title: Differentiation of recent and chronic myocardial infarction by cardiac computed tomography.
abstract: Clinical use of cardiac computed tomography is rapidly expanding, and its purpose may reach beyond noninvasive coronary angiography. We investigated the ability of 64-slice multidetector computed tomography to differentiate between recent and long-standing myocardial infarction (MI). Contrast-enhanced coronary computed tomographic (CT) scans (Siemens Sensation 64) of patients with a recent MI (< 7 days, n = 16), long-standing MI (> 12 months, n = 13), and no MI (n = 13) were retrospectively evaluated. To anticipate transmural variation of myocardial perfusion and to neutralize image noise, a series of thin, overlapping slices was created in parallel alignment to the myocardial wall. Within each of these slices, a small region of interest was placed at a constant in-plane position to measure the CT attenuation (Hounsfield units [HU]) at consecutive transmural locations of injured and normal remote myocardium. In addition, wall thickness and the myocardial cavity were measured. Significantly lower CT attenuation values were found in patients with long-standing MI (-13 +/- 37 HU) than in those with acute MI (26 +/- 26 HU) and normal controls (73 +/- 14 HU, p < 0.001). The attenuation difference between infarcted and remote myocardia was larger in patients with long-standing MI than in patients with recent MI (89 +/- 41 and 55 +/- 33 HU, respectively, p < 0.001). In addition, long-standing MI was associated with wall thinning (p < 0.01), and ventricular dilation (p < 0.05), whereas recent MI was not (p > 0.05). In conclusion, recent and long-standing MIs may be differentiated by computed tomography based on myocardial CT attenuation values and ventricular dimensions.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA. koennieman@hotmail.com
authors.forename: Koen
authors.initials: K
authors.lastname: Nieman
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Cury
authors.forename: Maros
authors.initials: M
authors.lastname: Ferencik
authors.forename: Cesar H
authors.initials: CH
authors.lastname: Nomura
authors.forename: Suhny
authors.initials: S
authors.lastname: Abbara
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Herman K
authors.initials: HK
authors.lastname: Gold
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Brady
mesh_terms: D017023:Coronary Angiography; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D014057:Tomography, X-Ray Computed