title: Data-driven respiratory motion tracking and compensation in CZT cameras: a comprehensive analysis of phantom and human images.
abstract: BACKGROUND
  This study described a method for tracking and compensating respiratory motion in cadmium-zinc-telluride (CZT) cameras. We evaluated motion effects on myocardial perfusion imaging and assessed the usefulness of motion compensation in phantom and clinical studies.
  
  
  METHODS
  SPECT studies were obtained from an oscillating heart phantom and 552 patients using CZT cameras with list-mode acquisition. Images were reformatted in 500-ms frames, and the activity centroid was calculated as respiratory signal. The myocardial perfusion, left ventricular (LV) wall thickness, and LV volume were assessed before and after the motion compensation technique.
  
  
  RESULTS
  In phantom studies, we documented only minimal bias between simulated and measured shifts. Significantly reduced tracer activity, increased wall thickness and decreased volume in scans with 15 mm or more axial shifts were noted. In clinical studies, there was a higher prevalence of significant motion after treadmill exercise. The motion compensation technique could successfully compensate those motion artifacts.
  
  
  CONCLUSIONS
  The described method allows for tracking and compensating respiratory motion in CZT cameras. Significant respiratory motion is still not uncommon using CZT cameras, especially in patients who underwent treadmill tests. Motion blurring can be compensated using image processing techniques and image quality could be significantly improved.
authors.affiliation: Department of Nuclear Medicine, National Taiwan University Hospital Yun-Lin Branch, No. 579, Sec. 2, Yunlin Rd., Douliou City, 640, Yunlin County, Taiwan, izonekochi@gmail.com.
authors.forename: Chi-Lun
authors.initials: CL
authors.lastname: Ko
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Wu
authors.forename: Mei-Fang
authors.initials: MF
authors.lastname: Cheng
authors.forename: Ruoh-Fang
authors.initials: RF
authors.lastname: Yen
authors.forename: Wen-Chau
authors.initials: WC
authors.lastname: Wu
authors.forename: Kai-Yuan
authors.initials: KY
authors.lastname: Tzen
mesh_terms: D000368:Aged; D000465:Algorithms; D016477:Artifacts; D019187:Cadmium Compounds; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods; D008297:Male; D008875:Middle Aged; D009038:Motion; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D013691:Tellurium; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation* / Q000379:methods; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
chemical_list: D019187:Cadmium Compounds; D013691:Tellurium; C028337:cadmium telluride