Four-dimensional (4D) PET/CT imaging of the thorax Journal Article

Authors: Nehmeh, S. A.; Erdi, Y. E.; Pan, T.; Pevsner, A.; Rosenzweig, K. E.; Yorke, E.; Mageras, G. S.; Schoder, H.; Vernon, P.; Squire, O.; Mostafavi, H.; Larson, S. M.; Humm, J. L.
Article Title: Four-dimensional (4D) PET/CT imaging of the thorax
Abstract: We have reported in our previous studies on the methodology, and feasibility of 4D-PET (Gated PET) acquisition, to reduce respiratory motion artifact in PET imaging of the thorax. In this study, we expand our investigation to address the problem of respiration motion in PET/CT imaging. The respiratory motion of four lung cancer patients were monitored by tracking external markers placed on the thorax. A 4D-CT acquisition was performed using a "step-and-shoot" technique, in which computed tomography (CT) projection data were acquired over a complete respiratory cycle at each couch position. The period of each CT acquisition segment was time stamped with an "x-ray ON" signal, which was recorded by the tracking system. 4D-CT data were then sorted into 10 groups, according to their corresponding phase of the breathing cycle. 4D-PET data were acquired in the gated mode, where each breathing cycle was divided into ten 0.5 s bins. For both CT and PET acquisitions, patients received audio prompting to regularize breathing. The 4D-CT and 4D-PET data were then correlated according to respiratory phase. The effect of 4D acquisition on improving the co-registration of PET and CT images, reducing motion smearing, and consequently increase the quantitation of the SUV, were investigated. Also, quantitation of the tumor motions in PET, and CT, were studied and compared. 4D-PET with matching phase 4D-CTAC showed an improved accuracy in PET-CT image co-registration of up to 41%, compared to measurements from 4D-PET with clinical-CTAC. Gating PET data in correlation with respiratory motion reduced motion-induced smearing, thereby decreasing the observed tumor volume, by as much as 43%. 4D-PET lesions volumes showed a maximum deviation of 19% between clinical CT and phase- matched 4D-CT attenuation corrected PET images. In CT, 4D acquisition resulted in increasing the tumor volume in two patients by up to 79%, and decreasing it in the other two by up to 35%. Consequently, these corrections have yielded an increase in the measured SUV by up to 16% over the clinical measured SUV, and 36% over SUV's measured in 4D-PET with clinical-CT Attenuation Correction (CTAC) SUV's. Quantitation of the maximum tumor motion amplitude, using 4D-PET and 4D-CT, showed up to 30% discrepancy between the two modalities. We have shown that 4D PET/CT is clinically a feasible method, to correct for respiratory motion artifacts in PET/CT imaging of the thorax. 4D PET/CT acquisition can reduce smearing, improve the accuracy in PET-CT co-registration, and increase the measured SUV. This should result in an improved tumor assessment for patients with lung malignancies. © 2004 American Association of Physicists in Medicine.
Keywords: adult; clinical article; controlled study; aged; aged, 80 and over; middle aged; positron emission tomography; cancer diagnosis; diagnostic accuracy; sensitivity and specificity; reproducibility of results; computer assisted tomography; image interpretation, computer-assisted; tumor volume; lung neoplasms; lung cancer; tomography, x-ray computed; patient monitoring; diagnostic imaging; algorithms; radiography, thoracic; feasibility study; image enhancement; subtraction technique; imaging, three-dimensional; pattern recognition, automated; positron-emission tomography; thorax radiography; artifacts; breathing mechanics; thorax; movement; humans; human; priority journal; article
Journal Title: Medical Physics
Volume: 31
Issue: 12
ISSN: 0094-2405
Publisher: American Association of Physicists in Medicine  
Date Published: 2004-12-01
Start Page: 3179
End Page: 3186
Language: English
DOI: 10.1118/1.1809778
PROVIDER: scopus
PUBMED: 15651600
Notes: Med. Phys. -- Cited By (since 1996):200 -- Export Date: 16 June 2014 -- CODEN: MPHYA -- Source: Scopus
Altmetric Score
MSK Authors
  1. Alexander Pevsner
    12 Pevsner
  2. Heiko Schoder
    302 Schoder
  3. Gikas S Mageras
    264 Mageras
  4. Ellen D Yorke
    321 Yorke
  5. Sadek Nehmeh
    67 Nehmeh
  6. John Laurence Humm
    348 Humm
  7. Yusuf E Erdi
    109 Erdi
  8. Steven M Larson
    810 Larson
  9. Olivia D Squire
    32 Squire