Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are normally expanded . No definite focal consolidation is seen . 1 .6 cm relatively rounded opacity is seen at the medial left lung base , may be artifactual , but underlying pulmonary nodule not excluded . The heart is not enlarged . The mediastinal and hilar contours are normal . There is no pleural effusion or pneumothorax . Within the limitations of chest radiography , no displaced rib fracture is detected .
    OUTPUT:
    
No evidence of acute intrathoracic injury . 1 .6 cm relatively rounded opacity is seen at the medial left lung base , may be artifactual , but underlying pulmonary nodule not excluded . Recommend oblique views or CT for further evaluation .