Skip to main content

Effects of multiphase versus single-phase CT angiography for the detection of distal cerebral vessel occlusion



The goal of this study was to determine whether the benefits of multiphase CTA (mCTA) over single-phase CTA (sCTA) for the detection of proximal cerebrovascular occlusions similarly extend to the distal cerebral vasculature.


Four attending radiologists, two neuroradiologists and two emergency radiologists, contributed as readers to this retrospective study. For each reader, two sessions were conducted, one using sCTA and one using mCTA. During each session, the reader interpreted the studies of 104 patients who underwent imaging for suspicion of acute ischemic stroke, resulting in a total of 832 interpretations. Changes in diagnostic accuracy, time to render final decision, and reported levels of reader confidence were quantitatively assessed. Further analysis comparing the effects for neuroradiologists versus emergency radiologists was additionally conducted.


Using mCTA resulted in a significant 5.0% absolute increase in sensitivity (91.6% vs. 96.6%, p = .004) and an insignificant increase in specificity (99.5% vs. 99.7%, p = .39). A significant reduction in reading time (66.7 s vs. 59.6 s, p = .001) and an increase in diagnostic confidence (2.26 vs. 2.58, p < .001) were observed. Using sCTA, higher sensitivity was achieved by neuroradiologists than emergency radiologists (96.0% vs. 86.9%, p = .002); using mCTA resulted in an absolute increase in sensitivity of 0.9% (97.4%, p = .44) for neuroradiologists and 9.6% (96.5%, p < .001) for emergency radiologists, eliminating significant differences between the groups (p = 0.57).


The use of mCTA results in increased sensitivity and negative predictive value, decreased reading time, increased diagnostic confidence, and the elimination of differences in accuracy between neuroradiologists and emergency radiologists.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3


  1. Menon BK, Demchuk AM (2011) Computed tomography angiography in the assessment of patients with stroke/TIA. Neurohospitalist 1(4):187–199

    Article  Google Scholar 

  2. Menon BK, Campbell BC, Levi C, Goyal M (2015) Role of imaging in current acute ischemic stroke workflow for endovascular therapy. Stroke 46(6):1453–1461

    CAS  Article  Google Scholar 

  3. Coutts SB, Lev MH, Eliasziw M, Roccatagliata L, Hill MD, Schwamm LH, Pexman JW, Koroshetz WJ, Hudon ME, Buchan AM (2004) ASPECTS on CTA source images versus unenhanced CT: added value in predicting final infarct extent and clinical outcome. Stroke 35(11):2472–2476

    Article  Google Scholar 

  4. Lum C, Ahmed ME, Patro S, Thornhill R, Hogan M, Iancu D, Lesiuk H, dos Santos M, Dowlatshahi D (2014) Computed tomographic angiography and cerebral blood volume can predict final infarct volume and outcome after recanalization. Stroke 45(9):2683–2688

    Article  Google Scholar 

  5. Demchuk AM, Goyal M, Yeatts SD, Carrozzella J, Foster LD, Qazi E, Hill MD, Jovin TG, Ribo M, Yan B (2014) Recanalization and clinical outcome of occlusion sites at baseline CT angiography in the Interventional Management of Stroke III trial. Radiology 273(1):202–210

    Article  Google Scholar 

  6. Berkhemer OA, Fransen PS, Beumer D, van den Berg LA, Lingsma HF, Yoo AJ, Schonewille WJ, Vos JA, Nederkoorn PJ, Wermer MJ (2015) A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med 372(1):11–20

    Article  Google Scholar 

  7. Goyal M, Demchuk AM, Menon BK, Eesa M, Rempel JL, Thornton J, Roy D, Jovin TG, Willinsky RA, Sapkota BL (2015) Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med 372(11):1019–1030

    CAS  Article  Google Scholar 

  8. Campbell BC, Mitchell PJ, Kleinig TJ, Dewey HM, Churilov L, Yassi N, Yan B, Dowling RJ, Parsons MW, Oxley TJ (2015) Endovascular therapy for ischemic stroke with perfusion-imaging selection. N Engl J Med 372(11):1009–1018

    CAS  Article  Google Scholar 

  9. Saver JL, Goyal M, Bonafe A, Diener H-C, Levy EI, Pereira VM, Albers GW, Cognard C, Cohen DJ, Hacke W (2015) Stent-retriever thrombectomy after intravenous t-PA vs t-PA alone in stroke. N Engl J Med 372(24):2285–2295

    CAS  Article  Google Scholar 

  10. Nogueira RG, Jadhav AP, Haussen DC, Bonafe A, Budzik RF, Bhuva P, Yavagal DR, Ribo M, Cognard C, Hanel RA (2018) Thrombectomy 6 to 24 hours after stroke with a mismatch between deficit and infarct. N Engl J Med 378(1):11–21

    Article  Google Scholar 

  11. Desai SM, Haussen DC, Aghaebrahim A, Al-Bayati AR, Santos R, Nogueira RG, Jovin TG, Jadhav AP (2018) Thrombectomy 24 hours after stroke: beyond DAWN. J NeurointervSurg 10(11):1039–1042

    Article  Google Scholar 

  12. Coutts SB, Modi J, Patel SK, Aram H, Demchuk AM, Goyal M, Hill MD (2012) What causes disability after transient ischemic attack and minor stroke? Results from the CT and MRI in the Triage of TIA and minor Cerebrovascular Events to Identify High Risk Patients (CATCH) Study. Stroke 43(11):3018–3022

    Article  Google Scholar 

  13. Coutts SB, Dubuc V, Mandzia J, Kenney C, Demchuk AM, Smith EE, Subramaniam S, Goyal M, Patil S, Menon BK (2015) Tenecteplase–tissue-type plasminogen activator evaluation for minor ischemic stroke with proven occlusion. Stroke 46(3):769–774

    CAS  Article  Google Scholar 

  14. A randomized controlled trial of TNK-tPA versus standard of care for minor ischemic stroke with proven occlusion (TEMPO-2) (2019) United States National Library of Medicine, National Institutes of Health. Accessed 1 July 2019

  15. Menon BK, d’Esterre CD, Qazi EM, Almekhlafi M, Hahn L, Demchuk AM, Goyal M (2015) Multiphase CT angiography: a new tool for the imaging triage of patients with acute ischemic stroke. Radiology 275(2):510–520

    Article  Google Scholar 

  16. Volny O, Cimflova P, Kadlecova P, Vanek P, Vanicek J, Menon BK, Mikulik R (2017) Single-phase versus multiphase CT angiography in middle cerebral artery clot detection—benefits for less experienced radiologists and neurologists. J Stroke Cerebrovasc Dis 26(1):19–24

    Article  Google Scholar 

  17. Byrne D, Sugrue G, Stanley E, Walsh J, Murphy S, Kavanagh E, MacMahon P (2017) Improved detection of anterior circulation occlusions: the “delayed vessel sign” on multiphase CT angiography. Am J Neuroradiol 38(10):1911–1916

    CAS  Article  Google Scholar 

  18. Amy Y, Zerna C, Assis Z, Holodinsky JK, Randhawa PA, Najm M, Goyal M, Menon BK, Demchuk AM, Coutts SB (2016) Multiphase CT angiography increases detection of anterior circulation intracranial occlusion. Neurology 87(6):609–616

    Google Scholar 

  19. Yang C-Y, Chen Y-F, Lee C-W, Huang A, Shen Y, Wei C, Liu H-M (2008) Multiphase CT angiography versus single-phase CT angiography: comparison of image quality and radiation dose. Am J Neuroradiol 29(7):1288–1295

    Article  Google Scholar 

  20. Boyd CA, Jayaraman MV, Baird GL, Einhorn WS, Stib MT, Atalay MK, Boxerman JL, Lourenco AP, Jindal G, Hidlay DT (2020) Detection of emergent large vessel occlusion stroke with CT angiography is high across all levels of radiology training and grayscale viewing methods. Eur Radiol 30(8):4447–4453

    Article  Google Scholar 

  21. Dorfman DD, Berbaum KS, Metz CE (1992) Receiver operating characteristic rating analysis: generalization to the population of readers and patients with the jackknife method. Invest Radiol 27(9):723–731

    CAS  Article  Google Scholar 

  22. Hillis SL, Berbaum KS, Metz CE (2008) Recent developments in the Dorfman-Berbaum-Metz procedure for multireader ROC study analysis. Acad Radiol 15(5):647–661

    Article  Google Scholar 

  23. Hillis SL, Obuchowski NA, Schartz KM, Berbaum KS (2005) A comparison of the Dorfman–Berbaum–Metz and Obuchowski-Rockette methods for receiver operating characteristic (ROC) data. Stat Med 24(10):1579–1607

    Article  Google Scholar 

  24. Smith EA, Senter RJ (1967) Automated readability index. AMRL-TR. Aerospace Medical Research Laboratories (US), pp 1–14.

  25. Obuchowski NA Jr, Rockette HE Jr (1995) Hypothesis testing of diagnostic accuracy for multiple readers and multiple tests an anova approach with dependent observations. Communications in Statistics-simulation and Computation 24(2):285–308

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Gerald M. Hefferman.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Hefferman, G.M., Baird, G.L., Swenson, D.W. et al. Effects of multiphase versus single-phase CT angiography for the detection of distal cerebral vessel occlusion. Emerg Radiol 28, 891–898 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Stroke
  • Transient ischemic attack
  • Cerebrovascular occlusion
  • Computed tomography angiography
  • Multiphase CTA
  • Neuroimaging