Myocardial ischemia in acute coronary syndrome: assessment using 64-MDCT.
OBJECTIVE
We investigated the performance of 64-MDCT myocardial imaging in assessing myocardial ischemia in acute coronary syndrome (ACS).


METHODS
Cardiac CT was performed in 35 patients with ACS: 24 patients with acute myocardial infarction (AMI) and 11 patients with unstable angina pectoris (UAP). We reconstructed 2D myocardial images at diastolic and systolic phases using the same raw data as those used for coronary CT angiography. The CT number in the myocardium was used as an estimate of ischemia. The myocardium was shown using a color scale that depicts faint low-density areas more clearly than gray scale. We evaluated the variations in myocardial enhancement during the cardiac cycle in the territory of the culprit lesion. In addition, we classified patients on the basis of the transmurality of myocardial enhancement and examined whether this feature correlates with myocardial damage.


RESULTS
Myocardial imaging at systole showed myocardial hypoenhancement in territories of the culprit lesion in 91% of patients with ACS, 96% of patients with AMI, and 75% of patients with UAP. The hypoenhancement areas at systole tended to be more extensive than those at diastole. The transmural extent of hypoenhancement at systole correlated with myocardial damage, which was shown by myocardial biomarkers.


CONCLUSIONS
CT myocardial imaging can be used to assess myocardial ischemia in the appropriate region of ACS with high sensitivity.
Nagao
Michinobu
M
Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295, Japan. minagao@m.ehime-u.ac.jp
Matsuoka
Hiroshi
H
Kawakami
Hideo
H
Higashino
Hiroshi
H
Mochizuki
Teruhito
T
Uemura
Masahiko
M
Shigemi
Susumu
S
D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging*; D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*