title: Adenosine-stress dynamic myocardial CT perfusion imaging: initial clinical experience.
abstract: OBJECTIVE
  To evaluate the feasibility of adenosine-stress dynamic myocardial volume perfusion imaging with second generation dual source computed tomography (CT) for the qualitative and quantitative assessment of myocardial blood flow (MBF) compared with stress perfusion and viability magnetic resonance imaging (MRI).
  
  
  METHODS
  Ten patients (8 male, 2 female, mean age 62.7 +/- 7.1 years) underwent stress/rest perfusion and delayed-enhancement MRI, and a cardiac CT protocol comprising prospectively electrocardiogram -triggered coronary CT angiography, dynamic adenosine-stress myocardial perfusion imaging using a "shuttle" mode, and delayed enhancement acquisitions. Two independent observers visually assessed myocardial perfusion defects. For semi-quantitative evaluation, CT- and MRI-derived myocardial-to-left ventricular upslope indices were compared. Additionally, absolute MBF was quantified based on dynamic perfusion CT and correlated with semi quantitative CT measurements. Myocardial perfusion analysis was performed on a segmental basis. Analysis used paired t tests, Wilcoxon signed-rank test, linear correlation, and Bland-Altman statistics.
  
  
  RESULTS
  A total of 149 segments (93.1%) were suitable for analysis. Sensitivity, specificity, positive and negative predictive values for detection of myocardial perfusion defects at CT compared with MRI were 86.1%, 98.2%, 93.9%, and 95.7%, respectively. Semiquantitative analysis of CT data showed significant differences between ischemic and nonischemic myocardium with a signal intensity upslope that was comparable with MRI-derived values (CT: 5.2 +/- 2 SI/s, MRI: 4.8 +/- 2.3 SI/s, P > 0.05). Moderate correlation was observed between absolute CT quantification of MBF and semi-quantitative CT measurements. Mean total dose length product for the entire cardiac CT protocol was 1290.4 +/- 233.3 mGy cm.
  
  
  CONCLUSIONS
  Adenosine-stress volumetric first pass CT perfusion imaging is feasible and may enable the evaluation of qualitative and semi quantitative parameters of myocardial perfusion in a comparable fashion as MRI.
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Gorka
authors.initials: G
authors.lastname: Bastarrika
authors.forename: Luis
authors.initials: L
authors.lastname: Ramos-Duran
authors.forename: Michael A
authors.initials: MA
authors.lastname: Rosenblum
authors.forename: Doo Kyoung
authors.initials: DK
authors.lastname: Kang
authors.forename: Garrett W
authors.initials: GW
authors.lastname: Rowe
authors.forename: U Joseph
authors.initials: UJ
authors.lastname: Schoepf
mesh_terms: D000241:Adenosine; D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005080:Exercise Test; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine