CT evidence of acute ischemia either alone or in combination with chronic ischemia or microangiopathy present within 24 hours of a nondisabling stroke can help predict risk of recurrent stroke for up to 90 days, researchers reported. Patients with transient ischemic attacks (TIA) or nondisabling strokes who showed evidence of acute and chronic ischemia and microangiopathy had an eight-fold increase in risk for having another stroke over the next 3 months, lead researcher Jason K. Wasserman, MD, PhD, of Ottawa Hospital Health Research Institute, Ontario, and colleagues wrote in the American Heart Association journal Stroke, published online Dec. 4.
There are currently two imaging modalities of choice for cerebrovascular stroke patients, a CT (computed tomography scanning) scan and MRI (Magnetic Resonance Imaging). One needs to consider the advantages, limitations, and economic issues related to each when choosing which modality to use on a patient
Patients in the ER with symptoms that suggest stroke require brain imaging to determine whether a ischemic or haemorrhagic stroke occurred by using either a CT scan or MRI. The CT scan is the imaging technique of choice due to its availability in most settings worldwide and its lower cost than a MRI.
From the medical point of view, the CT scan is highly informative, and exceeds 95% in instant detection of haemorrhage few minutes after its development, and can confirm or exclude the possibility of a haemorrhagic stroke in a reliable way. There are many advantages to using a CT scan, but there are two major drawbacks. First, is an ischemic stroke may not appear in a CT scan for up to 48 hours. Second, is the lack of sensitivity to the vetebro-basillar lesions, considering that 15% of all strokes occur in this region. A patient may need to undergo a MRI after a CT scan resulting in even higher costs. Although more costly, the MRI is more conclusive resulting in more effective treatment for the particular type of stroke.