Virtual reality simulation training in stroke thrombectomy centers with limited patient volume-Simulator performance and patient outcome.

BACKGROUND: Virtual reality simulation training may improve the technical skills of interventional radiologists when establishing endovascular thrombectomy at limited-volume stroke centers. The aim of this study was to investigate whether the technical thrombectomy performance of interventional radiologists improved after a defined virtual reality simulator training period. As part of the quality surveillance of clinical practice, we also assessed patient outcomes and thrombectomy quality indicators at the participating centers. METHODS: Interventional radiologists and radiology residents from three thrombectomy-capable stroke centers participated in a five months thrombectomy skill-training curriculum on a virtual reality simulator. The simulator automatically registered procedure time, the number of predefined steps that were correctly executed, handling errors, contrast volume, fluoroscopy time, and radiation dose exposure. The design was a before-after study. Two simulated thrombectomy cases were used as pretest and posttest cases, while seven other cases were used for training. Utilizing the Norwegian Stroke Register, we investigated clinical results in thrombectomy during the study period. RESULTS: Nineteen interventional radiologists and radiology residents participated in the study. The improvement between pretest and posttest cases was statistically significant for all outcome measures in both simulated cases, except for the contrast volume used in one case. Clinical patient outcomes in all three centers were well within the recommendations from multi-society consensus guidelines. CONCLUSION: Performance on the virtual reality simulator improved after training. Virtual reality simulation may improve the learning curve for interventional radiologists in limited-volume thrombectomy centers. No correlation alleged, the clinical data indicates that the centers studied performed thrombectomy in accordance with guideline-recommended standards.

Halved contrast medium dose in lower limb dual-energy computed tomography angiography-a randomized controlled trial.

OBJECTIVES: To compare vascular attenuation (VA) of an experimental half iodine-load dual-layer spectral detector CT (SDCT) lower limb computed tomography angiography (CTA) with control (standard iodine-load conventional 120-kilovolt peak (kVp) CTA). METHODS: Ethical approval and consent were obtained. In this parallel RCT, CTA examinations were randomized into experimental or control. Patients received 0.7 vs 1.4 mL/kg of iohexol 350 mgI/mL in the experimental- vs the control group. Two experimental virtual monoenergetic image (VMI) series at 40 and 50 kiloelectron volts (keV) were reconstructed. PRIMARY OUTCOME: VA. SECONDARY OUTCOMES: image noise (noise), contrast- and signal-to-noise ratio (CNR and SNR), and subjective examination quality (SEQ). RESULTS: A total of 106 vs 109 were randomized and 103 vs 108 were analyzed in the experimental vs, control groups, respectively. VA was higher on experimental 40 keV VMI than on control (p < 0.0001), but lower on 50 keV VMI (p < 0.022). Noise was higher on experimental 40 keV VMI than on control (p = 0.00022), but lower on 50 keV VMI (p = 0.0033). CNR and SNR were higher than the control on experimental 40 keV VMI (both p < 0.0001) and 50 keV (p = 0.0058 and p = 0.0023, respectively). SEQ was better on both VMIs in the experimental group than in the control (both p < 0.0001). CONCLUSIONS: Half iodine-load SDCT lower limb CTA at 40 keV achieved higher VA than the control. CNR, SNR, noise, and SEQ were higher at 40 keV, while 50 keV showed lower noise. CLINICAL RELEVANCE STATEMENT: Spectral detector CT with low-energy virtual monoenergetic imaging performed halved iodine contrast medium (CM) lower limb CT-angiography with sustained objective and subjective quality. This facilitates CM reduction, improvement of low CM-dosage examinations, and examination of patients with more severe kidney impairment. TRIAL REGISTRATION: Retrospectively registered 5 August 2022 at clinicaltrials.gov NCT05488899. KEY POINTS: • Contrast medium dosage may be halved in lower limb dual-energy CT angiography with virtual monoenergetic images at 40 keV, which may reduce contrast medium consumption in the face of a global shortage. • Experimental half-iodine-load dual-energy CT angiography at 40 keV showed higher vascular attenuation, contrast-to-noise ratio, signal-to-noise ratio, and subjective examination quality than standard iodine-load conventional. • Half-iodine dual-energy CT angiography protocols may allow us to reduce the risk of PC-AKI, examine patients with more severe kidney impairment, and provide higher quality examinations or salvage poor examinations when impaired kidney function limits the CM dose.

Severe nocturnal hypoxaemia in geriatric inpatients.

BACKGROUND: oxygen levels are decreased in older people especially in the supine position, and during sleep. Geriatric inpatients often suffer from stroke and heart disease. Respiratory control may be substantially affected. OBJECTIVE: the aim of this study was to examine oxygen levels during night in inpatients on geriatric medical wards to find out if they needed nocturnal oxygen therapy. DESIGN: prospective observational study. SETTING/PARTICIPANTS: we consecutively examined 133 patients with SpO(2) >or=92% in sitting position by an overnight -8-h pulse oximetry. Patients with severe obesity, dementia or pulmonary disease were excluded. The test was performed at least 4 days after the event in stroke cases. OUTCOME VARIABLES: ninety two patients, m/f 43/49, with mean age 78.3 +/- 6.9 SD completed the test. Sixty six patients suffered from stroke; 34 left-sided and 19 right-sided stroke. Nine patients suffered from a heart disease only, and 17 patients suffered from other diseases. RESULTS: according to the guidelines for long-term oxygen therapy recommendations for nocturnal oxygen therapy, we found that 26% of the patients fulfilled the criteria of SpO(2) or=30% of the time. There was a significant positive correlation between age and the amount of time with SpO(2) between 80 and 84% (0.215, P < 0.05). Diagnosis or severeness of disease did not significantly affect nocturnal SpO(2) %. The 1-year survival rate was 75% in group I (hypoxaemic) versus 84% in group II (normoxaemic) (NS). CONCLUSION: nearly 30% of the inpatients in geriatric medical wards suffered from severe oxygen-requiring nocturnal hypoxaemia irrespective of diagnosis.