Perfusion magnetic resonance imaging is used to study the process of blood movement through the vascular system. Using this method, it is possible to measure the volume of blood passing through them and the speed at which this process proceeds in the smallest capillaries.
The specifics of the procedure
The circulation of various fluids through human tissues is called perfusion. This type of diagnostics is used to assess blood flow and its correctness in the brain and liver capillaries. The technique of perfusion MRI belongs to the category of minimally invasive procedures.
During perfusion MRI, contrast agents are used, which, entering the arteries, are able to gradually stain them, so that during periodic registrations with a tomograph, a curve of hemodynamic parameters arises. These indicators and indicate deviations from the norm in the circulatory system. Gadolinium in the basis of the contrast does not react with the body and is very quickly excreted by the kidneys.
This research method is highly accurate and very informative. In medical practice, it is customary to combine it with magnetic resonance spectroscopy or angiography.
Diseases for which diagnosis is applied
Diagnosis using perfusion magnetic resonance imaging can be useful for any pathologies that are associated with disorders in the movement of blood through the blood vessels. This research method is widely used to detect circulatory pathologies in the human brain, which result in strokes, ischemic diseases and various tumor diseases. With the help of perfusion, it became possible to detect a decrease in blood flow in the vessels that feed the human brain at the initial, easily treatable stages. If initial symptoms of a neurological nature occur, you should immediately consult a doctor and, if he decides that this examination will help prevent the development of serious complications, be sure to undergo perfusion magnetic resonance imaging.
Perfusion diagnostics helps to assess the state of tumor neoplasms after undergoing radiation or chemical therapy, it detects radiation necrosis or recurrence of neoplasms.
The main goals of perfusion magnetic resonance imaging are the following:
- detection of microcirculation disorders in case of trauma to the skull or stroke;
- identifying the characteristics of a particular circulation to prepare for surgery;
- determination of the geodynamics of various new formations;
- monitoring the condition of tissues after chemotherapy or radiation therapy;
- determination of the presence of blockage of vessels or narrowing of the arteries.
In medical practice today, multiparametric magnetic resonance imaging is also used, which combines single-stage perfusion, diffusion and spectroscopic MRI. This type of multi-parameter diagnostics helps to diagnose and monitor the dynamics of prostate cancer in men in a qualified manner.
Referral for perfusion magnetic resonance imaging can be issued by:
But since impaired blood circulation can make its own adjustments to the diseases of doctors of other specializations, a referral for this examination can sometimes be obtained from other specialists.
It is possible to undergo perfusion MRI in every medical institution or clinic where the appropriate equipment is installed and there are specialists who are qualified to work with these devices.
Contraindications for the procedure
Sometimes patients believe that the main contraindication for any kind of magnetic resonance imaging may be their fear of enclosed spaces - claustrophobia. However, this is an erroneous opinion, because, firstly, to calm patients with these indications on the eve of the procedure, specialists can administer sedatives, and secondly, today there are open circuit tomographs, where there is no closed space. This issue should be discussed with the doctor when prescribing an examination in order to find out from him exactly where such equipment is.
In fact, perfusion MRI is contraindicated in cases of using contrast agents during pregnancy, in diagnosed renal failure, in the presence of sensitivity (allergy) to the substance in the composition of the contrast. It is possible to determine the presence of allergies before the start of the procedure by introducing a small amount of the drug as a sample half an hour before the scheduled MRI.
Another contraindication for tomography may be the presence in the patient's body of some metal implants (pacemakers, insulin pumps, dental pins, etc.), which can greatly damage the image obtained using a tomograph. Also, the metal in the body is able to heat up and can cause burns to the tissues to which it is adjacent.
Perfusion MR imaging technique
As a preparation for perfusion magnetic resonance imaging, it is recommended not to eat any food for 8 hours before the start of the study. Before starting the tomography itself, it is important to remove all metal objects from the body and remove the equipment, since all these things can degrade the quality of the images obtained and stop functioning normally themselves. The radiologist must be warned about the presence of artificial heart valves, hearing aids and other implants in the body.
During the diagnosis, the patient lying down is placed on the working surface of the tomograph, which can move in a horizontal plane. For those who are highly irritable, it is important to take sedatives on the eve of the study in order to remain still during the entire study.
The MRI procedure does not cause pain, and it does not affect the human body with ionizing radiation, so it can be safe even for children. The study lasts for half an hour, and its results are subject to interpretation during the next day after the perfusion MRI.