Background; It is possible to identify high-attenuation clots in pulmonary thromboembolism using non-contrast computed tomography (CT) of the chest. Such detection may be crucial for timely initiation of appropriate therapy. Aim and objectives; the aim of this study was to show the accuracy and usefulness of non-contrast CT in diagnosis of pulmonary embolism. Subjects and methods: The study was conducted in the Radiology Department at Beni-Suef University hospital to evaluate the role of non-contrast multi-slice computed tomography (MSCT) in detection of central pulmonary embolism using 16 slice MDCT. Result; hyperdense lumen sign shows an overall sensitivity of 50%, specificity of 100%, PPV (positive predictive value) of 100% while the NPV (negative predictive value) was 65.4%, having diagnostic value in detection of emboli which are located within the main pulmonary arteries, and the high-attenuated emboli (hyper-dense sign) in pulmonary artery had a sensitivity of 50 % and regarding the specificity was 100% for diagnosis of PE. Conclusion:  Positive hyper dense lumen sign can be prominent indicator of thrombus, which can be relied upon if (Computed Tomography Pulmonary Angiography) CTPA is not possible.