Document Detail


Cine phase-contrast MR flow measurements: improved precision using an automated method of vessel detection.
MedLine Citation:
PMID:  8188918     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: The purpose of this study was to construct a method of vessel edge detection that correctly identifies vessel pixels and to compare the interuser variability of cine phase contrast MR volumetric flow rates obtained with the conventional manual method and an automated method. MATERIALS AND METHODS: The automated method was developed based on a magnitude image threshold value and compared with the manual method in a flow phantom (three users) and in velocity images of the portal vein (five users). The threshold value determined from the magnitude image was applied to a region of interest surrounding the vessel of interest on the magnitude image to construct a vessel edge detection mask m(x,y). The velocity images were then multiplied by the mask m(x,y) and volumetric flow rates determined using the identified vessel pixels. RESULTS: In the flow phantom, flow measurements with the magnitude threshold method had significantly less interuser variability compared with the manual method (p < 0.01) and were within 10% (mean 6.0%) of the actual flow versus 35% (mean 18.6%) with the manual method. Regarding flow measurements in the portal vein of six volunteers, the magnitude threshold method was significantly more precise (p < 0.01) than the manual method with a mean standard deviation between the five users of 40.4 +/- 12.9 ml/min (range 22-60 ml/min) and 110.4 +/- 32.7 ml/min (range 70-155 ml/min), respectively. CONCLUSION: The magnitude threshold method of vessel edge detection developed in this study yields flow measurements that are accurate in the model system and have significantly less interuser variability than the manual method. This method shows promise for improving the precision of cine phase contrast flow measurements.
Authors:
D J Burkart; J P Felmlee; C D Johnson; R L Wolf; A L Weaver; R L Ehman
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of computer assisted tomography     Volume:  18     ISSN:  0363-8715     ISO Abbreviation:  J Comput Assist Tomogr     Publication Date:    1994 May-Jun
Date Detail:
Created Date:  1994-06-21     Completed Date:  1994-06-21     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  7703942     Medline TA:  J Comput Assist Tomogr     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  469-75     Citation Subset:  IM    
Affiliation:
Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905.
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MeSH Terms
Descriptor/Qualifier:
Adult
Blood Flow Velocity*
Blood Vessels / anatomy & histology*
Humans
Magnetic Resonance Imaging / methods*
Models, Structural
Portal Vein / anatomy & histology

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


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