NON-CONTRAST COMPUTED TOMOGRAPHY OF THE CHEST FOR DIAGNOSIS OF ANEMIA: A DIAGNOSTIC ACCURACY STUDY

Abstract

Background: Anemia is a widespread clinical condition with significant implications for patient morbidity and healthcare burden. While complete blood count (CBC) remains the standard for anemia diagnosis, imaging tools like non-contrast computed tomography (CT) of the chest are increasingly being explored for their ability to detect indirect signs of anemia and its potential underlying causes. This study evaluates the diagnostic accuracy of non-contrast CT chest in detecting anemia using hemoglobin values on CBC as the reference standard.

Objective: To determine the diagnostic accuracy of non-contrast computed tomography of the chest in diagnosing anemia, using hemoglobin levels from complete blood count as the gold standard.

Methods: A retrospective cross-sectional study was conducted at the Department of Radiology and Imaging, Liaquat University of Medical & Health Sciences (LUMHS) Jamshoro & Hyderabad, and the Advanced Diagnostic Centre, LUMHS Jamshoro, Sindh, Pakistan. A total of 201 adult patients (≥18 years) who underwent non-contrast chest CT and CBC within a 10-day interval were included. Exclusion criteria included the use of IV contrast, poor CT quality, presence of malignancy, recent blood transfusion, or IV hydration. Radiologic diagnosis of anemia was based on attenuation values <35 Hounsfield Units in the cardiac chambers. CBC-defined anemia was classified as hemoglobin <12 g/dL in females and <14 g/dL in males. Statistical analysis was conducted using SPSS version 22. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated.

Results: Of the 201 patients, 99 (49.3%) were males and 102 (50.7%) were females, with a mean age of 43.02 ± 15.62 years. Anemia was detected in 64 patients (31.8%) on CT and in 53 patients (26.4%) on CBC. Non-contrast CT chest showed a sensitivity of 81.13%, specificity of 85.81%, PPV of 67.19%, NPV of 92.70%, and an overall diagnostic accuracy of 84.58% compared to CBC.

Conclusion: Non-contrast CT chest demonstrates high diagnostic accuracy in identifying anemia, offering valuable support in clinical settings where hematologic testing may be delayed or when structural causes are suspected. Stratified analysis further indicates better diagnostic performance in younger individuals and females.