Diagnostic Value of Pulmonary Artery Hypodense and Hyperdense Luminal Sign in Non-Contrast Thoracic CT Scan for Detection of Pulmonary Embolism

Abstract

This study evaluates the diagnostic value of hyperdense and hypodense foci in the lumen of pulmonary arteries and their branches for pulmonary embolism in thoracic CT Scan without contrast. In this study, imaging data of 171 patients who underwent both Non-contrast thoracic CT Scan and CT angiography were assessed. First, non-contrast thoracic CTs done by a multidetector CT machine were evaluated for abnormal intraluminal densities in pulmonary arteries and their branches. Then, the results were compared with the results of pulmonary CT angiography. In 58 patients (43/92%), the intraluminal signs (including hyperdense and hypodense) were seen in non-enhanced CT. According to the obtained results, 18 (31%) cases had normal CT Angiography, 24 patients (37/41%) had evidence of central emboli, and 16 patients (58/27%) had evidence of peripheral embolism. For the hyperdense luminal sign, false-negative rate, false-positive rate, sensitivity, specificity, PPV, and NPV for pulmonary embolism were 13/5%, 4/1%, 48/89%, 98/44%, 75/86%, and 83/80%, respectively. For the hypodense luminal sign, false-negative rate, false-positive rate, sensitivity, specificity, PPV, and NPV for pulmonary embolism were 15/8%, 6/4%, 40%, 91/27%, 62/07%, and 80/99% respectively. The results indicate that the hyperdense luminal sign has a high specificity and NPV for the diagnosis of PE, especially for central embolism. However, the sensitivity and PPV of this sign are not significant. Also, the hypodense luminal sign has a high specificity and PPV for the diagnosis of PE, but its sensitivity and PPV are not substantial.