Tag: dose

  Barium swallows continue to prove their usefulness in a wide range of diagnosis and within Guys and ST Thomas’ Trust are the most common fluoroscopy procedure performed. They are performed mostly by the junior registrars and discussed with senior consultants to come to a useful conclusion to aid in the diagnosis or ongoing management of the patient. There is a general protocol registrars use to complete a study, which we are taught early in our training. However this varies depending on the clinical indication and question to be answered. As fluoroscopy is a dynamic test, the patterns of practice change in real time depending on the findings of the study. As with any fluoroscopic investigation, screening time has to be considered alongside the need for diagnostic images. Our project investigates the range of doses in over 400 barium/water soluble swallows performed within our trust over the period January to June 2017. We have reviewed the indications and protocols used with...

  Introduction: Videofluoroscopic swallow studies (VFSS) are used to assess the risk of airway compromise in patients with dysphagia. There is evidence to suggest that the optimisation of pulse rates in VFSS is paramount to the accurate detection of aspiration and penetration 1. This has implications for food and fluid viscosity and texture recommendations2, as well as length of stay and patient mortality3. This study aims to analyse the effect of higher pulse rates in VFSS on the detection of aspiration and patient dose. Objectives: 1) To optimise techniques and assess the effects of higher pulse rates on the detection of airway compromise events in VFSS for patients with dysphagia 2) To compare the patient radiation doses between teams A and B using different protocols and pulse rates Methodology: A prospective analysis of VFSS footage was collected over two rounds of the study between September 2016 and July 2017. Team B continued with their protocol of 7.5pps and team A started a protocol using 30pps. A radiation...

  Purpose: To assess the accuracy of estimates of peak skin dose (PSD) obtained from an open source (openSkin, as integrated into OpenREM) skin dose mapping software package and the accuracy of estimates of peak reference point air kerma obtained from a commercially available (DoseWatch, GE Healthcare©) dose management package. Materials and Methods: A 32 x 32 x 20 cm PMMA phantom was subject to a series of simple fluoroscopic and acquisition exposures in a Siemens Artis Zee cardiac catheter laboratory. Direct measurements of PSD were obtained using either an RTI T20 solid state dose meter or 35 x 43 cm Gafchromic XR-type film fixed to the exposed surface of the PMMA phantom. These measurements were then compared with the PSD values calculated by openSkin under conditions of matched-phantom geometry. The PSD measurements were also compared with the peak reference point air kerma values calculated by the DoseWatch cumulative incidence map, a feature of the commercially available DoseWatch dose management package. Results: The DoseWatch...

  The Ray Safe electronic staff dosimeter has been adopted by Philips Healthcare and integrated into its latest interventional x-ray units. These units are able to pick up the staff member wearing the dosimeter and assign the dose that they receive to the precise part of the examination as defined by the DICOM RDSR patient dose report. The staff doses are then exported in a format similar to a patient dose report. This work will present early findings of using this system, including pitfalls of implementation along with early analysis of data showing how staff dose may be analysed in conjunction with gantry geometry and patient dose. One interesting analysis has been the production of gantry angulation 'heat maps' showing at what angulation staff are receiving most dose - this may be of use for staff dose optimisation efforts. The system may also facilitate impact assessments of staff dose reduction strategies, such as the StarBoard radial armboard system. The longer term...

  Objectives Vascular surgeons are now routinely working with X-rays for endovascular aortic aneurysm repair (EVARs) procedures. We aim to assess the impact of finger dose from these procedures to all surgeons performing complex endovascular procedures (CEP) at our Trust. Methods Since July 2015 all surgeons performing CEP have routinely worn finger ring monitors after gaining appropriate infection control advice. Finger monitors are worn for a two monthly period on the middle finger of each hand. Collar dose and whole body monitoring was already in place for these users. At the end of each monitoring period patient dose data, in terms of dose area product (DAP) and reference point dose, were collated for each case performed. This data was then summarised for each user and collated with the badge results from the dosimetry service. Results are also compared to local Trust dose investigation levels (DILs) to ensure all users are not at risk of approaching a dose limit. Results The data for each monitored surgeon shows...

  Since the publication of IPEM Report 77 in 1997 the guidance for assessing typical skin dose rates likely to be received by patients undergoing fluoroscopic procedures has been to measure the dose rate at the surface of a phantom 20 cm in thickness. Increasingly in interventional cardiology, practitioners are making use of imaging projections that result in patient thickness being significantly greater than that currently considered typical for the purposes of performance testing. Consequently, the behaviour of modern fluoroscopic imaging systems at these steeper projections and the resulting typical patient skin dose rates is not likely to be well understood by users or the medical physics community supporting optimisation of such equipment. The Radiation Protection department at Mount Vernon Cancer Centre supports 10 cardiac catheterization labs across five NHS Trusts. A project was performed to assess the behaviour of these 10 systems and resulting typical skin dose rates using a set-up designed to mimic the steeper projections being performed...