The patient has no known history of collagen vascular disease. She admits sleeping almost exclusively on her right side. These imaging changes are most likely due to recurrent aspiration and an infectious bronchiolitis.

Centrilobular nodules are 5-10 mm nodules lying centrally within the pulmonary lobule.

They are encountered in infectious bronchiolitis, where they maybe unilateral or bilateral. They are also seen in subacute hypersensitivity pneumonitis,  RB-ILD, and pulmonary Langerhans cell histiocytosis.