Comparison of perfusion defects parameters in dual-energy computed tomography (CT) pulmonary angiography across...

This study aims to compare dual-energy computed tomography pulmonary angiography (DE-CTPA) perfusion defects (PD) parameters between the arterial (AP) and venous phases (VP).

This retrospective study analysed the database of patients who underwent dual-phase DE-CTPA examinations. The patients were categorised into three groups based on their Qanadli (Q) scores (Group A: Q = 0%, Group B: 0% < Q < 50%, and Group C: Q ≥ 50%). PD parameters, including perfusion defect volume (PDV) and its percentage relative to total lung volume (_RelPDV), were derived from the dual-phase DE-CTPA images. Differences in PD parameters were assessed between phases and among the three groups.

A total of 81 consecutive patients were included in the study (44 females [54.3%]; mean age: 68.37 ± 13.01 years). _RelPDV was significantly higher in the AP compared to the VP (P0.030). Phase comparisons within each group showed no statistically significant differences in PDV between the AP and VP for Group C. However, in Groups A and B, both PDV and _RelPDV were higher in the AP than in the VP (all P<0.05). When comparing the three groups, there were no statistically significant differences in PDV or _RelPDV for AP. In VP, PDV, and _RelPDV increased with higher Q scores, with Group C showing statistically significant differences compared to Groups A and B.

The PD parameters of DE-CTPA differed between AP and VP. This study highlights the limitations of relying on iodine maps in AP to estimate lung perfusion.