CT and MRI in acute hemorrhagic stroke

Endovascular neuroradiological treatment of acute ischemic stroke: techniques and results in 350 patients

BACKGROUND AND OBJECTIVES

Randomized trials have demonstrated the benefit of intra-arterial thrombolysis (IAT) for treatment of acute ischemic stroke, if performed within 6 hours of symptom onset.

METHODS

We report our experience with 350 acute stroke patients who were treated with IAT using urokinase at a single center. Predictors of favorable outcome were low National Institute of Health Stroke Scale (NIHSS) at admission (p<0.001), good collaterals (p<0.001) and successful endovascular recanalization (p<0.001). Recanalization rates of more than 75% could be achieved, when additional endovascular techniques such as mechanical fragmentation of the thrombus, thromboaspiration, percutaneous transluminal angioplasty, and implantation of stents were used.

RESULTS AND CONCLUSIONS

Predictors of unfavorable outcome were diabetes mellitus (p<0.001) and symptomatic hemorrhages (p<0.001). The latter occurred in 5% of our population. Preliminary results of new techniques including sonothrombolysis, angiojet aspiration, and laser recanalization of thromboembolic occlusions are discussed.

Actual diagnostic approach to the acute stroke patient

Since acute stroke is now considered a potentially treatable medical emergency, a rapid and correct diagnosis must be made. The first step is to exclude hemorrhage, then to visualize any early ischemic changes, demonstrate the presence of hypoperfusion and locate the presence of a vascular underlying pathology as well as elucidate the presence of a potential penumbra (tissue at risk). Thanks to improvements and advances in both MR and CT technology, this can now be done in a number of ways. At the moment, CT is the most widely available and fast method for obtaining imaging of the brain and neck vessels of patients presenting with acute stroke. MRI can provide more precise information, although it remains slightly more time-consuming, but is, however, the method of choice for follow-up imaging. The main point is to take the one-stop-shopping approach where imaging of the vessels and brain is done from the aortic arch to the circle of Willis in one single session in order to have all the necessary information in the acute phase.

Diagnostic imaging for intracerebral hemorrhage

Magnetic resonance imaging (MRI) is an excellent tool for the diagnosis and evaluation of intracerebral hemorrhage with its unique specificity to hemoglobin degradation products in different stages. Computed tomography (CT) remains the diagnostic test of choice in the setting of acute intracerebral hemorrhage because of its exquisite sensitivity and specificity for small amounts of intracerebral hemorrhage (although there is emerging evidence that MRI may be as sensitive as CT). The effects of the biochemical evolution of intracerebral hemorrhage on the temporal MRI signal changes are described. This article discusses imaging features of the common causes of intracerebral hemorrhage.

MR pattern of hyperacute cerebral hemorrhage

Magnetic resonance (MR) pattern of cerebral hemorrhage relates mainly to the relaxation and susceptibility effects of iron-containing hemoglobin degradation products, as well as to their intra- or extracellular location. The purpose of this article is to report two acute stroke patients who underwent thrombolytic therapy and developed hyperacute cerebral hemorrhage during their admission cerebral MR survey. They constitute the earliest MR appearance of hyperacute intracerebral bleeding reported in the literature, featuring increased diffusion properties and persistent susceptibility effect on perfusion-weighted imaging (PWI)-series.