title: Stress/rest circumferential strain in non-ischemia, ischemia, and infarction--quantification by 3 Tesla tagged magnetic resonance imaging.
abstract: BACKGROUND
  Adenosine triphosphate (ATP) induces relative hypoperfusion in significantly stenotic coronary arteries, but its effect on myocardial strain has not been used clinically for the detection of ischemia. The purpose of this study was to quantify ATP-stress-induced contractile impairment as altered myocardial strain in coronary artery disease (CAD) using tagged magnetic resonance (MR) and to evaluate its diagnostic capability in comparison with ATP-stress myocardial perfusion-MR.
  
  
  RESULTS
  Tagged MR and perfusion-MR under ATP-stress and rest conditions and late gadolinium enhancement (LGE) MR imaging were performed in 22 patients with suspected CAD. The peak absolute value of the circumferential strain (C-strain) was measured in 12 segments. Myocardial segments were categorized as non-ischemic (n=201), ischemic (n=42), or infarcted (n=21) according to the perfusion-MR and LGE MR imaging results. The absolute C-strain was significantly greater under ATP-stress (19±13%) (mean±SD) than under at-rest (15±11%, P<0.001) conditions in non-ischemic segments. Conversely, the absolute C-strain was significantly lower under ATP-stress (10±13%) than under at-rest (16±6%, P<0.01) conditions in ischemic segments. Optimal cutoff values for stress C-strain (-17.5%) could successfully differentiate segments with ischemia or infarction from non-ischemic ones with a sensitivity of 86%, a specificity of 65%, and an area under the curve of 0.79.
  
  
  CONCLUSIONS
  C-strain analysis using tagged MR could detect ATP-stress-induced contractile impairment in ischemic myocardium.
authors: Department of Radiology, Ehime University Graduate School of Medicine, Toon, Japan. tomozo0421@gmail.com
authors: Tomoyuki
authors: T
authors: Kido
authors: Michinobu
authors: M
authors: Nagao
authors: Teruhito
authors: T
authors: Kido
authors: Akira
authors: A
authors: Kurata
authors: Masao
authors: M
authors: Miyagawa
authors: Akiyoshi
authors: A
authors: Ogimoto
authors: Teruhito
authors: T
authors: Mochizuki
mesh_terms: D000255:Adenosine Triphosphate; D000368:Aged; D019540:Area Under Curve; D001696:Biomechanical Phenomena; D003287:Contrast Media; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D003287:Contrast Media; D000255:Adenosine Triphosphate; D019786:Gadolinium DTPA