title: Impact of coronary artery calcium characteristics on accuracy of CT angiography.
abstract: OBJECTIVE
  This study sought to evaluate which specific calcium characteristics impact diagnostic accuracy of coronary computed tomography angiography (CTA).
  
  
  BACKGROUND
  Coronary calcifications comprise one of the most significant factors interfering with diagnostic accuracy of coronary CTA. Despite this fact, there is paucity of data regarding this phenomenon.
  
  
  METHODS
  A total of 525 coronary lesions (252 calcified and 273 reference [noncalcified] lesions) within 97 arteries of 60 patients (19 women, age 63 ± 10 years) underwent assessment with both 2 × 64-slice computed tomography and intravascular ultrasound (IVUS). Nineteen calcium characteristics were determined. The main outcome was coronary CTA inaccuracy defined as the deviation of minimum lumen area within the calcification measured with coronary CTA from that measured with IVUS, in both absolute (mm(2)) and relative (%) terms.
  
  
  RESULTS
  Presence of calcification was found to be independently correlated to coronary CTA inaccuracy in both absolute and relative terms (p < 0.001 for both). The relative (%) inaccuracy of coronary CTA was independently correlated to total calcium length (p = 0.004), total calcium volume (p = 0.008), cross section calcium thickness (p = 0.023), cross section calcium area (p = 0.023), and cross section lumen area (p = 0.001). The absolute inaccuracy of CTA was correlated to calcium length (p = 0.010), calcium volume (p = 0.017), and cross section calcium area (p < 0.001). The presence of both total calcium arc ≥47° and mean lumen diameter of ≤2.8 mm provided the best predictive accuracy for detection of excessive lumen underestimation by CTA. The best accuracy for prediction of excessive lumen overestimation provided combination of 2 of 3 features: maximum calcium density <869 HU, OR whole calcium length <2.4 mm, OR total calcium volume <6.4 mm(3).
  
  
  CONCLUSIONS
  Our results indicate which specific calcium characteristics impact accuracy of coronary CTA in lumen assessment within calcified lesions. This may provide practical assistance in predicting coronary lumen underestimation or overestimation by coronary CTA, therefore mitigating risk of diagnostic errors in clinical practice.
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland. Electronic address: mkruk@ikard.pl.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Kruk
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Noll
authors.affiliation: Departments of Cardiology and Radiology, University of Giessen, Giessen, Germany; Departments of Cardiology and Radiology, University of Erlangen, Erlangen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Achenbach
authors.affiliation: Cardiovascular Research Foundation, New York, New York.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Pręgowski
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Kaczmarska
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Kryczka
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Radosław
authors.initials: R
authors.lastname: Pracoń
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Zofia
authors.initials: Z
authors.lastname: Dzielińska
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Sleszycka
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Witkowski
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Demkow
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Witold
authors.initials: W
authors.lastname: Rużyłło
authors.affiliation: Coronary Disease and Structural Heart Diseases Department, Invasive Cardiology and Angiology Department, Institute of Cardiology, Warsaw, Poland.
authors.forename: Cezary
authors.initials: C
authors.lastname: Kępka
mesh_terms: D002114:Calcinosis / Q000000981:diagnostic imaging*; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional
keywords: CI; CT; CTA; FFR; IVUS; MLA; NPV; PPV; computed tomography; computed tomography angiography; confidence intervals; coronary angiography; coronary artery disease; fractional flow reserve; intravascular ultrasound; minimum lumen area; negative predictive value; positive predictive value