Low-field magnetic resonance imaging using multiplicative regularization

In this paper we present a magnetic resonance imaging (MRI) technique that is based on multiplicative regularization. Instead of adding a regularizing objective function to a data fidelity term, we multiply by such a regularizing function. By following this approach, no regularization parameter needs to be determined for each new data set...

Inversion of incomplete spectral data using support information with an application to magnetic resonance imaging

In this paper we discuss an imaging method when the object has known support and its spatial Fourier transform is only known on a certain k-space undersampled pattern. The simple conjugate gradient least squares algorithm applied to the corresponding truncated Fourier transform equation produces reconstructions that are basically of a similar...

Shadow-free motorized capsule enables accurate beam positioning and sectorized OCT imaging of the esophagus

In this study, we demonstrate a 12x36 mm motorized capsule for OCT imaging of the esophagus. The capsule produces unobstructed images by using a distal reflector design, thus avoiding shadow caused by the motor wires. The motor synchronous control enables three working modes: circumferential imaging, angular sector imaging and accurate beam...

Conjugate gradient variants for ℓ _p -regularized image reconstruction in low-field MRI

We consider the MRI physics in a low-field MRI scanner, in which permanent magnets are used to generate a magnetic field in the millitesla range. A model describing the relationship between measured signal and image is derived, resulting in an ill-posed inverse problem. In order to solve it, a regularization penalty is added to the least...

Workshop on reconstruction schemes for magnetic resonance data: Summary of findings and recommendations

The high-fidelity reconstruction of compressed and lowresolution magnetic resonance (MR) data is essential for simultaneously improving patient care, accuracy in diagnosis and quality in clinical research. Sponsored by the Royal Society through the Newton Mobility Grant Scheme, we held a halfday workshop on reconstruction schemes for MR data...

Image Reconstuction in MRI: The Possibilities of Portable Low-cost MRI Scanners

Hydrocephalus is one of the most common abnormalities affecting the nervous system of children around the globe. Especially in developing countries hydrocephalus is a large problem. It is often left untreated resulting in suffering, brain damage, developmental delays and ultimately death. This makes an early detection more opportune than ever....