Ana M. Rojas Jiménez, Carlos M. Rodríguez Paz, Oscar M. Vila Nieto, Juan C. Gil Gallego, Pedro Martínez Cueto Hospital Universitario de Vigo, Spain
Stroke is an acute disease, in which reaction time is crucial for survival and the chances of recovery without sequelae for the patient.
In Galicia, the stroke and Tele-stroke code was implemented in 2016, allowing the rapid identification of people suffering from a stroke and their clinical characteristics to urgently transfer them to the nearest hospital prepared with diagnostic and treatment capacity, reducing the time of their start and avoiding transfers between hospitals.
Our hospital is one of the 3 tertiary hospitals in the community, which has a stroke unit with a neurologist and neuroradiologist available 24 hours a day. It has 6 semi-intensive care beds and two intervention rooms for recanalization treatment, admitting an average of 500 patients per year and performing about 170 thrombectomies per year.
Once the stroke code has been activated by the neurologist, we follow the following protocol in the radiology service:
1.- Multislice computed tomography (MCT) of the brain is performed without contrast with 0.625 mm slices, which will allow us to assess the early signs of infarction, rule out other entities that mimic it (mainly hemorrhage) and be able to determine a correct reading of the Alberta Stroke Program Early CT Score (ASPECTS) scale, which continues to be a fundamental piece of information for the inclusion-exclusion of patients who are candidates for thrombectomy in the first hours of onset of symptoms.
2.- Multiphase MCT is performed with a bolus of intravenous contrast (70 cc of Iopromide-Ultravist 370 mg/ml at a rate of 4 mL/s), acquiring three phases: The first arterial phase that extends from the aortic arch to the vertex, by visual assessment at the beginning of the filling of the ascending aorta. It is useful to assess vascular access, the presence of carotid stenosis and normal variants. The second early or equilibrium venous phase and the third late venous phase extend from the base of the skull to the vertex and both are performed 5 seconds after the acquisition of the previous phase and will allow collateral assessment.
3.- In the case of a stroke lasting more than 6 hours or of unknown onset, a brain MRI is also performed using two sequences, diffusion (DWI) and Flair, to assess mismatch as a time indicator of the onset of ischemia (4-5 hours) and calculate the infarct volume, which will be taken as inclusion-exclusion criteria for the administration of thrombolytics and/or for mechanical thrombectomy.
4.- In our center we do not routinely carry out CT perfusion studies, performing them in selected cases.
Once the diagnosis of stroke is made, it is the neurologist who indicates the recanalization treatment with either fibrinolytic and/or endovascular treatment, being immediately referred to the stroke unit or to the intervention room.
At 24 hours, a control is performed by means of head MCT without contrast, if possible with dual energy, to assess residual ischemia and the presence of bleeding or retention of contrast in the area of infarction with a view to starting antiaggregation or anticoagulation if necessary.
Image
Figure 1: Multiphase MCT image showing the filling defect in the M1 segment of the left middle cerebral artery (yellow arrow) and the intermediate collateral (red arrow heads). MR image using Flair and DWI sequences, showing the mismatch and measurement of the affected volume.
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Figure 2: Control head MCT in a dual-energy CT, performed 24 hours after mechanical thrombectomy revealing contrast retention in the right basal ganglia (yellow circle) and left cerebellar bleeding focus (red circle).
