn child in diagnostic radiology is of interest as a basis for risk estimates from medical exposure of the pregnant patient and occupational exposure of the pregnant worker. In this paper we describe a simple computer program, FetDose, which calculates the dose to the foetus from both medical and occupational exposures of the pregnant woman. It also calculates the risks of in utero exposure, compares calculated doses with published data in the literature and provides information on the natural spontaneous risks. The program will be a useful tool for the medical and paramedical personnel who are involved with foetal dose (and hence risks) calculations and counselling of pregnant women who may be concerned about in utero exposure of their foetuses.

Algorithms↗
PubMed2003

Patient dose values in a dedicated Greek cardiac centre.

The purpose of this study was to collect information on the practice and patient doses in a major Greek cardiac centre, investigate differences between senior cardiologists of various levels of experience and compare results with the literature, in order to optimize angiographic and interventional cardiology procedures. Radiation doses from 292 patients have been studied, 195 of which had undergone coronary angiography and 97 percutaneous transluminal coronary angioplasty. All procedures were undertaken on a Siemens Angioscop X-ray equipment. The system performed under automatic exposure control using pulsed fluoroscopy of 12.5 pulses s(-1) and cine frame rate of 25 frames s(-1). Dose-area product values, fluoroscopy times, total number of cine frames as well as operator's name were collected for each patient. Only senior cardiologists have participated in the study. Median values for dose-area product were 39.1 Gy cm(2) for coronary angiography and 58.3 Gy cm(2) for percutaneous transluminal coronary angioplasty. Median fluoroscopy time was 5.0 min and 9.7 min and median number of frames was 1588 and 1823 for coronary angiography and percutaneous transluminal coronary angioplasty, respectively. Comparison showed that patient dose-area product values were lower than other studies and fluoroscopy time values were comparable. However, the total number of frames used was much higher than other published results. Differences between cardiologists with increased experience have been found. Analysis of the patient dose values obtained initiated a program of radiation protection optimization. The need for continuous training in radiation protection for interventionalists has been verified.

Adult↗
PubMed2002

Development of isothiocyanate-enriched broccoli, and its enhanced ability to induce phase 2 detoxification enzymes in mammalian cells.

Broccoli florets contain low levels of 3-methylsuphinylpropyl and 4-methylsulphinylbutyl glucosinolates. Following tissue disruption, these glucosinolates are hydrolysed to the corresponding isothiocyanates (ITCs), which have been associated with anticarcinogenic activity through a number of physiological mechanisms including the induction of phase II detoxification enzymes and apoptosis. In this paper, we describe the development of ITC-enriched broccoli through the introgression of three small segments of the genome of Brassica villosa, a wild relative of broccoli, each containing a quantitative trait locus (QTL), into a broccoli genetic background, via marker-assisted selection and analysis of glucosinolates in the florets of backcross populations. Epistatic and heterotic effects of these QTLs are described. The ITC-enriched broccoli had 80-times the ability to induce quinone reductase (a standard assay of phase II induction potential) when compared to standard commercial broccoli, due both to an increase in the precursor glucosinolates and a greater conversion of these into ITCs.

Anticarcinogenic Agents↗
PubMed2002

Concerning the relationship between benefit and radiation risk, and cancers detected and induced, in a breast screening programme.

In a breast screening programme based upon X-ray mammography it is necessary to demonstrate that benefit, from reduced mortality arising from earlier diagnosis, exceeds any potential risk from future induction of breast cancers by ionizing radiation. A rigorous treatment of this problem would be both complex and subject to large statistical uncertainty, even if all necessary data were available. A more simplified approach is to show that the number of cancers detected exceeds the number potentially induced by a sufficient margin. These numbers are relatively well established, but this approach is less satisfactory owing to the question of what would constitute a sufficient margin. This paper attempts to explore a possible relationship between the detection/induction ratio and the benefit/risk ratio, using treatment outcome data from three independent sources and mortality reduction data. Agreement between these four sources is considered to be fair, given the nature of the data. The future screening of older women (over 65 years) is also found to have a significant effect on the final outcome. When current trends in such screening are allowed for, the benefit/risk ratio is found to be only marginally less than the detection/induction ratio.

Age Factors↗
PubMed2002

Two-view screening and extending the age range: the balance of benefit and risk.

The UK Breast Screening Programme intends to introduce two-view screening on all screening rounds, and also to extend the normal screening age range at its upper end from the present 64 years to 70 years. The implications of these changes for cancer detection:induction ratios and for benefit/risk ratios are discussed. It is shown that both ratios remain much greater than 1.0 at all screening ages. This is also true for younger women, subject to provisos regarding starting ages for annual screening as described in previous papers. The requirements for optimization in a breast screening programme are also discussed. It is suggested that benefit (rather than the benefit/risk ratio) should be maximized provided that benefit exceeds risk.

Adult↗
PubMed2002

Standards and guidelines for performing central dual X-ray densitometry from the Canadian panel of International Society for Clinical Densitometry.

The International Society for Clinical Densitometry (ISCD) is a multidisciplinary nonprofit global organization formed to ensure excellence in densitometry imaging, interpretation, and application. The Canadian panel of the ISCD represents ISCD in Canada and oversees Canadian bone densitometry certification programs. The standards of care from the Canadian panel of the ISCD have been developed in order to establish the minimum level of acceptable performance for the practice of bone densitometry in Canada. A variety of techniques are available for skeletal assessment of bone mineral density, which vary in accuracy, precision, and clinical utility as well as availability. This article focuses on central dual X-ray absorptiometry in adults and does not address densitometry in the pediatric population. Other technologies will be addressed in a subsequent article.

Absorptiometry, Photon↗
PubMed2002

Standards and guidelines for performing central dual X-ray densitometry from the Canadian Panel of International Society for Clinical Densitometry.

The International Society for Clinical Densitometry (ISCD) is a multidisciplinary nonprofit global organization formed to ensure excellence in densitometry imaging, interpretation, and application. The Canadian panel of the ISCD represents ISCD in Canada and oversees Canadian bone densitometry certification programs. The standards of care from the Canadian panel of the ISCD have been developed in order to establish the minimum level of acceptable performance for the practice of bone densitometry in Canada. A variety of techniques are available for skeletal assessment of bone mineral density, which vary in accuracy, precision, and clinical utility as well as availability. This article focuses on central dual X-ray absorptiometry in adults and does not address densitometry in the pediatric population. Other technologies will be addressed in a subsequent article.

Absorptiometry, Photon↗
PubMed2001

Effective dose in Albanian direct chest fluoroscopy.

In the absence of reliable supplies of X-ray film, direct fluoroscopy is still extensively used in Albania, with chest radiology a particularly common application. This paper aims to quantify both patient skin dose and the risk-related quantity effective dose for direct fluoroscopy units based in seven different Albanian X-ray departments. A standard Quality Assurance (QA) protocol was used to assess tube potential accuracy, half value layer and X-ray tube output of these units. Three groups of X-ray beam parameters were defined from the QA results, covering the range of chest posteroanterior (PA) fluoroscopy technique factors seen during the study. Organ-equivalent doses were then measured for a nominal PA chest fluoroscopy examination using a Rando anthropomorphic phantom loaded with lithium fluoride thermoluminescent dosimeter chips. Normalised organ dose factors are listed for the three groups of beam conditions simulated. Using these factors, effective dose for the seven systems surveyed was found to be between 0.06 and 0.42 mSv for a 20 s PA chest fluoroscopy examination. Mean effective dose for this group of systems was 0.22 mSv which is a factor of 13 greater than mean effective dose for film/screen PA chest radiography in the UK, whereas entrance surface dose was a factor of 50 greater than the current EU reference level.

Albania↗
PubMed2001

Training and accreditation in radiation protection for interventional radiology.

Training in radiation protection is a basic aspect of the optimisation of medical exposures. Council Directive 97/43/EURATOM establishes the need for an adequate theoretical and practical training of the staff working in radiological practices, and competence in radiation, for which Member States shall ensure the establishment of appropriate curricula. Keeping in mind the different specialities and professional responsibilities, training curricula must be proposed and endorsed to achieve a common core of knowledge in radiation protection throughout Europe, for different groups of health workers. In interventional radiology, previous initiatives led to the definition of a syllabus of educational objectives and to its testing in a specific course. The present paper presents educational objectives for interventional radiology, developed in the framework of the DIMOND European concerted action.

Accreditation↗
PubMed2001

Dose displays and record keeping.

In digital diagnostic and interventional radiology, patient dosimetry is essential. When considering the display requirements for interventionalists it is necessary to consider the basis for their information needs. An interventionalist must be made aware of the potential for deterministic and non-deterministic effects. Thus a display is required which provides an indication of whether skin effects are likely and this predicates a display of maximum estimated skin entrance dose. For non-deterministic effects, a display of dose-area product is useful. Unfortunately, neither display is generally available to the interventionalist, so inevitably they will remain in the dark about the potential radiological consequences of the procedure. Given the need to follow up patients, who may receive a high dose, it is important that the patient notes contain relevant dosimetry data. One way of achieving this in the future would be to link electronically the patient dosimetry device to the patient record in the Radiological Information System. This dictates a need to develop patient dosimetry record minimum dataset and equipment connectivity standards.

Data Display↗
PubMed2001

The use of dynamic phantoms in interventional radiology.

The authors have constructed a 2D motor-controlled test object phantom holder to simulate clinical situations in which patient movement could be a cause of image degradation. The PAtient MOvement SImulation Test Object (PAMOSITO) has been constructed with modular parts to use different mobile test objects and static structures. The system allows the programming of different cycles of movement along two axes. PAMOSITO has been used in X ray equipment dedicated to interventional radiology. Those systems usually allow for different values for frame rate, pulse width or weighted frame averaging methods. The influence of selecting different values of the parameters, patient movement and its relation to patient dose and image quality has been studied. Image blurring due to motion has been evaluated with Leeds test objects TO.10 and 18FG. Spatial resolution limits and the threshold contrast detail detectability performance have been studied.

Absorptiometry, Photon↗
PubMed2001

Equipment requirements and specification for digital and interventional radiology.

During the past decade there has been a substantial growth in digital and interventional radiology. Equipment requirements and specification for digital (interventional) radiology are necessary to facilitate the purchase of proper installations for specific purposes. Inappropriate equipment might lead to increased dose to patients and staff, insufficient image quality and, for interventional radiology, to inefficient procedures and the potential for deterministic effects to occur. The equipment requirements and specifications are of various types. Requirements for dose displays and dose record keeping are dealt with in a separate contribution to this workshop. Detailed information is presented in this contribution on requirements and specifications in relation to ergonomic, dosimetric and image quality aspects.

Humans↗
PubMed2001

Introduction to constancy check protocols in fluoroscopic systems.

Reference dose or guidance levels are a well established approach to the reduction of patient doses in diagnostic radiology. There are two main methods of determining reference doses, one involves patient dose measurements and the other phantom dosimetry. The latter approach lends itself to the development of constancy test protocols, which may be used as part of an acceptance testing programme or to compare the performance of different imaging systems. Various constancy test protocols and procedures have been proposed and these are reviewed. The constancy test protocols developed within the DIMOND concerted action will be described in detail. The advantages and disadvantages of the various methods and approaches are compared and contrasted. The complementary nature of constancy check protocols with patient dosimetry studies is discussed.

Fluoroscopy↗
PubMed2001

Deterministic effects in interventional radiology.

Since the development of interventional radiology, the number and complexity of procedures has increased significantly and continues to grow. Interventional radiology procedures offer substantial health care benefits. However, associated with the increasing complexity as well as a lack of quality control programmes and specific training in radiation protection, there is an increase in the occurrence of deterministic effects in both patients and staff. There is a growing literature of case reports describing deterministic effects. A review of some case reports and the response of various international organisations is presented. It is important that workers in interventional radiology are aware of the potential for deterministic effects and the dose threshold for their onset, so that patients can be followed up appropriately.

Adolescent↗
PubMed2001

Successes and failures in videoconferencing: a community health education programme.

Women's Health Queensland Wide began delivery of community education programmes for rural women via videoconferencing in the year 2000. A series of three, 90 min videoconference sessions from Brisbane were delivered to 13 sites in northern Queensland. The sessions related to health issues for women at midlife. The sessions were delivered by health experts in Brisbane, who provided a short presentation on their topic; the majority of the videoconference was dedicated to questions from the participants. Each site was supported by a technical coordinator, who ensured that the equipment functioned properly, and a local health worker, who facilitated women's participation in the videoconference as well as providing a local services perspective. Women's Health Queensland Wide was responsible for overall planning and promotion of the sessions. Feedback from these programmes demonstrated women's and health-care professionals' acceptance of videoconferencing as a mechanism for receiving health information. Sustainability of these programmes depends upon the following issues: cost, delivery model, and the availability of appropriate technology and women-friendly sites.

Attitude of Health Personnel↗
PubMed2001

Cancers detected and induced, and associated risk and benefit, in a breast screening programme.

Current cancer detection rates and dose levels in the UK Breast Screening Programme are used to compare numbers of cancers detected with numbers predicted to be induced by the screening process itself. Numbers of those detected are shown to exceed those induced by a large margin for women aged over 50 years. The associated benefit/risk ratio is also considered. For younger women this margin is progressively reduced but remains positive at least down to age 40 years, and possibly beyond. Women both with and without a family history of breast cancer are considered. Some implications for familial breast screening programmes are discussed. Some caution may be required before annual screening of women below the age of 35 years.

Adult↗