Uncorrected Proof Iran J Radiol. 2021 April; 18(2):e103789. Published online 2021 June 14. doi: 10.5812/iranjradiol.103789. Research Article A New Formula for Hemoglobin Level Prediction in Non-enhanced Brain Computed Tomography Scan Mohammad Reza Sasani 1 , Yaser Toloueitabar 2 , Nahid Rezaeian 2 , Leila Hosseini 2 , Fatemeh Zadehbagheri 2 , Marzieh Motevalli 2 , Mahdi Daliri 2 and Sanaz Asadian 1, 2, * 1 Medical Imaging Research Center, Department of Radiology, Shiraz University of Medical Sciences, Shiraz, Iran 2 Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran * Corresponding author: Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Email: asadian_s@yahoo.com Received 2020 April 20; Revised 2021 May 08; Accepted 2021 May 15. Abstract Background: For many patients with neurological complaints, a non-enhanced brain computed tomography (CT) scan is the first workup. In some of these patients, there is no pathological finding. Anemia is a condition that can present with neurological symp- toms without any imaging findings. The correlation of dural venous sinus density with hemoglobin (Hb) level has been shown in some recent studies. Objectives: This study aimed to propose a strategy to predict the level of Hb and investigate the possibility of underlying anemia based on dural venous sinus density to facilitate treatment. Patients and Methods: The CT scans of selected patients, who were referred to Faghihi Hospital in Shiraz, Iran, from October 2018 until February 2019, were reviewed in this study; the complete blood count (CBC) was measured for cases without any findings. The data of 78 patients, including CBC parameters and the mean Hounsfield unit (HU) in the superior sagittal sinus (SSS), torcula herophili (TH), and transverse sinuses (TS), were also analyzed. Results: A relatively strong direct linear correlation was found between the Hb level and HU. The Hb level was calculated based on the following formula: Hb level = 0.2 × SSS HU + 1.2 × sex factor - 0.01 × age (where sex factor is zero for females and one for males). Besides, measurement of the cutoff point for the mean HU of SSS, based on the ROC curve to predict anemia, showed that with SSS HU ≤ 50, anemia could be predicted with 84.62% sensitivity, 75.38% specificity, and 75.64% accuracy in the general population. Conclusion: A significant positive correlation was found between the Hb level and the mean HU of dural venous sinuses. Therefore, the level of Hb is predictable based on HU, and differential diagnoses are limited. Keywords: Cranial Venous Sinus Density, Hemoglobin, Brain Computed Tomography 1. Background Today, non-enhanced brain CT scan is performed as the first imaging step for most patients with neurological and psychological symptoms. However, in some of these pa- tients, there are no pathological imaging findings to ex- plain their signs and symptoms (1-3). One of the conditions presenting with neurological symptoms, without signifi- cant imaging findings, is anemia. It is the most common hematologic disorder, affecting 30% of the world’s popula- tion (4). This condition has non-specific symptoms, such as fatigue, palpitations, and exertional dyspnea (4, 5). It also causes neurological and psychological complaints, such as headache, poor concentration, and depression; even in the elderly, it is associated with a greater risk of Alzheimer’s disease (6-9). Recently, some studies have investigated the relation- ship between non-enhanced CT findings of different body areas and laboratory indicators of anemia. Recent stud- ies have demonstrated the association of the myocardium, interventricular septum, and aortic wall density in non- enhanced chest CT scan with anemia (10, 11). Other investi- gations have reported a correlation between dural venous sinus density and blood hemoglobin (Hb) levels (1-3). If the association between dural venous sinus density and ane- mia is confirmed, patients with neurological or psycho- logical complaints, without significant findings on non- enhanced brain CT scan, can be referred for further exam- inations and therapy, with the possibility of anemia as the underlying cause of their complaints. Although previous studies have demonstrated a significant correlation be- tween dural venous sinus density and Hb level (1-3), further investigations are needed to determine its reproducibility in different populations. Copyright © 2021, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.