Comparison of two different measurement methods in evaluating basilar atherosclerotic plaque using high-resolution MRI at 3 tesla

Isolated traumatic supraclinoid internal carotid artery dissection diagnosed by high-resolution vessel wall MRI

BACKGROUND

Isolated traumatic supraclinoid internal carotid artery (ICA) dissection is a rare complication of blunt craniomaxillofacial trauma, and differentiation from atherosclerosis is the key factor for confirming the diagnosis.

CASE DESCRIPTION

A 53-year-old man was admitted because of blunt trauma to his head and face. His primary manifestations were disability of abduction of the left eye on day 2, recurrent epistaxis and a blowing murmur in the left ear on day 4. Neurological physical examination showed bilateral normal pupil diameter, a corrected visual acuity of 0.6 in the right eye and 0.3 in the left eye, and loss of abduction of the left eye. Craniofacial computed tomography scans revealed multiple craniomaxillofacial fractures mainly including a LeFort III injury of the left maxilla, fractures of the left ramus of the mandible, fractures of the left orbital apex, fractures of the sellar turcica, etc. Brain magnetic resonance (MR) findings showed multifocal lacunar infarcts in the left hemisphere. Cerebral angiography demonstrated severe intraluminal stenosis of the left supraclinoid ICA, which was highly suspicious of arterial dissection. A high-resolution vessel wall MR imaging performed on day 7 showed proximal intramural subacute haemorrhage and two distal intimal flaps at the injured region, both of which facilitated the exclusion of atherosclerosis and thus, confirmation of isolated arterial dissection. The patient underwent treatment with endovascular stent placement and antiplatelet agents two weeks later and had no ictus of symptomatic stroke during the next half-year duration.

CONCLUSIONS

HR vw-MRI is able to assist in the diagnosis of isolated traumatic supraclinoid dissection complicated with underlying atherosclerosis.

The Longitudinal Distribution and Stability of Curved Basilar Artery Plaque: A Study Based on HR-MRI

AIMS

This study aims to evaluate the differences in the characteristics of atherosclerotic plaques in the proximal, curved, and distal segments of the curved basilar artery (BA) through high-resolution magnetic resonance imaging(HR-MRI).

METHODS

The imaging and clinical data of 146 patients were retrospectively analyzed. On the basis of three-dimensional (3D) time -of -flight magnetic resonance angiography (3D-TOF-MRA), 51 patients with BA curvature were selected for the study. The BA plaque is divided into three groups: proximal, curved, and distal. Plaques were identified and analyzed according to spin echo acquisition imaging via T1-weighted 3D volumetric isotropic Tse acquisition (T1W-3D -VISTA), and compare the differences in clinical related factors and plaque characteristics between groups. Diffusion-weighted imaging (DWI) and/or T2WI identified brainstem infarction. The patients were divided into symptomatic and asymptomatic groups. The correlation between plaque location and symptoms was identified and analyzed.

RESULTS

Among 51 patients, a total of 376 plaques were detected. Plaques in the proximal and curved segments are more common than those in the distal segments. Proximal plaques are more likely to have intraplaque hemorrhage ( P=0.002 ＜0.05). There was no significant difference in the distribution of criminal plaques and non-criminal plaques between each group (P=0.36 ＞0.05).

CONCLUSION

Plaques in the proximal and curved segments of the BA are more common than those in the distal segments. The proximal plaque is more prone to intraplaque hemorrhage.

Comparison of two different measurement methods in evaluating basilar atherosclerotic plaque using high-resolution MRI at 3 tesla

Background

To compare the Self-referenced and Referenced measurement methods in assessing basilar artery (BA) atherosclerotic plaque employing dark blood high-resolution MRI at 3 Tesla.

Methods

Forty patients with > 20% stenosis as identified by conventional MRA were recruited and evaluated on a 3 Tesla MRI system. The outer wall, inner wall and lumen areas of maximal lumen narrowing site and the outer wall and lumen areas of sites that were proximal and distal to the maximal lumen narrowing site were manually traced. Plaque area (PA), stenosis rate (SR) and percent plaque burden (PPB) were calculated using the Self-referenced and Referenced measurement methods, respectively. To assess intra-observer reproducibility, BA plaque was measured twice with a 2-week interval in between measurements.

Results

Thirty-seven patients were included in the final analysis. There were no significant differences in PA, SR and PPB measurements between the two methods. The intra-class coefficients and coefficient of variations (CV) ranged from 0.976 to 0.990 and from 3.73 to 5.61% for the Self-referenced method and ranged from 0.928 to 0.971 and from 4.64 to 9.95% for the Referenced method, respectively. Both methods are effective in the evaluation of BA plaque. However, the CVs of the Self-referenced method is lower than the Referenced measurement method. Moreover, Bland-Altman plots showed that the Self-referenced method has a narrower interval than the Referenced measurement method.

Conclusions

The Self-referenced method is better and more convenient for evaluating BA plaque, and it may serve as a promising method for evaluation of basilar atherosclerotic plaque.