Infarct Detection With a Comprehensive Cardiac CT Protocol

OBJECTIVES: Cardiac CT has the potential to offer comprehensive infarct detection by assessing regional wall motion abnormalities (RWMAs), rest perfusion defects (RPDs), and delayed contrast enhancement (DCE). However, the diagnostic accuracy of these techniques for the detection of myocardial infarction (MI) is unknown.

METHODS: Forty-eight patients with intermediate-to-high probability for coronary artery disease after single-photon emitting CT myocardial perfusion imaging were prospectively enrolled for a research comprehensive 64-detector row dual-source cardiac CT protocol that included cine images for RWMA, first-pass images for RPD, and delayed images for DCE. Blinded readers independently assessed each technique. Subsequently, a final combined analysis (cine + rest + DCE) was performed. The universal definition for MI by the 2007 American Heart Association task force was used as the “gold standard.”

RESULTS: Twenty-four of 48 patients (50%) had infarct by the universal definition. The combined CT analysis was most accurate (90%) with the highest per-patient sensitivity (88%) and specificity (92%) versus individual assessments (RWMA, 79% and 88%; RPD, 67% and 92%; DCE, 79% and 88%). Similar findings were observed on a per-vessel basis analysis. A combination of DCE and cine showed a good accuracy (85%) and high sensitivity (92%).

CONCLUSIONS: Infarct detection with CT is feasible with overall good diagnostic accuracy compared with the universal definition. A combined evaluation that included all techniques (cine, RPD, and DCE) had the highest diagnostic accuracy. These findings may have implications when designing future clinical and research CT protocols for optimal infarct detection.

PMID: 22210535

Posted in Computed Tomography and tagged , , , , , , .

2 Comments

  1. Interesting concept for a “CT One Stop Shop” approach for MI imaging. The high sensitivity of the combined approach to diagnose MI in this study is promising. Perhaps, with the ongoing progress in dose saving technologies, this approach will have clinical applications. As of now, I assume, most patients with MI will be evaluated with Echo and invasive angiography.

  2. This is an excellent paper! Eventually, post-processing of well-performed delayed enhancement CT might approach the CNR of an MRI, and the addition of stress perfusion to CT will truly make it a comprehensive cardiac evaluation. Radiation dose is obviously the concern, particularly for sites without the latest technology. We have performed delayed CTA for infarct with success, as well, in clinical scenarios where the referrer requests it (e.g., pacemaker patient).

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