What Does This Ultrasound Scan Report Of Lungs Indicate?

My husband has been treated for pneumonia for the last 10 days with antibiotics. He will see his doctor again for a follow-up xray in two weeks. The radiologist s report says that he has he has small right pleural effusion and mixed right perihilar and lung base opacities with volume loss. Mild interstitial opacities at the left base. No acute bony abnormality. The report also says that he has mixed right perihilar/lung base opacification and volume loss concerning for infection. Obstructing mass is not excluded. It says he has a possible lung mass. I do not understand what this means. Can you explain?