Noise properties of the inverse π-scheme exponential radon transform

Abstract

Because the effects of physical factors such as photon attenuation and spatial resolution are distance-dependent in single-photon emission computed tomography (SPECT), it has been widely assumed that accurate image reconstruction requires knowledge of the data function over 2(π) . In SPECT with uniform attenuation, Noo and Wagner recently showed that an accurate image can be reconstructed from knowledge of the data function over a contiguous (π) -segment. More generally, we proposed (π) -scheme SPECT that entails data acquisition over disjoint angular intervals without conjugate views, totaling to (π) radians, thereby allowing flexibility in choosing projection views at which the emitted gamma-rays may undergo the least attenuation and blurring. In this work, we study the general properties of the (π) -scheme inverse exponential Radon Transform, and discuss how to take advantage of the (π) -scheme flexibility to improve noise properties of short-scan SPECT.