Browsing by Keywords "MRI"
Now showing items 1-20 of 42
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A 600W on-coil Class-E RF power amplifier array with dynamic phase control for 3T MRI
(Bilkent University, 2022-09)Due to their size and cooling constraints, conventional Magnetic Resonance Imaging (MRI) places radio frequency (RF) amplifiers away from the scanner. These RF amplifiers have relatively low efficiency due to the matching ... -
Accelerating the co-simulation method for the design of transmit array coils for MRI
(Springer, 2020)Objective: Accelerating the co-simulation method for the design of transmit array (TxArray) coils is studied using equivalent circuit models. Materials and methods: Although the co-simulation method dramatically reduces ... -
Analysis of the electromagnetic field inside the gradient coils and investigation of the nerve and cardiac stimulation risk for the patients during MRI
(Bilkent University, 2008)During magnetic resonance imaging (MRI), the static magnetic field, the radio frequency field and the gradient fields are utilized. In the literature, there are several studies with the aim of understanding the bioeffects ... -
Assessment of liliequist membrane by 3D-SPACE technique at 3 T
(Springer, 2016)Introduction Liliequist membrane (LM) is the most important anatomic structure for the success of endoscopic third ventriculostomy (ETV). Identification of this membrane is difficult with conventional MRI techniques. ... -
Biofunctionalization of superparamagnetic iron oxide nanoparticles
(Bilkent University, 2011)Magnetic resonance imaging (MRI) has attracted intensive interest due to its non-invasive monitoring capacity. Gadolinium based contrast agents, most widely used CA, suffer from high level of toxicity and high threshold ... -
Cerebrovascular modelling for the management of aneurysm embolization using an intrasaccular flow diverter made by 3D printing
(Termedia Publishing House Ltd., 2022-10-15)Purpose: Using 3-dimensional (3D) printers, the creation of patient-specific models is possible before and after a therapeutic intervention. There are many articles about replicas for training and simulation of aneurysm ... -
Deep learning for accelerated 3D MRI
(Bilkent University, 2021-08)Magnetic resonance imaging (MRI) offers the flexibility to image a given anatomic volume under a multitude of tissue contrasts. Yet, scan time considerations put stringent limits on the quality and diversity of MRI data. The ... -
Deep unsupervised learning for accelerated MRI reconstruction
(Bilkent University, 2022-07)Supervised reconstruction models are characteristically trained on matched pairs of undersampled and fully-sampled data to capture an MRI prior, along with supervision regarding the imaging operator to enforce data ... -
Design and implementation of internal MRI coils using ultimate intrinsic
(Bilkent University, 2006)In this thesis, methods for optimization of internal magnetic resonance imaging coils have been developed. As a sample optimization endorectal coils were optimized. As the first step ultimate intrinsic signal-to-noise ... -
Design of a birdcage-like radio frequency transmit array coil for the magnetic resonance imaging using equivalent circuit model
(Bilkent University, 2016-05)One of the conditions to have a good magnetic resonance (MR) image is applying a homogeneous radio-frequency (RF) excitation (magnetic field) with effciently high intensity to the region of interest. However, there are ... -
Diffusion tensor imaging and T2 relaxometry of bilateral lumbar nerve roots: feasibility of in‐plane imaging
(Wiley, 2013)Lower back pain is a common problem frequently encountered without specific biomarkers that correlate well with an individual patient's pain generators. MRI quantification of diffusion and T2 relaxation properties may ... -
Driving mutually coupled gradient array coils in magnetic resonance imaging
(International Society for Magnetic Resonance in Medicine, 2019)Purpose In contrast to conventional linear gradients, gradient coil arrays with arbitrary spatial dependency might experience strong mutual coupling. Although conventional gradient power amplifiers with feedback loop might ... -
edaGAN: Encoder-Decoder Attention Generative Adversarial Networks for multi-contrast MR image synthesis
(Institute of Electrical and Electronics Engineers, 2022-05-16)Magnetic resonance imaging (MRI) is the preferred modality among radiologists in the clinic due to its superior depiction of tissue contrast. Its ability to capture different contrasts within an exam session allows it to ... -
Effects of psychosis-associated genetic markers on brain volumetry: A systematic review of replicated findings and an independent validation
(Cambridge University Press, 2022-09-28)Background. Given psychotic illnesses’ high heritability and associations with brain structure, numerous neuroimaging-genetics findings have been reported in the last two decades. However, few findings have been replicated. ... -
Endoluminal coils for interventional MRI procedures
(Bilkent University, 2010)In this study we designed endoluminal magnetic resonance imaging (MRI) coils to be used for interventional procedures under the guidance of MRI. The first coil we developed is a two-channel endocervical coil for the ... -
Exploiting lamina terminalis appearance and motion in prediction of hydrocephalus using convolutional LSTM network
(Elsevier Masson s.r.l., 2022-08-24)Background Evaluation of the lamina terminalis (LT) is crucial for non-invasive evaluation of the CSF diversion for the treatment of hydrocephalus. Together with deep learning algorithms, morphological and physiological ... -
Feasibility of 3-dimensional sampling perfection with application optimized contrast sequence in the evaluation of patients with hydrocephalus
(Lippincott Williams and Wilkins, 2015)Purpose This study aimed to investigate the effectiveness and additive value of T2W 3-dimensional sampling perfection with application optimized contrast (3D-SPACE) with variant flip-angle mode in imaging of all types of ... -
Feasibility of conductivity imaging using subject eddy currents induced by switching of MRI gradients
(John Wiley and Sons Inc., 2017)Purpose: To investigate the feasibility of low-frequency conductivity imaging based on measuring the magnetic field due to subject eddy currents induced by switching of MRI z-gradients. Methods: We developed a simulation ... -
Feasibility of freehand CT and 3-T MR guided brain aspiration biopsies with 18/20-gauge coaxial needles
(Springer, 2022-07)Background and purpose: An accurate histopathological examination with minimal neuronal damage is essential for optimizing treatment strategies of central nervous system lesions. We investigated the feasibility and safety ... -
Federated learning of generative ımage priors for MRI reconstruction
(Institute of Electrical and Electronics Engineers Inc., 2022-11-09)Multi-institutional efforts can facilitate training of deep MRI reconstruction models, albeit privacy risks arise during cross-site sharing of imaging data. Federated learning (FL) has recently been introduced to address ...
