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By modeling major degrading factors in SPECT imaging along with motion-compensated temporal denoising, 4D reconstruction is demonstrated to significantly improve the quality of reconstructed images in cardiac gated SPECT (GSPECT) at the standard dose level. The utility of 4D reconstruction for radiation dose reduction in GSPECT has not been studied despite increased concern in population based risk...
In this work we investigate the use of total variation (TV) regularization in the context of single photon emission computed tomography (SPECT), which is currently widely used for detection and evaluation of coronary artery diseases. Owing to its piecewise smoothing property, TV regularization is known to preserve discontinuities in the resulting images in inverse problems. Our goal is to study whether...
Recently we investigated the use of a Fourier harmonic model for determining the optical flow in a periodic image sequence, the goal of which was to exploit the temporal continuity and periodicity in the underlying motion field. In this work, we further develop this optical flow model by incorporating a spatially piecewise smoothness constraint (in the form of total variation) in order to better accommodate...
Recently we developed a periodic modeling approach for determining the optical flow in a periodic image sequence, which is demonstrated to be beneficial for noise reduction in motion-compensated 4D reconstruction of cardiac gated images. In this approach, a Fourier harmonic model is used to exploit the temporal continuity and periodicity of the motion field in the sequence. In this work, we further...
Recently we developed two image reconstruction approaches aimed to unify gated imaging and dynamic imaging in nuclear cardiac imaging, the goal being to obtain an image sequence from a single acquisition which shows both cardiac motion and tracer distribution change over the course of imaging. While both approaches exploit the similarity among the different cardiac gate intervals, they differ in the...
In image reconstruction gated acquisition is often used in order to deal with blur caused by organ motion in the resulting images. However, this is achieved almost inevitably at the expense of reduced signal-to-noise ratio in the acquired data. In this work, we propose a reconstruction procedure for gated images based upon use of discrete Fourier transform (DFT) basis functions, wherein the temporal...
Recently we developed an image reconstruction procedure aimed to unify gated imaging and dynamic imaging in nuclear cardiac imaging. It can yield a single image sequence to show simultaneously both cardiac motion and tracer distribution change over the course of imaging. In this work, we further develop and investigate the feasibility of our gated dynamic imaging procedure for perfusion defect detection...
Recently we proposed a reconstruction approach for gated cardiac images based on use of DFT basis functions, in which the temporal activity at each spatial location was regulated by a Fourier representation. In this work we further develop this approach in the context of single photon emission computed tomography (SPECT) which is often hampered by the increased noise due to gating. We will consider...
In cardiac imaging the data acquisition is often gated according to the ECG signal at the expense of signal to noise ratio in order to deal with cardiac motion. In this work, we propose a spatio-temporal reconstruction procedure by using a Fourier harmonic representation model for the temporal image activities. To further combat the increased imaging noise, we also include a spatial smoothing prior...
We propose a four-dimensional reconstruction method for noise reduction in gated cardiac SPECT images. Aiming to exploit the periodic nature of cardiac motion, we use a Fourier harmonic representation to model the image activities along the gated temporal dimension. We develop a penalized least-squares approach to reconstruct the different harmonics in the representation model, which also takes into...
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