Automatic head computed tomography image noise quantification with deep learning

Purpose: Computed tomography (CT) image noise is usually determined by standard deviation (SD) of pixel values from uniform image regions. This study investigates how deep learning (DL) could be applied in head CT image noise estimation.Methods: Two approaches were investigated for noise image estimation of a single acquisition image: direct noise image estimation using supervised DnCNN convolutional neural network (CNN) architecture, and subtraction of a denoised image estimated with denoising UNet-CNN experimented with supervised and unsupervised noise2noise training approaches. Noise was assessed with local SD maps using 3D- and 2D-CNN architectures. Anthropomorphic phantom CT image dataset (N = 9 scans, 3 repetitions) was used for DL-model comparisons. Mean square error (MSE) and mean absolute percentage errors (MAPE) of SD values were determined using the SD values of subtraction images as ground truth. Open-source clinical head CT low-dose dataset (N-train = 37, N-test( )= 10 subjects) were used to demonstrate DL applicability in noise estimation from manually labeled uniform regions and in automated noise and contrast assessment.Results: The direct SD estimation using 3D-CNN was the most accurate assessment method when comparing in phantom dataset (MAPE = 15.5%, MSE = 6.3HU). Unsupervised noise2noise approach provided only slightly inferior results (MAPE = 20.2%, MSE = 13.7HU). 2DCNN and unsupervised UNet models provided the smallest MSE on clinical labeled uniform regions.Conclusions: DL-based clinical image assessment is feasible and provides acceptable accuracy as compared to true image noise. Noise2noise approach may be feasible in clinical use where no ground truth data is available. Noise estimation combined with tissue segmentation may enable more comprehensive image quality characterization.Peer reviewe

Automaattisen sisällönkuvailun ohjelmiston rakentaminen – case Annif

Sisällönkuvailun automatisointiratkaisut ovat puhuttaneet kirjastomaailmassa viime vuosina, ja erilaisia kokeiluja on tehty niin Suomessa kuin maailmallakin. Kansalliskirjastossa kehitetty automaattisen sisällönkuvailun Annif-työkalu on herättänyt paljon mielenkiintoa monissa organisaatioissa ja kokemukset ensimmäisistä käyttöönotoista ovat olleet lupaavia. Mitä kehitysvalintoja Annifia rakennettaessa on tehty, ja minkälaisia haasteita kuvailun automatisointiin ylipäätään liittyy

Kohti lapsiperheiden ravitsemusopasta : suunnitelma aktivoivasta verkkomateriaalista

Tämän ravitsemuksellisen kehittämistyön tavoitteena oli aktivoida lapsiperheitä syömään ravitsemussuositusten mukaisesti vihanneksia, hedelmiä ja marjoja päivittäin. Tarkoituksena oli luoda teoreettinen pohja ja käytännön ideoita aktivoivan ravitsemusoppaan toteuttamista varten. Opinnäytetyömme toiminnallisen osuuden toteutimme lokakuussa 2016 osana Viisi per päivä -terveyskampanjaa. Griffith University ja tohtoriopiskelija Ville Lahtinen vastasivat Viisi per päivä -hankkeesta. Toiminnallisten interventiopäivien yhteydessä keskustelimme lasten kanssa pyrkien selvittämään tiedon tarvetta ja hyvinvointiosaamisen tasoa. Ohjaamiimme interventiopäiviin osallistui yhteensä noin 430 lasta, joista noin 150 lapsen kanssa kävimme keskusteluja. Näiden kokemuksien lisäksi syvensimme kohderyhmätuntemustamme monimuotoisella tiedonhaulla ja empiirisen kokemuksen kartuttamisella erilaisten toiminnallisten keinojen avulla. Keskusteluissa nousi esille puutteita lasten ja lapsiperheiden kasvisten käytön määrässä ja tiedollisessa osaamisessa. Näiden kokemusten pohjalta ideamme kehittämistyöhön muovautui ja muodostimme aktivoivan ravitsemusoppaan suunnitelman. Opinnäytetyön tuloksia voidaan hyödyntää näyttöön perustuvaa hyvinvointioppimista ja terveyttä edistävää materiaalia luotaessa. Tulemme toteuttamaan opinnäytetyössämme suunnitellun ravitsemuksellisen verkko-oppaan opintoihimme kuuluvana innovaatioprojektina.The purpose of this practice-based thesis was to design a practical method that would activate families with children aged from 6 to 12 to eat vegetables, fruits and berries according to the national dietary recommendations. To achieve the purpose, we created theoretical framework and a plan for implementing an activating nutritional guide. The practical part of our thesis was carried out in October 2016 as a part of Viisi per päivä project led by PhD student Ville Lahtinen from Griffith University. During the intervention days, we talked with the children trying to figure out the need for nutritional information and the level of wellbeing knowledge. There were approximately 430 children taking part on those intervention days, and we talked with about 150 children. We expanded our knowledge of the focus group and issue at hand by gathering study reports and empiric data. The conversations with the children brought up lack of nutritional knowledge amongst the focus group as well as lack of skills needed for healthy eating. Based on these experiences we formed the idea for our thesis and we started to design the structure and content for the nutritional guide. The results of this thesis can be used to create an evidence based nutritional guide that promotes health and learning for wellbeing. We will implement the nutritional online guide designed in the thesis as a part of our upcoming studies

Ultrasound backscattering is anisotropic in bovine articular cartilage

Collagen, proteoglycans and chondrocytes can contribute to ultrasound scattering in articular cartilage. However, anisotropy of ultrasound scattering in cartilage is not fully characterized.We investigate this using a clinical intravascular ultrasound device with ultrasound frequencies of 9 and 40 MHz. Osteochondral samples were obtained from intact bovine patellas, and cartilage was imaged in two perpendicular directions: through articular and lateral surfaces. At both frequencies, ultrasound backscattering was higher (p < 0.05) when measured through the lateral surface of cartilage. In addition, the composition and structure of articular cartilage were investigated with multiple reference methods involving light microscopy, digital densitometry, polarized light microscopy and Fourier infrared imaging. Reference methods indicated that acoustic anisotropy of ultrasound scattering arises mainly from non-uniform distribution of chondrocytes and anisotropic orientation of collagen fibers. To conclude, ultrasound backscattering in articular cartilage was found to be anisotropic and dependent on the frequency in use

Subacromial decompression versus diagnostic arthroscopy for shoulder impingement : a 5-year follow-up of a randomised, placebo surgery controlled clinical trial

Objectives To assess the long-term efficacy of arthroscopic subacromial decompression (ASD) by comparing it with diagnostic arthroscopy (primary comparison), a placebo surgical intervention, and with a non-operative alternative, exercise therapy (secondary comparison). Methods We conducted a multicentre, three group, randomised, controlled superiority trial. We included 210 patients aged 35-65 years, who had symptoms consistent with shoulder impingement syndrome for more than 3 months. 175 participants (83%) completed the 5 years follow-up. Patient enrolment began on 1 February 2005 and the 5-year follow-up was completed by 10 October 2018. The two primary outcomes were shoulder pain at rest and on arm activity measured with Visual Analogue Scale (VAS). Minimally important difference (MID) was set at 15. We used a mixed-model repeated measurements analysis of variance with participant as a random factor, the baseline value as a covariate and assuming a covariance structure with compound symmetry. Results In the primary intention to treat analysis (ASD vs diagnostic arthroscopy), there were no between-group differences that exceeded the MID for the primary outcomes at 5 years: the mean difference between groups (ASD minus diagnostic arthroscopy) in pain VAS were -2.0 (95% CI -8.5 to 4.6; p=0.56) at rest and -8.0 (-17.3 to 1.3; p=0.093) on arm activity. There were no between-group differences in the secondary outcomes or adverse events that exceeded the MID. In our secondary comparison (ASD vs exercise therapy), the mean differences between groups (ASD minus exercise therapy) in pain VAS were 1.0 (-5.6 to 7.6; p=0.77) at rest and -3.9 (-12.8 to 5.1; p=0.40) on arm activity. There were no significant between-group differences for the secondary outcomes or adverse events. Conclusions ASD provided no benefit over diagnostic arthroscopy (or exercise therapy) at 5 years for patients with shoulder impingement syndrome.Peer reviewe