Atypical Pneumonia: This is often characterized by ground glass opacities on imaging, especially in the lower lobes. The presentation can be nonspecific, and the appearance can be accentuated by low lung volumes.

Chronic Thromboembolic Disease: Mosaic attenuation can be a sign of chronic thromboembolic disease due to the variation in blood flow through the lungs. This condition can cause areas of ground glass opacification due to perfusion defects.
Airways Disease (e.g., Bronchiectasis, Chronic Bronchitis): These conditions can lead to mosaic attenuation due to air trapping and differences in lung density. Ground glass opacities can also be seen, especially if there's an infectious or inflammatory component.
Interstitial Lung Disease (ILD): Certain types of ILD, such as nonspecific interstitial pneumonia (NSIP), can present with ground glass opacities. The pattern can be diffuse but may appear more pronounced in certain areas, including the lower lobes.

Pulmonary Embolism (PE): Although mosaic attenuation can be seen in chronic conditions, it's crucial not to miss acute pulmonary embolism, which can present with similar imaging findings, especially if there are areas of oligemia.
Invasive Pulmonary Fungal Infections: In immunocompromised patients, fungal infections can cause ground glass opacities and must be considered due to their high mortality rate if untreated.

Lymphangitic Carcinomatosis: This condition involves the spread of cancer to the lymphatic vessels of the lung and can cause ground glass opacities and septal thickening.
Pulmonary Alveolar Proteinosis: A rare condition characterized by the accumulation of surfactant-like protein and phospholipids in the alveoli, leading to ground glass opacities on imaging.
Pulmonary Vasculitis (e.g., Wegener's Granulomatosis): These conditions can cause a variety of pulmonary findings, including ground glass opacities and mosaic attenuation, due to inflammation of the blood vessels.