title: The assessment of anemia from attenuation values of cranial venous drainage on unenhanced computed tomography of the head.
abstract: OBJECTIVE
  To determine if prediction of anemia is possible from quantitative analyses of unenhanced cranial computed tomography (CT) images.
  
  
  METHODS
  A retrospective chart review revealed 101 patients who had hemoglobin and hematocrit levels obtained within 24 hours of an unenhanced cranial CT. Regions of interest were the place on the torcular Herophili (confluence of sinuses) and the left and right transverse sinuses. Attenuation values were correlated with hemoglobin and hematocrit to investigate any possible relationship.
  
  
  RESULTS
  Hemoglobin levels were correlated with torcular and transverse sinus attenuation levels. For every 10 Hounsfield unit (HU) increase in torcular attenuation, hemoglobin levels increased by 16.3 g/L (P < .001). When subgroup analysis was performed, by sex, for every 10 HU increase in torcular attenuation, hemoglobin levels increased by 22.6 g/L (P < .001) in men and 8.96 g/L (P < .05) in women.
  
  
  CONCLUSIONS
  The attenuation values for venous drainage on unenhanced cranial CT constitute a practical adjunct in the assessment of anemia. Given the number of individuals undergoing CT without blood work, this rapid assessment technique for anemia is a convenient means for narrowing possible diagnoses.
authors.affiliation: Undergraduate Medical Education, School of Medicine, Queen's University, Kingston, Ontario, Canada. 8sgb@queensu.ca
authors.forename: Silvio G
authors.initials: SG
authors.lastname: Bruni
authors.forename: Francis M
authors.initials: FM
authors.lastname: Patafio
authors.forename: John A
authors.initials: JA
authors.lastname: Dufton
authors.forename: Robert L
authors.initials: RL
authors.lastname: Nolan
authors.forename: Omar
authors.initials: O
authors.lastname: Islam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000000981:diagnostic imaging*; D003392:Cranial Sinuses / Q000000981:diagnostic imaging*; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D006454:Hemoglobins