title: Clinical experience of strain imaging using DENSE for detecting infarcted cardiac segments.
abstract: BACKGROUND
  We hypothesised that myocardial deformation determined with magnetic resonance imaging (MRI) will detect myocardial scar.
  
  
  METHODS
  Displacement Encoding with Stimulated Echoes (DENSE) was used to calculate left ventricular strain in 125 patients (29 women and 96 men) with suspected coronary artery disease. The patients also underwent cine imaging and late gadolinium enhancement. 57 patients had a scar area >1% in at least one segment, 23 were considered free from coronary artery disease (control group) and 45 had pathological findings but no scar (mixed group). Peak strain was calculated in eight combinations: radial and circumferential strain in transmural, subendocardial and epicardial layers derived from short axis acquisition, and transmural longitudinal and radial strain derived from long axis acquisitions. In addition, the difference between strain in affected segments and reference segments, "differential strain", from the control group was analysed.
  
  
  RESULTS
  In receiver-operator-characteristic analysis for the detection of 50% transmurality, circumferential strain performed best with area-under-curve (AUC) of 0.94. Using a cut-off value of -17%, sensitivity was 95% at a specificity of 80%. AUC did not further improve with differential strain. There were significant differences between the control group and global strain circumferential direction (-17% versus -12%) and in the longitudinal direction (-13% versus -10%). Interobserver and scan-rescan reproducibility was high with an intraclass correlation coefficient (ICC) >0.93.
  
  
  CONCLUSIONS
  DENSE-derived circumferential strain may be used for the detection of myocardial segments with >50 % scar area. The repeatability of strain is satisfactory. DENSE-derived global strain agrees with other global measures of left ventricular ejection fraction.
authors.affiliation: Department of Radiology and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. johan.kihlberg@cmiv.liu.se.|Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden. johan.kihlberg@cmiv.liu.se.|Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. johan.kihlberg@cmiv.liu.se.
authors.forename: Johan
authors.initials: J
authors.lastname: Kihlberg
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden. haraldsson.henrik@gmail.com.|Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. haraldsson.henrik@gmail.com.|Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA. haraldsson.henrik@gmail.com.
authors.forename: Henrik
authors.initials: H
authors.lastname: Haraldsson
authors.affiliation: Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden. andreas.sigfridsson@gmail.com.
authors.forename: Andreas
authors.initials: A
authors.lastname: Sigfridsson
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden. tino.ebbers@liu.se.|Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. tino.ebbers@liu.se.
authors.forename: Tino
authors.initials: T
authors.lastname: Ebbers
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden. jan.engvall@regionostergotland.se.|Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. jan.engvall@regionostergotland.se.|Department of Clinical Physiology and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. jan.engvall@regionostergotland.se.
authors.forename: Jan E
authors.initials: JE
authors.lastname: Engvall
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001696:Biomechanical Phenomena; D002921:Cicatrix / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013318:Stroke Volume; D013548:Sweden; D016277:Ventricular Function, Left
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA