Bedre seleksjon av pasienter henvist til MR av prostata ved forhøyet PSA eller mistanke om prostatakreft

Bakgrunn: Pakkeforløp for prostatakreft ble introdusert i 2015, og er et standardisert pasientforløp som beskriver organiseringen av utredning og behandling, og konkrete forløpstider. Det er et mål at 70 % av alle Pakkeforløp gjennomføres innenfor anbefalt forløpstid, men kun 48,2 % oppfylte dette kriteriet i Helse Midt-Norge i 2. tertial 2020. Bedre utnyttelse av tilgjengelige ressurser er derfor ønskelig. Hovedoppgaven ønsker å utarbeide en oversiktlig rapport over pasienter som henvises til pre-biopsi MR av prostata, for i fremtiden å kunne utarbeide bedre retningslinjer for henvisning til MR prostata og Pakkeforløp for prostatakreft. Materiale og metode: En retrospektiv deskriptiv studie der vi har sett på pasientjournalene til 412 menn henvist til MR prostata på St. Olavs hospital mellom 1. januar og 31. desember 2016. Det ble samlet inn relevante kliniske variabler om henvisningsårsak, PSA, behandling osv., og forløpstider hvis de var registrert i et Pakkeforløp. Det ble brukt enkel deskriptiv statikk for å beskrive kohorten. Resultater: Forhøyet PSA var den klart vanligste henvisningsårsaken (77 %) til MR prostata. 189 av pasientene hadde positiv biopsi, 106 negativ biopsi, mens det hos 115 manglet informasjon om biopsi-status. 193 pasienter fikk behandling, 46 % med prostatektomi, 27 % med aktiv overvåkning, mens resten fikk stråling eller hormoner. Det var signifikante forskjeller mellom gruppene med positiv eller negativ biopsi når det bl.a. gjaldt alder, PSA, PSA-tetthet og palpasjonsfunn. Av pasienter med positiv eller negativ biopsi var 94 og 92 % registrert i et Pakkeforløp, respektivt, men bare 45 % av de uten informasjon om biopsi-status. Andelen Pakkeforløp som overholdt fristen for behandling var mellom 53-65 %. Konklusjon: Pakkeforløp for prostatakreft starter oftest på bakgrunn av forhøyet PSA. Fastleger bør legge ved informasjon om palpasjonsfunn og familiehistorie i henvisningen til urolog. De fleste pasientene med informasjon om biopsi-status var registrert i et Pakkeforløp. Dagens metoder for screening av prostatakreft er ikke gode nok for å hindre unødvendige MR-undersøkelser og start av Pakkeforløp for prostatakreft

Sensor Simulation and Environment Mapping using UWB Radar for Industrial Drone Inspection

The use of unmanned aerial drones for inspection of industrial environments have great potential in lowering both cost and risk. Development of such systems are going on at full speed, but many hurdles remain, especially that of creating robust sensors for object detection. The main obstacle is to find a sensor for object detection that is small, cheap, accurate and can fit on a small flying drone. Radar is proposed for this purpose, but little testing has been performed on smaller flying drones to either confirm or deny this prospect. New tools will need to be developed to increase the development process. In this thesis, a simulation framework has been implemented that allows for real-time testing of radar sensors within a 3D environment. The system is based on the software packages of ROS and Gazebo, using the ray-tracing technique to simulate the effects of electromagnetic waves on the environment. A radar sensor model was developed in Gazebo based on a 3D scanning lidar. The radar performed well through designed simulations, providing similar output to that of the radar sensor it simulates. In addition, a mapping technique called Occupancy Grid Mapping was implemented to complement the radar sensor, expanding its application area. The mapping technique showed good results, mapping clustered environments with low uncertainty

Spin‐up in a semicircular cylinder

This paper addresses the spin‐up from rest of a free‐surface fluid confined in a cylindrical container with a semicircular cross‐section. The flow in the various stages of the spin‐up process has been calculated numerically by using the finite‐volume technique on a three‐dimensional grid. Local grid refinement was applied in order to capture the effects of the boundary layer at the lateral boundaries and of the Ekman layer at the bottom. The numerical results agree very well with laboratory observations

Experimental investigation on the effect off near walls on the eigen frequency of a low specific speed francis runner

The importance to correctly predict the natural frequency of a turbine runner have been demonstrated several times. It is now common practice to include the added mass effect of the surrounding water when calculating the natural frequencies. In this paper the added mass effect of water on a simplified low specific speed francis turbine runner is experimentally investigated. Three cases are investigated. 1: The runner hanging in air. 2: The runner hanging in a tank of water. 3: The runner installed into the turbine housing. The measurements reveal a frequency reduction of about 40% when the runner is hanging in water. Installing the runner into the turbine housing does not significantly change the natural frequency of the main blade modes. Modes which vibrate heavily on the outside of the runner are visible in the water tank but becomes dampened when installed into the turbine housing

Spin-up in a rectangular tank with low angular velocity

A comparison is made between numerical and experimental results for spin-up from rest in a rectangular container. The numerical results were obtained by using a three-dimensional finite volume method on a supercomputer. The experiments were performed with water, using tracer particles floating at the free surface in order to visualize the flow field. The numerical and experimental results are in good agreement. They show the formation of a stable three-cell pattern. In contrast to similar experiments performed at higher angular velocities, the center cell of this pattern appears to be anticyclonic. Initially, the relation between vorticity ω and streamfunction ψ of this organized flow is linear, but it is seen to evolve slowly into a relation with ∂2ω/∂ψ2 < 0

Fluid structure interaction of Francis-99 turbine and experimental validation

The ability to predict a francis runners dynamic response to the exciting forces is paramount to avoid unwanted disintegration of the turbines components. In this article, each of the principal factors contributing to the dynamic response of the runner; eigenfrequency, mode shape, damping and pressure force, is individually examined and compared to the measured values from the Francis-99 runner. Even though the runner is made with a bolted connection between the blades and crown/band, and thus severely increasing the complexity, quite accurate predictions are possible using methods previously validated for massive and symmetric runners. All calculations are conducted on the best efficiency point and with eigenmodes corresponding to Nodal Diameter 4 as excited by the second harmonic of the guide vane passing frequency. The calculated natural frequency for the first two ND4 eigenmodes are within ±5% of the measured values. Further are the calculated eigenmodes, forcing pressure field and hydrodynamic damping all within measurement tolerances with some minor exceptions

Relative Enhanced Diffusivity in Prostate Cancer: Protocol Optimization and Diagnostic Potential

Background Relative enhanced diffusivity (RED) is a potential biomarker for indirectly measuring perfusion in tissue using diffusion‐weighted magnetic resonance imaging (MRI) with 3 b values. Purpose To optimize the RED MRI protocol for the prostate, and to investigate its potential for prostate cancer (PCa) diagnosis. Study Type Prospective. Population Ten asymptomatic healthy volunteers and 35 patients with clinical suspicion of PCa. Sequence 3T T2‐ and diffusion‐weighted MRI with b values: b = 0, 50, [100], 150, [200], 250, [300], 400, 800 s/mm2 (values in brackets were only used for patients). Assessment Monte Carlo simulations were performed to assess noise sensitivity of RED as a function of intermediate b value. Volunteers were scanned 3 times to assess repeatability of RED. Patient data were used to investigate RED's potential for discriminating between biopsy‐confirmed cancer and healthy tissue, and between true and false positive radiological findings. Statistical Tests Within‐subject coefficient of variation (WCV) to assess repeatability and receiver‐operating characteristic curve analysis and logistic regression to assess diagnostic performance of RED. Results The repeatability was acceptable (WCV = 0.2‐0.3) for all intermediate b values tested, apart from b = 50 s/mm2 (WCV = 0.3‐0.4). The simulated RED values agreed well with the experimental data, showing that an intermediate b value between 150‐250 s/mm2 minimizes noise sensitivity in both peripheral zone (PZ) and transition zone (TZ). RED calculated with the b values 0, 150 and 800 s/mm2 was significantly higher in tumors than in healthy tissue in both PZ (P < 0.001, area under the curve [AUC] = 0.85) and PZ + TZ (P < 0.001, AUC = 0.84). RED was shown to aid apparent diffusion coefficient (ADC) in differentiating between false‐positive findings and true‐positive PCa in the PZ (AUC; RED = 0.71, ADC = 0.74, RED+ADC = 0.77). Data Conclusion RED is a repeatable biomarker that may have value for prostate cancer diagnosis. An intermediate b value in the range of 150‐250 s/mm2 minimizes the influence of noise and maximizes repeatability. Level of Evidence: 2 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019