title: Automatic alignment of myocardial perfusion PET and 64-slice coronary CT angiography on hybrid PET/CT.
abstract: BACKGROUND
  Hybrid PET/CT allows for acquisition of cardiac PET and coronary CT angiography (CCTA) in one session. However, PET and CCTA are acquired with differing breathing protocols and require software registration. We aimed to validate automatic correction for breathing misalignment between PET and CCTA acquired on hybrid scanner.
  
  
  METHODS
  Single-session hybrid PET/CT studies of rest/stress (13)N-ammonia PET and CCTA in 32 consecutive patients were considered. Automated registration of PET left ventricular (LV) surfaces with CCTA volumes was evaluated by comparing with expert manual alignment by two observers.
  
  
  RESULTS
  The average initial misalignments between the position of LV on PET and CCTA were 27.2 ± 11.8, 13.3 ± 11.5, and 14.3 ± 9.1 mm in x, y, and z axes on rest, and 26.3 ± 10.2, 11.1 ± 9.5, and 11.7 ± 7.1 mm in x, y, and z axes on stress, respectively. The automated PET-CCTA co-registration had 95% agreement as judged visually. Compared with expert manual alignment, the translation errors of the algorithm were 5.3 ± 2.8 mm (rest) and 6.0 ± 3.5 mm (stress). 3D visualization of combined coronary vessel anatomy and hypoperfusion from PET could be made without further manual adjustments.
  
  
  CONCLUSIONS
  Software co-registration of CCTA and PET myocardial perfusion imaging on hybrid PET/CT scanners is necessary, but can be performed automatically, facilitating integrated 3D display on PET/CT.
authors.affiliation: Department of Imaging, and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
authors.forename: Ryo
authors.initials: R
authors.lastname: Nakazato
authors.forename: Damini
authors.initials: D
authors.lastname: Dey
authors.forename: Erick
authors.initials: E
authors.lastname: Alexánderson
authors.forename: Aloha
authors.initials: A
authors.lastname: Meave
authors.forename: Moisés
authors.initials: M
authors.lastname: Jiménez
authors.forename: Edgar
authors.initials: E
authors.lastname: Romero
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Jácome
authors.forename: Marco
authors.initials: M
authors.lastname: Peña
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
authors.forename: Piotr J
authors.initials: PJ
authors.lastname: Slomka
mesh_terms: D000465:Algorithms; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D049268:Positron-Emission Tomography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed