background: the purpose of this study is to demonstrate the advantages of gradient echo (gre) sequences in the detection and characterization of cerebral venous sinus thrombosis compared to conventional magnetic resonance sequences. methods: a total of 17 patients with cerebral venous thrombosis (cvt) were evaluated using different magnetic resonance imaging (mri) sequences. the mri sequences i...

background:  nowadays mri examinations have been widely used in clinical applications for many diagnoses. the use of contrast agent in mri improves lesion detection and characterization and causes more accurate diagnosis.  objectives: the aim of this study was comparing to optimal dose of magnevist contrast agent in modified t1w se (spin echo), t1w fse (fast spin echo) and t1w gre (gradient ech...

The basic idea of parallel imaging is to reduce the number of acquisition steps (i.e. phase-encoding steps) by decreasing the sampling density in kspace. Artefacts, in particular aliasing artefacts, that would result from the reduced sampling density are compensated by employing image data from several independent coil elements with different spatial sensitivity profi les for reconstruction. Th...

Many common magnetic resonance imaging sequences are classified either as spin echo or gradient echo techniques. Generally, a gradient echo occurs when spins are coherent regardless of their position within the sample. This occurs whenever the net gradient area since a previous echo is zero. In a spin echo, spins are coherent regardless of their resonance frequency [1]. Here we will focus on gr...

PURPOSE To compare the sensitivity of conventional spin-echo, fast spin-echo, fast fluid-attenuated inversion recovery (FLAIR), and turbo gradient spin-echo MR sequences in the detection of multiple sclerosis lesions. METHODS Conventional spin-echo, fast spin-echo, fast FLAIR, and turbo gradient spin-echo sequences were performed on a 1.0-T MR imager in seven patients with clinically definite...

PURPOSE To compare lesion enhancement after injection of gadopentetate dimeglumine on spin-echo and gradient-echo T1-weighted images. METHODS A total of 48 contrast-enhancing intracranial lesions were evaluated using a spin-echo and two gradient-echo T1-weighted pulse sequences. Percent contrast, contrast-to-noise, and signal-to-noise measurements were made on the spin-echo T1-weighted, three...

1 Introduction Rapid imaging sequences are characterized by a fast train of excitation and gradient pulses. Between excitation pulses or within TR, the magnetization is not able to return to its thermal equilibrium. As a consequence, excitation pulses will influence both the remaining transversal and the remaining longitudinal magnetization. The steady-state magnetization of a multi pulse exper...

Gradient-echo sequences are widely used in magnetic resonance imaging (MRI) for numerous applications ranging from angiography to perfusion to functional MRI. Compared with spin-echo techniques, the very short repetition times of gradient-echo methods enable very rapid 2D and 3D imaging, but also lead to complicated "steady states." Signal and contrast behavior can be described graphically and ...

Magnetic resonance imaging (MRI) based on gradient echoes is used in a wide variety of imaging techniques and clinical applications. Gradient echo sequences form the basis for an essential group of imaging methods that find widespread use in clinical practice, particularly when fast imaging is important, as for example in cardiac MRI or contrast-enhanced MR angiography. However, the term "gradi...