[Trauma emergency room cases before and during the COVID-19 pandemic : Data from an alpine trauma center]. / Schockraumpatienten vor und während der COVID-19-Pandemie : Daten eines alpinen Traumazentrums.

INTRODUCTION: The COVID-19 pandemic had a strong impact on the work of trauma medical teams. The aim of the study was to compare the trauma emergency room (TER) incidence and trauma mechanisms before and during the pandemic at a level I trauma center. OBJECTIVE: The TER incidence before and during the pandemic should be assessed to be prepared for future pandemics or new COVID-19 outbreaks. MATERIAL AND METHODS: Medical charts from all TER patients from March 2019 to February 2021 were analyzed. The incidence and trauma mechanisms of the 12 months before and the 12 months during the pandemic were compared. The trauma distribution and severity were described by the AIS and ISS, and the patients' country of residency was noted. RESULTS: The TER cases decreased from 694 before the COVID-19 pandemic to 477 cases during the pandemic (Incidence rate 0.69). The strongest decrease in trauma cases was noted in sports injuries (0.55), followed by suicide attempts (0.63), traffic accidents (0.71) and leisure accidents (0.76). The rate of patients with severe injuries (ISS ≥ 16) was comparable with 40% before the pandemic and 44% during the pandemic. Foreign residency of TER patients shifted from 37% before the pandemic to 16% during the pandemic. The number of foreign patients was significantly reduced during the pandemic (257 vs. 77). DISCUSSION: The TER incidence significantly decreased during the pandemic due to the imposed lockdowns during the peak winter tourism season. The rate of foreign TER patients changed during the pandemic, while the rate of severely injured patients remained stable.

Influence of Ultra-Low-Dose and Iterative Reconstructions on the Visualization of Orbital Soft Tissues on Maxillofacial CT.

BACKGROUND AND PURPOSE: Dose reduction on CT scans for surgical planning and postoperative evaluation of midface and orbital fractures is an important concern. The purpose of this study was to evaluate the variability of various low-dose and iterative reconstruction techniques on the visualization of orbital soft tissues. MATERIALS AND METHODS: Contrast-to-noise ratios of the optic nerve and inferior rectus muscle and subjective scores of a human cadaver were calculated from CT with a reference dose protocol (CT dose index volume = 36.69 mGy) and a subsequent series of low-dose protocols (LDPs I-4: CT dose index volume = 4.18, 2.64, 0.99, and 0.53 mGy) with filtered back-projection (FBP) and adaptive statistical iterative reconstruction (ASIR)-50, ASIR-100, and model-based iterative reconstruction. The Dunn Multiple Comparison Test was used to compare each combination of protocols (α = .05). RESULTS: Compared with the reference dose protocol with FBP, the following statistically significant differences in contrast-to-noise ratios were shown (all, P ≤ .012) for the following: 1) optic nerve: LDP-I with FBP; LDP-II with FBP and ASIR-50; LDP-III with FBP, ASIR-50, and ASIR-100; and LDP-IV with FBP, ASIR-50, and ASIR-100; and 2) inferior rectus muscle: LDP-II with FBP, LDP-III with FBP and ASIR-50, and LDP-IV with FBP, ASIR-50, and ASIR-100. Model-based iterative reconstruction showed the best contrast-to-noise ratio in all images and provided similar subjective scores for LDP-II. ASIR-50 had no remarkable effect, and ASIR-100, a small effect on subjective scores. CONCLUSIONS: Compared with a reference dose protocol with FBP, model-based iterative reconstruction may show similar diagnostic visibility of orbital soft tissues at a CT dose index volume of 2.64 mGy. Low-dose technology and iterative reconstruction technology may redefine current reference dose levels in maxillofacial CT.

Ultralow-dose computed tomography imaging for surgery of midfacial and orbital fractures using ASIR and MBIR.

The influence of dose reductions on diagnostic quality using a series of high-resolution ultralow-dose computed tomography (CT) scans for computer-assisted planning and surgery including the most recent iterative reconstruction algorithms was evaluated and compared with the fracture detectability of a standard cranial emergency protocol. A human cadaver head including the mandible was artificially prepared with midfacial and orbital fractures and scanned using a 64-multislice CT scanner. The CT dose index volume (CTDIvol) and effective doses were calculated using application software. Noise was evaluated as the standard deviation in Hounsfield units within an identical region of interest in the posterior fossa. Diagnostic quality was assessed by consensus reading of a craniomaxillofacial surgeon and radiologist. Compared with the emergency protocol at CTDIvol 35.3 mGy and effective dose 3.6 mSv, low-dose protocols down to CTDIvol 1.0 mGy and 0.1 mSv (97% dose reduction) may be sufficient for the diagnosis of dislocated craniofacial fractures. Non-dislocated fractures may be detected at CTDIvol 2.6 mGy and 0.3 mSv (93% dose reduction). Adaptive statistical iterative reconstruction (ASIR) 50 and 100 reduced average noise by 30% and 56%, and model-based iterative reconstruction (MBIR) by 93%. However, the detection rate of fractures could not be improved due to smoothing effects.

Fibro-osseous lesion of the middle turbinate: ossifying fibroma or fibrous dysplasia?

Benign fibro-osseous tumours of the head and neck region seldom appear in the midface and nasal cavity. Correct differential diagnosis of fibro-osseous tumours is crucial for adequate therapy, as their clinical aggressiveness seems to differ. The rather uncommon case of a 14-year-old boy with a tumour of the middle turbinate is presented. The radiologic appearance of the tumour, on computed tomography and magnetic resonance imaging scans, was consistent with fibrous dysplasia. Angiography revealed extensive vascularisation of the tumour from both the internal and external carotid arteries. To avoid ipsilateral blindness following embolisation, a superselective embolisation of the supplying blood vessels was performed. The tumour was completely resected via an endoscopic approach. Histopathology revealed an ossifying fibroma. This case emphasises the importance of interpretation of the clinical, radiological and histological features before planning definitive treatment. Moreover, when fibro-osseous tumours are suspected, the possibility of extensive, complicated vascularisation must be considered. This case underwent radical resection, with no recurrence after four years' follow up.

Electromechanical synchronization of the heterotopic and native heart by dual atrial stimulation following heart transplantation.

After heterotopic heart transplantation, a 59-year-old woman presented with remarkable symptoms of breathlessness and fatigue, despite excellent donor heart function. Asynchrony of donor and native heart provoked haemodynamic instability. Dual atrial pacemaker implantation lead to linkage and synchronization of atrial and ventricular contraction in both the donor and native heart with the faster organ executing the synchronization. Remarkable relief of symptoms has been evident during the long-term follow-up.

Comparison of low-contrast detail perception on storage phosphor radiographs and digital flat panel detector images.

A contrast detail analysis was performed to compare perception of low-contrast details on X-ray images derived from digital storage phosphor radiography and from a flat panel detector system based on a cesium iodide/amorphous silicon matrix. The CDRAD 2.0 phantom was used to perform a comparative contrast detail analysis of a clinical storage phosphor radiography system and an indirect type digital flat panel detector unit. Images were acquired at exposure levels comparable to film speeds of 50/100/200/400 and 800. Four observers evaluated a total of 50 films with respect to the threshold contrast for each detail size. The numbers of correctly identified objects were determined for all image subsets. The overall results show that low-contrast detail perception with digital flat panel detector images is better than with state of the art storage phosphor screens. This is especially true for the low-exposure setting, where a nearly 10% higher correct observation ratio is reached. Given its high detective quantum efficiency the digital flat panel technology based on the cesium iodide scintillator/amorphous silicon matrix is best suited for detection of low-contrast detail structures, which shows its high potential for clinical imaging.

Radial nerve palsy associated with humeral shaft fracture: evaluation with US--initial experience.

PURPOSE: To determine the feasibility of using ultrasonography (US) for evaluation of a radial nerve injury associated with humeral shaft fracture. MATERIALS AND METHODS: In a prospective study, 11 consecutive patients with sensorimotor radial deficiency after distal humeral fracture were evaluated with conventional radiography, US, electroneurography, and electromyography. Surgical repair of the fracture and nerve inspection were performed in five patients. The remaining six patients were successfully treated conservatively. The US appearance of the radial nerve was studied in 10 healthy volunteers and in the noninjured arm of the 11 patients for comparison. RESULTS: In five patients, US findings of a severely damaged radial nerve were confirmed at surgical nerve inspection. In one patient, the nerve was entrapped between fragments. One patient had a complete nerve dissection, one had a lacerated nerve from a loose compression plate, and one had a nerve riding on the edge of a bone fragment. In the fifth patient who underwent surgical inspection, the nerve was buried in the callus. In the six patients treated conservatively, US showed continuity of the nerve. CONCLUSION: US may be useful for accurate evaluation of the radial nerve in patients with nerve palsy associated with humeral shaft fracture.