SNR and total acquisition time analysis of multi-echo FLASH pulse sequence for current density imaging

Sadighi, Mehdi
Şişman, Mert
Eyüboğlu, Behçet Murat
Magnetic Resonance Current Density Imaging (MRCDI) is an imaging modality providing cross-sectionalcurrent densityðJ Þinformation inside the body. The clinical applicability of MRCDI is highly dependenton the sensitivity of the acquired noisy current-induced magnetic flux densityðB zÞdistributions.Here, a novel analysis is developed to investigate the combined effect of relevant parameters of the RFspoiled gradient echo (FLASH) pulse sequence on the SNR level and the total acquisition time (TAT) of theacquiredB zimages. The proposed analysis then is expanded for a multi-echo FLASH (ME-FLASH) pulsesequence to take advantage of combining the multiple echoes to achieveB combzdistribution with a higherSNR than the one achievable with a single echo acquisition.The optimized sequence parameters to acquire aB zdistribution with the highest possible SNR for agiven acquisition time or the desired SNR in the shortest scan time are estimated using the proposedanalysis. The analysis also provides different sets of sequence parameters to acquireB zdistributions withthe same SNR at almost the same TAT. Furthermore, the effects of intensive utilization of the gradientsand the magnetohydrodynamic (MHD) flow velocity on the acquiredB zdistribution in MRCDI experi-ments is investigated.The analytical results of the proposed analysis are validated experimentally using an imaging phantomhaving the conductivity and the relaxation parameters of the brain white matter tissue.
Journal Of Magnetic Resonance


Realization of magnetic resonance current density imaging at 3 Tesla,
Göksu, Cihan; SADIGHI, MEHDI; Eyüboğlu, Behçet Murat (2014-08-26)
Magnetic Resonance Current Density Imaging (MRCDI) is an imaging modality, which reconstructs electrical current density distribution inside a material by using Magnetic Resonance Imaging (MRI) techniques. In this study, a current source with maximum current injection capability of 224.7mA, under 1k Omega resistive load is used. Experiments are performed with a 2D uniform phantom, in which a current steering insulator is inserted. Magnetic flux density distributions are measured, and current density images ...
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...
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...
Magnetic Resonance - Electrical Impedance Tomography (MR-EIT) Research at METU
Eyüboğlu, Behçet Murat (2006-09-01)
Following development of magnetic resonance current density imaging (MRCDI), magnetic resonance - electrical impedance tomography (MR-EIT) has emerged as a promising approach to produce high resolution conductivity images. Electric current applied to a conductor results in a potential field and a magnetic flux density distribution. Using a magnetic resonance imaging (MRI) system, the magnetic flux density distribution can be reconstructed as in MRCDI. The flux density is related to the current density distr...
Electrical impedance tomography using the magnetic field generated by injected currents
Birgul, O; Ider, YZ (1996-11-03)
In 2D EIT imaging, the internal distribution of the injected currents generate a magnetic field in the imaging region which can be measured by magnetic resonance imaging techniques. This magnetic field is perpendicular to the imaging region on the imaging region and it can be used in reconstructing the conductivity distribution inside the imaging region. For this purpose, internal current distribution is found using the finite element method. The magnetic fields due to this current is found using Biot-Savar...
Citation Formats
M. Sadighi, M. Şişman, and B. M. Eyüboğlu, “SNR and total acquisition time analysis of multi-echo FLASH pulse sequence for current density imaging,” Journal Of Magnetic Resonance, vol. 333, no. 12, pp. 1–15, 2021, Accessed: 00, 2021. [Online]. Available: