title: Development and validation of an automatic method to detect the latest contracting viable left ventricular segments to assist guide CRT therapy from gated SPECT myocardial perfusion imaging.
abstract: The purpose of this study is to use ECG-gated SPECT MPI to detect the latest contracting viable left ventricular (LV) segments to help guide the LV probe placement used in CRT therapy and to validate segment selection against the visual integration method by experts.
  
  
  
  For each patient, the resting ECG-gated SPECT MPI short-axis images were sampled in 3D to generate a polar map of the perfusion distribution used to determine LV myocardial viability, and to measure LV synchronicity using our phase analysis tool. In the visual integration method, two experts visually interpreted the LV viability and mechanical dyssynchrony from the short-axis images and polar maps of viability and phase, to determine the latest contracting viable segments using the 17-segment model. In the automatic method, the apical segments, septal segments, and segments with more than 50% scar were excluded as these are not candidates for CRT LV probe placement. Amongst the remaining viable segments, the segments, whose phase angles were within 10° of the latest phase angle (the most delayed contracting segment), were identified for potential CRT LV probe placement and ranked based on the phase angles of the segments. Both methods were tested in 36 pre-CRT patients who underwent ECG-gated SPECT MPI. The accuracy was determined as the percent agreement between the visual integration and automatic methods. The automatic method was performed by a second independent operator to evaluate the inter-operator processing reproducibility.
  
  
  
  In all the 36 patients, the LV lead positions of the 1st choices recommended by the automatic and visual integration methods were in the same segments in 35 patients, which achieved an agreement rate of 97.2%. In the inter-operator reproducibility test, the LV lead positions of the 1st choices recommended by the two operators were in the same segments in 25 patients, and were in the adjacent segments in 7 patients, which achieved an overall agreement of 88.8%.
  
  
  
  An automatic method has been developed to detect the latest contracting viable LV segments to help guide the LV probe placement used in CRT therapy. The retrospective clinical study with 36 patients suggests that this method has high agreement against the visual integration method by experts and good inter-operator reproducibility. Consequently, this method is promising to be a clinical tool to recommend the CRT LV lead positions.
authors.affiliation: School of Computing, University of Southern Mississippi, Long Beach, MS, USA.
authors.forename: Weihua
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Cardiology, Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
authors.forename: Ningchao
authors.initials: N
authors.lastname: Tao
authors.affiliation: Department of Cardiology, Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Hou
authors.affiliation: Department of Cardiology, Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiology, Emory University School of Medicine, Atlanta, GA, 30032, USA.
authors.forename: Russell D
authors.initials: RD
authors.lastname: Folks
authors.affiliation: Department of Radiology, Emory University School of Medicine, Atlanta, GA, 30032, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Cooke
authors.affiliation: Department of Radiology, Emory University School of Medicine, Atlanta, GA, 30032, USA.
authors.forename: Valeria M
authors.initials: VM
authors.lastname: Moncayo
authors.affiliation: Department of Radiology, Emory University School of Medicine, Atlanta, GA, 30032, USA. ernest.garcia@emory.edu.
authors.forename: Ernest V
authors.initials: EV
authors.lastname: Garcia
authors.affiliation: Department of Cardiology, Nanjing Medical University, Nanjing, 210029, Jiangsu, China. jgzou@njmu.edu.cn.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Zou
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results
keywords: CRT; SPECT MPI; hear failure; left ventricular lead