Many athletic activities involve extreme spinal stress, but few involve such extreme forms of spinal mobility as that of circus contortionists. In this study, five female contortionists from a Mongolian circus school, between 20 and 49 years of age, were examined using a 3T cylindrical MR imaging system (Philips Achieva) to assess pathological changes that might be associated with the contortio...

Background Fetal cardiovascular MRI has been hampered by the lack of a reliable cardiac gating signal. A recently proposed solution to this problem is metric optimized gating (MOG) [1-3]. Here, we demonstrate the ability of MOG to acquire images of the fetal myocardium without conventional cardiac gating. Our work is motivated by the need for high-resolution dynamic imaging in the assessment of...

Oxygen causes an increase in the longitudinal relaxation rate of tissues through its T1-shortening effect owing to its paramagnetic properties. Due to such effects, MRI has been used to study oxygen-related signal intensity changes in various body parts including cerebrospinal fluid (CSF) space. Oxygen enhancement of CSF has been mainly studied using MRI sequences with relatively longer time re...

Fig 2. Three orthogonal slices from a time frame corresponding to the production of /s/ in /asa/ using sequence i8. (a) Midsagittal slice. Lines indicate slice locations corresponding to coronal (b) and axial (c) images. Arrows in (b) and (c) point out a critical feature of tongue shaping: the formation of a tongue groove. Towards Dynamic 3D MRI of Speech Yinghua Zhu, Yoon-Chul Kim, Michael Pro...

The purpose of this research is to perform automated analysis of 4D dynamic contrast enhanced MRI datasets (DCE-MRI) of the hand and wrist relating to rheumatoid arthritis (RA) studies. In DCE-MRI, sequences of images are acquired from the joints over time, during which a contrast agent pre-injected into a patient enhances disease affected tissues. Measurement of this enhancement, which is spec...

Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Vari...

INTRODUCTION: The reconstruction of sensitivity–encoded non–Cartesian undersampled MRI has been facilitated by the use of iterative techniques [1]. However, the ill-conditioning of the associated inverse problem produces residual aliasing and noise amplification. A proven approach to stabilize the reconstruction and to diminish these effects is the use of explicit regularization methods [2-3], ...

Introduction: Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) is a valuable tool used in a number of clinical applications. However, imaging of time-varying objects is a challenging task when both high spatial resolution and high temporal resolution is desired. It has been demonstrated that radial imaging techniques can yield increased temporal resolution without sacrificing sp...

i Populärvetenskaplig sammanfatting iii

OBJECTIVES Photodynamic therapy is a new focal therapy for prostate cancer. METHODS In this technique, a photosensitising agent is introduced intravenously, then activated by local laser illumination to induce tumour necrosis. Treatment efficacy is assessed by magnetic resonance imaging (MRI). RESULTS AND CONCLUSIONS We illustrate specific post-treatment MRI aspects at early and late follow...