•Surgeon eye lens dose measured in eight different interventional procedure types.•Dosemeters read by an iSO-17025 accredited service.•Median eye lens Hp(3) range, with ceiling shield: 20–60 μSv per ...single procedure.•CT-guided lung biopsy median eye lens Hp(3): 150μSv per single procedure.•Hp(3)/KAP shows a statistically significant dependency on the surgeon's height.
This study investigated the radiation dose to surgeon eye lens for single procedure and normalised to exposure parameters for eight selected neuroradiology, cardiovascular and radiology interventional procedures.
The procedures investigated were diagnostic study, Arteriovenous Malformations treatment (AVM) and aneurysm embolization for neuroradiology procedures, Coronary Angiography and Percutaneous Transluminal Coronary Angioplasty (CA-PTCA), Pacemaker and Implantable Cardioverter-Defibrillator implantation (PM-ICD), Endovascular Aortic Repair (EVAR) and Fenestrated Endovascular Aortic Repair (FEVAR) for cardiovascular and electrophysiology procedures. CT-guided lung biopsy was also monitored.
All procedures were performed with table-mounted and ceiling-suspended shields (0.5 mm lead equivalent thickness), except for FEVAR and PM-ICD where only a table mounted shield was present, and CT-guided lung biopsy where no shield was used. Dose assessment was performed using a dosemeter positioned close to the most exposed eye of the surgeon, outside the protective eyewear.
The surgeon most exposed eye lens median Hp(3) equivalent dose for a single procedure, without protective eyewear contribution, was 18 μSv for neuroradiology diagnostic study, 62 μSv for AVM, 38 μSv for aneurysm embolization, 33 μSv for CA-PTCA, 39 μSv for PM-ICD, 49 μSv for EVAR, 2500 μSv for FEVAR, 153 μSv for CT-guided lung biopsy.
In interventional procedures, the 20 mSv/year dose limit for surgeon eye lens exposure might be exceeded if shields or protective eyewear are not used.
Surgeon eye lens doses, normalised to single procedures and to exposure parameters, are a valuable tool for determining appropriate radiation protection measures and dedicated eye lens dosemeter assignment.
•Characterization of eye lens X-ray protection efficacy of different eyewear models.•Study of the influence of eyewear shape and ergonomics.•Combination of dosimetric measurements and geometrical ...modeling.•Introduction of the concept of Eye Protection Effectiveness, an “a priori” evaluation of the Dose Reduction Factor.
Radioprotection of the eye lens of medical staff involved in Surgical procedures is a subject of international debates since ICRP recommended, on 2011, a lower equivalent dose limit for the lens of the eye. In this work we address the effectiveness of different models of X-ray protective eyewear by relating actual dosimetry measurements to an ad hoc developed mathematical model, in order to disentangle the contribution of geometrical factors and shield capabilities. Phantom irradiation was carried out in fixed exposure conditions in angiographic room: we found that measured Dose Reduction Factors (DRF) strongly depend on the ergonomics of the investigated eyewear. Actually a very poor DRF was observed in the case of a glass model in spite of its high nominal attenuation, whereas a protective tool with low shielding capabilities such a visor resulted much more effective as a consequence of is shape (i.e. extended geometric protection of the eye lens). Our work highlights the need of the introduction of a specific parameter to quantify the effectiveness of the protection tools and able to predict their DRF by taking into account the geometry of the clinical condition of exposure. Aiming at making steps forward the standardization of the guidelines concerning the features of eye protective tools, we developed a simple mathematical model describing the eye lens irradiation geometry which allows the introduction, for each eyewear, of a comprehensive parameter, the Eye Protection Effectiveness (EPE), that, for any defined clinical irradiation condition and glass shielding capabilities and shape, defines the overall effective X-ray protection of the eyewear.
To investigate the effect of colour scale choice on diagnostic performance in the interpretation of medical images.
Twelve clinicians interpreted 210 myocardial computed tomography (CT) perfusion ...(CTP) examinations, and nine clinicians interpreted 165 magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC) prostate images. In three separate sessions, each participant read the same image set using greyscale, hot-iron, and rainbow scales, respectively. Participants scored their level of confidence for tumour presence in the ADC study, and for ischaemia in the CTP study, from 0 to 100. The area under the receiver operating characteristic (ROC) curve (AUC) was used as the performance metric. For cases that scored >50, CTP readers' agreement on the ischaemic transmural extent was analysed, and ADC map readers' selected values and coordinates for the lowest ADC within the detected tumour were compared across different colour scales.
For CTP detection, the AUC was up to 0.10 higher with greyscale, 0.67±0.02 (standard error), compared to rainbow, 0.56±0.02, and detection with hot-iron was in between (0.61±0.03). For ischaemic transmural lesion categorisation, observed inter-reader agreement was highest with greyscale for category 25–50%. There is a small tendency for rainbow and greyscale to outperform hot-iron in the detection of prostate tumours. The selected lowest ADC value and pixel localisation was similar with all colour scales.
The present findings suggest that colour visualisation has a measurable effect on CTP and ADC performance. Further investigation is necessary to determine the magnitude of the effect in diagnostic tasks.
•Choice of visualization colour scale significantly affects lesion detection performance and diagnostic decision consistency.•Myocardial perfusion CT readers have higher lesion detection performance and are more consistent when using greyscale.•The inverted rainbow and grey scales tend to outperform the hot-iron scale in prostate cancer detection.•We show that the choice of display colour scale for image visualization contributes to variability in reader performance.
