Are Computed Tomography HU Density Values Useful in Differentiating Embolism and Lymph Node at Hilar Level?

Abstract

Pulmonary embolism (PE) is a vascular disease that causes occlusion and narrowing of the pulmonary arteries in the acute or chronic process, has high morbidity and mortality, is still the most frequently diagnosed in emergency outpatient clinics and causes sudden death. Computed Tomography as a diagnosis is the most frequently used radiological examination in clinical practice. A total of 58 patients who had clinical complaints of chest pain and dyspnea and underwent thoracic CT angiography in the emergency outpatient clinic were included in the study. In our study on 58 patients, we looked at HU density values in the differentiation of lymph nodes, which are frequently confused with PE in the lung hilum. The mean HU densities of the patients with pulmonary embolism were 58.8±5.9 (52-75 HU), and the mean HU densities of the lymph node patients were 66.8±10 (44-87HU). The mean lymph node and thrombus density values from 58 embolism patients were measured as approximately 67 HU and 59 HU, respectively. Although lymph node HU values were higher than embolism in the vessel wall, no statistically significant difference could be obtained (p>0.005). The reason for this may be the age of the thrombus and the abundance of tissues of different densities around the measurement area. For this, a larger number of patients should be examined and thrombus densities of large lymph nodes and acute-chronic stages can be examined separately.