Quantification of Lung Perfusion Blood Volume With Dual-Energy CT: Assessment of the Severity of Acute Pulmonary Thromboembolism

OBJECTIVE. The purpose of this study was to evaluate the usefulness of quantification of lung perfused blood volume (PBV) with dual-energy CT (DECT) for assessment of the severity of acute pulmonary thromboembolism (PTE). MATERIALS AND METHODS. We retrospectively analyzed the records of 72 patients with PTE and 168 without PTE who underwent DECT. The PTE patients were divided into high-, intermediate-, and low-risk groups based on clinical symptoms and right ventricular dysfunction. Correlations between quantification of whole-lung PBV and clinical severity were evaluated. Also evaluated was the relation between quantification of whole-lung PBV and right-to-left ventricular diameter ratio on CT images, which was used as an indicator of right ventricular dysfunction. RESULTS. In the PTE and control groups, the whole-lung PBVs were 27.6 +/- 7.9 and 29.9 +/- 6.8 HU with a significant difference between them ( p < 0.0281). In the high-, intermediate-, and low-risk PTE groups, the whole-lung PBVs were 16.0 +/- 2.9, 21.0 +/- 4.2, and 31.4 +/- 5.8 HU with a significant difference between them ( p < 0.05). There was no significant difference in whole-lung PBV between the control group and the low-risk PTE group, but there was a significant difference between the control group and the other two PTE groups. In PTE patients, whole-lung PBV had negative correlation with right-to-left ventricular diameter ratio ( R = - 0.567, p < 0.001). CONCLUSION. Quantification of lung PBV with DECT is useful for assessment of the clinical severity of PTE and can be used as an indicator of right ventricular dysfunction.