Backgrounds:
The purpose of this study was to investigate vessel wall features visualization by high resolution magnetic resonance imaging (HRMRI) in a series of ischemic stroke patients and to identify differences between lesions in the anterior and posterior circulation.
Methods:
We consecutively recruited Chinese patients with acute ischemic stroke or transient ischemic attack from 2016 to 2018. All patients were scanned at 3T magnetic resonance imaging. We evaluated pre-and post-contrast cross-sectional views of M1 and M2 segments of middle cerebral arteries (MCAs), basilar arteries (BA) and V4 segments of vertebral arteries (VAs).
Results:
A total of 74 patients (males 52.3%; median age 62 years old) were included in this study, among which, 234 lesions were identified on HRMRI, including 117 MCA lesions, 26 BA lesions, and 91 VA lesions. The sensitivity and specificity of MRA for diagnosing stenosis in anterior circulation were 89.3% (95% CI, 81.8%- 94.2%) and 50.0 (95% CI, 9.2%- 90.8%). The sensitivity and specificity of MRA for diagnosing stenosis in posterior circulation were 73.2% (95% CI, 63.9%- 80.9%) and 40.0 (95% CI, 7.3%- 83.0%). VA had a significantly higher contrast enhancement index (43.71± 7.74,
p
<0.016) than MCA (23.32± 2.46) or BA (22.69± 5.31) . Anterior circulation plaques had higher degree of stenosis (anterior versus posterior: 68.5% vs. 62.9%,
p
=0.036), more eccentric distribution (anterior versus posterior: 70.1% versus 53.8%,
p
=0.015) and higher rate of intraplaque hemorrhage (anterior versus posterior: 17.1% versus 7.7%,
p
=0.046). The plaques in posterior circulation had a thicker lesion wall (posterior versus anterior 16.58± 8.25 mm
2
vs. 9.10± 4.07 mm
2
,
p
<0.001) and higher enhancement index (posterior versus anterior 39.04± 8.50 vs. 23.32± 2.46,
p
<0.001) than the plaques in anterior circulation.
Conclusions:
The lesions in posterior circulations could be obscure on MRA. The area stenosis, intraplaque hemorrhage and enhancement index differed between circulations.
High-Resolution Vessel Wall Magnetic Resonance Imaging of Small Unruptured Intracranial Aneurysms
