Prospective versus retrospective ECG-gated 64-detector coronary CT angiography for evaluation of coronary artery bypass graft patency: comparison of image quality, radiation dose and diagnostic accuracy

  • Jae Hwan Lee
  • Eun Ju Chun
  • Sang Il Choi
  • Mani Vembar
  • Cheong Lim
  • Kay-Hyun Park
  • Dong-Ju Choi
Original Paper


We aimed to evaluate image quality, radiation dose and diagnostic accuracy of coronary CT angiography (CCTA) with a prospectively gated transverse-axial scan (PGT) compared with a retrospectively gated helical scan (RGH), using a 64-slice scanner in patients who underwent coronary artery bypass graft (CABG). Of the 131 consecutive patients that underwent CABG using 64-slice multidetector row computed tomography during 2008, patients with heart rate (HR) of <75 beats/minute (bpm), and HR variation <10 bpm were included in the study. PGT was performed on 39 patients with 93 grafts, with RGH performed on 43 patients with 102 grafts. Image quality (1: excellent—4: poor) and estimated radiation dose were compared between the two groups. Of these, a total of 64 segments in 26 patients were subjected to invasive coronary angiography (ICA) for clinical reasons. Diagnostic accuracy of CCTA for evaluation of graft was performed between the two groups with ICA as a reference standard in terms of significant stenosis (≥ 50% of luminal stenosis). The image quality was not statistically different in the two groups. Mean effective radiation dose was 6.5 mSv in PGT-group, which was significantly lower than that in the RGH-group (21.2 mSv; P < 0.001). There was no statistically significant difference in diagnostic accuracy between the two groups (PGT-group versus RGH-group; 93.1% versus 91.4%). PGT can achieve dose reductions of up to 70% compared to RGH while maintaining image quality and high diagnostic accuracy in patients undergoing CABG.


Prospective coronary CT angiography CABG Radiation dose 



This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2010-0023504).

Conflict of interest



  1. 1.
    Fitzgibbon GM, Kafka HP, Leach AJ et al (1996) Coronary bypass graft fate and patient outcome: angiographic follow-up of 5, 065 grafts related to survival and reoperation in 1, 388 patients during 25 years. J Am Coll Cardiol 28(3):616–626PubMedCrossRefGoogle Scholar
  2. 2.
    Davis K, Kennedy JW, Kemp HG Jr et al (1979) Complications of coronary arteriography from the Collaborative Study of Coronary Artery Surgery (CASS). Circulation 59(6):1105–1112PubMedGoogle Scholar
  3. 3.
    Wyman RM, Safian RD, Portway V et al (1988) Current complications of diagnostic and therapeutic cardiac catheterization. J Am Coll Cardiol 12(6):1400–1406PubMedCrossRefGoogle Scholar
  4. 4.
    Hamon M, Lepage O, Malagutti P et al (2008) Diagnostic performance of 16- and 64-section spiral CT for coronary artery bypass graft assessment: meta-analysis. Radiology 247(3):679–686PubMedCrossRefGoogle Scholar
  5. 5.
    Malagutti P, Nieman K, Meijboom WB et al (2007) Use of 64-slice CT in symptomatic patients after coronary bypass surgery: evaluation of grafts and coronary arteries. Eur Heart J 28(15):1879–1885PubMedCrossRefGoogle Scholar
  6. 6.
    Hausleiter J, Meyer T, Hadamitzky M et al (2006) Radiation dose estimates from cardiac multislice computed tomography in daily practice: impact of different scanning protocols on effective dose estimates. Circulation 113(10):1305–1310PubMedCrossRefGoogle Scholar
  7. 7.
    Nickoloff EL, Alderson PO (2007) A comparative study of thoracic radiation doses from 64-slice cardiac CT. Br J Radiol 80(955):537–544PubMedCrossRefGoogle Scholar
  8. 8.
    Meyer TS, Martinoff S, Hadamitzky M et al (2007) Improved noninvasive assessment of coronary artery bypass grafts with 64-slice computed tomographic angiography in an unselected patient population. J Am Coll Cardiol 49(9):946–950PubMedCrossRefGoogle Scholar
  9. 9.
    Jabara R, Chronos N, Klein L et al (2007) Comparison of multidetector 64-slice computed tomographic angiography to coronary angiography to assess the patency of coronary artery bypass grafts. Am J Cardiol 99(11):1529–1534PubMedCrossRefGoogle Scholar
  10. 10.
    Earls JP, Berman EL, Urban BA et al (2008) Prospectively gated transverse coronary CT angiography versus retrospectively gated helical technique: improved image quality and reduced radiation dose. Radiology 246(3):742–753PubMedCrossRefGoogle Scholar
  11. 11.
    Earls JP, Schrack EC (2008) Prospectively gated low-dose CCTA: 24 months experience in more than 2, 000 clinical cases. Int J Cardiovasc Imaging 25(suppl 2):177–187Google Scholar
  12. 12.
    Maruyama T, Takada M, Hasuike T et al (2008) Radiation dose reduction and coronary assessability of prospective electrocardiogram-gated computed tomography coronary angiography: comparison with retrospective electrocardiogram-gated helical scan. J Am Coll Cardiol 52(18):1450–1455PubMedCrossRefGoogle Scholar
  13. 13.
    Shuman WP, Branch KR, May JM et al (2008) Prospective versus retrospective ECG gating for 64-detector CT of the coronary arteries: comparison of image quality and patient radiation dose. Radiology 248(2):431–437PubMedCrossRefGoogle Scholar
  14. 14.
    Klass O, Jeltsch M, Feuerlein S et al (2009) Prospectively gated axial CT coronary angiography: preliminary experiences with a novel low-dose technique. Eur Radiol 19(4):829–836PubMedCrossRefGoogle Scholar
  15. 15.
    Chazen JL, Prince MR, Yip R et al (2010) Post-CABG coronary CT angiography: radiation dose and graft image quality in retrospective versus prospective ECG gating. Acad Radiol 17(9):1122–1127PubMedCrossRefGoogle Scholar
  16. 16.
    Machida H, Masukawa A, Tanaka I et al (2010) Prospective electrocardiogram-gated axial 64-detector computed tomographic angiography vs retrospective gated helical technique to assess coronary artery bypass graft anastomosis: comparison of image quality and patient radiation dose. Circ J 74(4):735–740PubMedCrossRefGoogle Scholar
  17. 17.
    Chun EJ, Lee W, Choi YH et al (2008) Effects of nitroglycerin on the diagnostic accuracy of electrocardiogram-gated coronary computed tomography angiography. J Comput Assist Tomogr 32(1):86–92PubMedCrossRefGoogle Scholar
  18. 18.
    Ropers D, Pohle FK, Kuettner A et al (2006) Diagnostic accuracy of noninvasive coronary angiography in patients after bypass surgery using 64-slice spiral computed tomography with 330 ms gantry rotation. Circulation 114(22):2334–2341, quiz 2334PubMedCrossRefGoogle Scholar
  19. 19.
    Willmann JK, Weishaupt D, Kobza R et al (2004) Coronary artery bypass grafts: ECG-gated multi-detector row CT angiography—influence of image reconstruction interval on graft visibility. Radiology 232(2):568–577PubMedCrossRefGoogle Scholar
  20. 20.
    Hirai N, Horiguchi J, Fujioka C et al (2008) Prospective versus retrospective ECG-gated 64-detector coronary CT angiography: assessment of image quality, stenosis, and radiation dose. Radiology 248(2):424–430PubMedCrossRefGoogle Scholar
  21. 21.
    Morin RL, Gerber TC, McCollough CH (2003) Radiation dose in computed tomography of the heart. Circulation 107(6):917–922PubMedCrossRefGoogle Scholar
  22. 22.
    Zeger SL, Liang KY, Albert PS (1988) Models for longitudinal data: a generalized estimating equation approach. Biometrics 44(4):1049–1060PubMedCrossRefGoogle Scholar
  23. 23.
    Herzog BA, Wyss CA, Husmann L et al (2009) First head-to-head comparison of effective radiation dose from low-dose 64-slice CT with prospective ECG-triggering versus invasive coronary angiography. Heart 95(20):1656–1661PubMedCrossRefGoogle Scholar
  24. 24.
    Leschka S, Wildermuth S, Boehm T et al (2006) Noninvasive coronary angiography with 64-section CT: effect of average heart rate and heart rate variability on image quality. Radiology 241(2):378–385PubMedCrossRefGoogle Scholar
  25. 25.
    Herzog BA, Husmann L, Burkhard N et al (2009) Low-dose CT coronary angiography using prospective ECG-triggering: impact of mean heart rate and heart rate variability on image quality. Acad Radiol 16(1):15–21PubMedCrossRefGoogle Scholar
  26. 26.
    Herzog C, Zwerner PL, Doll JR et al (2007) Significant coronary artery stenosis: comparison on per-patient and per-vessel or per-segment basis at 64-section CT angiography. Radiology 244(1):112–120PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, B.V. 2011

Authors and Affiliations

  • Jae Hwan Lee
    • 1
  • Eun Ju Chun
    • 1
  • Sang Il Choi
    • 1
  • Mani Vembar
    • 2
  • Cheong Lim
    • 3
  • Kay-Hyun Park
    • 3
  • Dong-Ju Choi
    • 4
  1. 1.Divison of Cardiovascular Imaging, Department of RadiologySeoul National University Bundang HospitalGyeonggi-doKorea
  2. 2.Philips HealthcareCT Clinical ScienceClevelandUSA
  3. 3.Department of Thoracic and Cardiovascular SurgerySeoul National University Bundang HospitalGyeonggi-doKorea
  4. 4.Division of Cardiology, Department of Internal MedicineSeoul National University Bundang HospitalGyeonggi-doKorea

Personalised recommendations