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Clinical Images  |   March 2019
Anemia Diagnosed by Head Computed Tomography
Author Notes
  • From the Department of Emergency Medicine at Kingman Regional Medical Center in Arizona. 
  • Financial Disclosures: None reported. 
  • Support: None reported. 
  •  *Address correspondence to John Ashurst, DO, MSc, Department of Emergency Medicine, Kingman Regional Medical Center, 3269 Stockton Hill Rd, Kingman, AZ 86409-3619. Email: ashurst.john.32.research@gmail.com
     
Article Information
Imaging / Clinical Images
Clinical Images   |   March 2019
Anemia Diagnosed by Head Computed Tomography
The Journal of the American Osteopathic Association, March 2019, Vol. 119, 212. doi:https://doi.org/10.7556/jaoa.2019.035
The Journal of the American Osteopathic Association, March 2019, Vol. 119, 212. doi:https://doi.org/10.7556/jaoa.2019.035
After several days of generalized weakness, a 79-year-old man presented to the emergency department with a possible head injury due to a fall. He had a cerebral vascular accident several years prior, with residual left-sided weakness. Examination revealed skin pallor but no signs of trauma. Unenhanced head computed tomographic images (UHCT) showed no acute intracranial hemorrhage but demonstrated possible anemia because the dural venous sinus (DVS) had a measurement of 23.6 Hounsfield units (HUs) (image A and image B). His hemoglobin (Hb) level was low (3.1 g/dL). Fecal occult blood was detected, and the patient received a transfusion of 2 units of packed red blood cells. 
Attenuation of the DVS on UHCT has been shown to correlate with Hb and hematocrit to predict the degree of anemia.1-4 Chaudhry et al1 found that an attenuation of 36.3 HU (AUC, 0.56) in the DVS had moderate sensitivity (80%), high specificity (96.6%), and negative predictive value (99.6%) for diagnosing anemia (Hb <8 g/dL), and less than 42.35 HU (AUC, 0.94) demonstrated a high sensitivity (91.2%), specificity (88.5%), and negative predictive value (98.6%) for an Hb level less than 10 g/dL. Although Hb affects attenuation more than hematocrit, other factors, including age and sex, should be considered when determining the attenuation of the DVS.3,4 When sex is considered, an increase of 10 HU correlates to a 2.26-g/dL increase in Hb in males and 0.87-g/dL in females.3 
References
Chaudhry AA, Gul M, Chaudhry A, Sheikh M, Dunkin J. Quantitative evaluation of noncontrast computed tomography of the head for assessment of anemia. J Comput Assist Tomogr. 2015;39(6):842-848. doi: 10.1097/RCT.0000000000000306 [CrossRef] [PubMed]
Black DF, Rad AE, Gray LA, Campeau NG, Kallmes DF. Cerebral venous sinus density on noncontrast CT correlates with hematocrit. AJNR Am J Neuroradiol. 2011;32(7):1354-1357. doi: 10.3174/ajnr.A2504 [CrossRef] [PubMed]
Bruni SG, Patafio FM, Dufton JA, Nolan RL, Islam O. The assessment of anemia from attenuation values of cranial venous drainage on unenhanced computed tomography of the head. Can Assoc Radiol J. 2013;64(1):46-50. doi: 10.1016/j.carj.2011.08.005 [CrossRef] [PubMed]
Al-Ryalat NT, AlRyalat SA, Malkawi LW, Al-Zeena EF, Najar MS, Hadidy AM. Factors affecting attenuation of dural sinuses on noncontrast computed tomography scan. J Stroke Cerebrovasc Dis. 2016:25(10):2559-2565. doi: 10.1016/j.jstrokecerebrovasdis.2016.07.002 [CrossRef] [PubMed]