Positron emission tomography ( PET ) - Causes, Symptoms and Treatment .MF .
Positron Emission Tomography - is a new and modern way of accurate early diagnose a cancer, cardiac and neurological diseases.
Positron emission tomography - a complex study that used
in Oncology: cancer diagnosis, diagnosis of metastases, monitoring the effectiveness of treatment
cancer in cardiology: coronary heart disease, prior coronary artery bypass grafting
In Neurology: multiple sclerosis and other diseases
in psychiatry and gerontology - Alzheimer
Positron emission tomography provides information about the metabolism at the cellular level.
Positron emission tomography can detect signs of cancer at an early stage.
advantages of PET over other diagnostic methods:
- high diagnostic accuracy
- One study replaces several different kinds of diagnostic
- absence of pain or discomfort, and deleterious side effects
- opportunity to reach all the organs in one study
- Diagnosing diseasesearly stages
- exception of inefficient or unnecessary surgical or medical methods of treatment
- Positron emission tomography virtually harmless
Positron emission tomography - the latest diagnostic tool that allows doctors to evaluate the performance of the tissues and organs of your body.Unlike other imaging studies, the main task during positron emission tomography - not "Pictures photography" of internal organs, and obtaining a color image the chemical activity of the processes occurring in the body of the patient.When the tumor diseases of chemical processes vary accordingly changing their colors and intensity, thus, Positron emission tomography detects the disease at an early stage, when no structural (visible to the eye) changes have not yet occurred.
principle of positron emission tomography
Despite the introduction of a radioactive drug positron emission tomography virtually harmless.The radioactive drug is prepared in a cyclotron, and breaks down into non-radioactive components within an hour.The radiation dose with positron emission tomography is comparable to the irradiation dose x-rays and computed tomography
Positron emission tomography detects blood flow in tissues and tissue oxygen consumption and glucose.In the patient is administered a small amount of radioactive drug that enters the tissue.Radioactive drug emits a special, invisible rays.These rays are recorded PET scanner, which then transmits the information to the computer.The computer processes it and puts in a graphical view - builds the image.The more radioactive source is captured tissue, the more they look on the resulting image - such areas are called "hot", and vice versa, the less of the drug seized - the dimmer creates an image, such sites are referred to as "cold".The metabolism in malignant tumors is much higher than in healthy tissues so malignant tumors produce a brighter picture ( «hot»)
Most often positron emission tomography is used in the diagnosis of cancer.Also, positron emission tomography is used to diagnose diseases of the nervous system and the heart disease is based on a minimum of radioactive isotopes, practically harmless to the body amounts.
PET in oncology.Cancer Diagnosis
Positron Emission Tomography (PET) - the most modern methods of diagnosis and treatment monitoring of cancer.
Using positron emission tomography can detect cancer at an early stage, prior to disease progression.
modern cancer diagnosis using PET reveals the chain of affected tissue tumor by administration of a radioactive glucose, which is processed by all cells.Cells with increased metabolic perceive more glucose.It is this different cancer cells.Cancerous tumors consume more energy than healthy tissues, so they capture more of the radioactive source - so the tumor becomes visible during positron emission tomography.They are recorded and displayed on the scanner images.PET detects the size of the cancer even less than 1 cm. The radioactive substance administered to the organism loses its activity in a few hours and is harmless.The special value of this diagnostic method is that it allows you to choose the most the most appropriate form of therapy, especially lymphatic cancer.At the end of chemotherapy PET to determine the effectiveness of the treatment.
PET detects metastases when other diagnostic methods are powerless.For example, X-ray examination of the lungs may cause in the case of shading only suspicion of metastases.To confirm or refute suspicions can puncture tissue or PET, with only PET to determine the size of metastasis, and can also detect the spread of cancer cells in the early stages of the disease.
PET diagnostic accuracy of 80 to 95 percent, while the accuracy of the computer-tomographic diagnosis from 50 to 68 percent.Thus CT often indicates existing tumor recurrence or metastasis.
PET, unlike CT is able to identify the cause of growth of tumor markers and determine the further treatment.
PET at the expense of high precision allows to avoid surgical interventions for negative results of CT studies.
In determining neoplasia of the lymphatic system PET can replace a whole range of studies: X-ray, CT, MRI, scintigraphy of the skeleton.
PET, unlike other methods of research, makes the differentiation of healthy and diseased tissues: distinguish chronic inflammatory processes of cancer.However, other research methods, including a puncture with a negative result does not guarantee the absence of malignancy.
PET allows us not only to identify the indications for surgery, but also to create an optimal surgical plan.
Positron emission tomography is also used to determine the stage of cancer.In the past, doctors could judge the cancer affected lymph nodes only increase them.Using positron emission tomography may detect cancer affected lymph node before it began to increase, that allows for the treatment correctly.Note that some non-cancerous processes can also hit the lymph nodes, so in some cases 100% certainty that the cancer is not only gives a biopsy (surgical sampling of tissue for analysis) suspicious lymph node.
PET in cardiology.Diagnosis of heart disease
Positron emission tomography can detect areas of the heart with blood circulation disorders, so this research method used in the early detection of coronary heart disease and to identify old infarcts.Using positron emission tomography, it is possible to distinguish the dead portion of the heart muscle from a living, but bad shrinking due to low blood supply.In the latter case, the blood flow recovery operation will improve the function of the affected area.
PET is able to recognize the condition of the tissues of the heart muscle, and thereby determine the indication for heart surgery.If all the tissue "alive" enough to by-pass surgery or balloon dilatation.If found dead portions of tissue are determined by the indications for heart transplantation.
PET in neurology PET
reveals the early stages of diseases of the brain, leading to senile dementia.
PET determines whether the processes occurring in the brain, causing Parkinson's disease.Based on these data is assigned fairly effective therapy.
PET reveals the brain regions that cause epilepsy.Based on these studies there is planning surgery to remove the epileptogenic zones.
Positron emission tomography allows you to compare brain activity in patients with depression and brain activity in healthy people.Studies show that the activity of some depressed areas of the brain is reduced.While in the general practice of positron emission tomography for the diagnosis of depression is not being used.
Alzheimer's disease (senile dementia).Positron emission tomography detects changes in the brain in Alzheimer's disease at the earliest stages - when no: not yet manifested symptoms.Positron emission tomography helps to distinguish Alzheimer's disease from other disorders causing dementia (Parkinson's disease, Huntington's disease).
other brain diseases.Positron emission tomography is used to diagnose seizures in epilepsy and for the evaluation of brain function after a stroke.In some cases, the PET is used in schizophrenia.
Unfortunately, positron emission tomography there is only large regional Cetra Russia (as of April 2010 in Moscow, St. Petersburg, Yekaterinburg), while in Europe and the US Positron Emission Tomography (PET) has already received widespreadin the diagnosis of diseases.
What is commonly used positron - emission tomography?
most commonly used PET scans to detect cancer and to test the action of cancer treatment.
Positron - emission tomography of the brain are used to evaluate the condition of patients suffering from memory loss, seizures, or brain tumor.
Using PET scanning a specially trained doctor (radiologist) can check whether there were changes in the cells.
Before performing positron emission tomography injected radioactive sugar 18 FDG, which allows you to obtain an image of the metabolism of your body's cells.
How to prepare for positron emission tomography?
Positron emission tomography is usually carried out without hospitalization.Before the procedure, tell your doctor what medications you are taking, including vitamins, folk remedies, etc.Also tell your doctor if you are not suffering from any illness, especially diabetes - it can affect the results of the study.
Before performing Positron emission tomography can not eat anything at least 6 hours.In the evening before the study recommended a light dinner.If you are really worried, you can at night to drink or drugs Valerian Persen.
If performed positron emission tomography of the heart can not take caffeine-containing products within 24 hours.
Wear loose, comfortable clothing.Sometimes before the procedure required to change into a hospital gown.If carried out a study of the pelvic region may require the introduction of a catheter into the bladder through the urethra.
How to prepare for a PET scan?
- not eat for 12 hours prior to the study.Do not eat or drink anything except water.If your prescribed medications (except cough syrup) can be taken on an empty stomach, you can take them on the day of the survey.If you are told that you can not take medicine, do not take them.Do not chew gum, eat candy or take vitamins.
- Please, drink 6-8 glasses of water per day to study and several glasses of water a study day to avoid dehydration.
- last meal before the fasting should consist of foods with a low content of carbon.
- Do not exercise for at least 24 hours prior to the study.
- If possible, bring pictures of all the previous images, such as positron emission tomography, CT or MRI.They may be on tape or CD-ROM.Our doctors use them for comparison with the results of a new PET scan.
- Make sure that you are satisfied with the reception.Positron - emission tomography should be performed exactly at the scheduled time, so please come 15 minutes earlier.
- Wear comfortable clothing and dress warmly, as some offices where the scanning is carried out, can be cold.On the day of the study can not wear jewelry, and clothing should not be anything metal.
- can bring a compact disc (CD), to listen to during the PET scan procedure.We provide warm blankets.
- not come to the procedure with children or pregnant women, as you introduce a radioactive substance.
- If during the procedure is intended to introduce you to a drug to relax the lung muscles action, you have to come accompanied by a man who will take you home.
- If you will be scanning the pelvic area, the positron emission tomography before you can install a urinary catheter (a tube to drain urine).
• If you have diabetes, please discuss with your doctor's instructions regarding diet and medication.
• Please tell your doctor if you are currently taking medications granulocyte colony stimulating factor (G-CSF) (such as Neupogen (Neupogen) or neylasta (of Neulasta)) or products that promote the formation of red blood cells (such as Epogen (Epogen) or Procrit (Procrit)).
• Did your doctor ask for a CT scan PET apparatus after the PET scan.
sure to inform your doctor if you are pregnant or may be pregnant or breastfeeding.Bring a liter bottle of mineral water .
Do not forget to bring your old photographs -rentgenogrammy, CT.MR.The results of ultrasound, etc.
What to expect upon arrival at the PET Center?
nurse, specializing in the field of positron emission tomography will help you prepare for the scan.Nurse establish intravenous drip (a thin tube through which the medication is introduced and fluid) and measure the blood sugar level.
you introduce radiolabeled (radiotracer).After about 45 minutes after the start of the circulation of the radioactive label in the blood you are taken to a room for the PET scan.You will be asked to lie on your back on the table to be scanned.In most cases, the scan takes approximately 1 hour.
PET scan studies the living cells in action.
How is Positron Emission Tomography?
scanner located in a separate room.The unit itself looks like a large ring (computer tomography) - there are sensors that perceive radioactivity.
Before the start of the study you will put on a special couch built into the machine and will be put into a vein or a radioactive substance will inject it into a gas.Then, for 30-60 minutes, you will be asked to lie down, do not speak and do a minimum of movements - during which time the drug is distributed throughout the body.No discomfort does not arise from this.
Then couch with you "ride into the hole of the ring."The sensors will capture light and transmit signals to a computer that will process them and build the image.You will be asked to hold still for 30-45 minutes.
What will I feel during the exam?
After commissioning of the dropper you should not be a pain.During a PET scan you need to relax the procedure, do not move and do not worry.
You will not feel any radiation.Radiation released from the body during the day.
After positron emission tomography will not give you any special instructions, only recommend drinking lots of water.Ingested fluid will accelerate the excretion of radioactive substances from the body
To describe the resulting images usually requires 1-2 days, in some cases, research results can take a few hours - it will inform you doctor.