The computerised tomography scan (CT) provides x-ray images of sections of the brain. From these images the experienced doctor can make intelligent guesses as to the nature of the disease. Most of the times, these guesses, based as they are on a study of hundreds or even thousands of patients who have been followed up during and after treatment, prove correct.
If, however, a definitive diagnosis is required where no guesswork is involved, the diseased portion of the brain must be removed at operation and sent to the pathologist who will study it under the microscope. He will then offer a final opinion on the nature of the disease. Whilst such an approach is logical, it necessitates an operation.
We know, by experience, that the ring-shaped diseased areas seen on your patients CT scan and suspected to be tuberculomas, disappear in most cases on anti-tuberculosis drugs. We need to give these drugs for a long period of time (often up to 2 years) and follow the patients progress clinically and on serial CT scans. If the patient shows clinical improvement and CT scans show resolution of disease, there is not need to perform an operation.
If, however, the patients condition does not improve OR the scans show worsening of disease, it is wiser to remove the diseased tissue and obtain a definitive diagnosis.
Your doctor rightly feels that the disease will resolve under anti-tuberculosis treatment. It is only if the disease does not settle that he may consider an operation.