Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . A 1 cm nodular opacity seen in the retrocardiac region above the medial margin of the left hemidiaphragm . Moderate cardiomegaly is present . Otherwise cardiomediastinal and hilar contours unremarkable . There is no pleural effusion or pneumothorax . No rib fractures are identified .
    OUTPUT:
    
1 . No evidence of rib fractures . However this study is limited for detection of rib fractures and if there is high clinical concern dedicated rib views should be obtained . 2 . 1 cm nodule projecting over the left lower lobe is potentially calcified and could be due to overlying costochondral cartilage . This can be further assessed with shallow obliques .