Contrast-enhanced magnetic resonance angiography (CE-MRA) was first introduced for clinical studies approximately 20 years ago. Early work provided 3-4 mm spatial resolution with acquisition times in the 30-second range. Since that time there has been continuing effort to provide improved spatial resolution with reduced acquisition time, allowing high resolution 3D time-resolved studies. The pu...

PURPOSE To quantify the effects of using the fovea to Bruch's membrane opening (FoBMO) axis as the nasal-temporal midline for 30° sectoral (clock-hour) spectral domain optical coherence tomography (SDOCT) optic nerve head (ONH) minimum rim width (MRW) and area (MRA) calculations. METHODS The internal limiting membrane and BMO were delineated within 24 radial ONH B-scans in 222 eyes of 222 par...

We present a notion of frame multiresolution analysis on the Heisenberg group, abbreviated by FMRA, and study its properties. Using the irreducible representations of this group, we shall define a sinc-type function which is our starting point for obtaining the scaling function. Further, we shall give a concrete example of a wavelet FMRA on the Heisenberg group which is analogous to the Shannon...

Methods for constructing finite Parseval frames by using Walsh matrices and the discrete Vilenkin–Chrestenson transform are described.

An effective method based upon Alpert multiwavelets is proposed for the solution of Hallen’s integral equation. The properties of Alpert multiwavelets are first given. These wavelets are utilized to reduce the solution of Hallen’s integral equation to the solution of sparse algebraic equations. In order to save memory requirement and computation time, a threshold procedure is applied to obtain ...

This paper analyses performance of multiwavelets a variant of wavelet transform on compression of medical images. To do so, two processes namely, transformation for decorrelation and encoding are done. In transformation stage medical images are subjected to multiwavelet transform using multiwavelets such as GeronimoHardin-Massopust, Chui Lian, Cardinal 2 Balanced (Cardbal2) and orthogonal symme...

Orthogonal, semiorthogonal and biorthogonal wavelet bases are special cases of oblique multiwavelet bases. One of the advantage of oblique multiwavelets is the flexibility they provide for constructing bases with certain desired shapes and/or properties. The decomposition of a signal in terms of oblique wavelet bases is still a perfect reconstruction filter bank. In this paper, we present sever...

Two-direction multiscaling functions φ and two-direction multiwaveletsψ associated with φ are more general and more flexible setting than one-direction multiscaling functions and multiwavelets. In this paper, we investigate how to find and normalize point values and those of derivatives of the two-direction multiscaling functions φ and multiwavelets ψ. For finding point values, we investigate t...

A wavelet with composite dilations is a function generating an orthonormal basis or a Parseval frame for L2(Rn) under the action of lattice translations and dilations by products of elements drawn from non-commuting matrix sets A and B. Typically, the members of B are shear matrices (all eigenvalues are one) while the members of A are matrices expanding or contracting on a proper subspace of Rn...