PURPOSE To describe SequenceTree, an open source, integrated software environment for implementing MRI pulse sequences and, ideally, exporting them to actual MRI scanners. The software is a user-friendly alternative to vendor-supplied pulse sequence design and editing tools and is suited for programmers and nonprogrammers alike. METHODS The integrated user interface was programmed using the Q...

The operation of a single-shot cross-correlator based on a pulse replicator is described. The correlator uses a discrete sequence of sampling pulses that are nonlinearly mixed with the pulse under test. The combination of a high reflector and partial reflector replicates an optical pulse by multiple internal reflections and generates a sequence of spatially displaced and temporally delayed samp...

Some new symmetry theorems are presented which simplify the task of designing multiple-pulse radio-frequency pulse sequences in magic-angle-spinning solid-state NMR. The symmetry theorems apply to sequences denoted R N, which n consists of N repetitions of a pulse sequence element R, alternating in phase between the values "pnrN. Each R element ideally rotates the spins by an angle p about the ...

Abstract. A novel type of efficient broadband pulse, called second-order phase dispersion by optimised rotation (SORDOR), has recently been introduced. In contrast to adiabatic excitation, SORDOR-90 pulses provide effective transverse 90? rotations throughout their bandwidth, with a quadratic offset dependence the in x,y plane. Together phase-matched SORDOR-180 pulses, this enables Böhlen–Boden...

A wavelet transform is introduced as a means of detecting the characteristic scale or period T of a radar pulse sequence in an incoming stream of pulses. A particular choice of mother wavelet contains a fixed number, M , of cycles of a complex exponential, which provides a resolution of 1=M times T . The transform operates on interleaved pulse sequences and, by thresholding, determines T for ea...

PURPOSE To develop a robust technique for detecting blood oxygenation level-dependent (BOLD) contrast in the human breast and to evaluate the signal in healthy and malignant breast. MATERIALS AND METHODS The design of this study focused on determining the optimal pulse sequence and stimulus for detecting BOLD contrast in the breast. For this study a single-shot fast spin echo (SSFSE) sequence...

Pulses of 100-fsec duration are obtained by synchronous pumping of a colliding-pulse ring dye laser with a mode-locked Ar(+)-ion laser. Stable operation of the synchronously pumped colliding-pulse mode-locked laser over hours was obtained by a suitable choice of the distance between the gain and the absorber in combination with an appropriate pump-pulse sequence.

Background First-pass perfusion imaging using cardiac magnetic resonance (CMR) has become clinically applicable as an important tool for diagnosing coronary artery disease. We have recently demonstrated that high quality firstpass images can be acquired with an optimized spiral pulse sequence, but this sequence is only capable of imaging 3 short axis slices of the heart for a maximum heart rate...