Abstract
Introduction
Perfusion-CT (PCT) processing involves deconvolution, a mathematical operation that computes the perfusion parameters from the PCT time density curves and an arterial curve. Delay-sensitive deconvolution does not correct for arrival delay of contrast, whereas delay-insensitive deconvolution does. The goal of this study was to compare delay-sensitive and delay-insensitive deconvolution PCT in terms of delineation of the ischemic core and penumbra.
Methods
We retrospectively identified 100 patients with acute ischemic stroke who underwent admission PCT and CT angiography (CTA), a follow-up vascular study to determine recanalization status, and a follow-up noncontrast head CT (NCT) or MRI to calculate final infarct volume. PCT datasets were processed twice, once using delay-sensitive deconvolution and once using delay-insensitive deconvolution. Regions of interest (ROIs) were drawn, and cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in these ROIs were recorded and compared. Volume and geographic distribution of ischemic core and penumbra using both deconvolution methods were also recorded and compared.
Results
MTT and CBF values are affected by the deconvolution method used (p < 0.05), while CBV values remain unchanged. Optimal thresholds to delineate ischemic core and penumbra are different for delay-sensitive (145 % MTT, CBV 2 ml × 100 g−1 × min−1) and delay-insensitive deconvolution (135 % MTT, CBV 2 ml × 100 g−1 × min−1 for delay-insensitive deconvolution). When applying these different thresholds, however, the predicted ischemic core (p = 0.366) and penumbra (p = 0.405) were similar with both methods.
Conclusion
Both delay-sensitive and delay-insensitive deconvolution methods are appropriate for PCT processing in acute ischemic stroke patients. The predicted ischemic core and penumbra are similar with both methods when using different sets of thresholds, specific for each deconvolution method.
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Abbreviations
- PCT:
-
Perfusion-CT
- ASPECTS:
-
Alberta stroke program early CT score
- CBF:
-
Cerebral blood flow
- CBV:
-
Cerebral blood volume
- MTT:
-
Mean transit time
- ROI:
-
Region of interest
- NCT:
-
Noncontrast head CT
References
Shetty SK, Lev MH (2005) CT perfusion in acute stroke. Neuroimaging Clin N Am 15(3):481–501. doi:10.1016/j.nic.2005.08.004, ix
Pan J, Zhang J, Huang W, Cheng X, Ling Y, Dong Q, Geng D (2013) Value of perfusion computed tomography in acute ischemic stroke: diagnosis of infarct core and penumbra. J Comput Assist Tomogr 37(5):645–649. doi:10.1097/RCT.0b013e31829866fc
Wintermark M, Sesay M, Barbier E, Borbely K, Dillon WP, Eastwood JD, Glenn TC, Grandin CB, Pedraza S, Soustiel JF, Nariai T, Zaharchuk G, Caille JM, Dousset V, Yonas H (2005) Comparative overview of brain perfusion imaging techniques. J Neuroradiol J Neuroradiol 32(5):294–314
Sviri GE, Britz GW, Lewis DH, Newell DW, Zaaroor M, Cohen W (2006) Dynamic perfusion computed tomography in the diagnosis of cerebral vasospasm. Neurosurgery 59(2):319–325. doi:10.1227/01.NEU.0000222819.18834.33, discussion 319–325
Soustiel JF, Mahamid E, Goldsher D, Zaaroor M (2008) Perfusion-CT for early assessment of traumatic cerebral contusions. Neuroradiology 50(2):189–196. doi:10.1007/s00234-007-0337-7
Leiva-Salinas C, Provenzale JM, Wintermark M (2011) Responses to the 10 most frequently asked questions about perfusion CT. Am J Roentgenol 196(1):53–60. doi:10.2214/Ajr.10.5705
Leiva-Salinas C, Wintermark M (2010) Imaging of acute ischemic stroke. Neuroimaging Clin N Am 20(4):455. doi:10.1016/J.Nic.2010.07.002
Abels B, Klotz E, Tomandl BF, Kloska SP, Lell MM (2010) Perfusion CT in acute ischemic stroke: a qualitative and quantitative comparison of deconvolution and maximum slope approach. AJNR Am J Neuroradiol 31(9):1690–1698. doi:10.3174/ajnr.A2151
Konstas AA, Goldmakher GV, Lee TY, Lev MH (2009) Theoretic basis and technical implementations of CT perfusion in acute ischemic stroke, part 1: theoretic basis. AJNR Am J Neuroradiol 30(4):662–668. doi:10.3174/ajnr.A1487
Leiva-Salinas C, Provenzale JM, Kudo K, Sasaki M, Wintermark M (2012) The alphabet soup of perfusion CT and MR imaging: terminology revisited and clarified in five questions. Neuroradiology 54(9):907–918. doi:10.1007/s00234-012-1028-6
Calamante F, Gadian DG, Connelly A (2000) Delay and dispersion effects in dynamic susceptibility contrast MRI: simulations using singular value decomposition. Magn Reson Med Off J Soc Magn Reson Med Soc Magn Reson Med 44(3):466–473
Calamante F, Yim PJ, Cebral JR (2003) Estimation of bolus dispersion effects in perfusion MRI using image-based computational fluid dynamics. NeuroImage 19(2 Pt 1):341–353
Wu O, Ostergaard L, Weisskoff RM, Benner T, Rosen BR, Sorensen AG (2003) Tracer arrival timing-insensitive technique for estimating flow in MR perfusion-weighted imaging using singular value decomposition with a block-circulant deconvolution matrix. Magn Reson Med Off J Soc Magn Reson Med Soc Magn Reson Med 50(1):164–174. doi:10.1002/mrm.10522
Schaefer PW, Mui K, Kamalian S, Nogueira RG, Gonzalez RG, Lev MH (2009) Avoiding “pseudo-reversibility” of CT-CBV infarct core lesions in acute stroke patients after thrombolytic therapy the need for algorithmically “delay-corrected” CT perfusion map postprocessing software. Stroke J Cereb Circ 40(8):2875–2878
Wintermark M, Maeder P, Thiran JP, Schnyder P, Meuli R (2001) Quantitative assessment of regional cerebral blood flows by perfusion CT studies at low injection rates: a critical review of the underlying theoretical models. Eur Radiol 11(7):1220–1230
Wintermark M, Flanders AE, Velthuis B, Meuli R, van Leeuwen M, Goldsher D, Pineda C, Serena J, van der Schaaf I, Waaijer A, Anderson J, Nesbit G, Gabriely I, Medina V, Quiles A, Pohlman S, Quist M, Schnyder P, Bogousslavsky J, Dillon WP, Pedraza S (2006) Perfusion-CT assessment of infarct core and penumbra: receiver operating characteristic curve analysis in 130 patients suspected of acute hemispheric stroke. Stroke J Cereb Circ 37(4):979–985. doi:10.1161/01.STR.0000209238.61459.39
Puetz V, Dzialowski I, Hill MD, Demchuk AM (2009) The Alberta stroke program early CT score in clinical practice: what have we learned? Int J Stroke Off J Int Stroke Soc 4(5):354–364. doi:10.1111/j.1747-4949.2009.00337.x
Calamante F, Gadian DG, Connelly A (2002) Quantification of perfusion using bolus tracking magnetic resonance imaging in stroke: assumptions, limitations, and potential implications for clinical use. Stroke J Cereb Circ 33(4):1146–1151
Bivard A, Levi C, Spratt N, Parsons M (2013) Perfusion CT in acute stroke: a comprehensive analysis of infarct and penumbra. Radiology 267(2):543–550
Acknowledgments
MW receives research funding from GE Healthcare and Philips Healthcare.
Ethical standards and patient consent
We declare that all human and animal studies have been approved by the Institutional Review Board of the University of Virginia and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. We declare that all patients gave informed consent prior to inclusion in this study.
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We declare that we have no conflict of interest.
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Man, F., Patrie, J.T., Xin, W. et al. Delay-sensitive and delay-insensitive deconvolution perfusion-CT: similar ischemic core and penumbra volumes if appropriate threshold selected for each. Neuroradiology 57, 573–581 (2015). https://doi.org/10.1007/s00234-015-1507-7
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DOI: https://doi.org/10.1007/s00234-015-1507-7