title: Myocardial hypo-enhancement on resting computed tomography angiography images accurately identifies myocardial hypoperfusion.
abstract: OBJECTIVE
  The objective of this study was to test the diagnostic accuracy of myocardial CT perfusion (CTP) imaging using color and gray-scale image analysis.
  
  
  BACKGROUND
  Current myocardial CTP techniques have varying diagnostic accuracy and are prone to artifacts that impair detection. This study evaluated the diagnostic accuracy of color and/or gray-scale CTP and the application of artifact criteria to detect hypoperfusion.
  
  
  METHODS
  Fifty-nine prospectively enrolled patients with abnormal single-photon emission computed tomography (SPECT) studies were analyzed. True hypoperfusion was defined if SPECT hypoperfusion corresponded to obstructive coronary stenoses on CT angiography (CTA). CTP applied color and gray-scale myocardial perfusion maps to resting CTA images. Criteria for identifying artifacts were also applied during interpretation.
  
  
  RESULTS
  Using combined SPECT plus CTA as the diagnostic standard, abnormal myocardial CTP was present in 33 (56%) patients, 19 suggesting infarction and 14 suggesting ischemia. Patient-level color and gray-scale myocardial CTP sensitivity to detect infarction was 90%, with specificity 80%, and negative and positive predictive value of 94% and 68%. To detect ischemia or infarction, CTP specificity and positive predictive value were 92% whereas sensitivity was 70%. Gray-scale myocardial CTP had slightly lower specificity but similar sensitivity. Myocardial CTP artifacts were present in 88% of studies and were identified using our criteria.
  
  
  CONCLUSIONS
  Color and gray-scale myocardial CTP using resting CTA images identified myocardial infarction with high sensitivity as well as infarction or ischemia with high specificity and positive predictive value without additional testing or radiation. Color and gray-scale CTP had slightly better specificity than gray-scale alone.
authors.affiliation: Division of Cardiology, University of Washington, Seattle, WA 98195, USA.
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Busch
authors.forename: Adam M
authors.initials: AM
authors.lastname: Alessio
authors.forename: James H
authors.initials: JH
authors.lastname: Caldwell
authors.forename: Mohit
authors.initials: M
authors.lastname: Gupta
authors.forename: Songshou
authors.initials: S
authors.lastname: Mao
authors.forename: Jigar
authors.initials: J
authors.lastname: Kadakia
authors.forename: William
authors.initials: W
authors.lastname: Shuman
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
authors.forename: Kelley R
authors.initials: KR
authors.lastname: Branch
mesh_terms: D000368:Aged; D016477:Artifacts; D017023:Coronary Angiography / Q000379:methods*; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D014861:Washington