FastSPECT II is a SPECT imaging system developed at CGRI for small-animal imaging. It consists of sixteen stationary (i.e., non-moving) modular gamma-ray cameras. Each camera has an input face measuring about 120×120 mm^2.  GPU code was developed to speed up the pre-processing of the acquired data and the actual reconstruction via the expectation maximization maximum likelihood (MLEM) algorithm. Pre-processing of the data consisted in 2D maximum likelihood estimation of position of interaction for each detected gamma-ray photon.

The one-page highlight can be download here.

The manual for this toolkit can be downloaded here.

For further details and to obtain the FastSPECT II Image Reconstruction Toolbox, please contact Luca Caucci at


FastSPECT II: A Second Generation High-Resolution Dynamic SPECT Imager, Lars R. Furenlid, Donald W Wilson, Yi-chun Chen, Hyunki Kim, Philip J. Pietraski, Michael J. Crawford, Harrison H. Barrett, IEEE Trans Nucl Science, 51(3): 631-635, 2004.

Maximum-likelihood estimation with a contracting-grid search algorithm, J. Y. Hesterman, L. Caucci, M. A. Kupinski, H. H. Barrett, and L. R. Furenlid, IEEE Trans. Nucl. Sci., 57(3):1077-1084, 2010.  PMC293245.