Browsing by Author "Çukur, Tolga"
Now showing items 1-20 of 54
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3 boyutlu kartezyen olmayan paralel görüntülemede değişken görüntü alanına dayalı geriçatım
Şenel, Celal Furkan; Çukur, Tolga (IEEE, 2018)MRG’de yaygın olarak kullanılan geriçatım yöntemleri değişken yoğunluklu Kartezyen olmayan taramalara da uygulanabilmektedir; fakat bu durumda bu yöntemlerin genellikle yüksek hesaplama karmaşıklığı içeren çok ... -
Adaptive reconstruction for vessel preservation in unenhanced MR angiography
Ilıcak, Efe; Çetin, S.; Sarıtaş, Emine Ülkü; Ünal, G.; Çukur, Tolga (IEEE, 2016)The image quality of unenhanced magnetic resonance angiography, which images blood vessels without contrast agents, is limited by constraints related to scan time. To address this problem, techniques that undersample ... -
Anatomical measurements correlate with individual magnetostimulation thresholds for kHz‐range homogeneous magnetic fields
Demirel, Ömer Burak; Kılıç, Toygan; Çukur, Tolga; Sarıtaş, Emine Ülkü (Wiley, 2020)Purpose: Magnetostimulation, also known as peripheral nerve stimulation (PNS), is the dominant safety constraint in magnetic resonance imaging (MRI) for the gradient magnetic fields that operate around 0.1–1 kHz, and for ... -
Attentional modulation of hierarchical speech representations in a multitalker environment
Kiremitçi, İbrahim; Yılmaz, Özgür; Çelik, Emin; Shahdloo, Mohammad; Huth, A. G.; Çukur, Tolga (Oxford University Press, 2021-11)Humans are remarkably adept in listening to a desired speaker in a crowded environment, while filtering out nontarget speakers in the background. Attention is key to solving this difficult cocktail-party task, yet a detailed ... -
Biased competition in semantic representation during natural visual search
Shahdloo, Mohammad; Çelik, Emin; Çukur, Tolga (Elsevier, 2020)Humans divide their attention among multiple visual targets in daily life, and visual search can get more difficult as the number of targets increases. The biased competition hypothesis (BC) has been put forth as an ... -
BSSFP görüntülemede eliptik sinyal modeline dayali eşzamanlı parametre tahmini
Keskin, Kübra; Çukur, Tolga (IEEE, 2018)Faz döngülü dengeli kararlı-durum serbest devinim (bSSFP) görüntüleme tekniginde, görüntüde oluşan rezonans dışı frekanslardan kaynaklı sinyal düşüşlerinin uzamsal konumunu kaydırmak amacıyla her çekimde RF darbelerinin ... -
Category-selective top-down modulation in the fusiform face area of the human brain during visual search
Dar, Salman Ul Hassan; Çukur, Tolga (IEEE, 2017)Several regions in the ventral-temporal cortex of the human brain are thought to have representations of specific categories of objects. Furthermore, a distributed network of frontal and parietal brain regions is implicated ... -
Comparison of system-matrix-based and projection-based reconstructions for field free line magnetic particle imaging
Ilbey, S.; Top, C. B.; Güngör, A.; Çukur, Tolga; Sarıtaş, Emine Ülkü; Güven, H. E. (Infinite Science Publishing, 2017)In magnetic particle imaging (MPI), system sensitivity can be enhanced by scanning the sample along a field free line (FFL) instead of a field free point (FFP). FFL MPI data can then be processed via system-matrix or ... -
Compressed multi-contrast magnetic resonance image reconstruction using Augmented Lagrangian Method
Güngör, A.; Kopanoğlu, E.; Çukur, Tolga; Güven, H. E. (IEEE, 2016)In this paper, a Multi-Channel/Multi-Contrast image reconstruction algorithm is proposed. The method, which is based on the Augmented Lagrangian Method uses joint convex objective functions to utilize the mutual information ... -
Constrained ellipse fitting for efficient parameter mapping with phase-cycled bSSFP MRI
Keskin, K.; Yılmaz, Uğur; Çukur, Tolga (IEEE, 2021-08-05)Balanced steady-state free precession (bSSFP) imaging enables high scan efficiency in MRI, but differs from conventional sequences in terms of elevated sensitivity to main field inhomogeneity and nonstandard T2/T1 -weighted ... -
Cortical networks of dynamic scene category representation in the human brain
Keleş, Ümit; Kiremitçi, İbrahim; Gallant, J. L.; Çukur, Tolga; Çelik, Emin (Elsevier, 2021-07-24)Humans have an impressive ability to rapidly process global information in natural scenes to infer their category. Yet, it remains unclear whether and how scene categories observed dynamically in the natural world are ... -
Çoklu kontrast MRG’de çoklu görüntü geriçatımı
Özbey, Muzaffer; Çukur, Tolga (IEEE, 2021-07-19)Çoklu kontrastlı manyetik rezonans görüntülerinin (MRG) edinimi, tanı bilgi birikimini artırarak klinik tanıda önemli bir role sahiptir. Hastanın hareketsiz kalması gereken uzun tetkik süreleri, çoklu kontrast MRG ... -
Çoklu kontrast MRG’de tranfer öğrenme yöntemi ile birleşik geriçatım-sentez
Kaftan, İrem; Gevrek, Özgür Bora; Çukur, Tolga (IEEE, 2021-07-19)Manyetik rezonans görüntüleme (MRG) birçok hastalığın tanısında kullanılan müdahalesiz ve yumuşak doku kontrastı yüksek olan bir görüntüleme yöntemidir. MR sinyali görüntülenen dokunun yapısına göre değişkenlik gösterdiği ... -
Deep MRI reconstruction with generative vision transformer
Korkmaz, Yılmaz; Yurt, Mahmut; Dar, Salman Ul Hassan; Özbey, Muzaffer; Çukur, Tolga (Springer, 2021)Supervised training of deep network models for MRI reconstruction requires access to large databases of fully-sampled MRI acquisitions. To alleviate dependency on costly databases, unsupervised learning strategies have ... -
Digital computation of fractional Fourier and linear canonical transforms and sparse image representation
Koc, A.; Özaktaş, Haldun M.; Bartan, B.; Gundogdu, E.; Çukur, Tolga (IEEE, 2018)Fast and accurate digital computation of the fractional Fourier transform (FRT) and linear canonical transforms (LCT) are of utmost importance in order to deploy them in real world applications and systems. The algorithms ... -
Diyalog tabanlı metinlerde konu değişimi tespiti
Şenel, Lütfi Kerem; Yücesoy, Veysel; Koҫ, A.; Çukur, Tolga (IEEE, 2019-04)Son dönemde katlanarak gelişen haberleşme yöntemleri (internet, sosyal medya, akıllı telefon, vb.) sayesinde veriye ulaşmak ve paylaşmak kolaylaşmıştır. Özellikle son yıllarda sözlü ve yazılı paylaşım mecraları hızlı gelişim ... -
Enhanced phase-sensitive SSFP reconstruction for fat-water separation in phased-array acquisitions
Yılmaz, Özgür; Sarıtaş, Emine Ülkü; Çukur, Tolga (John Wiley and Sons Inc., 2016)Purpose: To propose and assess a method to improve the reliability of phase-sensitive fat–water separation for phased-array balanced steady-state free precession (bSSFP) acquisitions. Phase-sensitive steady-state free ... -
Factorized sensitivity estimation for artifact suppression in phase‐cycled bSSFP MRI
Bıyık, Erdem; Keskin, Kübra; Dar, Salman Ul Hassan; Koç, Aykut; Çukur, Tolga (Wiley, 2020)Objective: Balanced steady‐state free precession (bSSFP) imaging suffers from banding artifacts in the presence of magnetic field inhomogeneity. The purpose of this study is to identify an efficient strategy to reconstruct ... -
Fast system calibration with coded calibration scenes for magnetic particle imaging
İlbey, Serhat; Top, C. B.; Güngör, Alper; Çukur, Tolga; Sarıtaş, Emine Ülkü; Güven, H. Emre (IEEE, 2019)Magnetic particle imaging (MPI) is a relatively new medical imaging modality, which detects the nonlinear response of magnetic nanoparticles (MNPs) that are exposed to external magnetic fields. The system matrix (SM) method ... -
Faz döngülü bSSFP görüntülemede T1 ve T2 haritalamaya parametre tahmini yaklaşımı
Keskin, Kübra; Çukur, Tolga (IEEE, 2018)Faz döngülü dengeli kararlı-durum serbest devinim (bSSFP) sinyali eliptik sinyal modeline sahip olduğundan, T1 ve T2 relaksasyon zamanları tek bir faz döngülü bSSFP sekansından tahmin edilebilmektedir. Modelin parametreleri ...