This Article Full Text Full Text (PDF) All Versions of this Article: 37/7/1771    most recent 01.STR.0000227243.96808.53v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Murphy, B.D. Articles by Lee, T.-Y. Search for Related Content PubMed PubMed Citation Articles by Murphy, B.D. Articles by Lee, T.-Y. Pubmed/NCBI databases Medline Plus Health Information CT Scans Related Collections CT and MRI Acute Cerebral Infarction Angiography Computerized tomography and Magnetic Resonance Imaging

(Stroke. 2006;37:1771.)
© 2006 American Heart Association, Inc.

Original Contributions

Identification of Penumbra and Infarct in Acute Ischemic Stroke Using Computed Tomography Perfusion–Derived Blood Flow and Blood Volume Measurements

B.D. Murphy, BSc; A.J. Fox, MD; D.H. Lee, MD, BCh, FRCPC; D.J. Sahlas, MD; S.E. Black, MD; M.J. Hogan, MD; S.B. Coutts, MD; A.M. Demchuk, MD; M. Goyal, MD; R.I. Aviv, MD; S. Symons, MD; I.B. Gulka, MD, FRCPC; V. Beletsky, MD, PhD; D. Pelz, MD, FRCPC; V. Hachinski, MD; R. Chan, MD T.-Y. Lee, PhD

From the University of Western Ontario (B.D.M., T.-Y.L.), London, ON; Robarts Research Institute (B.D.M., T.-Y.L.) London, ON; Lawson Health Research Institute (B.D.M., T.-Y.L.), London, ON; London Health Sciences Centre (D.H.L., I.B.G., V.B., D.P., V.H., R.C.), London, ON; Sunnybrook Health Sciences Centre (A.J.F., D.J.S., S.E.B., R.I.A., S.S.), Toronto, ON; Foothills Medical Centre (S.B.C., A.M.D.), Calgary, AB; and Ottawa Health Research Institute (M.J.H., M.G.), Ottawa, ON.

Correspondence to Dr Ting-Yim Lee, Robarts Research Institute, Imaging Research Laboratories, 100 Perth Dr, London, ON, Canada, N6A 5K9. E-mail tlee{at}imaging.robarts.ca

Background and Purpose— We investigated whether computed tomography (CT) perfusion–derived cerebral blood flow (CBF) and cerebral blood volume (CBV) could be used to differentiate between penumbra and infarcted gray matter in a limited, exploratory sample of acute stroke patients.

Methods— Thirty patients underwent a noncontrast CT (NCCT), CT angiography (CTA), and CT perfusion (CTP) scan within 7 hours of stroke onset, NCCT and CTA at 24 hours, and NCCT at 5 to 7 days. Twenty-five patients met the criteria for inclusion and were subsequently divided into 2 groups: those with recanalization at 24 hours (n=16) and those without (n=9). Penumbra was operationally defined as tissue with an admission CBF <25 mL · 100 g^–1 · min^–1 that was not infarcted on the 5- to 7-day NCCT. Logistic regression was applied to differentiate between infarct and penumbra data points.

Results— For recanalized patients, CBF was significantly lower (P<0.05) for infarct (13.3±3.75 mL · 100 g^–1 · min^–1) than penumbra (25.0±3.82 mL · 100 g^–1 · min^–1). CBV in the penumbra (2.15±0.43 mL · 100 g^–1) was significantly higher than contralateral (1.78±0.30 mL · 100 g^–1) and infarcted tissue (1.12±0.37 mL · 100 g^–1). Logistic regression using an interaction term (CBFxCBV) resulted in sensitivity, specificity, and accuracy of 97.0%, 97.2%, and 97.1%, respectively. The interaction term resulted in a significantly better (P<0.05) fit than CBF or CBV alone, suggesting that the CBV threshold for infarction varies with CBF. For patients without recanalization, CBF and CBV for infarcted regions were 15.1±5.67 mL · 100 g^–1 · min^–1 and 1.17±0.41 mL · 100 g^–1, respectively.

Conclusions— We have shown in a limited sample of patients that CBF and CBV obtained from CTP can be sensitive and specific for infarction and should be investigated further in a prospective trial to assess their utility for differentiating between infarct and penumbra.

Key Words: blood volume • cerebral blood flow • cerebral infarction • computed tomography • penumbra

This article has been cited by other articles:

				A.A. Konstas, G.V. Goldmakher, T.-Y. Lee, and M.H. Lev Theoretic Basis and Technical Implementations of CT Perfusion in Acute Ischemic Stroke, Part 2: Technical Implementations AJNR Am. J. Neuroradiol., May 1, 2009; 30(5): 885 - 892. [Abstract] [Full Text] [PDF]

				A.A. Konstas, G.V. Goldmakher, T.-Y. Lee, and M.H. Lev Theoretic Basis and Technical Implementations of CT Perfusion in Acute Ischemic Stroke, Part 1: Theoretic Basis AJNR Am. J. Neuroradiol., April 1, 2009; 30(4): 662 - 668. [Abstract] [Full Text] [PDF]

				I.Y.L. Tan, A.M. Demchuk, J. Hopyan, L. Zhang, D. Gladstone, K. Wong, M. Martin, S.P. Symons, A.J. Fox, and R.I. Aviv CT Angiography Clot Burden Score and Collateral Score: Correlation with Clinical and Radiologic Outcomes in Acute Middle Cerebral Artery Infarct AJNR Am. J. Neuroradiol., March 1, 2009; 30(3): 525 - 531. [Abstract] [Full Text] [PDF]

				R. I. Aviv, C. D. d'Esterre, B. D. Murphy, J. J. Hopyan, B. Buck, G. Mallia, V. Li, L. Zhang, S. P. Symons, and T.-Y. Lee Hemorrhagic Transformation of Ischemic Stroke: Prediction with CT Perfusion Radiology, March 1, 2009; 250(3): 867 - 877. [Abstract] [Full Text] [PDF]

				K. Murayama, K. Katada, M. Nakane, H. Toyama, H. Anno, M. Hayakawa, D. San Millan Ruiz, and K. J. Murphy Whole-Brain Perfusion CT Performed with a Prototype 256-Detector Row CT System: Initial Experience Radiology, January 1, 2009; 250(1): 202 - 211. [Abstract] [Full Text] [PDF]

				T.J. Huynh, B. Murphy, J.A. Pettersen, H. Tu, D.J. Sahlas, L. Zhang, S.P. Symons, S. Black, T.-Y. Lee, and R.I. Aviv CT Perfusion Quantification of Small-Vessel Ischemic Severity AJNR Am. J. Neuroradiol., November 1, 2008; 29(10): 1831 - 1836. [Abstract] [Full Text] [PDF]

				P. W. Schaefer, E. R. Barak, S. Kamalian, L. R. Gharai, L. Schwamm, R. G. Gonzalez, and M. H. Lev Quantitative Assessment of Core/Penumbra Mismatch in Acute Stroke: CT and MR Perfusion Imaging Are Strongly Correlated When Sufficient Brain Volume Is Imaged Stroke, November 1, 2008; 39(11): 2986 - 2992. [Abstract] [Full Text] [PDF]

				J. M. Provenzale and M. Wintermark Optimization of Perfusion Imaging for Acute Cerebral Ischemia: Review of Recent Clinical Trials and Recommendations for Future Studies Am. J. Roentgenol., October 1, 2008; 191(4): 1263 - 1270. [Abstract] [Full Text] [PDF]

				J.M. Provenzale, K. Shah, U. Patel, and D.C. McCrory Systematic Review of CT and MR Perfusion Imaging for Assessment of Acute Cerebrovascular Disease AJNR Am. J. Neuroradiol., September 1, 2008; 29(8): 1476 - 1482. [Abstract] [Full Text] [PDF]

				M. G. Lansberg, V. N. Thijs, R. Bammer, J.-M. Olivot, M. P. Marks, L. R. Wechsler, S. Kemp, and G. W. Albers The MRA-DWI Mismatch Identifies Patients With Stroke Who Are Likely to Benefit From Reperfusion Stroke, September 1, 2008; 39(9): 2491 - 2496. [Abstract] [Full Text] [PDF]

				B. D. Murphy, A. J. Fox, D. H. Lee, D. J. Sahlas, S. E. Black, M. J. Hogan, S. B. Coutts, A. M. Demchuk, M. Goyal, R. I. Aviv, et al. White Matter Thresholds for Ischemic Penumbra and Infarct Core in Patients with Acute Stroke: CT Perfusion Study Radiology, June 1, 2008; 247(3): 818 - 825. [Abstract] [Full Text] [PDF]

				A. Bruno, T. A. Kent, B. M. Coull, R. R. Shankar, C. Saha, K. J. Becker, B. M. Kissela, and L. S. Williams Treatment of Hyperglycemia In Ischemic Stroke (THIS): A Randomized Pilot Trial Stroke, February 1, 2008; 39(2): 384 - 389. [Abstract] [Full Text] [PDF]

				R.I. Aviv, J. Mandelcorn, S. Chakraborty, D. Gladstone, S. Malham, G. Tomlinson, A.J. Fox, and S. Symons Alberta Stroke Program Early CT Scoring of CT Perfusion in Early Stroke Visualization and Assessment AJNR Am. J. Neuroradiol., November 1, 2007; 28(10): 1975 - 1980. [Abstract] [Full Text] [PDF]

				M. H. Lev CT/NIHSS Mismatch for Detection of Salvageable Brain in Acute Stroke Triage Beyond the 3-Hour Time Window: Overrated or Undervalued? Stroke, July 1, 2007; 38(7): 2028 - 2029. [Full Text] [PDF]

				T.-Y. Lee, B. D. Murphy, R. I. Aviv, A. J. Fox, S. E. Black, D. J. Sahlas, S. Symons, D. H. Lee, D. Pelz, I. B. Gulka, et al. Cerebral Blood Flow Threshold of Ischemic Penumbra and Infarct Core in Acute Ischemic Stroke: A Systematic Review Stroke, September 1, 2006; 37(9): 2201 - 2201. [Full Text] [PDF]