Coronary Computed Tomography Angiography with a Consistent Dose Below 1 mSv using Prospectively Electrocardiogram-Triggered High-Pitch Spiral Acquisition

Eur Heart J. 2009; 1(1):470

Achenbach S, Marwan M, Ropers D, Schepis T, Pflederer T, Anders K, Kuettner A, Daniel WG, Uder M, Lell MM

OBJECTIVES: 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: In 50 consecutive patients (body weight <100 kg, sinus rhythm <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).

RESULTS: 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.”

CONCLUSIONS: 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.

PMID: 19897497

4 Responses

  1. Ronen Rubinshtein, MD  on November 12th, 2009

    An important work! The consistently good image quality is reassuring. Results should be applicable to other vendors, although scan protocols may vary.
    Are we approaching the lower limit of “possible” radiation dose in selected patients without compromising image quality? It seems that advances in CT technology have changed the term “possible” quiet often in the last few years…

  2. Paul Schoenhagen, MD  on November 14th, 2009

    I do NOT think that these results are easily applicable to other vendors. The high-pitch mode is a feature of dual-source technology.

    See post from September 16:
    Diagnostic accuracy of high-pitch dual-source CT for the assessment of coronary stenosIs: first experience.
    Leschka S, Stolzmann P, Desbiolles L, Baumueller S, Goetti R, Schertler T, Scheffel H, Plass A, Falk V, Feuchtner G, Marincek B, Alkadhi H.
    Eur Radiol. 2009 Sep 16. 2009.

    On the other hand, use of 100kv tube voltage is applicable to scanners of those vendors that have already implemented 100 kV imaging.

  3. Paul Schoenhagen, MD  on February 3rd, 2010

    It should be noted that this is a selected patient population with a weight of 100kg, and a well controlled heart rate of 60 bpm.

  4. Paul Schoenhagen  on April 12th, 2011

    See also:

    Detection of Coronary Artery Stenoses by Low-Dose, Prospectively ECG-Triggered, High-Pitch Spiral Coronary CT Angiography.
    Stephan Achenbach, Tobias Goroll, Martin Seltmann, Tobias Pflederer, Katharina Anders, Dieter Ropers, Werner G. Daniel, Michael Uder, Michael Lell, and Mohamed Marwan.
    J Am Coll Cardiol Img 2011;4 328-337.


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