Mosaic Pattern of Lung Attenuation on Chest CT in Patients with Pulmonary Hypertension

A mosaic pattern of lung attenuation on chest computed tomography (CT) may be due to various etiologies. There is limited published data on CT results when used to evaluate pulmonary hypertension (PH). We retrospectively studied the frequency of mosaic pattern in patients with PH and the cause of the PH by diagnostic group, as well as the correlation between the mosaic pattern and the following: demographics, severity of the PH, main pulmonary artery (PA) size, PA/aorta (PA/Ao) ratio, pulmonary function tests (PFT), and ventilation perfusion scan results. Overall, 18% of the cohort had CT mosaic pattern (34/189). Mosaic pattern was present in 17/113 (15%) in Group 1 pulmonary arterial hypertension, 5/13 (28%) in Group 2 pulmonary venous hypertension and 8/50 (16%) in Group 3 PH. Conversely, Group 4 chronic thromboembolic PH was more prevalent in 4/8 (50%). Main PA size, PA/Ao ratio, and segmental perfusion defect were positively associated with mosaic pattern. In contrast, factors such as age, gender, body mass index, functional class, hemodynamic data, and PFT values were not associated with mosaic pattern. Mosaic pattern is not specific as an isolated finding for distinguishing the subtype of PH.