Blar i NTNU Open på forfatter "Løvstakken, Lasse"
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Blood Speckle-Tracking Based on High–Frame Rate Ultrasound Imaging in Pediatric Cardiology
Nyrnes, Siri Ann; Fadnes, Solveig; Wigen, Morten Smedsrud; Mertens, Luc; Løvstakken, Lasse (Peer reviewed; Journal article, 2020)Background: Flow properties play an important role in cardiac function, remodeling, and morphogenesis but cannot be displayed in detail with today’s echocardiographic techniques. The authors hypothesized that blood ... -
Cardiac power integral: a new method for monitoring cardiovascular performance
Rimehaug, Audun Eskeland; Lyng, Oddveig; Nordhaug, Dag Ole; Løvstakken, Lasse; Aadahl, Petter; Kirkeby-Garstad, Idar (Journal article; Peer reviewed, 2013)Cardiac power (PWR) is the continuous product of flow and pressure in the proximal aorta. Our aim was to validate the PWR integral as a marker of left ventricular energy transfer to the aorta, by comparing it to stroke ... -
Clutter Filter Wave Imaging
Salles, Sebastien; Løvstakken, Lasse; Aase, Svein Arne; Bjåstad, Tore Grüner; Torp, Hans (Journal article; Peer reviewed, 2019)The elastic properties of human tissue can be evaluated through the study of mechanical wave propagation captured using high frame rate ultrasound imaging. Methods such as block-matching or phase-based motion estimation ... -
Combined 2-D Vector imaging and Tracking Doppler for improved vascular blood velocity quantification
Avdal, Jørgen; Løvstakken, Lasse; Torp, Hans; Ekroll, Ingvild Kinn (Journal article; Peer reviewed, 2017)Measurement of the maximum blood flow velocity is the primary means for determining the degree of carotid stenosis using ultrasound. The current standard for estimating the maximum velocity is Pulsed Wave (PW) Doppler with ... -
Comparison of ultrasound vector flow imaging and CFD simulations with PIV measurements of flow in a left ventricular outflow trackt phantom - Implications for clinical use and in silico studies
Leinan, Paul Roger; Grønli, Thomas; Skjetne, Paal; Wigen, Morten Smedsrud; Urheim, Stig; Løvstakken, Lasse; Dahl, Sigrid Kaarstad (Peer reviewed; Journal article, 2022)In this study we have compared two modalities for flow quantification from measurement data; ultrasound (US) and shadow particle image velocimetry (PIV), and a flow simulation model using computational fluid dynamics (CFD). ... -
Data Adaptive 2-D Tracking Doppler for High-Resolution Spectral Estimation
Karabiyik, Yücel; Avdal, Jørgen; Ekroll, Ingvild Kinn; Fiorentini, Stefano; Torp, Hans; Løvstakken, Lasse (Peer reviewed; Journal article, 2019)Spectral broadening in pulsed-wave Doppler caused by the transit-time effect deteriorates the frequency resolution and may cause overestimation of maximum velocities in high-velocity blood flow regions and for large ... -
Deep learning applications in medical imaging - Deep Convolutional Generative adversarial networks
Dietrichson, Fabian (Master thesis, 2018)Medical imaging Medical imaging makes it possible to examine internal human tissue without performing surgery. Common medical imaging techniques include magnetic resonance (MR), computer tomography (CT), X-ray and ultrasound ... -
Deep Learning based Classification of Cardiac Events in Echocardiography
Langerud, Maren Andrea (Master thesis, 2022)Abstract will be available on 2023-01-29 -
Deep Learning for Deformation Analysis in Echocardiography
Seljelv, Sigvard Johansen (Master thesis, 2021)Hjartesjukdom er ei av dei leiande dødsårsakene i verda. Tidleg deteksjon av risikofaktorar er avgjerande for effektiv og nøyaktig behandling. I dag blir undersøkingar av pasientar oftast utført ved hjelp av hjarte-ultralyd, ... -
Deep Learning for Improved Precision and Reproducibility of Left Ventricular Strain in Echocardiography: A Test-Retest Study
Salte, Ivar Mjåland; Østvik, Andreas; Olaisen, Sindre Hellum; Karlsen, Sigve; Dahlslett, Thomas; Smistad, Erik; Eriksen-Volnes, Torfinn Kirknes; Brunvand, Harald; Haugaa, Kristina Ingrid Helena Hermann; Edvardsen, Thor; Dalen, Håvard; Løvstakken, Lasse; Grenne, Bjørnar Leangen (Peer reviewed; Journal article, 2023)Aims Assessment of left ventricular (LV) function by echocardiography is hampered by modest test-retest reproducibility. A novel artificial intelligence (AI) method based on deep learning provides fully automated ... -
Deep Learning in the Echocardiography Workflow: Challenges and Opportunities
Pasdeloup, David (Doctoral theses at NTNU;2023:390, Doctoral thesis, 2023)Echocardiography is the most widely used imaging technique for cardiac imaging due to its availability, low-cost and real-time capabilities. With numerous indicators of heart function, it now enables precise diagnosis of ... -
Detailed flow visualization in fetal and neonatal hearts using 2-D speckle tracking
Fadnes, Solveig; Nyrnes, Siri Ann; Wigen, Morten Smedsrud; Tegnander, Eva; Løvstakken, Lasse (Journal article, 2016)Two-dimensional blood speckle tracking has shown promise for measuring the complex flow patterns in neonatal hearts when based on linear array and high-frame-rate plane wave imaging. For phased array pediatric imaging, ... -
Echocardiographic Reference Ranges of Global Longitudinal Strain for All Cardiac Chambers Using Guideline-Directed Dedicated Views
Nyberg, John; Jakobsen, Even Olav; Østvik, Andreas; Holte, Espen; Stølen, Stian; Løvstakken, Lasse; Grenne, Bjørnar Leangen; Dalen, Håvard (Peer reviewed; Journal article, 2023)Background Myocardial deformation by echocardiographic strain imaging is a key measurement in cardiology, providing valuable diagnostic and prognostic information. Reference ranges for strain should be established from ... -
Enhanced analysis of ultrasonic impedance logs: Improved imaging and fluid channel detection
Hoff, Simon Andreas (Master thesis, 2020)Abstract: The aim of this thesis is to detect vertical features in the the casing cement of oil and gas wells by using pattern recognition techniques based on machine learning on ultrasonic log data. Detecting channels is ... -
Enhanced analysis of ultrasonic impedance logs: Improved imaging and fluid channel detection
Hoff, Simon Andreas (Master thesis, 2020)Målet med denne oppgaven er å detektere vertikale trekk i sementen rundt foringsrøret i olje- og gassbrønner ved å bruke mønstergjenkjenningsteknikker basert på maskinlæring på ultralydloggdata. Å oppdage kanaler er en ... -
Fully automatic real-time ejection fraction and MAPSE measurements in 2D echocardiography using deep neural networks
Smistad, Erik; Østvik, Andreas; Salte, Ivar Mjåland; Leclerc, Sarah; Bernard, Olivier; Løvstakken, Lasse (Journal article; Peer reviewed, 2018)Cardiac ultrasound measurements such as left ventricular volume, ejection fraction (EF) and mitral annular plane systolic excursion (MAPSE) are time consuming and highly observer dependent. In this work, we investigate if ... -
GPU Implementation of Aliasing-Resistant Blood Flow Estimation Using Doppler Ultrasound
Braserud, Emil (Master thesis, 2019)Denne masteroppgaven presenterer en ny metode for aliasing-korreksjon av Doppler ultralydmålinger, og en pipeline fra beamforming, til blodstrøms-estimasjon på en GPU/Tensorflow platform er presentert. Metoden bruker Doppler ... -
Hjertefasegjenkjenning og insuffisiens påvisning ved bruk av maskin læring på blodstrømsmålinger
Nedregård, Benjamin (Master thesis, 2020)Transittid blodstrømsmåling (TTFM) er teknikk brukt under koronar bypasskirurgi for å verifisere at blodforsyningen til hjertemuskelen er tilstrekkelig gjenopprettet. For best mulig vurderingsgrunnlag tolkes blodstrømsmålingen ... -
Implementation and Assessment of Supersonic Shear Imaging Techniques
Fermann, Benjamin Strandli (Master thesis, 2017)Shear Wave Elastography (SWE) is an ultrasound modality which can measure tissue elasticity quantitatively. It provides valuable diagnostic information in addition to conventional ultrasound modalities. SWE has been shown ... -
Implementation and optimization of ultrasound image classification and segmentation on a portable device based on deep learning
Vasilyev, Mikhail (Master thesis, 2018)Ultrasound imaging is a popular technology used in medicine for obtaining 2D and 3D images of body tissues. In echocardiography it is used to assess heart and detect potential cardiac diseases. Recent technological progress ...