title: Chronic myocardial infarction detection and characterization during coronary artery calcium scoring acquisitions.
abstract: BACKGROUND
  Hypoenhanced regions on multidetector CT (MDCT) coronary angiography correlate with myocardial hyperperfusion. In addition to a limited capillary density, chronic myocardial infarction (MI) commonly contains a considerable amount of adipose tissue.
  
  
  OBJECTIVE
  We explored whether regional myocardial hypoenhancement on contrast-enhanced MDCT could be identified with standard coronary artery calcium (CAC) scoring acquisitions with noncontrast CT.
  
  
  METHODS
  Consecutive patients with a history of MI who were referred for contrast-enhanced MDCT from November 2006 until March 2009 were studied. Noncontrast CT for CAC scoring was also performed. The correlation between regional myocardial hypoenhancement on contrast-enhanced CT and regional myocardial hypoattenuated areas on noncontrast CT was defined.
  
  
  RESULTS
  Eighty-three patients (mean age, 61.5+/-12.5 years; n=67; 81% male) with previous MI were studied. A total of 1411 myocardial segments were evaluated. Two hundred thirty-nine segments (17%) showed myocardial hypoenhancement by MDCT and 140 segments (9.6%) by CAC. On a patient level, noncontrast CT showed a sensitivity, specificity, positive predictive value, (PPV) and negative predictive value (NPV) of 66% (95% CI, 0.53-0.77), 100% (95% CI, 0.76-1.00), 100% (95% CI, 0.90-1.00), and 41% (95% CI, 0.26-0.58), respectively, to detect myocardial hypoenhancement. On a per segment level, noncontrast CT showed a sensitivity, specificity, PPV, and NPV of 58% (95% CI, 0.51-0.64), 100% (95% CI, 0.99-1.00), 99% (95% CI, 0.94-1.00), and 92% (95% CI, 0.90-0.93), respectively, to detect myocardial hypoenhancement.
  
  
  CONCLUSIONS
  Our findings suggest that chronic MI can be detected with standard CAC scoring acquisitions.
authors.affiliation: Department of Cardiovascular Imaging, Otamendi Hospital, Azcuenaga 870 (C1115AAB), Buenos Aires, Argentina. grodriguezgranillo@gmail.com
authors.forename: Gastón A
authors.initials: GA
authors.lastname: Rodríguez-Granillo
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Rosales
authors.forename: Paola
authors.initials: P
authors.lastname: Renes
authors.forename: Eduardo
authors.initials: E
authors.lastname: Diez
authors.forename: Jorge
authors.initials: J
authors.lastname: Pereyra
authors.forename: Estela
authors.initials: E
authors.lastname: Gomez
authors.forename: Gustavo
authors.initials: G
authors.lastname: De Lillo
authors.forename: Elina
authors.initials: E
authors.lastname: Degrossi
authors.forename: Alfredo E
authors.initials: AE
authors.lastname: Rodriguez
authors.forename: Eugene P
authors.initials: EP
authors.lastname: McFadden
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000473:pathology; D000368:Aged; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000473:pathology; D002908:Chronic Disease; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology; D009204:Myocardial Revascularization; D009206:Myocardium / Q000473:pathology; D009336:Necrosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016277:Ventricular Function, Left
chemical_list: D003287:Contrast Media