Document Detail


Calcium stone fragility is predicted by helical CT attenuation values.
MedLine Citation:
PMID:  10954300     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND AND PURPOSE: Helical CT has become the preferred method for imaging urinary calculi, and so it would be useful if data from helical CT could also be used to predict the number of shockwaves (SWs) needed to break a given stone. METHODS AND MATERIALS: We measured the number of SWs required to comminute calcium stones in vitro. RESULTS: The SW requirement correlated with stone size (volume, weight, diameter) and with helical CT attenuation values when the scans were performed at 3-mm collimation. When CT scans were performed at 1-mm collimation, the number of SWs needed for comminution did not correlate with helical CT attenuation values. This result indicates that the correlation with 3-mm scans was attributable to volume-averaging effects, in which smaller stones yield smaller attenuation values. That is, attenuation values from helical CT at larger beam collimation widths contain information about stone size that can be exploited to predict the fragility of calcium stones. We observed that for calcium stones, the number of SWs to comminution was generally less than half the stone CT attenuation value in Hounsfield units. This "half-attenuation rule" predicted the number of SWs needed to complete fragmentation for 95% of calcium stones (24/24 calcium oxalate monohydrate, 13/13 hydroxyapatite, 8/10 brushite stones). CONCLUSION: This in vitro study suggests that it may be possible to predict effective SW dose using helical CT prior to lithotripsy.
Authors:
K C Saw; J A McAteer; N S Fineberg; A G Monga; G T Chua; J E Lingeman; J C Williams
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of endourology / Endourological Society     Volume:  14     ISSN:  0892-7790     ISO Abbreviation:  J. Endourol.     Publication Date:  2000 Aug 
Date Detail:
Created Date:  2000-11-27     Completed Date:  2000-12-22     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8807503     Medline TA:  J Endourol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  471-4     Citation Subset:  IM    
Affiliation:
Methodist Hospital Institute of Kidney Stone Disease, Indianapolis, Indiana, USA.
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MeSH Terms
Descriptor/Qualifier:
Humans
Kidney Calculi / radiography*
Lithotripsy / adverse effects,  methods*
Predictive Value of Tests
Tomography, X-Ray Computed*
Grant Support
ID/Acronym/Agency:
P01 DK43881/DK/NIDDK NIH HHS

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


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