Abstract:

Objective  To assess the value of dual energy pulmonary angiography (DECTPA) with dual-source CT (DSCT) in pulmonary embolism (PE). Methods  Twenty patients(group A) suspected of PE underwent DECTPA with DSCT in dual energy mode attube voltages of 140 and 80?kV, and three kinds of axial images were acquired，which were 80kV, 140kV and merged images． The dual energy lung perfusion image (DEPI) was generated through dual energy software (using 140kV and 80kV images), while vascular multi-planar reformation (V-MPR) images were generated through DECT 3D software (using merged images). The difference in directly showing emboli by using DEPI and V-MPR and the advantage of DEPI combined with V-MPR were analyzed. Another sixteen cases (group B) of PE of thorax CTA with 64 slice spiral CTwere reviewed retrospectively.  Image quality of the two groups was  independently evaluated by two radiologists who were skilled in image postprocessing. Results  1）There was no difference in image quality between the two groups. (2) There was no difference in directly detecting emboli of pulmonary artery trunks and lobar arteries, but there was a difference in directly detecting emboli of segmental and sub-segmental arteries. (3) In DEPI, emboli of pulmonary artery trunks, lobar arteries and partial segmental arteries resulted in perfusion defect of lung tissue, while other segmental and sub-segmental arteries did not result in perfusion defect. Conclusion  DECTPA can show emboli as clearly as 64 slice spiral CT does in pulmonary embolism, and it can also assess blood perfusion of injured lung -tissue.

Key words: Perfusion; Pulmonary embolism; Tomography, X-ray computed; Dual-source CT