Impact of an AI software on the diagnostic performance and reading time for the detection of cerebral aneurysms on time of flight MR-angiography.

PURPOSE: To evaluate the impact of an AI-based software trained to detect cerebral aneurysms on TOF-MRA on the diagnostic performance and reading times across readers with varying experience levels. METHODS: One hundred eighty-six MRI studies were reviewed by six readers to detect cerebral aneurysms. Initially, readings were assisted by the CNN-based software mdbrain. After 6 weeks, a second reading was conducted without software assistance. The results were compared to the consensus reading of two neuroradiological specialists and sensitivity (lesion and patient level), specificity (patient level), and false positives per case were calculated for the group of all readers, for the subgroup of physicians, and for each individual reader. Also, reading times for each reader were measured. RESULTS: The dataset contained 54 aneurysms. The readers had no experience (three medical students), 2 years experience (resident in neuroradiology), 6 years experience (radiologist), and 12 years (neuroradiologist). Significant improvements of overall specificity and the overall number of false positives per case were observed in the reading with AI support. For the physicians, we found significant improvements of sensitivity on lesion and patient level and false positives per case. Four readers experienced reduced reading times with the software, while two encountered increased times. CONCLUSION: In the reading with the AI-based software, we observed significant improvements in terms of specificity and false positives per case for the group of all readers and significant improvements of sensitivity and false positives per case for the physicians. Further studies are needed to investigate the effects of the AI-based software in a prospective setting.

A multisensor implant for continuous monitoring of intracranial pressure dynamics.

In humans, intracranial pressure (ICP) is not only influenced by pathology, but also by orientation in space and body movements. Therefore, it is proposed to measure ICP dynamics and body acceleration simultaneously. An algorithm for acceleration analysis was developed to monitor orientation in space and allow more accurate examination of ICP dynamics during quiet periods. For continuous monitoring, an implant was developed and wireless data transmission was implemented; this prototype was successfully tested in five pigs. Hydrocephalus with increased ICP was experimentally induced in the animals using a surgical kaolin infusion. This model of porcine pathology was then tested with the implant with the aim for eventual use in humans. ICP dynamics and 2D-acceleration data were simultaneously recorded for up to two weeks. This study allowed 24-h monitoring and provided analysable data on porcine ICP dynamics with humanlike ICP waves, the so called B- and P-waves. Results show that acceleration often had a stronger influence on ICP than the amplitudes of the physiological ICP characteristics. With test animals in a standing position, without obvious body movement, ICP varied to an extent that made the characteristic ICP waves difficult to identify. These data allow us to conclude that analysis of both ICP and acceleration may be essential for autonomous implants.

Long-term performance of a CE-approved telemetric intracranial pressure monitoring.

Telemetric intracranial pressure (ICP) monitoring has been a challenge throughout several decades. Major obstruction was to minimize zero drift of absolute pressure sensors. A new promising product demonstrating in-vitro excellent long-term stability has been tested for its reliability in an animal model with a follow-up of up to 2 years. In "minipigs" sub-dural (Raumedic-STel®, Helmbrechts Germany) and intraparenchymal (Raumedic-PTel®) telemetric ICP probes have been inserted. Standard ICP probes (Raumedic Neurovent P®) served as controls. In regular intervals of 3 months the telemetrically and conventionally measured ICP have been compared. For each control a new conventional ICP probe has been inserted frontally to the telemetric device in the generalized anesthetized minipigs, resulting in overall 38 comparisons. Bland-Altman-plots, Chi2-tests and matched pair T-tests (significance level < 0.05) were used for data-analysis. The zero-shift was -1.7 ± 7.6 mm Hg (limits of agreement: 4.4 ± 1.9 mm Hg) and -3.0 ± 6.0 mm Hg (limits of agreement: 3.6 ± 2.6 mm Hg) in STel and PTel respectively meeting well the devices specification of ± 2 mm Hg drift per year. The reliability of both telemetric probes has been proved as quite comparable (p=0.2). These new telemetric ICP probes demonstrate reliable data during at least the first 6 months after implantation.

Hidden points of view in cross-cultural psychotherapy and ethnography.

This article examines the challenges posed by cross-cultural psychotherapy in a creolized world, and the way this intersects with issues faced by the ethnographer. It proposes 'the relational subject,' implicit in systemic psychotherapy and social anthropology, as a framework for an understanding of communication. In cross-cultural psychotherapy, this assumption is central to non-discriminatory and equitable treatment. Drawing on Bateson's ethnographic work, the article connects 'the relational subject' to what Bateson, following Whitehead, called 'the fallacy of misplaced concreteness' and later referred to as 'context.' The article examines the choices of 'context' first in ethnography and systemic psychotherapy and then in Bateson's own analysis of the Naven ritual. It is suggested that cross-cultural psychotherapy is psychotherapy in which the therapist keeps in mind, both her own and her client's contexts. This means an assessment of process (performative aspects) as well as content (semiotic aspects) and attention to 'moments' rather than longer sequences in the therapy.

Learning how to ask in ethnography and psychotherapy.

To social anthropologists an affinity with psychotherapy lies in the view that this discipline is a social science. Increasingly, social anthropologists offer comments and analyse their own data using psychotherapeutic or psychoanalytic frames of reference. At the same time, a methodological crisis has developed in ethnography. This is a crisis of how to carry out an ethnographic enquiry in a disciplined manner without either claiming to be a detached observer on the one hand or explaining away the subjective experiences of informants or clients with too much interpretation on the other. The aim of this paper is to address this crisis and to suggest ways in which ethnographers can use techniques from one type of psychotherapy, namely systemic or family psychotherapy in order to access social and psychological aspects of the lives of their informants. The paper achieves this by describing systemic psychotherapy and its theoretical foundations in the ethnographic work of Gregory Bateson. It then reviews the mainly medical anthropology literature in which the connection between psychotherapy and anthro pology has been discussed. While this literature has suggested a narrative and a performative approach to ethnographic data and, therefore, to informants, it has not extended the analytic frame to include the ethnographer him/herself within these frames. Clinical case material is presented to demonstrate how such an inclusion is central to the practice of systemic psychotherapy and to show that this type of material is ethnographic. The techniques of double description, hypothesising and circular questioning are described and demonstrated, and it is argued that adapting these to an ethnographic enquiry will enhance the validity of the anthropological project.