doi: 10.1161/01.STR.0000019125.80118.99
(Stroke. 2002;33:1786.)
© 2002 American Heart Association, Inc.
Original Contributions |
Correlation of Apparent Diffusion Coefficient and Computed Tomography Density in Acute Ischemic Stroke
From the Departments of Neuroradiology (T.K., O.V., J.F., B.E., C.K., H.Z.) and Neurology (V.G., J.R.), University-Hospital Hamburg Eppendorf, Hamburg, and Siemens Medical Solutions (E.K.), Erlangen, Germany.
Correspondence to Thomas Kucinski, University-Hospital Hamburg Eppendorf, Department of Neuroradiology, Martinistrasse 52, 20251 Hamburg, Germany. E-mail kucinski@ uke.uni-hanburg.de
Background and Purpose— Diffusion-weighted MR imaging is very sensitive for the detection of restricted molecular water diffusion in acute ischemic stroke. CT is sensitive to net water uptake in ischemic edema. We compared the decrease in the apparent diffusion coefficient (ADC) in diffusion-weighted MR imaging with CT density changes to study the correlation between diffusion restriction and water uptake in acute stroke patients.
Methods— Twenty-five patients with acute ischemic stroke of the anterior cerebral circulation underwent MR and CT imaging 1.3 to 5.4 hours after symptom onset. ADC and CT data were transferred into a common 3-dimensional space, and regions of decreased ADC (dADC) were superimposed onto the corresponding CT. Mean values of ADC and Hounsfield units (HU) were determined in comparison with the nonaffected hemisphere.
Results— Mean decrease in ADC (dADC) was 170±53x 10-6 mm2/s and corresponded to a decrease (dCT) in CT density of 1.3±0.7 HU. dCT showed a continuous linear decrease of 0.4 HU/h (r=0.55, P<0.01), whereas the decrease is ADC was almost complete after 1.5 hours. A correlation between the decrease in ADC and dCT was found (r=0.41, P=0.04).
Conclusions— The severity of diffusion restriction correlates with net water uptake in acute ischemic stroke. However, the underlying pathophysiology and different time courses indicate a common reason rather than a direct causality for both phenomena. The time delay and low value of CT density changes provide a reasonable explanation for the higher sensitivity of MR imaging in ischemic stroke.
Key Words: brain edema • cerebral infarction • computed tomography • magnetic resonance imaging, diffusion-weighted • stroke, acute
This article has been cited by other articles:
 |
|
 |
|
  C. Herweh, E. Juttler, P. D. Schellinger, E. Klotz, E. Jenetzky, B. Orakcioglu, K. Sartor, and P. Schramm Evidence Against a Perihemorrhagic Penumbra Provided by Perfusion Computed Tomography Stroke, November 1, 2007; 38(11): 2941 - 2947. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. W. Muir, J. Baird-Gunning, L. Walker, T. Baird, M. McCormick, and S. B. Coutts Can the Ischemic Penumbra Be Identified on Noncontrast CT of Acute Stroke? Stroke, September 1, 2007; 38(9): 2485 - 2490. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E.Y. Kim, J.W. Ryoo, H.G. Roh, K.H. Lee, S.S. Kim, I.C. Song, K.-H. Chang, and D.G. Na Reversed Discrepancy between CT and Diffusion-Weighted MR Imaging in Acute Ischemic Stroke. AJNR Am. J. Neuroradiol., October 1, 2006; 27(9): 1990 - 1995. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Tanaka, T. Ueguchi, E. Shimosegawa, N. Sasaki, T. Johkoh, H. Nakamura, and J. Hatazawa Effect of CT Acquisition Parameters in the Detection of Subtle Hypoattenuation in Acute Cerebral Infarction: A Phantom Study AJNR Am. J. Neuroradiol., January 1, 2006; 27(1): 40 - 45. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P.-S. Loh, K. S. Butcher, M. W. Parsons, L. MacGregor, P. M. Desmond, B. M. Tress, and S. M. Davis Apparent Diffusion Coefficient Thresholds Do Not Predict the Response to Acute Stroke Thrombolysis Stroke, December 1, 2005; 36(12): 2626 - 2631. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Y. Kim, D. G. Na, S. S. Kim, K. H. Lee, J. W. Ryoo, and H. K. Kim Prediction of Hemorrhagic Transformation in Acute Ischemic Stroke: Role of Diffusion-Weighted Imaging and Early Parenchymal Enhancement AJNR Am. J. Neuroradiol., May 1, 2005; 26(5): 1050 - 1055. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Kucinski, D. Naumann, R. Knab, V. Schoder, S. Wegener, J. Fiehler, A. Majumder, J. Rother, and H. Zeumer Tissue at Risk Is Overestimated in Perfusion-Weighted Imaging: MR Imaging in Acute Stroke Patients without Vessel Recanalization AJNR Am. J. Neuroradiol., April 1, 2005; 26(4): 815 - 819. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M. Somford, M. P. Marks, V. N. Thijs, and D. C. Tong Association of Early CT Abnormalities, Infarct Size, and Apparent Diffusion Coefficient Reduction in Acute Ischemic Stroke AJNR Am. J. Neuroradiol., June 1, 2004; 25(6): 933 - 938. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. W. Pexman, M. D. Hill, A. M. Buchan, A. M. Demchuk, P. A. Barber, J. E. Simon, S. B. Coutts, D. Saur, J. Rother, and T. Kucinski Hyperacute Stroke: Experience Essential When Reading Unenhanced CT Scans AJNR Am. J. Neuroradiol., March 1, 2004; 25(3): 516 - 518. [Full Text] [PDF]
|
|
|
|
|
|
F. Nicoli, Y. Lefur, B. Denis, J.P. Ranjeva, S. Confort-Gouny, and P.J. Cozzone Metabolic Counterpart of Decreased Apparent Diffusion Coefficient During Hyperacute Ischemic Stroke: A Brain Proton Magnetic Resonance Spectroscopic Imaging Study Stroke, July 1, 2003; 34 (7): e82 - e87. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Saur, T. Kucinski, U. Grzyska, B. Eckert, C. Eggers, W. Niesen, V. Schoder, H. Zeumer, C. Weiller, and J. Rother Sensitivity and Interrater Agreement of CT and Diffusion-Weighted MR Imaging in Hyperacute Stroke AJNR Am. J. Neuroradiol., May 1, 2003; 24(5): 878 - 885. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Doczi, A. Schwarcz, T. Kucinski, O. Vaterlein, J. Fiehler, B. Eckert, H. Zeumer, V. Glauche, J. Rother, E. Klotz, et al. Correlation of Apparent Diffusion Coefficient and Computed Tomography Density in Acute Ischemic Stroke * Response Stroke, May 1, 2003; 34 (5): e17 - e18. [Full Text] [PDF]
|
|