Document Detail


Reperfusion phenomenon masking acute and subacute infarcts at dynamic perfusion CT: confirmation by fusion of CT and diffusion-weighted MR images.
MedLine Citation:
PMID:  19933658     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: The purpose of this study was to evaluate cerebral blood flow, cerebral blood volume, mean transit time, time to peak, and delay in a selected sample of patients with visually normal or increased cerebral blood volume to facilitate detection of a postischemic CT perfusion hyperperfusion-reperfusion phenomenon that may mask subacute and acute infarcts. MATERIALS AND METHODS: Ten patients were included who had visually normal or elevated cerebral blood volume in infarcts larger than 1.5 cm confirmed on diffusion-weighted MR images within 48 hours of perfusion CT. The cases were selected from 371 perfusion CT studies of stroke patients (99 associated with positive diffusion-weighted imaging findings) reviewed over 2.5 years on a 64-MDCT scanner. The perfusion CT images were fused to the diffusion-weighted images for measurement of cerebral blood volume, cerebral blood flow, mean transit time, time to peak, and delay in each infarct versus the contralateral hemisphere. Two neuroradiologists reviewed the images in consensus. RESULTS: The mean time between symptom onset and perfusion CT was 3.9 days. Infarcts were in the middle cerebral artery (n = 7) and posterior cerebral artery (n = 3) distributions. Significant differences versus the contralateral finding were found in cerebral blood volume (p = 0.016; mean increase, 30.0%), mean transit time (p = 0.007; mean increase, 38.1%), time to peak (p = 0.005; mean increase, 17.7%), and delay (p = 0.030; mean increase, 124.9%). The difference in cerebral blood flow (p = 0.785; mean increase, 1.8%) was not statistically significant. Infarcts became enhanced on the dynamic perfusion CT images of eight of 10 patients and on the contrast-enhanced T1-weighted MR images of six of nine patients. CONCLUSION: Visual inspection of cerebral blood volume and cerebral blood flow maps alone is insufficient in the evaluation of infarcts. Mean transit time, time to peak, and delay maps also should be reviewed with dynamic source images to prevent misinterpretation of findings as false-negative. This phenomenon is unlikely to occur hyperacutely (< 8 hours after onset).
Authors:
Veena A Nagar; Alexander M McKinney; Ayse T Karagulle; Charles L Truwit
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  AJR. American journal of roentgenology     Volume:  193     ISSN:  1546-3141     ISO Abbreviation:  AJR Am J Roentgenol     Publication Date:  2009 Dec 
Date Detail:
Created Date:  2009-11-25     Completed Date:  2010-01-07     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7708173     Medline TA:  AJR Am J Roentgenol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1629-38     Citation Subset:  AIM; IM    
Affiliation:
Department of Radiology, University of Minnesota and Hennepin County Medical Center, Minneapolis, MN 55415, USA.
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MeSH Terms
Descriptor/Qualifier:
Acute Disease
Aged
Aged, 80 and over
Blood Flow Velocity / physiology
Blood Volume / physiology
Cerebral Infarction / diagnosis*,  physiopathology,  radiography
Cerebrovascular Circulation*
Diffusion Magnetic Resonance Imaging*
Female
Hemodynamics / physiology
Humans
Male
Middle Aged
Tomography, X-Ray Computed*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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