hi and thanks for the question, Diagnosis of peumonia, with proper antibiotics given without response could require a more critical look. This could be explained by the fact that there certainly exists a predisposition condition that makes you more liable than others to develop a respiratory tract infections. This could be the reason the doctor wants to know exactly the state of your chest structures by asking the CT scan. However, chest infections or pneumonia not responding to standard care should warrant exclusion of common infection such as pulmonary tuberculosis, or infections due to intracellular germs like mycoplasma pneumoniae. I suggest taking an appointment with your pulmonologist/internist for a complete clinical evaluation and exclusion of such common pathologies. Thanks and best regards, Luchuo, MD.