A workflow-integrated brain tumor segmentation system based on fastai and MONAI

Artificial intelligence (AI) has achieved great results in medical imaging tasks and has the potential to improve the experiences of clinicians and patients in the future, but on the way toward AI integration in medicine, there are many practical, technical, and societal challenges. In this thesis, we contribute to the development of AI integration in Helse Vest and present a brain tumor segmentation system integrated with their existing research PACS solution. We investigate to which degree integration of machine learning models is currently possible and if additional software development efforts are needed. The machine learning model used is developed with a library combining the two python-based deep learning libraries fastai and MONAI. This library is currently under development by researchers at Mohn Medical Imaging and Visualization Centre (MMIV), and we compare it with another state-of-the-art framework to quantify its potential usefulness. Additionally, we deploy it in a simple interactive web application. The thesis contains three studies that were conducted to discuss and answer our research goals. All studies used medical data from a data set coming out of the BraTS 2021 segmentation challenge, and our project is a part of MMIV's WIML project. Our achieved results open the way for future developers to continue workflow integrated machine learning in research PACS, and we see many possible directions to take future research.Masteroppgave i Programutvikling samarbeid med HVLPROG399MAMN-PRO

Continuous cardiac output measured with a Swan-Ganz catheter reacts too slowly in animal experiments with sudden circulatory failure

BACKGROUND: In many animal experiments, it is vital to detect sudden changes in cardiac output (CO). This porcine study compared CO that was measured with a Swan‐Ganz pulmonary catheter with the gold standard (which was a transit‐time flow probe around the pulmonary artery) during interventions that caused hemodynamic instability. METHODS: In one series, 7 pigs were exposed to sudden changes in CO. In another series, 9 pigs experienced more prolonged changes in CO. All the pigs had a Swan‐Ganz catheter placed into the pulmonary artery and a flow probe around the pulmonary artery. Adrenaline infusion and controlled hemorrhage were used to increase and decrease CO, respectively. The measurements of CO before and after each intervention were compared for correlation, agreement, and the time delay that it took each method to detect at least a 30% change in CO. A Bland–Altman test was used to identify correlations and agreements between the methods. RESULTS: In the first series, there was a delay of 5–7 min for the Swan Ganz catheter to register a 30% change in cardiac output, compared with the flow probe. However, during prolonged changes in CO in the second series, there was a good correlation between the 2 methods. Mixed venous oxygen saturation reacted faster to changes than did CO; both were measured via the Swan‐Ganz catheter. CONCLUSIONS: In many animal studies, the use of Swan‐Ganz catheters is suitable; however, in experiments with sudden hemodynamic instability, the flow probe is the most advantageous method for measuring CO

Carbon monoxide poisoning in Denmark with focus on mortality and factors contributing to mortality

IntroductionCarbon monoxide (CO) poisoning is frequent worldwide but knowledge regarding the epidemiology is insufficient. The aim of this study was to clarify the extent of this intoxication, its mortality and factors associated with mortality.Materials and methodsNational databases from Statistics Denmark were used to identify individuals who suffered from CO-poisoning during 1995-2015, as well as information regarding co-morbidities, mortality and manner of death.ResultsDuring the period from 1995 to 2015, 22,930 patients suffered from CO-poisoning in Denmark, and 21,138 of these patients (92%) were hospitalized. A total of 2,102 patients died within the first 30 days after poisoning (9.2%). Among these, 1,792 (85% of 2,102) were declared dead at the scene and 310 (15% of 2,102) died during hospitalization. Deaths due to CO-poisoning from smoke were intentional in 6.3% of cases, whereas deaths due to CO containing gases were intentional in 98.0% of cases. Among patients who survived >30 days, there was no significant difference in survival when comparing hyperbaric oxygen therapy (HBO) treatment with no HBO treatment after adjustment for age and co-morbidities such as drug abuse, psychiatric disease, stroke, alcohol abuse, arterial embolism, chronic obstructive pulmonary disease, cerebrovascular disease and atrial fibrillation. Several co-morbidities predicted poorer outcomes for patients who survived the initial 30 days.ConclusionsPoisoning from smoke and/or CO is a frequent incident in Denmark accounting for numerous contacts with hospitals and deaths. Both intoxication and mortality are highly associated with co-morbidities interfering with cognitive and physical function. Treatment with HBO was not seen to have an effect on survival