title: Comparison of postprocessing techniques for the detection of perfusion defects by cardiac computed tomography in patients presenting with acute ST-segment elevation myocardial infarction.
abstract: BACKGROUND
  Despite rapid advances in cardiac computed tomography (CT), a strategy for optimal visualization of perfusion abnormalities on CT has yet to be validated.
  
  
  OBJECTIVE
  We evaluated the performance of several postprocessing techniques of source data sets to detect and characterize perfusion defects in acute myocardial infarctions with cardiac CT.
  
  
  METHODS
  Twenty-one subjects (18 men; 60 +/- 13 years) that were successfully treated with percutaneous coronary intervention for ST-segment myocardial infarction underwent 64-slice cardiac CT and 1.5 Tesla cardiac magnetic resonance imaging (MRI) scans after revascularization. Delayed enhancement MR images were analyzed to identify the location of infarcted myocardium. Contiguous short-axis images of the left ventricular myocardium were created from the CT source images with 0.75-mm multiplanar reconstruction (MPR), 5-mm MPR, 5-mm maximal intensity projection (MIP), and 5-mm minimum intensity projection (MinIP) techniques. Segments already confirmed to contain infarction by MRI were then evaluated qualitatively and quantitatively with CT.
  
  
  RESULTS
  Overall, 143 myocardial segments were analyzed. On qualitative analysis, the MinIP and thick MPR techniques had greater visibility and definition than the thin MPR and MIP techniques (P < 0.001). On quantitative analysis, the absolute difference in Hounsfield unit attenuation between normal and infarcted segments was significantly greater for the MinIP (65.4 Hounsfield unit [HU]) and thin MPR (61.2 HU) techniques. However, the relative difference in Hounsfield unit attenuation was significantly greatest for the MinIP technique alone (95%; P < 0.001). Contrast to noise was greatest for the MinIP (4.2) and thick MPR (4.1) techniques (P < 0.001).
  
  
  CONCLUSIONS
  The results of our current investigation found that MinIP and thick MPR detected infarcted myocardium with greater visibility and definition than MIP and thin MPR.
authors.affiliation: Department of Radiology and Division of Cardiology, Massachusetts General Hospital, Boston, MA 02114-2750, USA.
authors.forename: Ian S
authors.initials: IS
authors.lastname: Rogers
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Cury
authors.forename: Ron
authors.initials: R
authors.lastname: Blankstein
authors.forename: Michael D
authors.initials: MD
authors.lastname: Shapiro
authors.forename: Koen
authors.initials: K
authors.lastname: Nieman
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Brady
authors.forename: Suhny
authors.initials: S
authors.lastname: Abbara
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D003287:Contrast Media; D003326:Coronary Circulation; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol; D019786:Gadolinium DTPA