Purpose: Nonstationarity of CT noise presents a major challenge to the assessment of image quality. This work presents models for imaging performance in both filtered backprojection (FBP) and penalized likelihood (PL) reconstruction that describe not only the dependence on the imaging chain but also the dependence on the object as well as the nonstationary characteristics of the signal and nois...

Introduction: Vascular-space-occupancy (VASO) MRI (1) produces cerebral blood volume (CBV)-weighted images by employing inversion recovery to null the blood signal. Depending on the TR used, the residual magnetization in tissue, however, is only about 10-20% of the equilibrium signal intensity at the time of inversion (TI), which yields a relatively low signal-to-noise ratio (SNR). It has been ...

Introduction: First-pass perfusion MRI is a promising technique for detecting ischemic heart disease. However, the diagnostic value of the method is limited by the low spatial coverage, resolution, SNR, and cardiac motion related image artifacts. Parallel imaging methods have been applied in myocardial perfusion MRI, but the spatial coverage and SNR remain limited. Time-resolved data acquisitio...

Parallel imaging using sophisticated receiver coils has improved the clinical feasibility of magnetic resonance coronary angiography (MRCA). These techniques, however, are not readily available outside advanced imaging centers. Our custom-made 2-element phased array coil is readily and inexpensively assembled to address this limitation and enable the widespread application of MRCA. The 2-elemen...

Introduction: The outcome of automated quantitative morphometric population studies relies greatly on the quality of the cerebral anatomical images. For these applications, it is crucial that the images be uniform and have high spatial resolution, SNR (signal-to-noise ratio) and CNR (contrast-to-noise ratio) between brain tissues. This study evaluates the performance of three different T1-weigh...

Background Ultrahigh field cardiac MR (CMR) is an area of vigorous ongoing research and is regarded as one of the most challenging MRI applications since image quality is not always exclusively defined by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The progress in the field has been driven by pioneering explorations into hardware developments which focused on novel multichann...

Purpose: Multi-echo Dixon-based methods have recently gained attention for use in contrast-enhanced MR angiography (CE-MRA) due to their ability to suppress the high signal from fat while avoiding subtraction errors due to motion between preand post-contrast images in subtraction CE-MRA. Additionally, multi-echo Dixon CE-MRA provides improved signal-to-noise ratio (SNR) and contrast-to-noise ra...

Arteriosclerosis a widespread disease of the arteries. It is a kind of arteriosclerosis that causes coronary artery disease (CAD) in the form stenosis that is narrow downing of arteries. The X-ray angiography images suffer from background artefacts which obscure the visualization of the image to identify the stenosis. The artefacts must be eliminated to have an improved visualization of the blo...