title: Emergency cardiac CT for suspected acute coronary syndrome: qualitative and quantitative assessment of coronary, pulmonary, and aortic image quality.
abstract: OBJECTIVE
  The purpose of this study was to determine whether a dedicated coronary CT protocol provides adequate contrast enhancement and artifact-free depiction of coronary, pulmonary, and aortic circulation.
  
  
  METHODS
  Dedicated coronary 64-MDCT data sets of 50 patients (27 men; mean age, 54 +/- 12.4 years) consecutively admitted from the emergency department with suspected acute coronary syndrome were analyzed. Two independent observers graded overall coronary arterial image quality and qualitative and quantitative contrast opacification, motion, and streak artifacts within the pulmonary arteries and aorta.
  
  
  RESULTS
  Coronary image quality was excellent in 48 patients (96%) and moderate in two patients (4%). Eleven left main and 22 left upper lobar pulmonary arteries were not visualized. Qualitative evaluation showed pulmonary arterial tree opacification to be excellent except for the right and left lower lateral and posterior segmental branches (52-54% rate of poor opacification). Quantitative evaluation showed four central (8%), six lobar (8%), and 206 segmental (29%) branches had poor contrast opacification (< 200 HU). Nineteen right upper lobar arteries (38%) were slightly and one was severely affected by streak artifact. At the segmental pulmonary artery level, marked differences in contrast enhancement were detected between the upper (292 +/- 72 HU) and both the middle (249 +/- 85 HU) and the lower lobes (248 +/- 76 HU) (p < 0.01). Mean aortic opacification was 300 +/- 34 HU with excellent contrast homogeneity without severe motion or streak artifacts.
  
  
  CONCLUSIONS
  In the evaluation of patients presenting to the emergency department with suspected acute coronary syndrome, a dedicated coronary CT protocol enables excellent assessment of the coronary arteries and proximal ascending aorta but does not depict the pulmonary vasculature well enough for exclusion of pulmonary embolism.
authors: Cardiac MRI-PET-CT Program, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors: Jonathan D
authors: JD
authors: Dodd
authors: Sanjeeva
authors: S
authors: Kalva
authors: Antonio
authors: A
authors: Pena
authors: Fabien
authors: F
authors: Bamberg
authors: Michael D
authors: MD
authors: Shapiro
authors: Suhny
authors: S
authors: Abbara
authors: Ricardo C
authors: RC
authors: Cury
authors: Thomas J
authors: TJ
authors: Brady
authors: Udo
authors: U
authors: Hoffmann
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001027:Aortography / Q000379:methods*; D017023:Coronary Angiography / Q000379:methods*; D003422:Critical Care / Q000379:methods*; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*