Stroke is one of the leading causes of death and the leading cause of permanent
disability. Identifying the underlying etiology is crucial as secondary stroke prevention
strategies vary depending on the cause of the stroke. However, in approximately 30% of
patients, no clear etiology can be identified (cryptogenic stroke), preventing these
patients from receiving targeted treatment.
Recent findings indicate that features of plaque vulnerability are associated with acute
ischemic stroke which also applies to patients with cryptogenic stroke who have a carotid
artery stenosis of less than 50%. Features of plaque vulnerability can be assessed by
high-resolution carotid magnetic resonance imaging (MRI) which enables noninvasive
detailed characterization of atherosclerotic carotid artery plaques. Hence, plaque
imaging allows to detect vulnerable plaques and to further stratify stroke etiology. In
addition, plaque imaging may identify patients with vulnerable plaques who are at risk
for a recurrent ischemic stroke or TIA.
However, integrating multisequence high-resolution, contrast-enhanced MRI into the
standard diagnostic workflow of acute stroke would prove difficult, thus calling for
simpler imaging protocols. Unlike other features of plaque vulnerability, intraplaque
hemorrhage (IPH) can be reliably detected by standard coils and conventional native
black-blood fat-saturated T1-weighted sequences. Given the frequency of IPH, previous
study results, and additional literature evidencing the importance of IPH as a marker for
plaque vulnerability and risk of stroke recurrence, a single black-blood fat-saturated
T1-weighted sequence was added to the MR imaging protocol for the diagnostic work-up of
stroke patients at LMU hospital.
Patients with acute ischemic stroke, who received non-contrast carotid MRI for routine
diagnostic work-up, will be asked whether they are willing to participate in a
prospective, longitudinal study with telephone follow-up to assess recurrent ischemic
stroke or TIA. In addition, this study will analyse retrospectively obtained data
collected through clinical routine. These analyses will be done on all patients who
received non-contrast carotid MRI for routine diagnostic work-up over the last years.
This approach allows to estimate the prevalence of IPH in an unselected patient
population.
In principle, the detection of IPH points towards the presence of an increased plaque
vulnerability. However, it is unknown whether IPH can be reliably detected on routine
clinical scans and whether information on the presence or absence of IPH should influence
clinical decision making. Depending on the results, the outcome of this study might
benefit future generations of patients by improving the diagnostic assignment to a
specific stroke etiology and risk assessment with respect to recurrent vascular events.