A new simple iterative reconstruction algorithm for SPECT transmission measurement

Abstract

This paper proposes a new iterative reconstruction algorithm for transmission tomography and compares this algorithm with several other methods. The new algorithm is simple and resembles the emission ML-EM algorithm in form. Due to its simplicity, it is easy to implement and fast to compute a new update at each iteration. The algorithm also always guarantees non-negative solutions. Evaluations are performed using simulation studies and real phantom data. Comparisons with other algorithms such as convex, gradient, and logMLEM show that the proposed algorithm is as good as others and performs better in some cases.

Pretreatment 18F-FAZA PET Predicts Success of Hypoxia-Directed Radiochemotherapy Using Tirapazamine

“…The microPET uses OSEM for iterative image reconstruction instead of RAMLA on the MOSAIC scanner (42). However, both algorithms have similar performance characteristics (43). To further minimize potential effects on the measurements of the T/B ratio, all images obtained from the microPET were reconstructed (as on the MOSAIC scanner) without attenuation or scatter correction, and the data analyses were performed in the same way.…”

Attenuation map estimation with SPECT emission data only

“…Holding x at its current value, the attenuation map μ is then updated with an ML-EM-like algorithm (Hwang and Zeng, 2005): $${\mu }_i^{\text{italicnew}}=\frac{{\mu }_i^{\text{italicold}}}{{\displaystyle {\sum }_j{a}_{\text{italicij}}}}{\displaystyle \sum _j{a}_{\text{italicij}}}\frac{{\displaystyle {\sum }_k{a}_{\text{italickj}}}{x}_k^{\text{italicnew}}}{p_j}$$ where μ i is the estimated attenuation map pixel i , and the x new is the estimated image in the same iteration from equation (4). a ij is the known coefficient that represents the contribution of image pixel i to projection bin j with the old attenuation map μ.…”

Calculated attenuation correction for awake small animal brain PET studies

“…Previous studies have demonstrated the importance of at tenuation correction (AC) on the quantitative accuracy of the reconstructed images for both rats and mice in emission to mography [4,5]. Conventionally, AC is performed using either a transmission (TX) or a computed tomography scan.…”