Prospectively ECG-triggered high-pitch spiral acquisition for coronary CT angiography using dual source CT: technique and initial experience

• Published in: European radiology 2009-11, Vol.19 (11), p.2576-2583
• Main Authors: Lell, Michael, Marwan, Mohamed, Schepis, Tiziano, Pflederer, Tobias, Anders, Katharina, Flohr, Thomas, Allmendinger, Thomas, Kalender, Willi, Ertel, Dirk, Thierfelder, Carsten, Kuettner, Axel, Ropers, Dieter, Daniel, Werner G., Achenbach, Stephan
• Format: Article
• Language: English
• Subjects: Body Weight; Cardiac; Contrast agents; Coronary Angiography - methods; Coronary vessels; Datasets; Diagnostic Radiology; Electrocardiography - methods; Female; Heart - diagnostic imaging; Heart Rate; Humans; Image Processing, Computer-Assisted; Imaging; Internal Medicine; Interventional Radiology; Male; Medical imaging; Medicine; Medicine & Public Health; Models, Anatomic; Neuroradiology; Patients; Prospective Studies; Radiation; Radiation Dosage; Radiology; Sensors; Tomography; Tomography, Spiral Computed - methods; Tomography, X-Ray Computed - methods; Ultrasound
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-009-1558-4

Objective We evaluated radiation exposure and image quality of a new coronary CT angiography protocol, high-pitch spiral acquisition, using dual source CT (DSCT). Material and methods Coronary CTA was performed in 25 consecutive patients with a stable heart rate of 60 bpm or less after premedication, using 2 × 128 0.6-mm sections, 38.4-mm collimation width and 0.28-s rotation time. Tube settings were 100 kV/320 mAs and 120 kV/400 mAs for patients below and above 100-kg weight, respectively. Data acquisition was prospectively ECG-triggered at 60% of the R–R interval using a pitch of 3.2 (3.4 for the last 10 patients). Images were reconstructed with 75-ms temporal resolution, 0.6-mm slice thickness and 0.3-mm increment. Image quality was evaluated using a four-point scale (1 = excellent, 4 = unevaluable). Results Mean range of data acquisition was 113 ± 22 mm, mean duration was 268 ± 23 ms. Of 363 coronary artery segments, 327 had an image quality score of 1, and only 2 segments were rated as “unevaluable”. Mean dose–length product (DLP) was 71 ± 23 mGy cm, mean effective dose was 1.0 ± 0.3 mSv (range 0.78–2.1 mSv). For 21 patients with a body weight below 100 kg, mean DLP was 63 ± 5 mGy cm (0.88 ± 0.07 mSv; range 0.78–0.97 mSv). Conclusion Prospectively ECG-triggered high-pitch spiral CT acquisition provides high and stable image quality at very low radiation dose.