The inversion of electron density from total electron content (TEC) measurements of GPS radio occultation is investigated by means of simulated data from the International Reference Ionosphere IRI-2001 and observations by the GPS/MET satellite experiment. In both cases a meridional slice of electron density is derived for northern summer solstice June/July 1995 from the midnight to the noon sec...

Background The border zone of myocardial scar after myocardial infarction (MI) plays an important role for arrhythmia formation. For this reason, high-resolution 3D information of scar tissue for planning of electrophysiological interventions after MI is highly desirable. This study evaluates sharpness of the borders (SB) of scar after MI by a self-navigated isotropic 3D free-breathing wholehea...

Background Small-Animal Look-Locker Inversion Recovery (SALLI) is a novel imaging method that generates simultaneously cardiac T1 maps, cine MR and inversion recovery-prepared images for high heart rates. T1 mapping by SALLI has been tested and compared with histology, however the assessment of left ventricular (LV) function has not yet been validated. Our aim was to compare the measurement of ...

Background Myocardial T1 mapping at 1.5T and 3T distinguishes powerfully between normal and diseased tissue with focal and diffuse pathology. We recently reported the first human myocardial T1s at 7T using the ShMOLLI +IE inversion recovery sequence. Yet even using a unique 7T scanner with 16kW RF output, perfect magnetization inversion was impossible. We now introduce a saturation recovery met...

Introduction: Multiple acquisitions along the longitudinal magnetization curve as done with the Look-Locker (LL) technique perturbs the inversion recovery curve. The b-SSFP sequence perturbs magnetization minimally compared to other sequences [1]. However, when inversion recovery is incomplete (if TRseq<5T1max) or the flip angle is relatively large (>10° for GM/WM/CSF mapping), a three paramete...

Following administration of Gd-DTPA, infarcted myocardium exhibits delayed enhancement and can be imaged using an inversion-recovery sequence. A conventional segmented acquisition requires a number of breath-holds to image the heart. Single-shot phase-sensitive inversion-recovery (PSIR) true-FISP may be combined with parallel imaging using SENSE to achieve high spatial resolution. SNR may be im...

Background Quantitative myocardial T1 mapping provides in-vivo tissue characterization for assessment of cardiomyopathies. Pre and post-contrast T1 maps can be used to calculate the extracellular volume fraction (ECV) to detect diffuse myocardial fibrosis. Several imaging approaches have recently been proposed for measuring T1 values [1-4], but no head-to-head comparison has been reported to cr...

This paper proposes a bit error recovery method for Internet facsimile images compressed with Group 3, Extended 2 Dimensional MMR coding scheme. When an error occurs in an MMR coded bitstream, the bitstream cannot be correctly decoded after the error point. To prevent losing valid information after an error, we developed an error recovery system that detects bit errors and applies bit-inversion...