Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright frontal chest radiograph demonstrates improved lung volumes . There is no pleural effusion or pneumothorax . The pulmonary vasculature is normal in appearance . Moderate cardiomegaly is unchanged . There is marked calcification of the aortic knob . Median sternotomy wires and surgical clips superimposed upon the mediastinum are unchanged . A left axillary pacemaker is again noted , with atrial and ventricular leads taking a contiguous and expected course .
    OUTPUT:
    
Improved lung volumes , no CHF .