Multidetector Computed Tomography for Coronary Stents Imaging: High-Voltage (140-kVp) Prospective ECG-Triggered Versus Standard-Voltage (120-kVp) Retrospective ECG-Gated Helical Scanning

Objective: To compare prospective electrocardiogram (ECG)-triggered high-voltage coronary computed tomography (CT) angiography (CTA; 140-kVp P-cCTA) with retrospective ECG-gated standard-voltage cCTA (120-kVp R-cCTA), in patients with coronary stents. Methods: Fifty-two patients with coronary stents were studied with 64-slice multidetector scanner. Ninety-three stents were analyzed: 55 with 140-kVp P-cCTA and 38 with 120-kVp R-cCTA. Image quality (IQ), diagnostic confidence (DC), in-stent assessable lumen, artificial narrowing, and effective radiation dose were compared between techniques. Results: Image quality and DC were significantly better for the 140-kVp P-cCTA in comparison with the 120-kVp R-cCTA (IQ, 1.1 +/- 0.36 vs 1.7 +/- 0.60, respectively; P < 0.00001. Diagnostic confidence: 1.1 +/- 0.29 vs 1.5 +/- 0.65 respectively; P < 0.0001). In-stent assessable lumen and artificial narrowing were comparable between the techniques. Effective dose was lower for the 140-kVp P-cCTA (6.7 +/- 2.07 mSv vs 15.8 +/- 6.89 mSv; P < 0.0001). Conclusions: High voltage combined with axial prospective ECG-triggered scan improved IQ and DC in stent cCTA imaging but failed to improve the diameter of in-stent assessable lumen and to reduce the artificial narrowing compared with the 120-kVp R-cCTA. Effective dose was 60% lower for the 140-kVp P-cCTA.