Decreased Opacity without Cystic Walls

Vascular causes of mosaic perfusion include chronic pulmonary thromboembolism and pulmonary arterial hypertension.

Mosaic attenuation can be seen in a variety of airway diseases including bronchiectasis, cystic fibrosis, allergic bronchopulmonary aspergillosis (ABPA) (Fig. 24.1), asthma (Fig. 24.2), and constrictive bronchiolitis.

Distribution

Areas of mosaic perfusion in chronic thromboembolism or pulmonary arterial hypertension are typically segmental or subsegmental in distribution [1].

Distribution

In patients with mosaic attenuation secondary to airways disease, lobular areas of low attenuation are common.

Pulmonary arterial hypertension may be idiopathic or arise in association with chronic pulmonary thromboembolism; pulmonary embolism caused by tumor cells, parasitic material, or foreign material; parenchymal lung disease; liver disease; vasculitis; human immunodeficiency virus infection; or a left-to-right cardiac shunt [1].

Inciting causes of asthma include environmental allergens, viral infections, exercise, analgesics, air pollution, weather changes, cigarette smoke, occupational sensitizing agents, and irritants [2]. Conditions associated with constrictive bronchiolitis include heart–lung or lung transplantations, chronic allograft rejection, allogeneic bone marrow transplantation with chronic graft-versus-host disease, and collagen vascular diseases, especially rheumatoid arthritis [3].

Key Points for Differential Diagnosis

Please refer to section “Mosaic Attenuation” Chap. 13.

Key Points for Differential Diagnosis

Please refer to section “Mosaic Attenuation” Chap. 13.