Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart is not enlarged . The cardiomediastinal silhouette is within normal limits . The right hemidiaphragm is slightly elevated . No CHF , focal infiltrate , effusion or pneumothorax is detected . There is some platelike atelectasis at the right base posteriorly . No free air is seen beneath the diaphragms .
    OUTPUT:
    
Platelike atelectasis , thought to lie at the right base posteriorly . No frank infiltrate or consolidation more typical for pneumonia identified . Slight elevation of the right hemidiaphragm , of uncertain chronicity . Otherwise , no acute pulmonary process identified .