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Objective: Attenuation has a significant influence on data and consequently on image quality. Attenuation correction corrects the weakening of the gamma photons in various depths. Non-diagnostic, low-dosage CT is usually used for attenuation correction when images are taken with a SPECT/CT. The purpose of the study was to determine the influence of attenuation correction in SPECT/CT on image quality in NEMA body phantom analysis in different background/sphere ratios.
Material and Methods: The NEMA IEC Body Phantom was filled with isotope technetium-99m (99mTc), with a different ratio between the phantom background and spheres. The images were reconstructed using filtered back projection (FBP), non-corrected iterative reconstruction (IR), and iterative reconstruction using computer tomography for attenuation correction (CT-AC). The average number of counts in the background and in all six spheres was measured. This was followed by a comparison of the contrast in images that were reconstructed using different methods.
Results: The average number of counts in sphere increased as we increased the activity concentration ratio between the background and sphere. Statistical analysis showed that contrast is significantly divergent between different methods of reconstruction.
Conclusion: The use of iterative reconstruction with CT-AC improves the contrast and image quality compared to iterative reconstruction and FBP.
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2. James A Patton, Timothy G Turkington. SPECT/CT Physical Principles and Attenuation Correction. J Nucl Med Technol 2008;36: 1–10. doi: 10.2967/jnmt.107.046839
3. Magdy M K Ed. Basic Sciences of Nuclear Medicine. London: Springer, 2011.
4. Dale L. Bailey, Anthony Parker J. Nuclear Medicine in clinical diagnosis and treatment. 3rd ed. Churchill Livingstone, 2004.
5. Mariani G, Flotats A, Israel O, Kim EE, Kim E.E, Kuwert T. Clinical Applications of SPECT/CT: New Hybrid Nuclear Medicine Imaging System. Wien: Nuclear Medicine Section International Atomic Energy Agency, 2008.
6. Grosser OS, Kupitz D, Ruf J, et al. Optimization of SPECT-CT Hybrid Imaging Using Iterative Image Reconstruction for Low-Dose CT: A Phantom Study. PLoS ONE 2015; 10(9). doi.org/10.1371/journal.pone.0138658
7. Suzuki A, Koshida K, Matsubara K. Effects of Pacemaker, Implantable Cardioverter Defibrillator, and Left Ventricular Leads on CT-Based Attenuation Correction. J Nucl Med Technol 2014; 42: 37–41. doi: 10.2967/jnmt.113.133736
8. Apostolopoulos D, Savvopoulos C. What is the benefit of CT-based attenuation correction in myocardial perfusion SPET?. Hell J Nucl Med 19 2016;(2):89-92. doi: 10.1967/s0024499100360
9. Yong-Soon P, Woo-Hyun K, Dong-Oh S, et al. A Study on the Change in Image Quality before and after an Attenuation Correction with the Use of a CT Image in a SPECT/CT Scan. Journal of the Korean Physical Society 2012; 61 (12): 2060-2067. doi:10.3938/jkps.61.2060
10. Sung WC, Yong JS, Jin EK, Jae SL, Dong SL. Evaluation of image quality using CT attenuation correction in SPECT/CT. J Nucl Med 2013;54(2). supplement 2 2621
11. Schulz V, Nickel I, Nömayr A, et al. Effect of CT-based attenuation correction on uptake ratios in skeletal SPECT. Nuklearmedizin 2007; 46(1):36-42. doi: 10.1055/s-0037-1616624
12. Malkerneker D, Brenner R, Martin WH, et al. CT-based attenuation correction versus prone imaging to decrease equivocal interpretations of rest/stressTc-99m tetrofosmin SPECT MPI. J Nucl Cardiol 2007;14:314–323. doi: 10.1016/j.nuclcard.2007.02.005
13. Pazhenkottil AP, Ghadri JR, Nkoulou RN, et al. Improved Outcome Prediction by SPECT Myocardial Perfusion Imaging After CT Attenuation Correction. J Nucl Med 2011;52 (2):196–200. doi: 10.2967/jnumed.110.080580
14. Fricke E, Fricke H, Weise R, et al. Attenuation Correction of Myocardial SPECT Perfusion Images with Low-Dose CT: Evaluation of the Method by Comparison with Perfusion PET. J Nucl Med 2005;46:736–744.
15. Tamam M, Mulazimoglu M, Edis N, et al. The Value of Attenuation Correction in Hybrid Cardiac SPECT/CT on Inferior Wall According to Body Mass Index. World J Nucl Med 2016;15(1):18–23. doi: 10.4103/1450-1147.167586
16. Narayanan MV, King MA, Pretorius PH, et al. Human-Observer Receiver-Operating-Characteristic Evaluation of Attenuation, Scatter, and Resolution Compensation Strategies for 99m Tc Myocardial Perfusion Imaging. J Nucl Med 2003;44:1725–1734.
17. Thompson JD, Hogg P, Manning DJ, et al. A free-response evaluation determining value in the computed tomography attenuation correction image for revealing pulmonary incidental findings: a phantom study. Acad Radiol 2014;21(4):538–545. doi: 10.1016/j.acra.2014.01.003