title: Incremental value of adenosine-induced stress myocardial perfusion imaging with dual-source CT at cardiac CT angiography.
abstract: OBJECTIVE
  First, to assess the feasibility of a protocol involving stress-induced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angiography in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population.
  
  
  METHODS
  Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-five patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a)Coronary arterial stenoses were scored for severity and reader confidence at cardiac CT angiography, (b)myocardial perfusion defects were identified and scored for severity and reversibility at CT perfusion imaging, and (c)coronary stenosis severity was reclassified according to perfusion findings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated.
  
  
  RESULTS
  With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specificity, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased significantly, from 0.77 to 0.90 (P < .005).
  
  
  CONCLUSIONS
  A combination protocol involving adenosine perfusion CT imaging and cardiac CT angiography in a dual-source technique is feasible, and CT perfusion adds incremental value to cardiac CT angiography in the detection of significant CAD.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, Mass., USA.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Rocha-Filho
authors.forename: Ron
authors.initials: R
authors.lastname: Blankstein
authors.forename: Leonid D
authors.initials: LD
authors.lastname: Shturman
authors.forename: Hiram G
authors.initials: HG
authors.lastname: Bezerra
authors.forename: David R
authors.initials: DR
authors.lastname: Okada
authors.forename: Ian S
authors.initials: IS
authors.lastname: Rogers
authors.forename: Brian
authors.initials: B
authors.lastname: Ghoshhajra
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Gudrun
authors.initials: G
authors.lastname: Feuchtner
authors.forename: Wilfred S
authors.initials: WS
authors.lastname: Mamuya
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Brady
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Cury
mesh_terms: D000241:Adenosine / Q000008:administration & dosage; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007479:Iopamidol; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon; D036542:Tomography, Spiral Computed / Q000379:methods*; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D014665:Vasodilator Agents; D007479:Iopamidol; D000241:Adenosine