Most clinical magnetic resonance systems do not have access to ultrashort echo time (UTE) imaging. The aim of this project was to develop a fully independent imaging insert for clinical MR systems to provide this new research application without disturbing routine operation. The initial clinical target for the system was improved orthopedic upper limb imaging using ultrashort repeat and echo ti...

PURPOSE To assess the ability of postmortem radiography and magnetic resonance (MR) imaging to depict occult cervical spine injuries as compared with anatomic and pathologic findings. MATERIALS AND METHODS The cervical spines of 10 adult accident victims underwent radiography and MR imaging, with T1-weighted, fast spin-echo T2-weighted, and four gradient-echo pulse sequences. The frozen speci...

Breast magnetic resonance imaging (MRI) demands the competing factors of high spatial resolution, good temporal resolution, high signal-to-noise ratios, and complete bilateral breast coverage. Achieving these competing factors requires modern MRI equipment with high magnetic field strength and homogeneity, high maximum gradient strength with short rise times, dedicated multichannel bilateral br...

Introduction. Non-balanced steady-state free precession sequences (SSFP-FID and SSFP-echo) are gradient-spoiled pulse sequences that provide high signal even in presence of long T1 values, because the transverse magnetization is not completely incoherent by means of radiofrequency spoiling. Contrary to balanced SSFP sequences they do not suffer from off-resonance banding artifacts, making them ...

PURPOSE: Sodium (Na) MRI offers direct information on the glycosaminoglycan concentration in cartilage. In vivo Na-MRI, however, is very challenging because of low Na sensitivity, low tissue concentration, and short biexponential transverse relaxation times (T2). Sequences capable of maximizing signal-to-noise ratio (SNR) are therefore highly desirable. Many groups addressed this issue by devel...

This manuscript examines the origins and nature of the function-derived activation detected by magnetic resonance imaging at ultrahigh fields using different encoding methods. A series of preclinical high field (7 T) and ultra-high field (17.2 T) fMRI experiments were performed using gradient echo EPI, spin echo EPI and spatio-temporally encoded (SPEN) strategies. The dependencies of the fMRI s...

ture to monitoring intravascular contrast agents or consent) , respectively, that have been acquired in the abvisualizing brain function. In particular, gradient-echo MRI sence and presence of macroscopic magnetic field gradients. sequences sensitized to alterations of cerebral blood oxygenThe images were obtained at 2.0 T (Siemens Magnetom ation (CBO) have resulted in exciting new tools for hi...

T2* weighted 3D Gradient Echo (GRE) acquisition is the main sequence used for Susceptibility Weighted Imaging (SWI) and Quantitative Susceptibility Mapping (QSM). These applications require a long echo time (TE) to build up phase contrast, requiring a long repetition time (TR), and leading to excessively lengthy scans. The long TE acquisition creates a significant amount of unused time within e...

Seven intraparenchymal hematomas (four venous and three arterial) were placed in the brains of six dogs in order to study the MR appearance of acute hemorrhage and to evaluate the effects of several variables on the signal intensity of the hematoma. MR imaging at 0.6 and 1.5 T was performed by using standard short and long TR spin-echo and low-flip-angle gradient-echo sequences. Sequential exam...

For more than a decade, turbo spin echo (TSE) pulse sequences have been suggested as an alternative to echo planar imaging (EPI) sequences for fMRI studies. Recent development in parallel imaging has renewed the interest in developing more robust TSE sequences for fMRI. In this study, a modified half Fourier acquisition single-shot TSE (mHASTE) sequence has been developed with a three-fold GRAP...