The pulmonary arterial morphology of patients with pulmonary embolism (PE) is diverse and it is unclear how the different vascular lesions evolve after initiation of anticoagulant treatment. A better understanding of the evolution of computed tomography pulmonary angiography (CTPA) findings after the start of anticoagulant treatment may help to better identify those PE patients prone to develop chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to assess the evolution of various thromboembolic lesions on CTPA over time after the initiation of adequate anticoagulant treatment in individual acute PE patients with and without an ultimate diagnosis of CTEPH.

We analysed CTPA at diagnosis of acute PE (baseline) and at follow-up in 41 patients with CTEPH and 124 patients without an ultimate diagnosis of CTEPH, all receiving anticoagulant treatment. Central and segmental pulmonary arteries were scored by expert chest radiologists as normal or affected. Lesions were further subclassified as 1) central thrombus, 2) total thrombotic occlusion, 3) mural thrombus, 4) web or 5) tapered pulmonary artery.

Central thrombi resolved after anticoagulant treatment, while mural thrombi and total thrombotic occlusions either resolved or evolved into webs or tapered pulmonary arteries. Only patients with an ultimate diagnosis of CTEPH exhibited webs and tapered pulmonary arteries on the baseline scan. Moreover, such lesions always persisted after follow-up.

Webs and tapered pulmonary arteries at the time of PE diagnosis strongly indicate a state of chronic PE and should raise awareness for possible CTEPH, particularly in patients with persistent dyspnoea after anticoagulant treatment for acute PE.

肺栓塞 (PE) 患者的肺动脉形态多种多样，在开始抗凝治疗后不同的血管病变如何演变尚不清楚。更好地了解抗凝治疗开始后计算机断层扫描肺血管造影 (CTPA) 结果的演变可能有助于更好地识别那些容易发展为慢性血栓栓塞性肺动脉高压 (CTEPH) 的 PE 患者。我们的目的是评估在最终诊断为 CTEPH 和未最终诊断为 CTEPH 的个体急性 PE 患者开始充分抗凝治疗后，CTPA 上各种血栓栓塞病变的演变。

我们对 41 名 CTEPH 患者和 124 名最终未确诊为 CTEPH 的患者（均接受抗凝治疗）诊断急性 PE（基线）和随访时的 CTPA 进行了分析。中央和节段性肺动脉由专业的胸部放射科医师评分为正常或受影响。病变进一步细分为 1) 中央血栓，2) 完全血栓闭塞，3) 附壁血栓，4) 蹼或 5) 锥形肺动脉。

抗凝治疗后中央血栓消退，而附壁血栓和完全血栓闭塞要么消退，要么演变成网状或锥形肺动脉。只有最终诊断为 CTEPH 的患者在基线扫描中表现出蹼和锥形肺动脉。此外，此类病变在随访后始终存在。

PE 诊断时的蹼和锥形肺动脉强烈提示慢性 PE 状态，应提高对可能的 CTEPH 的认识，尤其是急性 PE 抗凝治疗后持续呼吸困难的患者。