All the diseases occur in the beginning stage as a result of certain biochemical changes developing in an abnormal manner. These changes are in molecular and cellular level in the beginning whereas spread to the tissues, organs and organ systems afterwards causing structural changes. Thus, the detection and measurement of such biochemical changes significantly matters for the diagnosis of the diseases The information to be obtained is important for the explanation of the causes, taking of protective measures and follow-up of treatment responses as well as the diagnosis of the disease. PET/CT is a single patient bed imaging system combining the positron emission tomography and computerized tomography techniques. The CT and PET images of the patient, lying on a mobile patient bed, are taken subsequently. PET, likewise other nuclear medicine practices, is a method which images the body functions and metabolism after administering the radioactive imaging agents to the patient via oral, venous or respiratory means.

 

The most important difference of the imaging agents used for PET are that these include the main biological infrastructural building blocks C (carbon), O2 (oxygen), F (flourine) and N2 (nitrogen) and resemble very similar chemical structures with such elements. Thus, these imaging agents act like the aforementioned molecules in the body. The biological behaviours of the PET imaging agents are detected within the body and it is accordingly possible to obtain molecular level information about the functions of the cells, tissues and organs.

 

PET is a very diagnostic tool for the cases where a structural disorder is not eminent however abnormal biochemical movements have started; i.e. early phases of the diseases.


CT forms the other half of the system through which the images are taken and used for determining the structural changes, determination of the spots, obtaining detailed anatomic information for lesions and surrounding structures and also for making certain adjustments on the PET images. PET/CT is sine qua non (inevitable) for the health institutions who deem to provide good health services since a very high-tech device that has the ability of detecting any and all biochemical changes to arise during the early phases or late phases of the diseases. The new advances in PET/CT branch have made the implementations more simple, fast and economic. One of the important issues of PET/CT is the radiation dose exposed by the patient during the process. The new systems enable the use of lesser PET imaging agents and low doses of CT whereas have made the exposed radiation doses to be pulled down to minimum. PET/CT is frequently used for diagnosing, phase designation, re-phasing and future estimations of  the hidden cancer cases. Besides, the system is also used for following and assessing the responses to the treatment, determination of suitable biopsy zone, radiotherapy planning as well as understanding the relapses and far metastasis phenomenons.

 

In a lesser, but steadily increasing, frequency, PET/CT applications are used for heart diseases (coronary artery disease, determination of the liveliness of heart muscle, heart muscle diseases, follow-up of patients undergone by-pass etc.), brain and nerve diseases (dementia, brain cancer, biopsy zone determination, brain development disorders, Parkinson disease, epilepsy, stroke, certain genetically inhering diseases etc.), psychiatric diseases (schizophrenia, attention deficit disorders, hyper-kinetic diseases, anxiety, panic attacks, speaking disorders, alcohol and drug addictions, neuro-transmitter and receptor disorders etc.)

 

Thanks to the data and contribution it provides, the patient is also saved from unnecessary interventions and tests, unusable treatments and complications thereof, unnecessary costs and loss of valuable times.

 

For information and appointment
Prof.Dr. Mehmet Ali ÖZGÜVEN Nuclear Medicine Specialist