BACKGROUND AND PURPOSE Early assignment of disease progression among patients with X-linked adrenoleukodystrophy (ALD) is critical for the appropriate selection of effective therapy. We evaluated the association between contrast enhancement on T1-weighted spin-echo MR images and disease progression. METHODS Clinical charts of patients with X-linked ALD were reviewed for age, availability of M...

A discrete-time analog echo canceller is described that reduces the echo in the front end of Gigabit Ethernet twisted-pair interfaces. Echo cancellation in the analog domain by means of four taps reduces the complexity of the digital echo canceller and crosstalk cancellers. Designed in a 0.4m CMOS technology, the circuit employs an LMS algorithm to adapt to the cable length and impedance discon...

BACKGROUND The present study sought to determine if echo-Doppler-derived pulmonary vascular resistance (PVR echo), net-atrioventricular compliance (Cn) and tricuspid peak systolic annular velocity (Sa), as parameters of right ventricular function, have value in predicting exercise capacity in patients with mitral stenosis (MS). METHODS AND RESULTS Thirty-two patients with moderate or severe M...

In this study, spin-echo and gradient-echo-based perfusion magnetic resonance imaging (MRI) techniques are systematically compared with respect to their application in the human brain. Six healthy subjects were evaluated with both techniques consecutively and injected twice with a gadolinium-based contrast agent. In accordance with theoretical predictions and with previous animal experiments, t...

In several cases (e.g., thermal noise, weather echoes, ...), the incoming signal to a radar receiver can be assumed to be Rayleigh distributed. When estimating the mean power from the inherently fluctuating Rayleigh signals, it is necessary to average either the echo power intensities or the echo logarithmic levels. Until now, it has been accepted that averaging the echo intensities provides sm...

The oral and parenteral infections of chimpanzees receiving echo Types 6 and 4 viruses successively are described. The two infections, spaced 2(1/2) months apart, and given by the same route in each animal, failed to induce overt disease. The inapparent infections were demonstrated by virus excretion in the throat and the stools and the development of neutralizing antibodies. Complement-fixing ...

Functional MRI studies on humans with BOLD contrast are increasingly performed at high static magnetic field in order to exploit the increased sensitivity. The downside of high-field fMRI using the gradient-echo echo-planar imaging (GE-EPI) method is that images are typically very strongly affected by image distortion and signal loss. It has been demonstrated at 1.5 T and 3 T that image artifac...

PURPOSE To examine the interaction of echo train length and interecho spacing and their effects on image quality and contrast in fast spin-echo sequences of the cervical spine. METHODS Forty-three patients with suspected cervical disk disease were prospectively evaluated with fast spin-echo with varying echo train lengths and interecho spacing. A flow phantom was used to confirm findings rela...

Echo canceller plays an important role in the full-duplex communication system. Conventional implementations of echo cancellers are often the adaptive transversal filter architectures due to the simplicity and robustness of stability and convergence. However, the conventional echo cancellers suffer from high cost problem especially when the response time of the echo is long. In this paper, a ne...

Earlier we proposed modeling echo residuals by using multiple echo models built from a set of speci c announcement. Experienced callers may interrupt the prompt by speaking the keywords over the prompt. This leads to incomplete prompt echoes that was not properly modeled by multiple echo models. In this study, we investigate further improvements by building an echo model of each word in the ent...