Lobar pulmonary perfusion quantification with dual-energy CT angiography: Interlobar variability and relationship with regional clot burden in pulmonary embolism

Hye Ju Lee; Mark Wanderley; Vivian Cardinal da Silva Rubin; Ana Clara Tude Rodrigues; Amanda Rocha Diniz; Jose Rodrigues Parga; Marcelo Britto Passos Amato

doi:10.1016/j.ejro.2022.100428

Lobar pulmonary perfusion quantification with dual-energy CT angiography: Interlobar variability and relationship with regional clot burden in pulmonary embolism

Eur J Radiol Open. 2022 Jun 8:9:100428. doi: 10.1016/j.ejro.2022.100428. eCollection 2022.

Authors

Hye Ju Lee¹, Mark Wanderley¹, Vivian Cardinal da Silva Rubin¹, Ana Clara Tude Rodrigues², Amanda Rocha Diniz², Jose Rodrigues Parga¹, Marcelo Britto Passos Amato³

Affiliations

¹ Department of Radiology, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
² Echocardiography Laboratory, Department of Radiology, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
³ Pneumology Division, Instituto do Coracao, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.

Abstract

Purpose: Semi-automated lobar segmentation tools enable an anatomical assessment of regional pulmonary perfusion with Dual-Energy CTA (DE-CTA). We aimed to quantify lobar pulmonary perfusion with DE-CTA, analyze the perfusion distribution among the pulmonary lobes in subjects without cardiopulmonary diseases and assess the correlation between lobar perfusion and regional endoluminal clots in patients with acute pulmonary embolism (PE).

Methods: We evaluated 151 consecutive subjects with suspected PE and without cardiopulmonary comorbidities. DE-CTA derived perfused blood volume (PBV) of each pulmonary lobe was measured applying a semi-automated lobar segmentation technique. In patients with PE, blood clot location was assessed, and CT-based vascular obstruction index of each lobe (CTOI_lobe) was calculated and classified into three groups: CTOI_lobe= 0, low CTOI_lobe (1-50%) and high CTOI_lobe (>50%).

Results: Among patients without PE (103/151, 68.2%), median lobar PBV was 13.7% (IQR 10.2-18.0%); the right middle lobe presented lower PBV when compared to all the other lobes (p < .001). In patients with PE (48/151, 31.8%), lobar PBV was 12.6% (IQR 9.6-15.7%), 13.7% (IQR 10.1-16.7%) and 6.5% (IQR 5.1-10.2%) in the lobes with CTOI_lobe= 0, low CTOI_lobe and high CTOI_lobe scores, respectively, with a significantly decreased PBV in the lobes with high CTOI_lobe score (p < .001). ROC analysis of lobar PBV for prediction of high CTOI_lobe score revealed AUC of 0.847 (95%CI 0.785-0.908).

Conclusion: Pulmonary perfusion was heterogeneously distributed along the pulmonary lobes in patients without cardiopulmonary diseases. In patients with PE, the lobes with high vascular obstruction score (CTOI_lobe> 50%) presented a decreased lobar perfusion.

Keywords: Blood volume; CTOI, Computed tomography obstruction index; Computed tomography angiography; DE-CTA, Dual-energy computed tomography angiography; Dual-energy computed tomography (DECT); PBV, Perfused blood volume; Pulmonary embolism; Pulmonary perfusion.