MRT most commonly stands for two things depending on context: Magnetic Resonance Tomography, which is the European term for an MRI scan, or the Mediator Release Test, a blood test used to identify food sensitivities. If you encountered the term in a medical imaging context, especially from a German or European source, it refers to the same scan Americans call an MRI. If you came across it in the context of food sensitivities, digestive issues, or an elimination diet, it refers to a blood test that measures how your white blood cells react to specific foods and chemicals.
MRT as Magnetic Resonance Tomography
In much of Europe, particularly Germany, the abbreviation MRT stands for Magnetic Resonance Tomography. It is the exact same imaging technology that English-speaking countries call MRI (Magnetic Resonance Imaging). The machine, the process, and the results are identical. The difference is purely linguistic.
If your doctor in Europe orders an MRT, you’ll lie inside a large tube-shaped magnet while the machine uses magnetic fields and radio waves to create detailed images of your organs, soft tissues, joints, or brain. There is no radiation involved, unlike CT scans or X-rays. You may see the term on European medical records, radiology reports, or hospital websites.
MRT as the Mediator Release Test
The other common meaning of MRT is the Mediator Release Test, a patented blood test designed to detect food sensitivities. Unlike food allergies, which trigger an immediate immune response (think hives or throat swelling), food sensitivities cause delayed, lower-grade reactions. These can include bloating, headaches, joint pain, skin flare-ups, or chronic digestive issues that are difficult to trace back to a specific food.
The test works by exposing a sample of your blood to 170 or more foods and food chemicals, then measuring whether your white blood cells shrink. When white blood cells encounter a substance they react to, they release inflammatory chemicals called mediators and lose volume in the process. The MRT measures that volume change to determine which foods provoke the strongest reaction. Results are color-coded: green for low reactivity, yellow for moderate, and red for high.
How MRT Differs From Allergy Testing
Standard allergy tests (skin pricks or blood panels measuring IgE antibodies) detect true allergies, which involve one specific branch of the immune system. MRT targets a different problem entirely. It aims to catch reactions that don’t show up on allergy tests but still cause symptoms. These reactions can involve multiple immune pathways, which is why traditional allergy testing often comes back normal for people with food sensitivities.
The MRT is a refined version of an older test called the ALCAT. The key technical improvement is a patented measurement method that more precisely identifies the starting and ending volume of each white blood cell, giving a more accurate read on whether mediators were actually released. The ALCAT used a less precise baseline, which led to more inconsistent results.
What Happens After the Test
MRT results are typically paired with a structured eating plan called the LEAP protocol (Lifestyle Eating and Performance). A dietitian uses your results to build an elimination diet that starts with only your lowest-reactivity foods, then gradually reintroduces others over roughly three months.
Phase 1 is the most restrictive. You eat only from a narrow list of your safest foods, with no gluten, dairy, caffeine, alcohol, added sugars, or dietary supplements. Even leftovers are off limits, since foods can develop new chemical compounds as they sit. Phase 2 introduces one new food at a time, and you monitor for symptoms like digestive discomfort or skin reactions. If a food triggers a response, it gets removed. Phase 3 loosens the restrictions further, and after the full three months, you begin slowly reintroducing the remaining foods.
The process requires working with a Certified LEAP Therapist, which is a registered dietitian trained specifically in interpreting MRT results and guiding the protocol.
The Debate Over Scientific Validity
MRT is one of the more controversial tests in nutrition and immunology. The American Academy of Allergy, Asthma & Immunology has stated that it is not a validated testing procedure, and that no current test can reliably identify food sensitivities. The organization does not recommend it for clinical use.
Supporters of MRT point to patient-reported improvements, particularly in people with irritable bowel syndrome and chronic migraines who saw symptom reduction after following the LEAP protocol. Critics counter that the elimination diet itself, not the blood test, likely deserves the credit. Removing common trigger foods like gluten, dairy, and processed additives tends to help many people with digestive issues regardless of what a blood test says.
This is worth knowing before you invest in the test. No major medical organization currently endorses MRT, and research supporting it comes primarily from the company that manufactures it rather than independent peer-reviewed studies.
Cost and Insurance Coverage
MRT is not cheap, and most insurance plans do not cover it. The test itself typically costs several hundred dollars, and you’ll also need to factor in the cost of follow-up consultations with a LEAP-certified dietitian to interpret results and build your eating plan. Some insurance providers may reimburse a portion depending on your plan, so it’s worth calling ahead. You can also use a Health Savings Account or Flexible Spending Account to pay for the test and related appointments.