Evaluation of high-pitch dual-source CT angiography for evaluation of coronary and carotid-cerebrovascular arteries

Abstract

Objectives: To explore the feasibility and diagnostic accuracy of a combined one-step high-pitch dual-source computed tomography angiography (CTA) technique for evaluation of coronary and carotid-cerebrovascular arteries.

Materials and methods: 85 symptomatic patients suspected of coronary artery and cerebrovascular disease referred for simultaneous coronary and carotid-cerebrovascular CTA were included. Additional invasive angiography of the coronary and cerebral arteries was performed within 30 days in 23 and 13 patients, respectively. The objective parameters of image quality, the mean CT attenuations, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were evaluated. The subjective image quality of vessels was also assessed by 2 independent radiologists blinded to the patients' medical history and scan protocols. The diagnostic performance of CTA including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the detection or exclusion of significant artery stenosis was calculated using the chi-squared test of contingency and correlated with the results of invasive angiography representing the standard of reference.

Results: Image quality was rated excellent (score 1) in 95.3% (1074/1127), good (score 2) in 3.3% (37/1127), adequate (score 3) in 1.0% (11/1127), and non-diagnostic (score 4) in 0.4% (5/1127) of coronary segments. Image quality of carotid and cerebral vessels was rated mostly excellent (score 1, 95.12% [78/82]; score 2, 3.66% [3/82]; score 3, 1.22% [1/82]). The sensitivity, specificity, PPV and NPV for the detection of coronary stenosis were 92.2% (81.1-97.7%), 95.2% (91.7-97.5%), 79.6% (67.1-89.1%) and 98.3% (95.8-99.5%), respectively. For the detection of carotid and cerebral artery stenosis, CTA demonstrated a sensitivity of 92.8% (80.5-98.4%), a specificity of 93.5% (88.3-96.8%), a PPV of 79.6% (65.6-89.7%) and a NPV of 97.9% (94.1-99.5%). The effective radiation dose was 1.42±0.44mSv (range, 0.88-3.35mSv).

Conclusion: Dual-source CT with a one-step high-pitch scan protocol for combined coronary and carotid-cerebrovascular CTA provides good image quality and a high diagnostic accuracy for the simultaneous evaluation of coronary, carotid and cerebral artery stenosis and may be a useful examination with relatively low radiation exposure in patients with suspected coronary and carotid-cerebrovascular disease.

Keywords: Cerebrovascular angiography; Coronary angiography; High-pitch dual-source CT.