PET CT scan and MRIs are two common imaging techniques used for the diagnosis of abnormalities in the body. Both tests rely on different sets of principles for detection of abnormalities in the body. PET CT scan is more advanced than MRI, as PET scan uses radioactive tracer for detection of abnormalities in the body.
The chief advantage of PET CT over MRI is that PET CT can detect cancer at a very early metabolic stage when the symptoms are not even clear or visible to the patient.
MRI uses laws of magnetism for detection of abnormality-MRI uses magnetic field to create images of the abnormality. MRI also uses magnetic waves which can displace metallic implants. Therefore, MRI is not practical for patients who have metallic implants in their body. Although PET CT scan uses radioactive tracer, it may cause allergy in some patients and also exposes patient to any radiations.
What is PET CT Scan?
PET CT scan is the combination of Positron Emission Technology (PET) and Computed Tomography (CT Scan) for creating images to detect abnormalities in the body. PET CT scan uses radioactive tracer like FDG (Fluorodeoxyglucose) which can detect abnormality at the metabolic level. Radioactive tracer highlights the abnormal cells, which consumes more glucose comparing normal cells. CT helps to create the images of the condition and helps to detect the area suffering cancer condition.
Also Read: How Whole Body PET Scan Is The Best Option For Cancer Staging?
Main Uses of PET CT:
- Helps to detect cancer in any part of the body
- Helps to detect the stage of cancer
- Helps to monitor the cancer before and after treatment
- Evaluating heart function and blood flow
- PET CT is very helpful in detecting neurological diseases like epilepsy, Parkinson’s and Alzheimer
What is MRI?
MRI is another imaging diagnostic procedure that used different principle for diagnosis comparing PET CT scan. MRI uses magnetic waves for the detection of abnormalities in the body by highlighting the anatomy of the site. MRI also uses contrast material in some cases to detect the condition more accurately and easily. MRI has the advantage over PET CT of not exposing patient to harmful radiations.
What Are The Main Functions of MRIs?
MRI is highly useful and specific to abnormality detection of soft tissue structures, like the brain, muscle, and surrounding tissues. MRI is essential in brain imaging after strokes, assessing multiple sclerosis, and identifying different tumor types. MRI is also useful for spinal cord evaluation. MRI is often used to image joints, cartilage, and ligaments, they can also be used to image organs in the abdomen. MRI can also be an important factor to identify abnormalities related to the heart and heart vessels or surrounding tissue specific to the heart.
| Feature | PET CT Scan | MRI Scan |
| Technology Used | X-rays with radioactive tracer | Magnetic field with radiofrequency waves |
| Information Provided | Metabolic activity, functional process and anatomical detail | High resolution structure and soft tissue details |
| Radiation Exposure | Exposure of radiation due to CT scan and radioactive tracer | No radiation used |
| Best For | Cancer, Metastasis, Treatment, Active diseases | Brain, Muscles, Ligaments, Tissues |
| Duration | 40 to 70 minutes | 30 to 90 minutes |
| Preparation | Requires fasting and radioactive injection is needed | Patient need to remove metallic objects |
| Safety | Radiation exposure, not suitable for pregnant women | Not applicable for patient with metallic implants like pacemaker |
| Detection | Early detection at metabolic level before structure changes appear | Detects structural changes |
| Cost | More expensive | Expensive and depends on body part to be scanned |
| Availability | Limited Availability | More widely available comparing PET CT |
When Do Doctors Utilize A PET CT Scan?
PET CT is typically performed when – cancer is suspected – whether to see if cancer has spread or to evaluate treatment efficacy – or to locate recurrent tumor activity- not including its ever-evolving role in studying brain lesions and identifying heart disease.
When Do Physicians Utilize MRI?
MRI can typically be useful when an image of the brain is necessary, which includes anything from a herniated disc or spinal cord compression, as well as musculoskeletal evaluation (i.e. cartilage, ligaments, bones) to imaging of abdominal or pelvic organs, and even ruling out cardiovascular disease and complex imaging for evaluation.
What are the Benefits of PET CT and MRI?
PET CT has several benefits, including early detection of metabolic changes, and the ability to get both functional and anatomical imaging in a single scan. PET CT is useful for cancer staging and monitoring, and in the identification of metastases which may be missed on CT or MRI alone, and is a central element in treatment planning for patients with cancer.
MRI has it’s own advantages as well. MRI has zero radiation, gives better detail of soft tissues, and is safe for repeat scans. MRI is also very useful in detecting problems in the CNS in the brain and spine, provides a detailed view of protective and functional function of musculoskeletal structures when looking for tears and fractures, and in some cases can provide 3D imaging without the use of contrast.
Limitations of PET CT
- Radiation exposure to the patient
- High cost and limited availability
- Need radioactive tracer like FDG glucose
- Not suitable for pregnant patients
Limitations of MRI
- Time-consuming and noisy scan.
- Fear of closed spaces in some patients
- Not applicable for patient with metallic implants in the body
- More expensive than CT scans.
Conclusion
PET CT and MRI are advanced diagnostic techniques that produce images for identifying abnormalities in the body. PET CT is more advanced, expensive, and specifically targeted compared to MRI scan. The principal advantage of PET CT over MRI scan is that PET CT is able to detect the cancer at a very early stage of metabolism, at a stage that the patient is asymptomatic or presenting symptoms at a late stage.
In contrast, the MRI scan uses the principle of magnetism as a means to detect abnormality. MRI scan uses magnetic field to create images of abnormality in health.
Additionally, as a magnetic wave can displace metallic implant, it is not applicable for patients with metallic implant in their body. There are several advantages and disadvantages of both these diagnostic procedures with the decision being made by an individual provider.
Frequently Asked Questions
Q. Which test is more specific PET CT or MRI?
PET CT is more specific comparing MRI scan.
Q. Which test is more expensive PET CT or MRI?
PET CT scan is more expensive comparing MRI scan.
Q. Which test is suitable for pregnant women PET CT or MRI?
MRI is suitable for pregnant women because MRI does not use radiation.
Q. Which test is more suitable widely available PET CT or MRI?
MRI is widely available comparing PET CT scan.
Q. Where to get PET scan in Delhi?
You can contact carebox to book your PET scan at cheapest cost.
