title: MDCT angiography of acute chest pain: evaluation of ECG-gated and nongated techniques.
abstract: OBJECTIVE
  The objective of our study was to compare MDCT angiography protocols used in patients with acute chest pain caused by vascular, nonvascular, and cardiac abnormalities.
  
  
  METHODS
  In four groups of 20 patients with chest pain each, four MDCT protocols were used based on monitoring vascular attenuation: pulmonary embolism (150 H at pulmonary artery), aortic dissection (200 H at aortic arch), chest pain (200 H at pulmonary artery), and chest pain with ECG gating (150 H at pulmonary artery). Vascular enhancement was assessed by attenuation measurements taken from locations in the pulmonary artery (n = 3) and thoracic aorta (n = 4). The appearance of the coronary artery in regard to opacification and motion was assessed on a scale of 1 to 5 (best).
  
  
  RESULTS
  The mean pulmonary artery and aorta attenuation (372 H and 352 H, respectively) was significantly higher (p < 0.005, Student's t test) and the number of vessel attenuation points measuring less than 200 H (1/140) was significantly smaller (p < 0.001, chi-square test) in the chest pain compared with the dissection (318 H, 310 H; 16/140), gated chest pain (304 H, 286 H; 17/14), and pulmonary embolism (302 H, 220 H; 28/140) groups. The median coronary artery visualization score was 4; the proximal regions received a significantly (p < 0.005, Mann-Whitney test) higher grade compared with the middle and distal regions (medians, 5, 4, and 2, respectively). Artifacts were noted on the gated scans.
  
  
  CONCLUSIONS
  The chest pain protocol can be used to assess both the pulmonary arteries and the thoracic aorta, whereas the ECG-gating protocol appears to be a promising adjunct for a comprehensive single chest pain protocol.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215, USA.
authors.forename: Vassilios D
authors.initials: VD
authors.lastname: Raptopoulos
authors.forename: Phillip B
authors.initials: PB
authors.lastname: Boiselle
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Michailidis
authors.forename: Jason
authors.initials: J
authors.lastname: Handwerker
authors.forename: Adeel
authors.initials: A
authors.lastname: Sabir
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Edlow
authors.forename: Ivan
authors.initials: I
authors.lastname: Pedrosa
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Kruskal
mesh_terms: D000208:Acute Disease; D000784:Aortic Dissection / Q000150:complications / Q000175:diagnosis*; D000792:Angiography / Q000379:methods*; D017545:Aortic Aneurysm, Thoracic / Q000150:complications / Q000175:diagnosis*; D002637:Chest Pain / Q000209:etiology*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed / Q000379:methods