American Journal of Neuroradiology 28:927-932, May 2007
© 2007 American Society of Neuroradiology
BRAIN
Reproducibility of Quantitative CT Brain Perfusion Measurements in Patients with Symptomatic Unilateral Carotid Artery Stenosis
a Department of Radiology, University Medical Center, Utrecht, The Netherlands
b Philips Medical Systems, Best, The Netherlands
c Department of Radiology, Leiden University Medical Center, Utrecht, The Netherlands
Address correspondence to Annet Waaijer, MD, Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht NL-3508 GA, The Netherlands; e-mail: annetwaaijer{at}planet.nl/a.waaijer-2{at}azu.nl
BACKGROUND AND PURPOSE: To establish intraobserver and interobserver variability for regional measurement of CT brain perfusion (CTP) and to determine whether reproducibility can be improved by calculating perfusion ratios.
MATERIALS AND METHODS: CTP images were acquired in 20 patients with unilateral symptomatic carotid artery stenosis (CAS). We manually drew regions of interest (ROIs) in the cortical flow territories of the anterior (ACA), middle (MCA), and posterior (PCA) cerebral arteries and the basal ganglia in each hemisphere; recorded cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT); and calculated ratios of perfusion values between symptomatic and asymptomatic hemisphere. We assessed intraobserver and interobserver variability by performing a Bland-Altman analysis of the relative differences between 2 observations and calculated SDs of relative differences (SDDrel) as a measure of reproducibility. We used an F test to assess significance of differences between SDDrel of absolute CTP values and CTP ratios, and the Levine test to compare the 4 perfusion territories.
RESULTS: MTT was the most reproducible parameter (SDDrel 
10%). Intraobserver and interobserver variability were higher for absolute CTP values compared with CTP ratios for CBV (16%–17% versus 11%–16%) and CBF (18% versus 10%–13%) but not for MTT (5%–9%). Reproducibility was best in the MCA territory: SDDrel was 11% for perfusion ratios of all 3 parameters.
CONCLUSION: MTT is the most reproducible CTP parameter in patients with unilateral symptomatic CAS. Measurement variability in CBV and CBF can be improved if CTP ratios instead of CTP values are used. The MCA territory shows the least measurement variability.
This article has been cited by other articles:
 |
|
 |
|
  G. Petralia, L. Preda, S. Raimondi, G. D'Andrea, P. Summers, G. Giugliano, F. Chiesa, and M. Bellomi Intra- and Interobserver Agreement and Impact of Arterial Input Selection in Perfusion CT Measurements Performed in Squamous Cell Carcinoma of the Upper Aerodigestive Tract AJNR Am. J. Neuroradiol., June 1, 2009; 30(6): 1107 - 1115. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A.S. Vagal, J.L. Leach, M. Fernandez-Ulloa, and M. Zuccarello The Acetazolamide Challenge: Techniques and Applications in the Evaluation of Chronic Cerebral Ischemia AJNR Am. J. Neuroradiol., May 1, 2009; 30(5): 876 - 884. [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]
|
|
|
|
|
|
K.H. Kang, H.S. Kim, and S.Y. Kim Quantitative Cerebrovascular Reserve Measured by Acetazolamide-Challenged Dynamic CT Perfusion in Ischemic Adult Moyamoya Disease: Initial Experience with Angiographic Correlation AJNR Am. J. Neuroradiol., September 1, 2008; 29(8): 1487 - 1493. [Abstract] [Full Text] [PDF]
|
|