Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph was provided . The lungs appear clear without definite signs of pneumonia or CHF . On slight apical lordotic positioning , evaluation is slightly limited through the lower lungs . No effusion or pneumothorax seen . Cardiomediastinal silhouette is normal . Bony structures are intact .
    OUTPUT:
    
No acute intrathoracic process .