title: Transmural perfusion gradient in adenosine triphosphate stress myocardial perfusion computed tomography.
abstract: BACKGROUND
  The aim of the present study was to assess semi-quantification of myocardial perfusion using adenosine triphosphate (ATP)-stress myocardial perfusion computed tomography (MPCT) in patients with coronary artery disease (CAD).
  
  
  RESULTS
  Seventeen patients with CAD underwent ATP-stress MPCT, stress myocardial perfusion scintigraphy (MPS) and coronary angiography (CAG). With ATP loading (0.16 mg·kg⁻¹·min⁻¹, 5 min) and slow infusion of contrast medium (2 ml/s, 100 ml), stress images were acquired using prospective electrocardiogram-gated 64-slice CT. Stress MPCT images were analyzed according to the transmural perfusion gradient (TMPG; difference between subendocardial and epicardial attenuation, divided by wall thickness; Hounsfield units [HU]/mm) per segment, and summed TMPG was compared with those of stress MPS and CAG per territory and patient, respectively. There were 36 CAG-proved stenotic vessels in 51 (17 × 3) territories. There were significant correlations between TMPG and MPS stress score per segment, per territory and per patient, respectively (P<0.05). Summed TMPG in territories with and without >70% coronary stenosis was 32.3HU/mm (-1.9~90.9) and 14.5 HU/mm (-5.6~38.4; P<0.05). For detecting coronary artery stenosis, sensitivity, specificity, positive and negative predictive values using the summed TMPG were 72%, 87%, 93% and 57%, in comparison with summed MPS (64%, 73%, 85%, and 46%).
  
  
  CONCLUSIONS
  Semi-quantification of myocardial perfusion using TMPG has great potential to evaluate the severity of myocardial ischemia, similarly to MPS score.
authors.affiliation: Department of Diagnostic and Therapeutic Radiology, Ehime University Graduate School of Medicine.
authors.forename: Kohei
authors.initials: K
authors.lastname: Hosokawa
authors.forename: Akira
authors.initials: A
authors.lastname: Kurata
authors.forename: Teruhito
authors.initials: T
authors.lastname: Kido
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Shikata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imagawa
authors.forename: Kanji
authors.initials: K
authors.lastname: Kawachi
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ogimoto
authors.forename: Jitsuo
authors.initials: J
authors.lastname: Higaki
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kido
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Higashino
authors.forename: Teruhito
authors.initials: T
authors.lastname: Mochizuki
mesh_terms: D000255:Adenosine Triphosphate / Q000008:administration & dosage*; D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000503:physiopathology; D004562:Electrocardiography / Q000379:methods; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D012720:Severity of Illness Index; D014055:Tomography, Emission-Computed / Q000379:methods*
chemical_list: D000255:Adenosine Triphosphate