### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
report is: Normal CT attenuation characteristics of the gray and white matter of both cerebral hemispheres. No focal or enhancing lesions are detected Normal dimensions and configurations of the supra and infra tentorial ventricular system Neither intra nor extra axial collections. No brain edema. No mid line shift. Normal appearance of posterior fossa structures. Normal CT features and appearance of the bony cranial vault Opinion: Negative CT study of the brain and posterior fossa structures..

### output:

Hello, Your CT scan first is entirely normal. To break it down line by line: Normal CT attenuation characteristics of the gray and white matter of both cerebral hemispheres.- This states that the difference in density between the gray matter (the nerve cells) and white matter (the cables of the nerve cells) looks as it is supposed to. No focal or enhancing lesions are detected-This says that there are no tumors, infection or inflammation. Normal dimensions and configurations of the supra and infra senatorial ventricular system-this discussed the normal fluid filled spaces that are found in the brain. It states that the fluid filled spaces in the top and bottom part of the brain are normal. Neither intro nor extra axial collections.- This states that there are no abnormal collections of fluid within or outside the brain. No brain edema.- No swelling of the brain No mid-line shift.- A midline shift occurs when swelling or a tumor pushes part of the brain to the opposite side, that is a part of the brain that is for example that a part of the brain that should be on the left side of the brain would be pushed to the right side, passed the center point of the skull. Normal appearance of posterior fossa structures.- This is simply referring to a part of the brain that lies in the back of the head which includes the brain stem and cerebellum. These look normal on the scan. Normal CT features and appearance of the bony cranial vault-the skull and the space in which the brain is contained looks normal Opinion: Negative CT study of the brain and posterior fossa structures - A "negative" study is simply one which did not find anything abnormal. Hope I have answered your query. Let me know if I can assist you further. 