Respiratory motion artifacts on PET emission images obtained using CT attenuation correction on PET-CT

  • Medhat M. Osman
  • Christian Cohade
  • Yuji Nakamoto
  • Richard L. WahlEmail author
Short Communication


PET-CT scanners allow generation of transmission maps from CT. The use of CT attenuation correction (CTAC) instead of germanium-68 attenuation correction (Ge AC) might be expected to cause artifacts on reconstructed emission images if differences in respiratory status exist between the two methods of attenuation correction. The aim of this study was to evaluate for possible respiratory motion artifacts (RMA) in PET images attenuation corrected with CT from PET-CT in clinical patients. PET-CT scans were performed using a Discovery LS PET-CT system in 50 consecutive patients (23 males, 27 females; mean age 58.2 years) with known or suspected malignancy. Both CTAC and Ge AC transmission data obtained during free tidal breathing were used to correct PET emission images. Cold artifacts at the interface of the lungs and diaphragm, believed to be due to respiratory motion (RMA), that were seen on CTAC images but not on the Ge AC images were evaluated qualitatively on a four-point scale (0, no artifact; 1, mild artifact; 2, moderate artifact; 3, severe artifact). RMA was also measured for height. Curvilinear cold artifacts paralleling the dome of the diaphragm at the lung/diaphragm interface were noted on 84% of PET-CT image acquisitions and were not seen on the 68Ge-corrected images; however, these artifacts were infrequently severe. In conclusion, RMA of varying magnitude were noted in most of our patients as a curvilinear cold area at the lung/diaphragm interface, but were not diagnostically problematic in these patients.


PET/CT Image fusion Artifact Respiratory motion 


  1. 1.
    Beyer T, Townsend DW, Brun T, Kinahan PE, Charron M, Roddy R, Jerin J, Young J, Byars L, Nutt R. A combined PET/CT scanner for clinical oncology. J Nucl Med 2000; 41:1369–1379.PubMedGoogle Scholar
  2. 2.
    Kinahan PE, Townsend DW, Beyer T, Sashin D. Attenuation correction or a combined 3D PET/CT scanner. Med Phys 1998; 25:2046–2053.CrossRefPubMedGoogle Scholar
  3. 3.
    Akhurst T, Chisin R. Hybrid PET/CT machines: optimized PET machines for the new millennium? J Nucl Med 2000; 41:961–962.PubMedGoogle Scholar
  4. 4.
    Goerres GW, Kamel E, Heidelberg T-NH, Schwitter MR, Burger C, von Schulthess GK. PET-CT image co-registration in the thorax: influence of respiration. Eur J Nucl Med 2002; 29:351–360.CrossRefGoogle Scholar
  5. 5.
    Nehmeh S, Erdi Y, Ling C, Rosenzweig K, Schoder H, Larson S, Macapinlac H, Squire O, Humm J. Effect of respiratory gating on quantifying PET images of lung cancer. J Nucl Med 2002; 43:876–881.PubMedGoogle Scholar
  6. 6.
    Miyauchi T, Raylman RR, Kison PV, Paberzs, Shreve PD, Wahl RL. Can respiratory gated FDG-PET improve quality in thoracic and upper abdominal tumor imaging? J Nucl Med 1996; 35:135 Suppl.Google Scholar
  7. 7.
    Osman MM, Cohade C, Nakamoto Y, Wahl RL. Clinically significant inaccurate localization of lesions with PET-CT: frequency in 275 patients. J Nucl Med 2003 (in press)Google Scholar

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Medhat M. Osman
    • 2
  • Christian Cohade
    • 1
  • Yuji Nakamoto
    • 1
  • Richard L. Wahl
    • 1
    Email author
  1. 1. Department of Radiology, Division of Nuclear MedicineThe Johns Hopkins University School of MedicineBaltimoreUSA
  2. 2. Department of Internal Medicine, Division of Nuclear MedicineSaint Louis UniversitySt. LouisUSA

Personalised recommendations