Justification of radiological requests, standardization of procedures and optimization of protection measures are key principles in the protection of individuals exposed to ionizing radiation for diagnostic purposes. Nowhere is this more pertinent than in the imaging of children and, following the recent introduction of the Ionising Radiation (Medical Exposure) Regulations, there is now a regulatory requirement for diagnostic radiology departments to demonstrate compliance with these principles. A study was undertaken to compare all aspects of paediatric radiological practice at two specialist and two non-specialist centres. An initial study involved analysis of nearly 3000 patient doses. The second phase of the project involved assessment of referral criteria, radiographic technique and approximately 100 radiographs at each centre by two consultant paediatric radiologists. While all radiographs were found to be diagnostically acceptable, major differences in technique were evident, reflecting the disparity in experience between staff at the specialist and non-specialist centres. The large number of sub-optimum films encountered at the latter suggests that there is a need for specific training of less experienced radiographic and clinical staff.

A dosimetric survey of 14 routine X-ray examinations in children was carried out between 1993 and 1995. Two children's hospitals and four general hospitals took part in the survey which involved the calculation and measurement of nearly 3000 doses. Entrance surface doses (ESD) were calculated from exposure factors for radiographic procedures, and dose-area products (DAP) were recorded for both radiographic and fluoroscopic procedures. Doses were in good agreement with earlier studies, but for some procedures were significantly lower than those reported from other European countries. The main dose influencing factors for radiographic procedures were found to be the speed of the film-screen system and the use of an antiscatter grid. For the main head/trunk examinations, specialist centres often delivered higher doses to the younger children as a result of widespread use of a grid. In fluoroscopy, where the main dose influencing factors were the use of a grid and the dose rate dependence of the image intensifier, the children's hospitals consistently delivered significantly lower doses. Both ESDs and DAPs were found to increase with patient age for the main head/trunk examinations, although in some cases (AP/PA chest) this relationship was weak. The dependence of dose on age necessitates the subdivision of the paediatric sample into a number of age categories. It is suggested that all authors use the same age groupings.

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It has been proposed that a shift to glucose metabolism is integral to development of hibernating myocardium (HM). We tested the hypothesis that diabetic hearts have impaired contractile function during hibernation. Fifteen swine were divided into control (CON; n=8) and streptozotocin (STZ)‐treated (100 mg/kg; n=7) groups. Animals were chronically instrumented to measure coronary blood flow (CBF) and regional wall thickening (WT). Aortic and coronary sinus blood samples were obtained so that myocardial glucose uptake (MGU) could be calculated. HM was induced by 6 repetitive episodes of 90‐min coronary stenosis (30% reduction in baseline CBF) followed by reperfusion every 12 h. Inotropic reserve was assessed with isoproterenol (ISO, 0.2 μg/kg/min, i.v.). Plasma glucose was elevated in STZ compared to CON. In CON, MGU was increased 2‐fold during hibernation compared to baseline, whereas MGU was not affected in STZ; glycogen deposition was prominent in CON but negligible in STZ. Nevertheless, decreases in WT in HM stabilized at a similar level in CON and STZ (−22% and −14%, respectively). Furthermore, ISO caused equivalent, substantial increases in WT in HM of CON and STZ. We conclude that 1) diabetes does not impair contractile function in HM, 2) augmented glucose metabolism is not an essential feature of HM, and 3) inotropic reserve of HM remains intact in diabetic hearts.