Differentiating Between Acute Pulmonary Embolism and CTEPH Using Dual-Energy CT

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) tended to have different dual-energy computed tomography (DECT)-based vascular parameters compared with patients with acute pulmonary embolism (PE), according to a study published in the Journal of Thoracic Imaging.

DECT was used to assess patterns of vascular and lung parenchymal enhancement in patients with suspected CTEPH and in those with acute PE. Different DECT-based parameters were evaluated that highlighted patterns of vascular kinetics. Specifically, total DECT-based parenchymal attenuation in Hounsfield unit (LungHU), percentage of perfused blood volume (PBV), peak enhancement of main pulmonary artery (PApeak in HU), maximum enhancement corresponding to 100, and the ratio of PApeak to LungHU were examined.

Compared with patients with a negative CT, patients with CTEPH tended to have lower LungHU, lower PBV, and higher PApeak/LungHU ratio. Compared with patients with acute PE, patients with CTEPH tended to have lower LungHU, lower PBV, and higher PApeak/LungHU ratio. However, no statistically significant differences were observed between patients with acute PE and those with negative CT.

The researchers wrote, “DECT-based vascular parameters have the potential to differentiate patients with acute vs chronic pulmonary embolism.” They added that DECT could potentially detect “the presence of small vessel disease, monitor its progression, and assess response to therapy.”

Reference

Nallasamy N, Bullen J, Karim W, Heresi GA, Renapurkar RD. Evaluation of vascular parameters in patients with pulmonary thromboembolic disease using dual-energy computed tomography [published December 17, 2018]. J Thorac Imaging. doi:10.1097/RTI.0000000000000383