MRI is more sensitive than CT in the diagnosis of acute stroke

According to the results of the most comprehensive study to compare two imaging techniques for emergency diagnosis of suspected cases of stroke, magnetic resonance imaging (MRI) can give a diagnosis of stroke. acute hypersensitivity is compared to tomography (CT).

The difference between MRI and CT is due to the superiority of MRI in detecting cases of acute ischemic stroke, the most common stroke, caused by blood clots. This study was carried out by doctors from the National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH). The findings were published in the medical journal The Lancet on January 27, 2007.

Dr. Elias A. Zerhouni, NIH President said: 'NIH research results on imaging techniques for diagnosing acute stroke can be applied directly to clinical practice. The patients who participated in this study were patients who were suspected of having a typical emergency hospital stroke on a daily basis. '

According to Dr. Walter J. Koroshetz, deputy director of NINDS, this study is also a good news for patients. He said: 'Research results show that about 25% of stroke patients are hospitalized within the first three hours of the onset, this is the time allowed to apply a blood clot-breaking therapy, which does not show any signs of injury. In other words, it is possible to completely avoid brain damage in some victims of stroke if they quickly clear blocked blood vessels. '

Researchers have conducted this study

CT scanner (Photo: cancerhelp.org.uk)

to determine if MRI is superior to CT in diagnosing cases of acute ischemic and haemorrhagic stroke (due to blood flowing to the brain). Standard CT uses X-rays passing through the body at different angles and is processed by the computer into cross-sectional images or images that cut the structure of the body or internal organs. Standard MRI uses radio waves created by computers and a powerful magnet to produce detailed cut images or three-dimensional images of the internal structure of the body and nerves. Contrast dye can be used in both MRI and CT scans to increase the clarity of certain areas or tissues.

Research results show that unenhanced MRI has a sensitivity of about 5 times and 2 times the accuracy of unenhanced CT in the diagnosis of ischemic stroke. In the diagnosis of acute intracranial hemorrhage, unenhanced CT and MRI are equally effective. Unenhanced CT is the standard for emergency treatment of strokes, first to eliminate hemorrhagic strokes, which cannot be treated with therapy that breaks blood clots.

Dr. Steven Warach, head of NINDS's Stroke Therapy and Diagnostic Division and a senior researcher, said: 'Many patients with suspected stroke end up being diagnosed differently at admission. Most victims who are likely to have a stroke will be evaluated by general doctors first. These doctors may be very afraid to treat patients in the direction of treating stroke if they are not sure about the accuracy of diagnosis. The results of our study show that MRI is twice as accurate as distinguishing cases of stroke and stroke. Based on these results, MRI becomes the preferred imaging technique in diagnosing acute stroke patients . "

The research team hopes that thanks to the increasing accuracy in diagnosis, MRI can bring better efficacy to patients and, above all, reduce the cost of care for stroke patients. The increasing use of acute treatments and early start to prevent relapse.

The study included 356 sudden suspicious patients who went to the Stroke Treatment Center at Suburban Hospital in Bethesda, Maryland. This is the leading stroke treatment center designed to stabilize and treat patients with acute stroke. Stroke specialists have conducted a clinical assessment on all emergency patients, including the NIH Stroke Scale which is used to measure the severity of stroke. MRI was performed before CT in 304 patients. Patients who do not receive an MRI or CT scan will be excluded from the analysis group. The image is made by two neurosurgeons and two neurologists who specialize in strokes randomly and independently.

Research results show that standard MRI outperforms standard CT in detecting acute stroke, especially ischemic stroke. All four doctors who read the results showed homogeneous results with or without signs of stroke in more than 80% of patients who received MRI compared to over 56% of patients receiving unenhanced CT scans. There were no significant differences between the two techniques used in the diagnosis of acute intracranial hemorrhage. This is completely consistent with previous findings.

Dr Koroshetz said: 'Although MRI has a high degree of accuracy in detecting stroke-induced lesions at the beginning, it cannot replace the doctor's clinical judgment in diagnosing stroke. and determine the direction of treatment. In the future, more research is needed to determine whether advanced CT-enhanced CT techniques can provide the same level of clinical information more quickly but at a lower cost. '

Hong Linh