Korean Journal of Radiology

The Korean Society of Radiology (대한영상의학회)
권호 표지
DOI QR코드

DOI QR Code

Myocardial Coverage and Radiation Dose in Dynamic Myocardial Perfusion Imaging Using Third-Generation Dual-Source CT

  • Received : 2019.05.07
  • Accepted : 2019.08.30
  • Published : 2020.01.01
Download PDF
⟨ Previous Next ⟩

Abstract

Objective: Third-generation dual-source computed tomography (3rd-DSCT) allows dynamic myocardial CT perfusion imaging (dynamic CTP) with a 10.5-cm z-axis coverage. Although the increased radiation exposure associated with the 50% wider scan range compared to second-generation DSCT (2nd-DSCT) may be suppressed by using a tube voltage of 70 kV, it remains unclear whether image quality and the ability to quantify myocardial blood flow (MBF) can be maintained under these conditions. This study aimed to compare the image quality, estimated MBF, and radiation dose of dynamic CTP between 2ndDSCT and 3rd-DSCT and to evaluate whether a 10.5-cm coverage is suitable for dynamic CTP. Materials and Methods: We retrospectively analyzed 107 patients who underwent dynamic CTP using 2nd-DSCT at 80 kV (n = 54) or 3rd-DSCT at 70 kV (n = 53). Image quality, estimated MBF, radiation dose, and coverage of left ventricular (LV) myocardium were compared. Results: No significant differences were observed between 3rd-DSCT and 2nd-DSCT in contrast-to-noise ratio (37.4 ± 11.4 vs. 35.5 ± 11.2, p = 0.396). Effective radiation dose was lower with 3rd-DSCT (3.97 ± 0.92 mSv with a conversion factor of 0.017 mSv/mGy∙cm) compared to 2nd-DSCT (5.49 ± 1.36 mSv, p < 0.001). Incomplete coverage was more frequent with 2nd-DSCT than with 3rd-DSCT (1.9% [1/53] vs. 56% [30/54], p < 0.001). In propensity score-matched cohorts, MBF was comparable between 3rd-DSCT and 2nd-DSCT in non-ischemic (146.2 ± 26.5 vs. 157.5 ± 34.9 mL/min/100 g, p = 0.137) as well as ischemic myocardium (92.7 ± 21.1 vs. 90.9 ± 29.7 mL/min/100 g, p = 0.876). Conclusion: The radiation increase inherent to the widened z-axis coverage in 3rd-DSCT can be balanced by using a tube voltage of 70 kV without compromising image quality or MBF quantification. In dynamic CTP, a z-axis coverage of 10.5 cm is sufficient to achieve complete coverage of the LV myocardium in most patients.

Keywords

Acknowledgement

This study was partly supported by a departmental research grant from Siemens Japan.

References

  1. Schuijf JD, Ko BS, Di Carli MF, Hislop-Jambrich J, Ihdayhid AR, Seneviratne SK, et al. Fractional flow reserve and myocardial perfusion by computed tomography: a guide to clinical application. Eur Heart J Cardiovasc Imaging 2018;19:127-135 https://doi.org/10.1093/ehjci/jex240
  2. Nakamura S, Kitagawa K, Goto Y, Omori T, Kurita T, Yamada A, et al. Incremental prognostic value of myocardial blood flow quantified with stress dynamic computed tomography perfusion imaging. JACC Cardiovasc Imaging 2019;12(7 Pt 2):1379-1387 https://doi.org/10.1016/j.jcmg.2018.05.021
  3. Kitagawa K, Goto Y, Nakamura S, Takafuji M, Hamdy A, Ishida M, et al. Dynamic CT perfusion imaging: state of the art. Cardiovasc Imaging Asia 2018;2:38-48 https://doi.org/10.22468/cvia.2018.00031
  4. Yang DH, Kim YH, Roh JH, Kang JW, Han D, Jung J, et al. Stress myocardial perfusion CT in patients suspected of having coronary artery disease: visual and quantitative analysis-validation by using fractional flow reserve. Radiology 2015;276:715-723 https://doi.org/10.1148/radiol.2015141126
  5. Rochitte CE, George RT, Chen MY, Arbab-Zadeh A, Dewey M, Miller JM, et al. Computed tomography angiography and perfusion to assess coronary artery stenosis causing perfusion defects by single photon emission computed tomography: the CORE320 study. Eur Heart J 2014;35:1120-1130 https://doi.org/10.1093/eurheartj/eht488
  6. Goto Y, Kitagawa K, Uno M, Nakamori S, Ito T, Nagasawa N, et al. Diagnostic accuracy of endocardial-to-epicardial myocardial blood flow ratio for the detection of significant coronary artery disease with dynamic myocardial perfusion dual-source computed tomography. Circ J 2017;81:1477-1483 https://doi.org/10.1253/circj.CJ-16-1319
  7. Coenen A, Lubbers MM, Kurata A, Kono A, Dedic A, Chelu RG, et al. Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis. Eur Radiol 2017;27:2309-2316 https://doi.org/10.1007/s00330-016-4567-0
  8. Vliegenthart R, De Cecco CN, Wichmann JL, Meinel FG, Pelgrim GJ, Tesche C, et al. Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension: insights from a multicenter registry. J Cardiovasc Comput Tomogr 2016;10:301-308 https://doi.org/10.1016/j.jcct.2016.05.005
  9. Rossi A, Dharampal A, Wragg A, Davies LC, van Geuns RJ, Anagnostopoulos C, et al. Diagnostic performance of hyperaemic myocardial blood flow index obtained by dynamic computed tomography: does it predict functionally significant coronary lesions? Eur Heart J Cardiovasc Imaging 2014;15:85- 94 https://doi.org/10.1093/ehjci/jet133
  10. Bamberg F, Becker A, Schwarz F, Marcus RP, Greif M, von Ziegler F, et al. Detection of hemodynamically significant coronary artery stenosis: incremental diagnostic value of dynamic CT-based myocardial perfusion imaging. Radiology 2011;260:689-698 https://doi.org/10.1148/radiol.11110638
  11. Kim SM, Kim YN, Choe YH. Adenosine-stress dynamic myocardial perfusion imaging using 128-slice dual-source CT: optimization of the CT protocol to reduce the radiation dose. Int J Cardiovasc Imaging 2013;29:875-884 https://doi.org/10.1007/s10554-012-0138-x
  12. Fujita M, Kitagawa K, Ito T, Shiraishi Y, Kurobe Y, Nagata M, et al. Dose reduction in dynamic CT stress myocardial perfusion imaging: comparison of 80-kV/370-mAs and 100-kV/300-mAs protocols. Eur Radiol 2014;24:748-755 https://doi.org/10.1007/s00330-013-3063-z
  13. Meinel FG, Canstein C, Schoepf UJ, Sedlmaier M, Schmidt B, Harris BS, et al. Image quality and radiation dose of low tube voltage 3rd generation dual-source coronary CT angiography in obese patients: a phantom study. Eur Radiol 2014;24:1643-1650 https://doi.org/10.1007/s00330-014-3194-x
  14. Meyer M, Haubenreisser H, Schoepf UJ, Vliegenthart R, Leidecker C, Allmendinger T, et al. Closing in on the K edge: coronary CT angiography at 100, 80, and 70 kV-initial comparison of a second- versus a third-generation dual-source CT system. Radiology 2014;273:373-382 https://doi.org/10.1148/radiol.14140244
  15. Nakayama Y, Awai K, Funama Y, Hatemura M, Imuta M, Nakaura T, et al. Abdominal CT with low tube voltage: preliminary observations about radiation dose, contrast enhancement, image quality, and noise. Radiology 2005;237:945-951 https://doi.org/10.1148/radiol.2373041655
  16. Bahner ML, Bengel A, Brix G, Zuna I, Kauczor HU, Delorme S. Improved vascular opacification in cerebral computed tomography angiography with 80 kVp. Invest Radiol 2005;40:229-234 https://doi.org/10.1097/01.rli.0000155281.32319.52
  17. Kurobe Y, Kitagawa K, Ito T, Kurita Y, Shiraishi Y, Nakamori S, et al. Myocardial delayed enhancement with dual-source CT: advantages of targeted spatial frequency filtration and image averaging over half-scan reconstruction. J Cardiovasc Comput Tomogr 2014;8:289-298 https://doi.org/10.1016/j.jcct.2014.06.004
  18. Kurita Y, Kitagawa K, Kurobe Y, Nakamori S, Nakajima H, Dohi K, et al. Estimation of myocardial extracellular volume fraction with cardiac CT in subjects without clinical coronary artery disease: a feasibility study. J Cardiovasc Comput Tomogr 2016;10:237-241 https://doi.org/10.1016/j.jcct.2016.02.001
  19. Mahnken AH, Klotz E, Pietsch H, Schmidt B, Allmendinger T, Haberland U, et al. Quantitative whole heart stress perfusion CT imaging as noninvasive assessment of hemodynamics in coronary artery stenosis: preliminary animal experience. Invest Radiol 2010;45:298-305 https://doi.org/10.1097/RLI.0b013e3181dfa3cf
  20. Einstein AJ, Moser KW, Thompson RC, Cerqueira MD, Henzlova MJ. Radiation dose to patients from cardiac diagnostic imaging. Circulation 2007;116:1290-1305 https://doi.org/10.1161/CIRCULATIONAHA.107.688101
  21. So A, Imai Y, Nett B, Jackson J, Nett L, Hsieh J, et al. Technical note: evaluation of a 160-mm/256-row CT scanner for whole-heart quantitative myocardial perfusion imaging. Med Phys 2016;43:4821
  22. Yi Y, Wu W, Lin L, Zhang HZ, Qian H, Shen ZJ, et al. Singlephase coronary artery CT angiography extracted from stress dynamic myocardial CT perfusion on third-generation dualsource CT: validation by coronary angiography. Int J Cardiol 2018;269:343-349 https://doi.org/10.1016/j.ijcard.2018.06.112
  23. Kalra MK, Maher MM, Toth TL, Schmidt B, Westerman BL, Morgan HT, et al. Techniques and applications of automatic tube current modulation for CT. Radiology 2004;233:649-657 https://doi.org/10.1148/radiol.2333031150
  24. Bamberg F, Hinkel R, Schwarz F, Sandner TA, Baloch E, Marcus R, et al. Accuracy of dynamic computed tomography adenosine stress myocardial perfusion imaging in estimating myocardial blood flow at various degrees of coronary artery stenosis using a porcine animal model. Invest Radiol 2012;47:71-77  https://doi.org/10.1097/RLI.0b013e31823fd42b