Feasibility of CT attenuation values in the diagnosis of anemia

PURPOSE: To verify the possible correlation between CT attenuation value and hemoglobin (Hb). MATERIALS AND METHODS: CT attenuation was evaluated in 113 CT studies. Anemia was defined as an Hb level less than 14 g/dl in males and less than 12 g/dl in females. Hb was compared visually by grading (Grade 1: cardiac muscle density much higher than lumen, Grade 2: cardiac muscle density higher than lumen, Grade 3: cardiac muscle density equal to lumen), and with HU of CT attenuation on unpaired t-test (p<0.01). Correlations were calculated using the linear regression method. RESULTS: Hb of less than 6 g/dl was found to be Grade 1, while that over 12 g/dl was considered Grade 3 on visual grading. The attenuation numbers of subjects with anemia yielded low values, whereas those of normal subjects were higher. There were significant differences between subjects with anemia and normal subjects (p<0.01). HU versus hemoglobin showed a linear increase, with a correlation coefficient of 0.76. CONCLUSIONS: This simple, readily available information may provide a valuable adjunct in the interpretation of CT examinations.