Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient upright position . Comparison is made with the next preceding PA and lateral chest examination of ___ . The heart size remains unchanged and is well within normal limits . No configurational abnormality is seen . The pulmonary vasculature is not congested . Again noted are bilateral patchy widely disseminated parenchymal densities in both lungs predominantly in the lower lung fields . They are of similar character as they have been seen on previous examinations . On the next preceding study of ___ , the patient had undergone improvement of these lung changes , but they have now again increased and are similar to those encountered during examinations in ___ . Noteworthy is that the pleural spaces remain now free both laterally and posteriorly . No pneumothorax has developed .
    OUTPUT:
    
The described changes must be identified as " atypical " . The waxing and waning that has been noticed of these changes overtime makes an infectious course unlikely unless clinical tests have documented such possibility . Pulmonary vascular congestion is most unlikely as the heart remains normal in size throughout . Vasculitis changes in the pulmonary tissue are a possibility but can not be specifically diagnosed with plain x-ray .