Clinical value of deep vein thrombosis density on pre-contrast and post-contrast lower-extremity CT for prediction of pulmonary thromboembolism

Abstract

Background There was a lack of studies assessing the relationship between deep vein thrombosis (DVT) Hounsfield unit (HU) density and pulmonary thromboembolism (PTE). Purpose To evaluate the clinical value of DVT density measured on pre- and post-contrast lower-extremity computed tomography (CT) for the prediction of PTE. Material and Methods From 2017 to 2021, patients who underwent pulmonary CT angiography within one week after diagnosis of DVT on lower-extremity CT were included in this retrospective study. Then, the patients without PTE were included in “DVT group” and those with both DVT and PTE were included in the “DVT-PTE group.” The DVT HU density was measured by drawing free-hand region of interests (ROIs) within the thrombus at the most proximal filling defect level. A receiver operating characteristic (ROC) analysis was used to evaluate the predictive value of DVT density for the risk of PTE. Results This study included a total of 94 patients (DVT group: n=56; DVT-PTE group: m=38). DVT density was significantly higher in the DVT-PTE group than the DVT group in both pre-contrast (53.5 ± 6.2 HU vs. 44.1 ± 7.9 HU; P < 0.001) and post-contrast CT (67.0 ± 8.6 HU vs. 57.1 ± 10.6 HU; P < 0.001). ROC analysis revealed that the area under curve, sensitivity, and specificity for predicting the risk of PTE were 0.739, 71.1%, and 64.2%, respectively, at a DVT density cutoff of 48.2 HU on pre-contrast CT and were 0.779, 73.7%, and 69.6% at a DVT density cutoff of 61.8 HU on post-contrast CT. Conclusion The DVT density on both pre- and post-contrast CT could be a predictive factor of PTE.

The accuracy of the Hounsfield unit in pulmonary embolism diagnostics

“…In line with our data, we can say that the mean HU values of non-contrast areas (thought to be a thrombus) measured in the study group and the mean HU values of non-contrast areas measured in the control group included a statistically significant difference up to the level of the interlobar branch. Another conclusion is that pulmonary thrombus may cause an increase in HU value, which was seen in other thrombus studies [10,15].…”

“…In contrast, the HU value in the DVT alone group was 44.1 before contrast and 57.1 after (p< 0.001). The study concluded that HU value intensity on pre-and post-contrast CT may be a predictive factor for PE [15].…”

“…Previous studies have examined the diagnostic accuracy of HU values on CT for cranial venous thrombosis and deep vein thrombosis (DVT) [10,15]. In this study, we aimed to demonstrate the diagnostic accuracy of HU value for PE based on the hypothesis that acute thrombosis causes an increase in HU value on CT.…”