Topics:
Non-invasive imaging: Echocardiography, MR/CT, Nuclear
Authors: Prof. Dr. Stephen Schröder,
Göppingen, Germany
The need for radiation exposure is still the ”Achilles heel” of cardiac CT. In meantime, new scanner generations and dedicated scan protocols minimizing radiation dose are available. In the current publication, image quality and radiation dose were evaluated using latest technology.
The results indicate that cardiac CT can be performed in selected and well prepared patients with a rather low radiation dose.
This constitutes a real step forward in the use of cardiac CT.
AIMS:
We evaluated the feasibility and image quality of a new scan mode for coronary computed tomography angiography (CTA) with an effective dose of less than 1 mSv.
METHODS AND RESULTS:
In 50 consecutive patients (body weight <or= 100 kg, sinus rhythm <or=60 b.p.m. after pre-medication, coronary CTA was performed using a dual-source CT system with 2 x 128 x 0.6 mm collimation, 0.28 s rotation time, a pitch of 3.2 or 3.4, 100 kV tube voltage and current of 320 mA s. Data acquisition was prospectively triggered at 60% of the R-R interval and completed within one cardiac cycle. Image quality was evaluated using a four-point scale (1 = absence of any artefacts to 4 = uninterpretable). In all 50 patients, imaging was successful. Mean duration of data acquisition was 258 +/- 20 ms. Mean dose-length product was 62 +/- 5 mGy cm, the effective dose was 0.87 +/- 0.07 mSv (0.78-0.99 mSv). Of the 742 coronary artery segments, 94% had an image quality score of 1, 5.0% a score of 2, 0.9% a score of 3, and 4 segments (0.5%) were 'uninterpretable'.
CONCLUSION: In non-obese patients with a low and stable heart rate, prospectively ECG-triggered high-pitch spiral coronary CTA provides excellent image quality at a consistent dose below 1.0 mSv.
References
Eur Heart J. 2010 Feb;31(3):340-6
The content of this article reflects the personal opinion of the
author/s and is not necessarily the official position of the
European Society of Cardiology.