Stroke MRI and CT Scans: Differences and Benefits

by | Sep 21, 2023

To determine if you have suffered from a stroke or have the potential to undergo another one, there are two types of tests that you can get to see what the status may be. Those two tests are the MRI and CT scans.

Nurse operating MRI scan for stroke with a patient lying down

Introduction to Stroke Screening and Diagnosis

CT and MRI scans are used to determine if there is a hemorrhage in the brain and also look for blockages developing that can cause a stroke to happen. There are two types of strokes that stroke screening looks for during the screening process and the use of the MRI and CT scans.

  • Hemorrhagic stroke
  • Ischemic stroke

The least common stroke type is hemorrhagic stroke, which develops when blood vessels in or around the brain weaken. The blood loss develops between the inner and outer layers of the brain tissue. The more common stroke is ischemic stroke that happens when the blood supply is reduced heavily to the brain. Brain tissue needs a steady flow of nutrients, oxygen, and blood for operation, and when that flow is stopped, a stroke will happen.

Read our “Stroke Causes, Symptoms, Diagnosis, and Treatment: A Complete Guide” blog post to stay informed about the types of stroke, symptoms, screening, diagnosis, treatment options, stroke management, and more. 

What Are the Causes of Stroke?

When the blood supply to the brain is reduced or interrupted, it causes brain cells to die, leading to a stroke. Age, gender, and genetic predisposition are all risk factors that can increase a person’s chances of stroke. Individuals over 55 years, for example, are more vulnerable than younger people, as are men than women.

A family history of stroke can also increase someone’s susceptibility to stroke. Other stroke causes include high blood pressure, diabetes, obesity, high cholesterol, smoking, and excessive alcohol consumption.

Read more about stroke screening and stroke management and prevention with Dr. Manish Taneja and the stroke care and treatments at our specialized stroke clinic at Supreme Vascular and Interventional Clinic in Singapore.

Controllable Risk Factors


Controllable risk factors are lifestyle choices that can be changed to reduce the risk of having a stroke. Eating healthy, exercising regularly, and monitoring your blood pressure are three common lifestyle choices that can be made to significantly reduce your chance of having a stroke. Other controllable risk factors that may also require the help of a medical professional include:

  • Diabetes
  • Heart disease
  • High cholesterol
  • High blood pressure (hypertension)
  • Obesity and physical inactivity
  • Alcohol abuse
  • Smoking

Uncontrollable Risk Factors

Aging is a part of life and while there are things we can do to prevent medical conditions from happening, there are others that cannot be changed. If you believe you are at risk of a stroke, a medical professional can start a treatment plan involving medication or regular monitoring. Other uncontrollable risk factors include:

    • Being over the age of 55.
    • Sex: females have a higher risk after menopause.
    • Personal and family medical history.
    • Environmental factors such as access to water and healthy foods.
    • Prior stroke, TIA (transient ischemic stroke), or heart attacks

MRI Scans in Diagnosing Stroke

What does the MRI scan show you?

The MRI scan can give the most accurate picture of brain tissue, blood vessels, and arteries. This is essential when determining if a stroke has happened recently or in the past. As radiation is not used when having an MRI scan, there is no risk of exposure to radiation.

The MRI can see the scarring left behind. An MRI scan will last anywhere from a half hour to an hour, depending on how in-depth they need. It will be longer if they cover both sides of the brain.

MRI scans are used to review current brain activity, and they can seek out brain tissue damage with radio waves and magnetic fields. Those suffering from a hemorrhage stroke can watch dye injected into the brain tissue and see how it flows.

Because of the powerful radio waves, silent strokes that show no symptoms can be detected. Any time there is a possibility you may have a stroke, or one could happen, you should have an MRI done to assess your brain activity and the tissue surrounding the area.  If you have had a stroke in the past, signs of the damage will show on the MRI, and they can get an approximate date of how long ago it happened.

What are the benefits of an MRI?

An MRI (Magnetic Resonance Imaging) scan can be highly beneficial for the evaluation and diagnosis including:

  • Detailed Imaging: MRI provides detailed and high-resolution images of the brain, allowing healthcare providers to visualize the brain’s structure and detect abnormalities, including the location and size of a stroke.
  • Early Detection: MRI is sensitive to changes in brain tissue, which means it can detect signs of a stroke even in its early stages. This early detection can be critical for prompt medical intervention and treatment.
  • Differentiation of Stroke Types: MRI can help differentiate between ischemic strokes (caused by a blocked blood vessel) and hemorrhagic strokes (caused by bleeding in the brain).
  • Assessment of Stroke Severity: MRI can provide information about the extent and severity of the stroke, helping healthcare providers assess the potential impact on the patient’s neurological function.
  • Identification of Stroke Mimics: Sometimes, conditions can mimic stroke symptoms but have different causes and treatment requirements. MRI can help identify these stroke mimics, ensuring that patients receive the appropriate care.
  • Planning Treatment: MRI scans can assist in treatment planning by revealing the precise location and size of the stroke. This information can guide decisions about medication, clot-busting therapies (for ischemic strokes), or surgical interventions (for hemorrhagic strokes).
  • Monitoring Progress: Follow-up MRI scans can be used to monitor the progression of a stroke, assess the effectiveness of treatment, and determine if there are any complications or recurrent strokes.
  • Identification of Contributing Factors: MRI may also reveal underlying conditions that contributed to the stroke, such as arterial abnormalities, tumors, or blood vessel diseases. Identifying these factors can help prevent future strokes.
  • Evaluation of Perfusion: Advanced MRI techniques, such as perfusion imaging, can assess blood flow within the brain. This information can be crucial in determining the viability of brain tissue and guiding treatment decisions.

Overall, MRIs are valuable in the diagnosis and management of strokes for medical practitioners to make informed decisions about treatment strategies and improving patient outcomes. However, the difference between MRI vs. CT scans may depend on several factors like the patient’s condition and the availability of equipment and expertise, which is why it is important to have access to expert care and high-end technology in a world-class specialized stroke clinic in Singapore.


CT Scans in Diagnosing Stroke

What does the CT scan show you?

When you undergo the CT Scan, you can be injected with a contrast dye that highlights your blood vessels. The image is then available to see these white vessels and determine how they supply the brain.

The CT scan with the contract material can take up to 30 minutes to complete the scan. The radiologist then reviews it, and that can take an hour or two to process. CT scans are used for suspected strokes because they will reflect any changes or abnormalities in the brain.

If you or your healthcare provider believe you have suffered a stroke recently, you should have a CT scan done within the hour of arriving at the hospital. This scan needs to be done first before moving on to other tests. As long as the test is done within the first few hours following the event believed to be a stroke, there will be signs, and it can be detected on the CT scan.

If you experienced a stroke in the past that had significant trauma to your brain tissue, there will be white spots that indicate a previous stroke happened. You can have your stroke assessed and treatment started because the results are provided much quicker with a CT scan than an MRI. This is why these are the most popular scans for strokes.

What are the benefits of a CT scan?

While MRI offers some advantages for certain aspects of stroke assessment, CT scans have the following benefits:

  • Speed: CT scans are typically faster to perform than MRI scans. In situations where time is critical, such as in acute stroke cases, CT scan can be advantageous since it allows for quicker assessment and treatment decisions.
  • Availability: CT scanners are more widely available than MRI machines. This means faster stroke evaluations, which is crucial for time-sensitive treatments like thrombolytic therapy for ischemic strokes.
  • Identification of Hemorrhage: CT scans are particularly effective at detecting hemorrhagic strokes, where bleeding occurs in the brain. The ability to quickly confirm the presence of bleeding is essential for determining the appropriate treatment approach.
  • Bone Imaging: CT scans are better at visualizing bone structures, which can be helpful in cases where skull fractures or other bone abnormalities contribute to the stroke symptoms or complicating treatment decisions.
  • Calcium Scoring: CT scans can assess the presence of calcifications in the carotid arteries, which can be a risk factor for stroke. This information can guide treatment decisions and preventive measures.
  • Assessment of Brain Tissue Changes: While MRI provides highly detailed images of brain tissue, CT scans can still reveal significant changes in brain structure caused by a stroke. This information is crucial for assessing the extent and location of brain damage.
  • Ruling Out Other Conditions: CT scans can help rule out other conditions that may mimic stroke symptoms, such as brain tumors, abscesses, or other intracranial abnormalities.
  • Assessment of Large Vessel Occlusion: CT angiography (CTA) is a specialized CT technique that can be used to assess blood vessels in the brain. It is valuable for identifying large vessel occlusions, which can inform treatment decisions, particularly for ischemic strokes.

Therefore, thanks to the speed, accessibility, and ability to quickly detect hemorrhages, CT scans are valuable in the evaluation and management of stroke, especially in the initial assessment of stroke patients and can guide treatment decisions in acute situations. However, the choice between a CT scan and an MRI may depend on the patient’s specific stroke situation and conditions.


Commonly Asked Questions Answered by Dr. Manish Taneja

1. MRI and CT Scan: What’s the difference? 

Dr. Manish Taneja: The main difference is that CT scan requires contrast and radiation whereas an MRI scan will not. However, different patients have different risk factors. If I am wanting to see more of the small blood vessels and what damages they are causing to a patient’s brain, then an MRI scan is better.

2. Which would you choose?

Dr. Manish Taneja: I will say MRI! 

3. Is the CT scan considered three dimensional? What about an MRI scan?

Dr. Manish Taneja: MRI scans used to be 3D and CT scans were 2D. Nowadays with newer technology, CT scan technology is so well developed so both can give a three dimensional view, depending on what information we require. Accuracy of both are equally good but if going into technical details, the MRI shows more brain substance better than a CT scan. 


MRI or CT Scan for Stroke

If you are unsure which scan to get for a potential stroke, it is essential to start with the CT Scan first and foremost. The results of the CT scan will be available in the same day, whereas an MRI scan can take some time to do and then you have to wait for the results to be determined.

The results of an MRI, however, are more accurate and can pinpoint past strokes and tiny abnormalities that a CT scan cannot pick up on. This is why if you believe you have suffered from a stroke or may be experiencing signs of one developing, you should have both tests done to get the best results.

Need for Information about Stroke Diagnosis?

If a stroke is not correctly diagnosed with a CT scan, MRI scan, or both, you may not get the appropriate treatment you need. If you want more information about your vascular system and stroke situation, we invite you to contact our Supreme Vascular and Interventional Clinic today.

    Doctors discuss diagnosis for patient undergoing mri or ct scan for stroke.
    Brain Aneurysm MRI and CT Scans

    To assess and diagnose a possible brain aneurysm in Singapore, Dr. Manish Taneja conducts a CT scan (computed tomography) or an MRI (magnetic resonance imaging) to obtain detailed images of your brain’s blood vessels and structures.

    When Should You Go For a Brain Scan?

    Don’t worry if you feel like you are somehow pressing the panic button by asking a doctor for a brain scan if you feel that something is wrong with your body. Popular culture has encouraged some people to think that a brain scan is an extreme medical intervention that should only be done in extreme cases, but that is simply not the case. The reality is that you can and should ask for a brain scan from your doctor if you fear that you might be suffering from a brain aneurysm or that you might be at risk for one.

    The brain scan can help identify any blockages or other issues within one’s blood vessels to help identify where the problems might exist and allow doctors to take the time to suggest correction treatments for those issues.

    We provide brain aneurysm detection and care at our specialized brain aneurysm clinic at Supreme Vascular and Interventional Clinic in Singapore.

    How are Brain Aneurysms Detected?

    There are a variety of ways that a medical professional can identify a brain aneurysm. It is often the case that an angiogram might be recommended to help identify a brain aneurysm, but there are other means of identifying one as well. Learn more about what is involved when it comes to a brain aneurysm MRI and CT scan.


    Visit the Supreme Vascular and Interventional Clinic for a Stroke MRI or CT Scan

    Don’t be afraid to request medical treatment at our specialized stroke clinic in Singapore if you fear you’re at risk of a stroke or suffering one. The Supreme Vascular and Interventional Clinic offers state-of-the-art care and latest treatment options with stroke specialist, Dr. Manish Taneja. Reach out and contact us with your concerns if you are concerned that you might be dealing with a stroke situation.

    Stroke Resources

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    We’ve Got You Covered for Specialized Stroke Screening, Prevention, and Management

    Imagine heart attacks where the blood flow to your heart is blocked. Similarly, a stroke occurs when the blood flow to your brain is interrupted becoming a “brain attack”. When blood supply does not reach a certain part, brain cells begin to die. Different types of stroke include ischemic strokes (blockage of blood vessel due to blood clot) or a mini stroke, a TIA (transient ischemic attack), with no permanent damage yet serious. Stroke also occurs when a blood vessel in the brain pops causing bleeding in the brain.

    Certain areas of the brain can be affected by stroke and some symptoms of a stroke including cardiovascular disease, diabetes, and high blood sugar levels increase the risk of stroke whereas an active lifestyle or controlling high cholesterol reduces the risk. How well do you know stroke? Find tips to prevent and manage stroke and the newer technology and treatments available. 

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    Discover brain aneurysm resources that go beyond the basics designed for patients. Understand the meaning of  a brain aneurysm condition, the causes, symptoms, signs, and more. Connect with your brain health.

    Put Brain Aneurysm on Your Health Radar

    Did you experience the worst headache of your life? Could it be a brain aneurysm that ruptures, which means bleeding in the brain? Thoughts could be racing through your mind. Then what is the difference between unruptured (a weak or thin spot on an artery in the brain that balloons) or ruptured brain aneurysm? If you’re wondering, then the Supreme Vascular and Interventional Clinic is here to help. It’s important to look out for the tell-tale brain aneurysm symptoms, signs, causes, and risk factors.

    Dr. Manish Taneja has been performing brain aneurysm treatments since 1995 from surgical clipping to latest minimally invasive procedures. Each patient is unique as is the size and location of the aneurysm. Your brain has different conditions to treat the aneurysm and artery vessel walls of a blood vessel in the brain. This calls for personalised brain aneurysm treatment depending on your symptoms, family, history, medication, and more. A simple CT scan could be just what the doctor ordered and the first step in early detection and prevention of a brain aneurysm. Come in for an easy consultation with our brain aneurysm specialist in Singapore to be on your health radar.

    Other Health Conditions

    The Supreme Vascular and Interventional Clinic is your “go-to” facility for various conditions and treatments. To arrange an appointment with Dr. Manish Taneja, our neurointervention specialist, contact us. You can also call us at (+65) 6904 8084 for a consultation.