BACKGROUND AND PURPOSE The pattern of edema caused by craniopharyngiomas and other common suprasellar masses could be useful for determining the differential diagnosis of lesions in this region. The purpose of this study was to ascertain whether the pattern of edema spread on MR images can be used in the diagnosis of craniopharyngiomas. METHODS The preoperative MR images in eight consecutive ...

We describe a combined nonlinear acoustic echo cancellation and residual echo suppression system. The echo canceler uses parallel Hammerstein branches consisting of fixed nonlinear basis functions and linear adaptive filters. The residual echo suppressor uses an Artificial Neural Network for modeling of the residual echo spectrum from spectral features computed from the far-end signal. We show ...

One hundred twenty-two consecutive patients (104 men; 18 women) were studied to determine the incidence and natural history of pericardial effusion occurring 2, 5, 10, and 20 to 50 days after cardiac surgery. Three patients had pericardial effusions before and 103 patients (91 men; three women) had effusions after surgery. Effusions were first recorded on the second postoperative day in 72 pati...

A short echo time (TE = 24 ms) semiadiabatic localization by adiabatic selective refocusing (LASER) sequence was designed and optimized for full-intensity proton magnetic resonance spectroscopy ((1) H MRS) at 4 T. The sequence was combined with VAPOR water suppression and three-dimensional outer volume suppression for improved localization and suppression of unwanted coherences. Artifact-free, ...

INTRODUCTION Susceptibility-induced magnetic field and chemical shift increase image distortion at high field. For a 2D fast spin echo (FSE) sequence used to obtain T2 contrast, the anatomy is distorted in the readout direction generating hypoand hyper-intense signals close to interfaces limiting the precision for morphological studies as well as generating an ambiguous contrast. Increasing the...

In spectroscopy, it is conventional to treat pulses much stronger than the linewidth as delta functions. In NMR, this assumption leads to the prediction that ! pulses do not refocus the dipolar coupling. However, NMR spin echo measurements in dipolar solids defy these conventional expectations when more than one ! pulse is used. Observed effects include a long tail in the CPMG echo train for sh...

BACKGROUND AND PURPOSE There is a paucity of literature that supports the Consortium of Multiple Sclerosis Centers guideline that proton density MR imaging is a core spinal cord sequence. We hypothesized that proton density fast spin-echo imaging is superior to T2 fast spin-echo MR imaging for the detection of cervical cord MS lesions. This study compared the detection rate and conspicuity of c...