FAQ

The PET MRI (Positron Emission Tomography with Magnetic Resonance) examination is an innovative hybrid test. It use modern technology to simultaneous image acquisition combining anatomy and the metabolic function of internal organs. They are performed for diagnostic and scientific purposes. It allows the imaging of many pathological conditions existing in the body, including tumors that accumulate the administered radiotracer (occurring with increased glucose metabolism), inflammation and infectious diseases, the study of single tumors, distant metastases, lymph nodes, the assessment of the stage of neoplasm of the so-called staging, control of response to treatment (surgical, radio- and chemotherapy).

PET MRI technique is very innovative and uses modern technologies. It allows to scan the entire body (from the top of the head to the half of the thighs) not only in terms of anatomical (organ structure) but also in metabolic terms. Thanks to this, we can see the anatomy and function of internal organs, which enables very accurate diagnostics of pathological changes at the cellular level (at a very early stage of the disease). The test is non-invasive, painless, and the given marker does not affect the patient’s well-being. An additional advantage of PET MRI is low doses of ionizing radiation, derived only from the given radiotracer. There is no additional radiation from magnetic resonance (in contrast to hybrid tests using computed tomography – PET / CT).

Both hybrid tests show a certain similarity due to the use of PET in imaging, however, there are significant differences between them. PET MRI provides a lower dose of ionizing radiation because there is no additional radiation from magnetic resonance. PET MRI provides a more accurate anatomical image of tissues and organs than the one from PET CT, and differences in the physiological and pathologically changed tissues are better visible in magnetic resonance. Thanks to this, we can make a faster and more accurate diagnosis. In both PET studies, it is possible to detect anomalies at the cellular level, i.e. at a very early stage of the disease. Both tests are painless, non-invasive and using the latest technologies. In PET MRI, there is a greater contrast in functional imaging and the ability to differentiate between live and necrotic tissue after surgery or radiotherapy. Additionaly PET MRI is a useful tool for imaging low-grade lymphomas. According to reports (SNMMI’60th Annual Meeting in Vancouver, British Columbia) PET MRI shows high sensitivity in detecting recurrences of prostate cancer. In PET MRI, we can use contrast enhancement of tissues after administration of MRI-specific contrast agents. In addition, when performing PET MRI, we can use the DWI (Diffusion-Weighted Imaging) value – that is, diffusion-dependent imaging, which is very effective in detecting very early changes, e.g. in the case of a stroke.

Before starting the test, the patient should be fasting (minimum 6 hours). Increased blood glucose level (over 160 mg%) is a contraindication to the test, because the images obtained at that time are non-diagnostic and poor in quality, due to the high background from the surrounding tissues. 24 h before the test, a low carbohydrate diet is recommended, strong physical effort should be avoided, alcohol should not be consumed and tobacco products should not be smoked. The patient must be well hydrated before performing the test. It is recommended to drink a large amount of still water (no taste, no additives, no sugar), because the marker is mainly excreted through the urinary system. Thus, the exposure to ionizing radiation is reduced and the excretion of the radiotracer from the body is accelerated. It is recommended to empty the bladder before PET MRI and after acquisition. After the test, it is recommended to avoid contact with pregnant women and small children for about 24 h.

Each time a decision about qualifying a patient is made by a medical doctor based on a medical history. According to our standards, patients receive a free qualification of a doctor specializing in nuclear medicine. It should be remembered that each PET MRI examination is associated with exposure to ionizing radiation (although the exposure is minimal, ionizing radiation should be used only in justified cases). In such cases, the ALARA principle is used – as low as reasonably achievable (as small doses of ionizing radiation as reasonably possible). Always diagnostic or therapeutic benefits obtained using an isotope must overcome the risk of exposure to ionizing radiation. Therefore, our specialists will evaluate and indicate the most beneficial diagnostic tests from the point of view of the patient’s health.

• study of the physiology and metabolism of lesions (and not only their anatomy) in the course of diseases with excessive glucose uptake contained in the given marker,
• mainly oncological diagnostics or other disorders involving excessive accumulation of glucose by cells,
• examination of individual lung tumors,
• diagnosis of neoplasms of unknown origin (location of the primary tumor focus),
• mass characteristics around the pancreas,
• assessment of the severity of tumors (including head and neck, lung, breast, esophagus, pancreas, large intestine, malignant lymphoma, malignant melanoma),
• assessment of the effectiveness of the therapy (radiotherapy, chemotherapy, after surgery).

No, because the doses of radiopharmaceuticals are selected individually for each patient (calculated on the basis of body weight – 4 MBq / 1 kg of body mass). We give the lowest possible doses of radiotracers, but sufficient to achieve the expected diagnostic benefits. When exposed to ionizing radiation and the selection of isotope doses, the ALARA principle is used – as low as reasonably achievable (as small doses as reasonably possible). In the case of PET / MRI studies, there is no additional exposure from magnetic resonance to ionizing radiation (in contrast to hybrid tests using PET / CT computed tomography). In addition, the unbound isotope is quickly excreted from the body mainly in the urine. The 18F isotope used for the study has a relatively short physical half-life – 110 minutes, i.e. after that time, half of the given radiotracer activity in the body becomes 220 min. there is already ¼ of the initial amount and so up to the complete decomposition of the radiotracer. According to the principles of radiation protection, it is assumed that after 10 half-lives (T1/2), the marker disintegrates completely.

Magnetic resonance imaging under the NFZ is carried out in accordance with the queue of waiting persons.
The patient waits 2-3 days for private magnetic resonance imaging.
We perform PET/MRI examinations on each Thursday.