Magnetohydrodynamic Flow Imaging Using Spin-Echo Pulse Sequence

Eroğlu, Hasan Hüseyin
Eyüboğlu, Behçet Murat
In this study, magnetohydrodynamic (MHD) flow of conductive liquids due to injection of electrical current during magnetic resonance imaging (MRI) is investigated. A spin-echo based MRI pulse sequence is proposed to image the MHD flow. Magnetic resonance (MR) phase effects of the MHD flow is related to the MRI pulse parameters and injected current. Average velocity distributions of the MHD flow are reconstructed using the MR phase images. The method is validated by numerical simulations. The reconstruction error is 29 % for 1 mA injected current with 20 ms duration when signal to noise ratio of the MHD phase measurements is 35. It is possible to obtain information about the MHD flow and determine viscosity inhomogeneities inside the imaged medium by using the MHD phase and velocity distributions. Design of a pulse sequence that generates an MHD flow with constant velocity at each data acquisition period may reduce the reconstruction error. By this way, the method may be utilized in imaging of liquid media, such as blood or cerebrospinal fluid surrounded by excitable tissue.
2019 27th Signal Processing and Communications Applications Conference (SIU)


RF Coil Design for MRI Applications in Inhomogeneous Main Magnetic Fields
Yılmaz, Ayşen; Eyueboglu, B. M. (2006-09-01)
Conventional Magnetic Resonance Imaging (MRI) techniques require homogeneous main magnetic fields. However, MRI applications that are executed in inhomogenous main magnetic fields have been developed in recent years. In this study, RF coil geometries are designed for MRI applications in inhomogeneous magnetic fields. Method of moments is used to obtain the current density distribution on a predefined surface that can produce a desired magnetic field, which is perpendicular to the given inhomogenous main mag...
Magnetic Resonance Imaging in Inhomogeneous Magnetic Fields with Noisy Signal
Arpinar, V. E.; Eyüboğlu, Behçet Murat (2008-11-27)
In this study, an image reconstruction algorithm for a Magnetic Resonance Imaging (MRI) system with inhomogeneous magnetic fields is proposed. The proposed reconstruction algorithm uses spatial distributions of main magnetic field, Radio Frequency (RF) and gradient fields as inputs, together with the pulse sequence and the noisy Magnetic Resonance (MR) signal. To calculate the noise signal, noise model for MRI with homogeneous fields is extended for inhomogeneous magnetic fields. Using this embedded noise m...
Induced Current Magnetic Resonance Electrical Impedance Tomography with z-Gradient Coil
Eroglu, Hasan H.; Eyuboglu, Murat (2014-08-30)
Magnetic Resonance Electrical Impedance Tomography (MREIT) is a medical imaging method that provides images of electrical conductivity at low frequencies (0-1 kHz). In MREIT, electrical current is applied to the body via surface electrodes and corresponding magnetic flux density is measured by means of Magnetic Resonance (MR) phase imaging techniques. By utilizing the magnetic flux density measurements and surface potential measurements images of true conductivity distribution can be reconstructed. In order...
Experimental and mathematical investigation of mass transfer in food andhydrogel systems using magnetic resonance imaging and NMR relaxometry
Çıkrıkcı, Sevil; Öztop, Halil Mecit; Department of Food Engineering (2019)
Nuclear magnetic resonance (NMR) and Magnetic Resonance Imaging (MRI) are well-known non-invasive characterization methods used in a wide range of areas; from medical to food applications. NMR experiments are conducted either through spectroscopy with high resolution systems or with relaxometery (Time Domain NMR) through mid or low field systems. Time domain NMR is primarily based on relaxation times and diffusion measurements from the signal coming from the whole sample while MRI enables to visualize the i...
Coil sensitivity map calculation using biot-savart law at 3 tesla and parallel imaging in MRI
Esin, Yunus Emre; Alpaslan, Ferda Nur; Department of Computer Engineering (2017)
Coil spatial sensitivity map is considered as one of the most valuable data used in parallel magnetic resonance imaging (MRI) reconstruction. In this study, a novel sensitivity map extraction method is introduced for phased-array coils. Proposed technique uses Biot-Savart law with coil shape information and low-resolution phase image data to form sensitivity maps. The performance of this method has been tested in the parallel image reconstruction task using sensitivity encoding technique. In MRI, coil sensi...
Citation Formats
H. H. Eroğlu, M. SADIGHI, and B. M. Eyüboğlu, “Magnetohydrodynamic Flow Imaging Using Spin-Echo Pulse Sequence,” presented at the 2019 27th Signal Processing and Communications Applications Conference (SIU), Sivas, Turkey, 2019, Accessed: 00, 2020. [Online]. Available: