Abstract
Objective:Application of distinct positron emission tomography (PET) scan reconstruction algorithms can lead to statistically significant differences in measuring lesion functional properties. We looked at the influence of two-dimensional filtered back projection (2D FBP), two-dimensional ordered subset expectation maximization (2D OSEM), three-dimensional ordered subset expectation maximization (3D OSEM) without 3D maximum a posteriori and with (3D OSEM MAP) on lesion hypoxia tracer uptake using a pre-clinical PET scanner.Methods:Reconstructed images of a rodent tumor model bearing P22 carcinosarcoma injected with hypoxia tracer Copper-64-Diacetyl-bis (N4-methylthiosemicarbazone) (i.e. Cu-64 ATSM) were analyzed at 10 minute intervals till 60 minute post injection. Lesion maximum standardized uptake values (SUVmax) and SUVmax/background SUVmean (T/B) were recorded and investigated after application of multiple algorithm and reconstruction parameters to assess their influence on Cu-64 ATSM measurements and associated trends over time.Results:SUVmaxSUVmax or T/B between 2D FBP, exhibited convergence for OSEM reconstructions while ANOVA results showed a significant difference in SUVmax or T/B between 2D FBP, 2D OSEM, 3D OSEM and 3D OSEM MAP reconstructions across all time frames. SUVmax and T/B were greatest in magnitude for 2D OSEM followed by 3D OSEM MAP, 3D OSEM and then 2D FBP at all time frames respectively. Similarly SUVmax and T/B standard deviations (SD) were lowest for 2D OSEM in comparison with other algorithms.Conclusion:Significantly higher magnitude lesion SUVmax and T/B combined with lower SD were observed using 2D OSEM reconstruction in comparison with 2D FBP, 3D OSEM and 3D OSEM MAP algorithms at all time frames. Results are SUVmax or T/B between 2D FBP, consistent with other published studies however more specimens are required for full validation.
Highlights
Tumors can often grow rapidly outstripping the blood supply they depend upon leaving regions with low oxygenation
We present the effects of applying different image reconstruction algorithms to scans acquired from a rat tumor model at 10 min intervals upto an hour post injection of Cu-64 ATSM with a commercial pre-clinical Positron emission tomography (PET) scanner
Individual reconstruction algorithm’s mean taban SUVortalama (T/B) was greatest in magnitude for 2D OSEM followed by 3D maksimum a posteriori olmaksızın (3D OSEM) MAP, 3D OSEM and 2D FBP, Figure 6
Summary
Tumors can often grow rapidly outstripping the blood supply they depend upon leaving regions with low oxygenation. Known as hypoxia [1], this phenomenon can reduce the efficacy of treatment regimens e.g. chemotherapy and radiotherapy due to diminished blood supply typical of malignant lesions [2]. The most common of these is F-18 attached to a glucose analogue F-18 fluorodeoxyglucose (FDG) to image glucose metabolism as many cancer cells exhibit enhanced glycolysis [6]. In this context, small bore animal PET scanners offer advantages of accurate quantitative scanning in oncological [7,8] imaging applications leading to greater understanding of functional processes prior to potential translation to the clinic
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
