<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>Qanadli SD</dc:creator>
  <dc:creator>Jouannic AM</dc:creator>
  <dc:creator>Dehmeshki J</dc:creator>
  <dc:creator>Lu TL</dc:creator>
  <dc:date>2015</dc:date>
  <dc:description xmlns:ns0="xml" ns0:lang="en">OBJECTIVES
To determine inter-session and intra/inter-individual variations of the attenuations of aortic blood/myocardium with MDCT in the context of calcium scoring. To evaluate whether these variations are dependent on patients' characteristics.


METHODS
Fifty-four volunteers were evaluated with calcium scoring non-enhanced CT. We measured attenuations (inter-individual variation) and standard deviations (SD, intra-individual variation) of the blood in the ascending aorta and of the myocardium of left ventricle. Every volunteer was examined twice to study the inter-session variation. The fat pad thickness at the sternum and noise (SD of air) were measured too. These values were correlated with the measured aortic/ventricular attenuations and their SDs (Pearson). Historically fixed thresholds (90 and 130 HU) were tested against different models based on attenuations of blood/ventricle.


RESULTS
The mean attenuation was 46 HU (range, 17-84 HU) with mean SD 23 HU for the blood, and 39 HU (10-82 HU) with mean SD 18 HU for the myocardium. The attenuation/SD of the blood were significantly higher than those of the myocardium (p &lt; 0.01). The inter-session variation was not significant. There was a poor correlation between SD of aortic blood/ventricle with fat thickness/noise. Based on existing models, 90 HU threshold offers a confidence interval of approximately 95% and 130 HU more than 99%.


CONCLUSIONS
Historical thresholds offer high confidence intervals for exclusion of aortic blood/myocardium and by the way for detecting calcifications. Nevertheless, considering the large variations of blood/myocardium CT values and the influence of patient's characteristics, a better approach might be an adaptive threshold.</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>https://sonar.ch/global/documents/550</dc:identifier>
  <dc:language>eng</dc:language>
  <dc:relation>info:eu-repo/semantics/altIdentifier/doi/10.1371/journal.pone.0124175</dc:relation>
  <dc:relation>info:eu-repo/semantics/altIdentifier/pmid/25875629</dc:relation>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:source>PloS one. - 2015</dc:source>
  <dc:subject xmlns:ns1="xml" ns1:lang="en">Aged</dc:subject>
  <dc:subject xmlns:ns2="xml" ns2:lang="en">Calcinosis</dc:subject>
  <dc:subject xmlns:ns3="xml" ns3:lang="en">Coronary Vessels</dc:subject>
  <dc:subject xmlns:ns4="xml" ns4:lang="en">Female</dc:subject>
  <dc:subject xmlns:ns5="xml" ns5:lang="en">Heart</dc:subject>
  <dc:subject xmlns:ns6="xml" ns6:lang="en">Humans</dc:subject>
  <dc:subject xmlns:ns7="xml" ns7:lang="en">Male</dc:subject>
  <dc:subject xmlns:ns8="xml" ns8:lang="en">Middle Aged</dc:subject>
  <dc:subject xmlns:ns9="xml" ns9:lang="en">Tomography, X-Ray Computed</dc:subject>
  <dc:title xmlns:ns10="xml" ns10:lang="en">CT attenuation values of blood and myocardium: rationale for accurate coronary artery calcifications detection with multi-detector CT.</dc:title>
  <dc:type>http://purl.org/coar/resource_type/c_6501</dc:type>
</oai_dc:dc>