The two main types of stroke are hemorrhagic and ischemic. Acute ischemic stroke is a medical emergency when there is interruption of blood flow to the brain. This can happen either due to bleeding in the brain or blockage in an artery. Symptoms of acute ischemic stroke are sudden confusion, trouble speaking or understanding, paralysis or numbness of the face, arm or leg, and severe headache.( Silver, et al, 2009) If you experience any of these symptoms, it is essential to seek medical help immediately. There are two types of ischemic stroke; embolic and thrombotic. Thrombotic strokes happen when a clot forms in one of the arteries that supply blood to the brain. Embolic strokes occur when a clot forms elsewhere in the body and then travels to the brain, which blocks an artery. Ischemic strokes can be treated with medication or surgery. Medications called thrombolytics can be used to dissolve clots and improve blood flow to the brain. Surgery may be necessary to remove clots or repair damaged arteries. If you have had an ischemic stroke, it is essential to take steps to reduce your risk of having another one. These steps include maintaining a healthy weight, eating a healthy diet, and regular exercising (Bonaffini, 2002).
Fortunately, there are treatments available that can help to minimize the damage caused by an ischemic stroke. There are many different types of treatments available for acute ischemic stroke, depending on the individual case. Some common treatments include thrombolytic (clot-busting drugs), angioplasty and stenting (to reopen blocked arteries). The first step in treating ischemic stroke is to dissolve the clot by administering an intravenous tissue plasminogen activator (IV tPA). The second step is determining what caused the clot. This can be done with either computerized tomography pulmonary angiography (CTP) or magnetic resonance imaging (MRI). Prompt medical attention is essential to ensure the best possible outcome. With early diagnosis and treatment, many people who suffer from an ischemic stroke can make a full or partial recovery. Time is critical when it comes to treating this condition. The sooner someone gets to the hospital, the better their chances are for a full recovery (Brauer, 2003).
In the range of neuroimaging, CT perfusion (CTP) and DW-MRI are two imaging methods widely used for diagnosing ischemic stroke. Over the past few decades, CTP (or CT angiography) has been the preferred examination for assessing patients with ischemic stroke symptoms and the suspected involvement of intracranial vessels. However, there are limitations with CT scans, for example, if the patient is allergic to iodine, if the patient has metal in their body, or if the scan needs to be done at a higher resolution. Recent non-randomized studies have questioned this traditional workhorse imaging modality. A new magnetic resonance imaging (MRI) scanner called DWI-MRI scans is more accurate than CTP scans and can be performed in minutes rather than hours. As the debate rages on regarding CTP versus DTI interpretation for the diagnosis of ischemic stroke, it’s important to note that many stroke diagnoses continue to be falsely treated with reperfusion therapy. With a possible false-positive rate as high as 40%, it’s vital to not only be able to identify a stroke on CTP correctly but also an appropriately negative cerebrovascular study.
CTP and DW-MRI are the two standard modalities arising from the acute supervision of patients presenting with stroke. Diagnosing ischemic stroke has always been difficult. Many factors can make it harder to diagnose a stroke, such as the location of the affected area of the brain and age. Finding an imaging modality that can detect an ischemic stroke as accurately as possible is crucial to saving time and life. There is debate over which imaging modality is more accurate for diagnosing ischemic stroke, with some studies indicating CTP is more accurate and others finding DW-MRI to be superior Studies have compared the use of CTP and DW-MRI for the diagnosis of acute ischemic stroke. A study found that CTP was more accurate than DW-MRI in identifying the location of the stroke. CTP was also able to identify smaller areas of stroke than DW-MRI (Phillips, 2001). However, it is generally accepted that both modalities are highly accurate, with CTP tending to be slightly more sensitive and DW-MRI slightly more specific. CTA is generally considered slightly more sensitive than MRI, meaning it is more likely to detect ischemic strokes (Ledezma, Fiebach, & Wintermark, 2009).
It is also slightly less specific, meaning it is more likely to produce false positives. This is not a significant concern as CTA is typically followed up with MRI to confirm the diagnosis. RI is typically slightly more specific than CTA, meaning it is less likely to produce false positives. However, it is also slightly less sensitive, meaning it is more likely to miss an ischemic stroke. Again, this is not a significant concern as MRI can be repeated if there are concerns about the initial results. Overall, both CTA and MRI are highly accurate for diagnosing ischemic stroke. The decision of the method to use should be made depending on the client, considering each individual’s strengths and weaknesses (Konstas, Wintermark, & Lev, 2011).
The well-known type of stroke are hemorrhagic and ischemic. Ischemic stroke, the more common type, happens when a clot of blood blocks a blood vessel in the brain. Hemorrhagic stroke occurs when a blood vessel in the brain ruptures and bleeds. CTP (computed tomography angiography) and DW-MRI (diffusion-weighted magnetic resonance imaging) are two imaging modalities that can be used to diagnose ischemic stroke. Both have their advantages and disadvantages. (Scaroni, et al ,2006)CTP is generally considered more accurate than DW-MRI in diagnosing small vessel occlusions. Still, it is more invasive than injecting contrast dye into the bloodstream. In addition, CTP carries a small risk of allergic reaction to the contrast dye. DW-MRI does not require an injection of contrast dye, so it is noninvasive. However, it is not as accurate as CTP in diagnosing small vessel occlusions. In addition, DW-MRI can be less reliable in patients with diabetes or other conditions that cause changes in the structure of blood vessels (Hennerici, 2003).
There are two main types of ischemic stroke: thrombotic and embolic. Thrombotic strokes happen when a clot forms inside one of the arteries that supply blood to the brain. Embolic strokes occur when a clot forms in another part of the body, such as the heart, and then travels to the brain (Pestalozza,et al ,2002). CTP (computed tomography angiography) is a specialized CT scan that can visualize the arteries in the brain and look for blockages. DW-MRI (diffusion-weighted magnetic resonance imaging) is an MRI scan that can detect changes in water diffusion in the brain, indicating areas of ischemia (reduced blood flow). Both CTP and DW-MRI are noninvasive and generally considered safe. (Meuli, 2004). There is no radiation exposure with either technique. The main risks with CTP are allergic reactions to contrast material or kidney problems in people with pre-existing kidney disease. The main risks with DW-MRI are claustrophobia (fear of enclosed spaces) and discomfort from lying still for an extended period. CTA is the more commonly used method, as it is faster and easier to perform. However, it does carry a small risk of causing a stroke, which is why MRI is sometimes preferred. MRI is more expensive and takes longer, but it is much safer (Halpin, 2004).
There are two main types of ischemic stroke: those caused by a clot of blood in the arteries supplying the brain with blood (thrombotic stroke) and those caused by a clot which forms in the heart and then is pumped to the brain (embolic stroke). Clotting is the most common cause of ischemic stroke. CTP (computed tomography perfusion) is a medical imaging type that can diagnose ischemic stroke. CTP uses X-rays to take pictures of the brain and measure the amount of blood flow to different brain parts. (Wintermark, & Fiebach, 2008). CTP can identify areas of the brain that are not getting enough blood flow (ischemic areas).DW-MRI (diffusion-weighted magnetic resonance imaging) is another medical imaging type that can diagnose ischemic stroke. DW-MRI uses magnetic fields and radio waves to take pictures of the brain. DW-MRI can identify brain areas that do not get enough blood flow (ischemic areas). Both CTP and DW-MRI are effective methods for diagnosing ischemic stroke. (Caso, & Hacke, 2002).
However, each method has its advantages. There is still debate over which imaging modality is best for diagnosing acute ischemic stroke, with some studies favoring CTP and DW-MRI. However, it seems that both have their advantages and disadvantages. CTP and DW-MRI are both used to diagnosis ischemic stroke. CTP uses less radiation; however DW-MRI provides more detailed images. CTP is more widely available and easier to perform, while DW-MRI provides more thorough facts on the location and extent of the stroke. Ultimately, deciding which modality to use should be made case-by-case, considering the individual patient’s needs.
References
Bonaffini, N., Altieri, M., Rocco, A., & Di Piero, V. (2002). Functional neuroimaging in acute stroke. Clinical and Experimental Hypertension, 24(7-8), 647-657.
Brauer, M. (2003). In vivo monitoring of apoptosis. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 27(2), 323-331.
Caso, V., & Hacke, W. (2002). The very acute stroke treatment: fibrinolysis and after. Clinical and Experimental Hypertension, 24(7-8), 595-602.
Halpin, S. F. S. (2004). Brain imaging using multislice CT: a personal perspective. The British Journal of Radiology, 77(suppl_1), S20-S26.
Hennerici, M. (2003). Imaging in stroke. Remedica.
Konstas, A. A., Wintermark, M., & Lev, M. H. (2011). CT perfusion imaging in acute stroke. Neuroimaging Clinics, 21(2), 215-238.
Ledezma, C. J., Fiebach, J. B., & Wintermark, M. (2009). Modern imaging of the infarct core and the ischemic penumbra in acute stroke patients: CT versus MRI. Expert Review of Cardiovascular Therapy, 7(4), 395-403.
Meuli, R. A. (2004). Imaging viable brain tissue with CT scan during acute stroke. Cerebrovascular Diseases, 17(Suppl. 3), 28-34.
Pestalozza, I. F., Legge, S. D., Calabresi, M., & Lenzi, G. L. (2002). Ischaemic penumbra: highlights. Clinical and experimental hypertension, 24(7-8), 517-529.
Phillips, M. D. (2001, December). Brain perfusion imaging. In Seminars in Cerebrovascular Diseases and Stroke (Vol. 1, No. 4, pp. 317-325). WB Saunders.
Scaroni, R., Tambasco, N., Cardaioli, G., Parnetti, L., Paloni, F., Boranga, B., & Pelliccioli, G. P. (2006). Multimodal use of computed tomography in early acute stroke, part 2. Clinical and Experimental Hypertension, 28(3-4), 427-431.
Silver, L. E., Harrison, P., Segal, H., Syed, A., Mehta, Z., & Rothwell, P. M. (2009). Oral Sessions Thursday, 28 May 2009. Cerebrovasc Dis, 27(6), 1-241.
Wintermark, M., & Fiebach, J. (2008). Imaging of brain parenchyma in stroke. Handbook of clinical neurology, 94, 1011-1019.
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