title: Does two-segment image reconstruction at 64-section CT coronary angiography improve image quality and diagnostic accuracy?
abstract: OBJECTIVE
  To prospectively evaluate the effect of single- versus two-segment image reconstruction on image quality and diagnostic accuracy at 64-section multidetector computed tomographic (CT) coronary angiography by using conventional coronary angiography as the reference standard.
  
  
  METHODS
  The study design was approved by a human research committee; patients gave informed consent. The study was HIPAA compliant. Forty consecutive patients (22 men, 18 women; mean age, 61 years +/- 8 [standard deviation]) underwent both 64-section multidetector CT coronary angiography and conventional angiography. All data sets were reconstructed by using single- and two-segment image reconstruction algorithms, with resulting temporal resolution of 82.5-165 msec. Two experienced observers independently evaluated image quality and signs of coronary artery disease. A five-level grading scheme was used to grade stenosis (0%, <50%, <70%, <99%, 100%) and image quality (1[unacceptable] to 5[excellent]). Interobserver correlation, Spearman correlation coefficients, and diagnostic accuracy were calculated.
  
  
  RESULTS
  Six hundred coronary artery segments were visible on conventional angiograms, of which 560 (93.3%) were seen by using single-segment and 561 (93.5%) were seen by using two-segment image reconstruction (P=.35). Mean quality scores were not significantly different (P=.22) for single- (3.1 +/- 0.9) and two-segment (3.2 +/- 0.8) reconstruction. Significantly (P=.03) better image quality was observed for two-segment reconstruction only at heart rates of 80-82 beats per minute, at which temporal resolution was approximately 83 msec. For grading coronary artery stenosis, correlation was 0.64 for single- and 0.66 for two-segment reconstruction (P=.43). Significant stenosis (>50%) was detected on a per-segment basis with 77.1% sensitivity and 98.6% specificity by using single-segment and with 79.2% sensitivity and 99.1% specificity by using two-segment image reconstruction.
  
  
  CONCLUSIONS
  At heart rates of more than 65 beats per minute, use of two-segment reconstruction improves image quality at multidetector CT coronary angiography but does not significantly affect overall diagnostic accuracy compared with single-segment reconstruction.
authors.affiliation: Department of Radiology, Medical University of South Carolina, 169 Ashley Ave, Charleston, SC 29425, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Herzog
authors.forename: Shaun A
authors.initials: SA
authors.lastname: Nguyen
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Savino
authors.forename: Peter L
authors.initials: PL
authors.lastname: Zwerner
authors.forename: Josh
authors.initials: J
authors.lastname: Doll
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Nielsen
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Flohr
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
authors.forename: Philip
authors.initials: P
authors.lastname: Costello
authors.forename: U Joseph
authors.initials: UJ
authors.lastname: Schoepf
mesh_terms: D000465:Algorithms; D017023:Coronary Angiography / Q000379:methods*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed