This study analyzed the radiation exposure of a new ultra-low dose (ULD) protocol compared to a high-quality (HQ) protocol for CT-torsion measurement of the lower limb. The analyzed patients (n = 60) were examined in the period March to October 2019. In total, 30 consecutive patients were examined with the HQ and 30 consecutive patients with the new ULD protocol comprising automatic tube voltage selection, automatic exposure control, and iterative image reconstruction algorithms. Radiation dose parameters as well as the contrast-to-noise ratio (CNR) and diagnostic confidence (DC; rated by two radiologists) were analyzed and potential predictor variables, such as body mass index and body volume, were assessed. The new ULD protocol resulted in significantly lower radiation dose parameters, with a reduction of the median total dose equivalent to 0.17 mSv in the ULD protocol compared to 4.37 mSv in the HQ protocol (p < 0.001). Both groups showed no significant differences in regard to other parameters (p = 0.344–0.923). CNR was 12.2% lower using the new ULD protocol (p = 0.033). DC was rated best by both readers in every HQ CT and in every ULD CT. The new ULD protocol for CT-torsion measurement of the lower limb resulted in a 96% decrease of radiation exposure down to the level of a single pelvic radiograph while maintaining good image quality.

Background: The prone position is one of the most frequently used treatment options for infants with Robin sequence (RS), but its effect and its safety regarding the increased risk of sudden infant death syndrome are controversial. Methods: In a prospective randomized crossover study, we investigated the effects of the prone versus supine position on obstructive sleep apnea (OSA) using polygraphy. Infants with RS admitted to the University Hospital Tuebingen between 4/2021 and 5/2023 were analyzed for their obstructive apnea index (OAI), oxygen desaturation index < 80%, minimum and basal oxygen saturation, basal and highest transcutaneous carbon dioxide level, and respiratory and heart rate in both sleep positions. Results: A total of 29 children were analyzed. A total of 21/29 children were measured in both positions, while 6/29 children were only measured in the supine position and 2/29 only in the prone position. We found no significant difference in the OAI for the supine versus prone position in main effects analyses. In unadjusted linear model analysis, infants in the supine position had an OAI of 9.9 (95% CI, −2.4, 22.3) events/h higher than those in the prone position. A total of 13/21 infants benefitted from the prone position, whilst 8/21 had a worsening of their OSA. We found no evidence of a significant interaction between sleeping position and syndromic status. Conclusions: Prone positioning improves, but does not eliminate, OSA symptoms in infants with RS, and severe OSA may often persist. There are infants in whom a change to the prone position leads to a worsening of their OSA.