May Be Caused by

Achalasia

Aspiration pneumonia

Atelectasis of lower lobe

Bronchiectasis

Bronchogenic cyst

Cardiac tumor

Cystic adenomatoid malformation

Diaphragmatic hernia

Dilated azygos vein

Discogenic disease

Esophageal carcinoma

Esophageal leiomyoma

Esophageal mass

Esophageal varices

Extramedullary hematopoiesis

Fracture

Fungal pneumonia

Histoplasmoma

Hydatid cyst

Intralobar pulmonary sequestration

Left atrial enlargement

Left ventricular aneurysm

Localized fibrous tumor of pleura

Lung abscess

Lung granuloma

Lung neoplasm

Lymphadenopathy

Mesothelioma

Neurogenic tumor

Osteoarthritic spurring

Osteomyelitis

Paraspinal abscess

Paraspinal hematoma

Pleural effusion

Pleural metastasis

Pneumonia

Pulmonary infarction

Saccular bronchiectasis

Spinal lesion

Spinal neoplasm

Thoracic aortic aneurysm

Thoracic aortic ectasia

Thoracic kidney

Tuberculosis