EIT is suitable for monitoring the dynamic effects of PEEP variations on the regional change of tidal volume. It is superior to global ventilation parameters in assessing the beginning of alveolar recruitment and lung collapse.

Dynamic thoracic EIT is capable of detecting changes of the ventilation distribution in the lung. Nevertheless, it has yet to become an established clinical tool. Therefore, it is necessary to consider application scenarios wherein fast and distinct changes of the tissue conductivities are to be found and also have a clear diagnostic significance. One such a scenario is the artificial ventilation of patients suffering from the acute respiratory distress syndrome (ARDS). New protective ventilation strategies involving recruitment manoeuvres are associated with noticeable shifts of body fluids and regional ventilation, which can quite easily be detected by EIT. The bedside assessment of these recruitment manoeuvres will help the attending physician to optimize treatment. Hence, we performed an animal study of lavage-induced lung failure and investigated if EIT is capable of qualitatively as well as quantitatively monitoring lung recruitment during a stepwise PEEP trial. Additionally, we integrated EIT into a fuzzy controller-based ventilation system which allows one to perform automated recruitment manoeuvres (open lung concept) based on online PaO2 measurements. We found that EIT is a useful tool to titrate the proper PEEP level after fully recruiting the lung. Furthermore, EIT seems to be able to determine the status of recruitment when combining it with other physiological parameters. These results suggest that EIT may play an important role in the individualization of protective ventilation strategies.

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Computed tomography fluoroscopy (CT fluoroscopy) enables real-time image control over the entire body with high geometric accuracy and, for the most part, without significant interfering artifacts, resulting in increased target accuracy, reduced intervention times, and improved biopsy specimens [1--4]. Depending on the procedure being used, higher radiation doses than in conventional CT-supported interventions might occur. Because the radiologist is present in the CT room during the intervention, he is exposed to additional radiation, which is an important aspect. Initial experience with CT fluoroscopically guided interventions is from the work of Katada et al. in 1994 [5] and only relatively few reports on radiation aspects in CT fluoroscopy are found in the literature [1, 2, 6--11]. To date, there are no reported injuries to patients and radiologists occurring with CT fluoroscopy. The time interval since the wide use of CT fluoroscopy is too short to have data on late effects to the operator using CT fluoroscopy on a daily basis. In addition, the spectrum of CT fluoroscopically guided interventional procedures will expand and more sophisticated procedures requiring longer fluoroscopy times will be performed. Thus, effective exposure reduction is very important. The purpose of our study was to assess the radiation dose to the operator's hand by using data from phantom measurements. In addition, we investigated the effect of a lead drape on the phantom surface adjacent to the scanning plane, the use of thin radiation protective gloves, and the use of different needle holders.

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