Sathya Vijayakumar

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A novel technique called "k-t GRAPPA" is introduced for the acceleration of dynamic magnetic resonance imaging. Dynamic magnetic resonance images have significant signal correlations in k-space and time dimension. Hence, it is feasible to acquire only a reduced amount of data and recover the missing portion afterward. Generalized autocalibrating partially(More)
Partially parallel imaging (PPI) is a widely used technique in clinical applications. A limitation of this technique is the strong noise and artifact in the reconstructed images when high reduction factors are used. This work aims to increase the clinical applicability of PPI by improving its performance at high reduction factors. A new concept, image(More)
been widely adopted for treatment of atrial fibrillation (AF), recurrence rates remain unacceptably high with persistent and longstanding AF. As evidence emerges for non-PV substrate changes in the pathogenesis of AF, more extensive ablation strategies need further study. Methods: We modified our PV antrum isolation procedure to include abatement of(More)
PURPOSE To develop an arrhythmia-insensitive rapid (AIR) cardiac T1 mapping pulse sequence for quantification of diffuse fibrosis. METHODS An arrhythmia-insensitive cardiac T1 mapping pulse sequence was developed based on saturation recovery T1 weighting, which is inherently insensitive to heart rate and rhythm, and two single-shot balanced steady-state(More)
Generalized autocalibrating partially parallel acquisitions (GRAPPA), an important parallel imaging technique, can be easily applied to radial k-space data by segmenting the k-space. The previously reported radial GRAPPA method requires extra calibration data to determine the relative shift operators. In this work it is shown that pseudo-full k-space data(More)
OBJECTIVES The aim of this study was to assess acute ablation injuries seen on late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) immediately post-ablation (IPA) and the association with permanent scar 3 months post-ablation (3moPA). BACKGROUND Success rates for atrial fibrillation catheter ablation vary significantly, in part because of(More)
BACKGROUND Magnetic resonance imaging (MRI) allows visualization of location and extent of radiofrequency (RF) ablation lesion, myocardial scar formation, and real-time (RT) assessment of lesion formation. In this study, we report a novel 3-Tesla RT -RI based porcine RF ablation model and visualization of lesion formation in the atrium during RF energy(More)
In magnetic resonance imaging, multi-channel phased array coils enjoy a high signal to noise ratio (SNR) and better parallel imaging performance. But with the increase in number of channels, the reconstruction time and requirement for computer memory become inevitable problems. In this work, principle component analysis is applied to reduce the size of data(More)
The advent of partially parallel k-space data acquisition and reconstruction techniques has resulted in a drastic reduction in acquisition time. In this work, we have shown that the use of a new hybrid technique for reconstruction of partial k-space data can reduce acquisition time without loss of spatiotemporal resolution. The technique is termed hybrid(More)