Investigations of the incidence and the extent of the asymptomatic early stages of extracranial arterial disease (EAD) have been restricted for methodical reasons. Direct Continuous Wave-Doppler examination has given highly accurate results in the location and correct estimation of the degree of EAD both for the carotid (97%) and the vertebral arteries (90%), as shown from a detailed comparison with carotid (n = 604) and vertebral (n = 426) angiograms. Compared with this degree of reliability, the validity of normal auscultation for the diagnosis of EAD is shown to be poor: if bruits are taken as the only signs of associated EAD in patients with systemic atherosclerosis, only 27.6% in a group of 123 patients would have been correctly diagnosed. This parallels the number of false-positives (22.6%) in patients with normal results. The frequency and degree of EAD was studied by the use of direct Doppler examination in 2009 neurologically asymptomatic patients admitted either with severe vascular (n = 375) or coronary atherosclerosis (n = 262) or with high-risk factors (n = 1370). The frequency was significantly higher (32.8%) in patients with peripheral vascular disease than in those with coronary artery disease (6.8%) and in risk-factor patients (5.9%). The combination and degree of vessel involvement are presented in detail and their possible prognostic significance discussed.

Cancer of the brain and central nervous system (CNS) is the second most common of all pediatric cancers. Treatment of many of these cancers includes radiation therapy of which radiation induced cerebral necrosis (RICN) can be a severe and potentially devastating side effect. Risk factors for RICN include brain volume irradiated, the dose given per fraction and total dose. Thirteen pediatric patients were selected for this study to determine the difference in predicted risk of RICN when treating with volumetric modulated arc therapy (VMAT) compared to passively scattered proton therapy (PSPT) and intensity modulated proton therapy (IMPT). Plans were compared on the basis of dosimetric endpoints in the planned treatment volume (PTV) and brain and a radiobiological endpoint of RICN calculated using the Lyman-Kutcher-Burman probit model. Uncertainty tests were performed to determine if the predicted risk of necrosis was sensitive to positional errors, proton range errors and selection of risk models. Both PSPT and IMPT plans resulted in a significant increase in the maximum dose to the brain, a significant reduction in the total brain volume irradiated to low doses, and a significant lower predicted risk of necrosis compared with the VMAT plans. The findings of this study were upheld by the uncertainty analysis.

Purpose: Several vendors of diagnostic lead apron used routinely in radiology/fluoroscopy claim to manufacture 0.5 mm lead equivalent shielding. The purpose of this investigation was to address the concern of the weight of lead aprons versus the radiation protection they provide. Methods: Seven diagnostic lead aprons were measured and compared for their radiation transmission and attenuation characteristics. The measurements were performed on a Philips Integris. Two settings were used, normal (76 kVp, 14.3 mA) and high (110 kVp, 12.3 mA) to represent typical patient and large patient thickness. Plastic water was placed on the table to represent patient scatter. A Capintec PM‐500 ion chamber was placed at approximate chest height where hospital personnel would stand. An uncovered, i.e. lead‐unhindered, ion chamber reading was taken to establish the baseline reading of an unprotected personnel. The ion chamber was then wrapped with 0.5mm 99.9% pure Pb material to establish the measurement reading when a diagnostic lead apron attenuates as adequately as 0.5mm Pb. The lead aprons were measured one at a time with the ion chamber fully covered and enclosed within the aprons. Results: On Normal fluoroscopy setting, the 0.5mm pure Pb showed a transmission of 0.4%. No aprons showed a transmission value as low as 0.5mm Pb. The lowest transmission value measured from the aprons was 2.0%, having a 1.5% higher transmission than pure lead. On High fluoroscopy setting, the lowest apron transmission measurement was at 2.8%, which was comparable to the 0.5mm pure Pb which gave a transmission of 3.0%. Conclusion: At Normal fluoroscopy setting, the 0.5mm Pb provided an attenuation that could not be matched by any apron measured. At High fluoroscopy setting, only one apron exhibited comparable transmission values as 0.5mm pure Pb.

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