Time-of-flight PET/CT suppresses CT based attenuation correction and scatter coincidence correction errors due to misalignment of the gastrointestinal tract

Document Type : Original Article

Authors

Hirosaki University Graduate School of Health Sciences, Hirosaki-shi, Aomori, Japan

Abstract

Objective(s): This study aimed to examine the influence of changes in CT values on PET images, specifically focusing on errors in CT-based attenuation correction and scatter coincidence correction (CTAC/SC) caused by gastrointestinal gas. Furthermore, it aimed to demonstrate the effectiveness of time-of-flight (TOF) PET in reducing CTAC/SC errors.
Methods: PET images were reconstructed using multiple CT images with varying CT values. The study then compared the fluctuations in pixel values of the PET images corresponding to the different CT values utilized for CTAC/SC between non-TOF and TOF acquisitions.
Results: PET pixel values fluctuated with changes in CT values. In the phantom study, TOF showed a significantly smaller change in PET pixel value of 1.00±0.27 kBq/mL compared to 3.72±1.33 kBq/mL in the non-TOF at sites with a CT change of +1000 HU. In the patient study, a linear regression analysis was performed to determine the effect of changes in CT values due to gastrointestinal gas migration on standard uptake value (SUV).The results showed that the TOF group had a lower ratio of change in SUV to change in CT values compared to the non-TOF group. These findings revealed that PET pixel values exhibited fluctuations in response to changes in CT values, and TOF-PET effectively mitigated CTAC/SC errors arising from gastrointestinal gas.
Conclusions: TOF-PET has the potential to reduce the occurrence of suspicious accumulation.

Keywords

Main Subjects


  1. Beyer T, Townsend DW, Brun T, Kinahan PE, Charron M, Roddy R, et al. A combined PET/CT scanner for clinical oncology. J Nucl Med. 2000; 41(8):1369-79.
  2. Kinahan PE, Townsend DW, Beyer T, Sashin D. Attenuation correction for a combined 3D PET/CT scanner. Med Phys. 1998; 25(10):2046-53.
  3. Kinahan PE, Hasegawa BH, Beyer T. X-ray-based attenuation correction for positron emission tomography/computed tomography Semin Nucl Med. 2003; 33(3): 166-79.
  4. Goerres GW, Kamel E, Heidelberg TN, Schwitter MR, Burger C, von Schulthess GK. PET-CT image co-registration in the thorax: influence of respiration. Eur J Nucl Med Mol Imaging. 2002; 29(3):351-60.
  5. Beyer T, Antoch G, Blodgett T, Freudenberg LF, Akhurst T, Mueller S. Dual-modality PET/CT imaging: the effect of respiratory motion on combined image quality in clinical oncology. Eur J Nucl Med Mol Imaging. 2003; 30(4):588-96.
  6. Gould KL, Pan T, Loghin C, Johnson NP, Guha A, Sdringola S. Frequent diagnostic errors in cardiac PET/CT due to mis-registration of CT attenuation and emission PET images: a definitive analysis of causes, consequences, and corrections. J Nucl Med. 2007; 48(7):1112-21.
  7. Martinez-Möller A, Souvatzoglou M, Navab N, Schwaiger M, Nekolla SG. Artifacts from misaligned CT in cardiac perfusion PET/CT studies: frequency, effects, and potential solutions. J Nucl Med. 2007; 48(2):188-93.
  8. Nakamoto Y, Chin BB, Cohade C, Osman M, Tatsumi M, Wahl RL. PET/CT: artifacts caused by bowel motion. Nucl Med Commun. 2004; 25(3):221-5.
  9. Lodge MA, Chaudhry MA, Udall DN, Wahl RL. Characterization of a perirectal artifact in 18F-FDG PET/CT. J Nucl Med. 2010; 51(10):1501-6.
  10. Kubota K, Itoh M, Ozaki K, Ono S, Tashiro M, Yamaguchi K, et al. Advantage of delayed whole-body FDG-PET imaging for tumour detection. Eur J Nucl Med. 2001; 28(6):696-703.
  11. Matsuda H, Tsuji S, Shuke N, Sumiya H, Tonami N, Hisada K. Noninvasive measurements of regional cerebral blood flow using technetium-99m hexamethyl-propylene amine oxime. Eur J Nucl Med. 1993; 20(5):391-401.
  12. Filipović M, Comtat C, Stute S. Time-of-flight (TOF) implementation for PET recon-struction in practice. Phys Med Biol. 2019; 64(23):23NT01.
  13. Karp JS, Surti S, Daube-Witherspoon ME, Muehllehner G. Benefit of time-of-flight in PET: experimental and clinical results. J Nucl Med. 2008; 49(3):462-70.
  14. Conti M. Why is TOF PET reconstruction a more robust method in the presence of inconsistent data? Phys Med Biol. 2011; 56(1):155-68.
  15. Son JW, Kim KY, Yoon HS, Won JY, Ko GB, Lee MS, et al. Proof-of-concept prototype time-of-flight PET system based on high-quantum-efficiency multianode PMTs. Med Phys. 2017; 44(10):5314-5324.
  16. Watanabe Y, Hosokawa S, Otaka Y, Takahashi Y. Relationship between CT Numbers and Artifacts Obtained Using CT-based Attenuation Correction of PET/CT. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2020; 76(9):955-962.
  17. Schneider CA, Rasband WS, Eliceiri KW. NIH Image to ImageJ: 25 years of image analysis.Nat Methods. 2012; 9(7):671-5.
  18. Lois C, Jakoby BW, Long MJ, Hubner KF, Barker DW, Casey ME, et al. An assessment of the impact of incorporating time-of-flight information into clinical PET/CT imaging. J Nucl Med. 2010; 51(2):237-45.
  19. Iagaru A, Minamimoto R, Levin C, Barkhodari A, Jamali M, Holley D, et al. The potential of TOF PET-MRI for reducing artifacts in PET images. EJNMMI Phys. 2015; 2(Suppl 1):A77.
  20. Mehranian A, Wollenweber SD, Walker MD, Bradley KM, Fielding PA, Huellner M, et al. Deep learning-based time-of-flight (ToF) image enhancement of non-ToF PET scans. Eur J Nucl Med Mol Imaging. 2022; 49(11):3740-3749.