Diagnostic Success of Non-contrast Computed Tomography Findings in Central Acute Pulmonary Thromboembolism: A Case Control Study.

Abstract

Objective: Computed tomography pulmonary angiography (CTPA) is the gold standard in the diagnosis of pulmonary thromboembolism (PTE) but it cannot be used safely in conditions such as renal failure and contrast allergy. Therefore, recognition of emboli with non-contrast thoracic CT can be useful in the management of PTE. The aim of our study was to determine the diagnostic success of non-contrast thoracic CT findings in the diagnosis of PTE.

Material and methods: Patients who had both non-contrast thorax CT and CTPA imaging within 24 hours and were diagnosed with PTE were analyzed. A control group was formed by randomization in a 1:1 ratio (n = 55). CTPA images of the patients in both groups were evaluated blindly by two expert radiologists and demographic and clinical characteristics were recorded.

Results: Fifty-five patients had embolism. The mean age was 68.5±15.2. Mortality rates were 36.4% in the embolism group and 40.0% in the control group. The main pulmonary artery diameter was significantly higher in the PTE group (32.0 mm vs. 29.4 mm, P = 0.007). The mean attenuation of the pulmonary blood pool in the PTE group was higher than that of the control group [46.2 Hounsfield units (HU) (29.4-63.9) vs. 41.1 HU (32.5-62.4)] (P = 0.025).

Conclusion: Direct and indirect findings obtained from non-contrast thoracic CT can help the diagnosis, in patients in whom CTPA cannot be performed. Diagnostic utility may increase when the presence of these findings is evaluated together with clinical and laboratory findings. Validation studies should be performed in larger populations.