Journal Article

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

Schepis, Tiziano, Allmendinger, Thomas, Kalender, Willi, Anders, Katharina, Kuettner, Axel, Pflederer, Tobias, Daniel, Werner G., Ertel, Dirk, Thierfelder, Carsten, Marwan, Mohamed, Ropers, Dieter, Flohr, Thomas, Lell, Michael, Achenbach, Stephan

2009

Overview

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.

• Publisher: Springer-Verlag,Springer Nature B.V
• Subject: 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