Image quality, radiation dose, and diagnostic accuracy of prospectively ECG-triggered high-pitch coronary CT angiography at 70 kVp in a clinical setting: comparison with invasive coronary angiography.
PURPOSE
To investigate image quality, radiation dose, and diagnostic performance of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) at 70 kVp compared to invasive coronary angiography (ICA) as reference standard.


MATERIALS AND METHODS
Forty-three patients underwent prospectively ECG-triggered high-pitch CCTA at 70 kVp using 30 cc (11 g iodine) contrast medium and ICA. Subjective and objective image quality was evaluated for each CCTA study. CCTA performance for diagnosing ≥50% stenosis was assessed. Results were stratified according to heart rate (HR), body mass index (BMI), Agatston score, and image quality.


RESULTS
At CCTA, 94.3% (500/530) of coronary segments were of diagnostic quality. Using ICA as reference standard, sensitivity and accuracy were 100% and 93.0% on a per-patient basis. Per-vessel and per-segment performances were 92.2% and 89.5%; 79.5% and 88.3%, respectively. No differences were found in diagnostic accuracy between different HR, BMI, and calcification subgroups (all P > 0.05) on a per-patient basis. However, low image quality reduced diagnostic accuracy on a per-patient, per-vessel and per-segment basis (all P < 0.05). The mean effective radiation dose was 0.2 ± 0.0 mSv.


CONCLUSION
Our presented protocol results in an effective radiation dose of 0.2 mSv and high diagnostic accuracy for stenosis detection in a selected, non-obese population.


KEY POINTS
Prospectively ECG-triggered high-pitch CCTA at 70 kVp is feasible. This protocol has a high diagnostic accuracy for stenosis detection. The mean effective radiation dose was 0.2 ± 0.0 mSv. Only 30 cc of contrast material is used in this protocol. Low image quality reduced diagnostic accuracy of CCTA.
['Zhang|Long Jiang|LJ|', 'Wang|Yining|Y|', 'Schoepf|U Joseph|UJ|', 'Meinel|Felix G|FG|', 'Bayer|Richard R|RR|', 'Qi|Li|L|', 'Cao|Jian|J|', 'Zhou|Chang Sheng|CS|', 'Zhao|Yan E|YE|', 'Li|Xie|X|', 'Gong|Jian Bin|JB|', 'Jin|Zhengyu|Z|', 'Lu|Guang Ming|GM|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D015992:Body Mass Index D003287:Contrast Media D017023:Coronary Angiography D023921:Coronary Stenosis D004562:Electrocardiography D005260:Female D006321:Heart D006339:Heart Rate D006801:Humans D008297:Male D008875:Middle Aged D011446:Prospective Studies D011829:Radiation Dosage D012015:Reference Standards D012680:Sensitivity and Specificity D014057:Tomography, X-Ray Computed D061205:Vascular Calcification
Coronary CT angiography High-pitch acquisition Low contrast medium Low kilovoltage Prospective ECG gating