title: Three-dimensional quantification of myocardial perfusion during regadenoson stress computed tomography.
abstract: BACKGROUND
  There is no accepted methodology for CT-based vasodilator stress myocardial perfusion imaging and analysis. We developed a technique for quantitative 3D analysis of CT images, which provides several indices of myocardial perfusion. We sought to determine the ability of these indices during vasodilator stress to identify segments supplied by coronary arteries with obstructive disease and to test the accuracy of the detection of perfusion abnormalities against SPECT.
  
  
  METHODS
  We studied 93 patients referred for CT coronary angiography (CTCA) who underwent regadenoson stress. 3D analysis of stress CT images yielded segmental perfusion indices: mean X-ray attenuation, severity of defect and relative defect volume. Each index was averaged for myocardial segments, grouped by severity of stenosis: 0%, <50%, 50-70%, and >70%. Objective detection of perfusion abnormalities was optimized in 47 patients and then independently tested in the remaining 46 patients.
  
  
  RESULTS
  CTCA depicted normal coronary arteries or non-obstructive disease in 62 patients and stenosis of >50% in 31. With increasing stenosis, segmental attenuation showed a 7% decrease, defect severity increased 11%, but relative defect volume was 7-fold higher in segments with obstructive disease (p<0.001). In the test group, detection of perfusion abnormalities associated with stenosis >50% showed sensitivity 0.78, specificity 0.54, accuracy 0.59. When compared to SPECT in a subset of 21 patients (14 with abnormal SPECT), stress CT perfusion analysis showed sensitivity 0.79, specificity 0.71, accuracy 0.76.
  
  
  CONCLUSIONS
  3D analysis of vasodilator stress CT images provides quantitative indices of myocardial perfusion, of which relative defect volume was most robust in identifying segments supplied by arteries with obstructive disease. This study may have implications on how CT stress perfusion imaging is performed and analyzed.
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States. Electronic address: vmoravi@bsd.uchicago.edu.
authors.forename: Victor
authors.initials: V
authors.lastname: Mor-Avi
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States; Sorbonne Universités, UPMC University Paris 06, CNRS 7371, INSERM 1146, Laboratoire d'Imagerie Biomédicale, F-75013 Paris, France.
authors.forename: Nadjia
authors.initials: N
authors.lastname: Kachenoura
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States.
authors.forename: Francesco
authors.initials: F
authors.lastname: Maffessanti
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Bhave
authors.affiliation: Aurora Health Care, Milwaukee, WI, United States.
authors.forename: Steven
authors.initials: S
authors.lastname: Port
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Lodato
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States.
authors.forename: Sonal
authors.initials: S
authors.lastname: Chandra
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Freed
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States.
authors.forename: Roberto M
authors.initials: RM
authors.lastname: Lang
authors.affiliation: University of Chicago Medical Center, Chicago, IL, United States.
authors.forename: Amit R
authors.initials: AR
authors.lastname: Patel
mesh_terms: D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods; D011687:Purines; D011720:Pyrazoles; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014665:Vasodilator Agents
chemical_list: D011687:Purines; D011720:Pyrazoles; D014665:Vasodilator Agents; C430916:regadenoson
keywords: Cardiovascular CT; Coronary artery disease; Multi-detector CT; Myocardial ischemia; Myocardium; Perfusion