The use of out-of-plane high Z patient shielding for fetal dose reduction in computed tomography: Literature review and comparison with Monte-Carlo calculations of an alternative optimisation technique.

When performing CT examinations on pregnant patients, great effort should be dedicated towards optimising the exposure of the mother and the conceptus. For this purpose, many radiology departments use high-Z garments to be wrapped around the patient's lower abdomen for out-of-plane organ shielding to protect the fetus. To assess their current protection efficiency, we performed a literature review and compared the efficiencies mentioned in the literature to Monte-Carlo calculations of CT protocols for which the overall scan length was reduced. We found 11 relevant articles, all of them reporting uterus exposure due to CT imaging performed for exclusion of pulmonary embolism, one of the leading causes of peripartum deaths in western countries. Uterus doses ranged between 60 and 660 µGy per examination, and relative dose reductions to the uterus due to high-Z garments were between 20 and 56%. Calculations showed that reducing the scan length by one to three centimetres could potentially reduce uterus dose up to 24% for chest imaging, and even 47% for upper abdominal imaging. These dose reductions were in the order of those achieved by high-Z garments. However, using the latter may negatively influence the diagnostic image quality and even interfere with the automatic exposure control system thus increasing patient dose if positioned in the primary beam, for example in the overranging length in helical acquisition. We conclude that efforts should be concentrated on positioning the patient correctly in the gantry and optimising protocol parameters, rather than using high-Z garments for out-of-plane uterus shielding

Continuous parallel ESI-MS analysis of reactions carried out in a bespoke 3D printed device

Herein, we present an approach for the rapid, straightforward and economical preparation of a tailored reactor device using three-dimensional (3D) printing, which can be directly linked to a high-resolution electrospray ionisation mass spectrometer (ESI-MS) for real-time, in-line observations. To highlight the potential of the setup, supramolecular coordination chemistry was carried out in the device, with the product of the reactions being recorded continuously and in parallel by ESI-MS. Utilising in-house-programmed computer control, the reactant flow rates and order were carefully controlled and varied, with the changes in the pump inlets being mirrored by the recorded ESI-MS spectra

Relações hídricas em povoamento de eucalipto com diferentes densidades populacionais.

Em experimento realizado na regiao de Santa Barbara (MG) no periodo de agosto de 1994 a fevereiro de 1995, avaliaram-se a precipitacao pluviometrica interna, a evapotranspiracao da cultura (ETc) e o regime hidrico do solo sob povoamento de Eucalyptus grandis (dos 32 aos 38 meses de idade) com densidades populacionais variando de 500 a 5.000 plantas ha-1. A unidade volumetrica do solo, em uma secao de controle de 0 a 285 cm de profundidade, foi determinado quinzenalmente, por meio de moderacao de neutrons. A interpretacao de agua pelas copas aumentou linearmente com o aumento da populacao de plantas, enquanto a ETc nao foi significativamente influenciada. A unidade do solo tendeu a aumentar com a reducao da populacao de plantas. A umidade do solo em todas as epocas monitoradas nunca apresentou valores inferiores aquele correspondente a agua retida a tensao de 1,5 MPa

Status Report on Education in the Economics of Animal Health: Results from a European Survey

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Comparison of organ doses and image quality between CT and flat panel XperCT scans in wrist and inner ear examinations

The aim of this study was to evaluate and compare organ doses delivered to patients in wrist and petrous bone examinations using a multislice spiral computed tomography (CT) and a C-arm cone-beam CT equipped with a flat-panel detector (XperCT). For this purpose, doses to the target organ, i.e. wrist or petrous bone, together with those to the most radiosensitive nearby organs, i.e. thyroid and eye lens, were measured and compared. Furthermore, image quality was compared for both imaging systems and different acquisition modes using a Catphan phantom. Results show that both systems guarantee adequate accuracy for diagnostic purposes for wrist and petrous bone examinations. Compared with the CT scanner, the XperCT system slightly reduces the dose to target organs and shortens the overall duration of the wrist examination. In addition, using the XperCT enables a reduction of the dose to the eye lens during head scans (skull base and ear examinations