Accessibility, interdisciplinarity and practice:The benefits and challenges of hosting an online, interdisciplinary conference on singing

In May 2020, the Spheres of Singing conference, which was initially intended as an in-person event, was instead hosted online. A key ambition was to make the conference accessible for both practitioners and researchers from various disciplines. The conference exceeded in its aim in several ways. It was free and featured contributions from around the world, including 45 presentations, four workshops, six open discussions and three lecture-recitals. The interdisciplinary array of sessions included: health and wellbeing, practice research, musicology, teaching, conducting, pedagogy, and virtual choirs. In terms of attendee interest, all 450 live attendance tickets sold out in 24 hours, with additional tickets made available to allow asynchronous attendance. Such enthusiasm demonstrates an interdisciplinary event on singing was both timely and necessary. The organisers developed a survey to gather feedback, measure impact, and help determine future directions. A significant finding is that practitioners were motivated to attend, specifically because it was an online event. However, there were challenges caused by moving the conference online, particularly when it came to relying on technology and integrating live singing activities. By analysing the feedback gathered from delegates, the article will consider three areas: creating an inviting event for practitioners and researchers, technological challenges when hosting an online conference on singing, and integrating live, synchronous singing activities into an online conference

Radiation dose reduction of 50% in dynamic myocardial CT perfusion with skipped beat acquisition:a retrospective study

Background: Dynamic myocardial computed tomography perfusion (CTP) is a novel imaging technique that increases the applicability of CT for cardiac imaging; however, the scanning requires a substantial radiation dose. Purpose: To investigate the feasibility of dose reduction in dynamic CTP by comparing all-heartbeat acquisitions to periodic skipping of heartbeats. Material and Methods: We retrieved imaging data of 38 dynamic CTP patients and created new datasets with every fourth, third or second beat (Skip1:4, Skip1:3, Skip1:2, respectively) removed. Seven observers evaluated the resulting images and perfusion maps for perfusion deficits. The mean blood flow (MBF) in each of the 16 myocardial segments was compared per skipped-beat level, normalized by the respective MBF for the full dose, and averaged across patients. The number of segments/cases whose MBF was &lt;1.0 mL/g/min were counted. Results: Out of 608 segments in 38 cases, the total additional number of false-negative (FN) segments over those present in the full-dose acquisitions and the number of additional false-positive cases were shown as acquisition (segment [%], case): Skip1:4: 7 (1.2%, 1); Skip1:3: 12 (2%, 3), and Skip1:2: 5 (0.8%, 2). The variability in quantitative MBF analysis in the repeated analysis for the reference condition resulted in 8 (1.3%) additional FN segments. The normalized results show a comparable MBF across all segments and patients, with relative mean MBFs as 1.02 ± 0.16, 1.03 ± 0.25, and 1.06 ± 0.30 for the Skip1:4, Skip1:3, and Skip1:2 protocols, respectively. Conclusion: Skipping every second beat acquisition during dynamic myocardial CTP appears feasible and may result in a radiation dose reduction of 50%. Diagnostic performance does not decrease after removing 50% of time points in dynamic sequence.</p