Principles and concepts of gradient echo (GRE) imaging are the basis of many applications on modern MR-systems. The most obvious difference between Spin Echo and GRE imaging is related to the pulse sequence elements that are used to generate an MR signal (see figure 1). While two rf-pulses (90 and 180) are used for spin refocusing and spin echo generation, GRE imaging is based on only a single ...

One of the most frequently used methods in the speech disfluence therapy is the one based on the acoustical echo. A patient, who is a subject to therapy, hears his own voice with some delay and, thanks to that, his speech fluency increases. As it turned out a therapeutic effect can also be achieved by feedback of the speech with other human senses, such as touch or sight. The article presents a...

The exact relationship between ultrasonograms and histological findings of the pancreas was investigated in 24 postmortem materials consisting of II cases of normal pancreas, 9 of pancreatic tumor and 4 of chronic pancreatitis, Normal pancreas showed a smooth contour and a homogeneous echo pattern with uniform echo intensity which was 10 dB higher than that of the normal liver. Pancreatic tumor...

Echo is defined as the delayed and attenuated version of the original signal produced by some device, such as a loudspeaker. As a consequence a person listens to a delayed replica of its own voice signal. This is an undesired effect that appears whenever the output signal is fed back into the system’s input and it can be quite disturbing on voice conversations. Echo arises in long distance comm...

An asymmetric spin echo (aSE) technique was developed to produce uniform, robust fat-water separation in mice at 7T using Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-squares estimation method (IDEAL). The aSE technique had superior image quality as compared to gradient echo IDEAL estimation. Both the spin echo and gradient echo IDEAL techniques resulted in more accura...

BACKGROUND AND PURPOSE 3D turbo field echo with diffusion-sensitized driven-equilibrium preparation is a non-echo-planar technique for DWI, which enables high-resolution DWI without field inhomogeneity-related image distortion. The purpose of this study was to evaluate the feasibility of diffusion-sensitized driven-equilibrium turbo field echo in evaluating diffusivity in the normal pituitary g...

BACKGROUND AND PURPOSE Spontaneous echo contrast in cardiac chamber has been indicated as a source of cerebral embolism. The nature of the echocardiographic smokelike signal is still not fully understood. This study was designed to regenerate spontaneous echo contrast and verify its thromboembolic characters in an in vitro model. METHODS Spontaneous echo contrast was reproduced in an expansio...

With the advent of packetized audio transmission, such as voice over IP (VoIP), and Voice over WLAN (VoWLAN), echo cancellation has put forth many challenging requirements. When an adaptive filter echo cancellation algorithm is used, its performance can be greatly increased, and its complexity can be reduced if it is only applied to the active regions in which echo exists. The proposed scheme e...