Review
Prospective versus retrospective ECG-gated multislice CT coronary angiography: A systematic review of radiation dose and diagnostic accuracy

https://doi.org/10.1016/j.ejrad.2011.01.070Get rights and content

Abstract

Purpose

To perform a systematic review of the radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated multislice CT coronary angiography.

Materials and methods

A search of Pubmed/Medline and Sciencedirect databases for English literature was performed to identify studies comparing prospective and retrospective ECG-gated multislice CT angiography in the diagnosis of coronary artery disease. Effective dose, dose length product, image quality and diagnostic value were compared between two groups of studies.

Results

22 studies were included for analysis. The mean effective dose of prospective ECG-gated scans was 4.5Ā mSv (95% CI: 3.6, 5.3Ā mSv), which is significantly lower than that of retrospective scans, which is 13.8Ā mSv (95% CI: 11.5, 16.0Ā mSv) (pĀ <Ā 0.001). The mean dose length product was 225Ā mGyĀ cm (95% CI: 188, 262Ā mGyĀ cm) and 822Ā mGyĀ cm (95% CI: 630, 1013Ā mGyĀ cm) for the prospective and retrospective ECG-gated scans, respectively, indicating a statistically significant difference between these two protocols (pĀ <Ā 0.0001). The mean sensitivity and specificity of multislice CT angiography in the diagnosis of coronary artery disease was 97.7% (95% CI: 93.7%, 100%) and 92.1% (95% CI: 87.2%, 97%) for prospective ECG-gated scans; 95.2% (95% CI: 91%, 99.5%) and 94.4% (95% CI: 88.5%, 100%) for retrospective ECG-gated scans, respectively, with no significant difference for sensitivity but significant difference for specificity (pĀ =Ā 0.047).

Conclusion

Multislice CT coronary angiography with prospective ECG-gating leads to a significant reduction of radiation dose when compared to that of retrospective ECG-gating, while offering comparable image quality and diagnostic value.

Introduction

Since the introduction of 64- or more-slice CT technology, multislice CT (MSCT) angiography has been increasingly used in the diagnosis of coronary artery disease (CAD) due to its improved spatial and temporal resolution [1], [2], [3], [4]. Studies have shown that MSCT angiography is a highly accurate method compared to invasive coronary angiography as it provides high sensitivity and specificity [1], [2], [3], [4], [5], [6]. In particular, MSCT angiography has been reported to demonstrate a very high negative predictive value (more than 95%), indicating that it can be used as a reliable screening technique for patients suspected of CAD, thereby reducing the need for invasive coronary angiography [5]. The non-invasive nature of MSCT angiography and increased availability of MSCT scanners have led to rapidly increasing numbers of CT examinations performed worldwide. However, high radiation dose of MSCT angiography and its associated risk of radiation-induced malignancy have raised serious concerns in the medical field [7], [8], [9], [10].

In response to these concerns, tremendous progress has been made to lower radiation dose for cardiac MSCT angiography, and various strategies have been proposed to address this issue. These include automatic tube current modulation, reduced X-ray tube voltage and tube current, scan range, and prospective ECG-gating [11]. Of these dose-saving strategies, prospective ECG-gated scanning represents the most recently developed approach with significant reduction of radiation dose when compared to conventional retrospective ECG-gating [12].

Radiation exposure with prospective ECG-gating has been increasingly studied and evaluated with retrospective-gating in the literature [11], [12], [13], [14]. Despite promising results having been achieved in dose reduction, there are concerns about the image quality and diagnostic value of prospective ECG-gating, since only a portion of data is acquired when compared to the volumetric data that is available with retrospective-gating protocol. Thus, the purpose of this study was to perform a systematic review of radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated MSCT angiography in the diagnosis of CAD, based on the currently available literature.

Section snippets

Criteria for data selection and literature searching

A search of Pubmed/Medline and Sciencedirect databases of English literature was performed for articles comparing prospective ECG-gated MSCT angiography with retrospective ECG-gated scans in patients with suspected or confirmed CAD. Inclusion criteria required that articles must be peer-reviewed and published in the English language. The keywords used in searching the references included: MSCT angiography with prospective ECG-gating/ECG-triggering, radiation dose of MSCT angiography, diagnostic

General information

25 studies met the selection criteria and 22 were eligible for analysis [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40]. Three studies were excluded from the analysis as they either focused on the assessment of coronary stenting or coronary bypass instead of coronary artery disease [38], [39], [40]. There are altogether 37 comparisons from these 22 studies as seven studies involved different

Discussion

Our analysis presents three findings which we consider important for clinical application of MSCT angiography in CAD: first, prospective ECG-gating leads to a significant reduction of DLP and effective dose by more than 60% (up to 90% in some studies) when compared to retrospective ECG-gating. Second, diagnostic image quality of prospective ECG-gating is comparable to that of retrospective ECG-gating, in terms of both subjective and objective assessment of coronary segments. This indicates that

Conflict of interest

None.

References (54)

  • K. Kitagawa et al.

    Prospective ECG-gated 320 row detector computed tomography: implications for CT angiography and perfusion imaging

    Int J Cardiovasc Imaging

    (2009)
  • M.E. Dewey et al.

    Noninvasive coronary angiography by 320-row computed tomography with lower radiation exposure and maintained diagnostic accuracy: comparison of results with cardiac catheterization in a head-to-head pilot investigation

    Circulation

    (2009)
  • A.W. Leber et al.

    Diagnostic accuracy of dual-source multi-slice CT coronary angiography in patients with an intermediate pretest likelihood for coronary artery disease

    Eur Heart J

    (2007)
  • J.F. Paul et al.

    Strategies for reduction of radiation dose in cardiac multislice CT

    Eur Radiol

    (2007)
  • D.J. Brenner et al.

    Computed tomographyā€“ā€“an increasing source of radiation exposure

    N Engl J Med

    (2007)
  • J. Hausleiter et al.

    Estimated radiation dose associated with cardiac CT angiography

    JAMA

    (2009)
  • G.L. Raff et al.

    Radiation dose from cardiac computed tomography before and after implementation of radiation dose-reduction techniques

    JAMA

    (2009)
  • Z. Sun et al.

    Angiography in cardiac imaging. Part III: radiation risk and dose reduction

    Singapore Med J

    (2010)
  • Z. Sun et al.

    Angiography in cardiac imaging: prospective ECG-gating or retrospective ECG-gating?

    Biomed Imaging Interv J

    (2010)
  • L. Husmann et al.

    Feasibility of low-dose coronary CT angiography: first experience with prospective ECG-gating

    Eur Heart J

    (2008)
  • B.A. Herzog et al.

    First head-to-head comparison of effective radiation dose from low-dose 64-slice CT with prospective ECG-triggering versus invasive coronary angiography

    Heart

    (2009)
  • International Commission on Radiological Protection

    Recommendations of the International Commission on Radiological Protection

    (2007)
  • W.P. Shuman et al.

    Prospective versus retrospective ECG gating for 64-detector CT of the coronary arteries: comparison of image quality and patient radiation dose

    Radiology

    (2008)
  • J. Earls et al.

    Prospectively gated transverse coronary CT angiography versus retrospectively gated helical CT technique: improved image quality and reduced radiation dose

    Radiology

    (2008)
  • F.J. Ribicki et al.

    Initial evaluation of coronary images from 320-detector row computed tomography

    Int J Cardiovasc Imaging

    (2008)
  • N. Hirai et al.

    Prospective versus retrospective ECG-gated 64-detector coronary CT angiography: assessment of image quality, stenosis, and radiation dose

    Radiology

    (2008)
  • E.P. Efstathopoulos et al.

    Reduction of the estimated radiation dose and associated patient risk with prospective ECG-gated 256-slice CT coronary angiography

    Phys Med Biol

    (2009)
  • Cited by (81)

    • Imaging of Heritable Thoracic Aortic Disease

      2022, Seminars in Roentgenology
    • Plan optimization for mediastinal radiotherapy: Estimation of coronary arteries motion with ECG-gated cardiac imaging and creation of compensatory expansion margins

      2018, Radiotherapy and Oncology
      Citation Excerpt :

      Our Hospital authorized the retrospective use of the anonymized image set for the study purposes. All ECG-gated CT scans were performed on the same 64 slices CT scanner (Lightspeed VCT Scanner, General Electric Healthcare, Waukesha, WI, USA), with intravenous contrast (Ultravist 370 mg/ml), adopting a dedicated retrospective ECG-gated spiral algorithm [10ā€“12]. A spiral CT scan with continuous table movement and data acquisition was performed; simultaneously, the patientā€™s ECG was recorded and images acquired across different heartbeats, creating a heart phase-consistent sequence.

    View all citing articles on Scopus
    View full text