Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left chest wall dual lead pacing device is again seen . Median sternotomy wires are noted as well as a prosthetic valve . There is left basilar opacity both laterally and at the retrocardiac region medially , unchanged from prior . This could represent loculated effusion with possible superimposed parenchymal opacity . There is no large right pleural effusion . Superiorly , the lungs are clear .
    OUTPUT:
    
Persistent left basilar opacity compared to prior , potentially a loculated effusion although superimposed consolidative process or underlying lesion or possible .