Clinical and imaging features of vertebrobasilar dolichoectasia combined with posterior circulation infarction: A retrospective case series study

Clinical applications of arterial spin labeling of the intracranial compartment in vascular anomalies-A case-based review

Arterial spin labeling (ASL) is a magnetic resonance perfusion technique that allows for quantification of cerebral blood flow (CBF) without the use of contrast or radiation. Several applications of ASL have been described in diagnosis of strokes and stroke mimics, intracranial tumors, and other conditions. Various vascular anomalies exhibit specific CBF patterns that correlate with different signal intensities on ASL. In this case-based review, we demonstrate the utility of ASL in diagnosis and surveillance of vascular anomalies in the intracranial compartment.

Characteristics and evaluation of atherosclerotic plaques: an overview of state-of-the-art techniques

Atherosclerosis is an important cause of cerebrovascular and cardiovascular disease (CVD). Lipid infiltration, inflammation, and altered vascular stress are the critical mechanisms that cause atherosclerotic plaque formation. The hallmarks of the progression of atherosclerosis include plaque ulceration, rupture, neovascularization, and intraplaque hemorrhage, all of which are closely associated with the occurrence of CVD. Assessing the severity of atherosclerosis and plaque vulnerability is crucial for the prevention and treatment of CVD. Integrating imaging techniques for evaluating the characteristics of atherosclerotic plaques with computer simulations yields insights into plaque inflammation levels, spatial morphology, and intravascular stress distribution, resulting in a more realistic and accurate estimation of plaque state. Here, we review the characteristics and advancing techniques used to analyze intracranial and extracranial atherosclerotic plaques to provide a comprehensive understanding of atheroma.

Studying the imaging features and infarction mechanism of vertebrobasilar dolichoectasia with high-resolution magnetic resonance imaging

The mechanisms underlying ischemic infarction in patients with vertebrobasilar dolichoectasia (VBD) remain unclear. In this study, we retrospectively analyzed the imaging characteristics of high-resolution magnetic resonance imaging (HR-MRI) in patients with VBD to explore the possible mechanisms of ischemic stroke (IS) in patients with VBD. Patients with VBD were recruited from the HR-MRI database between July 2017 and June 2021. HR-MRI was used to evaluate the diameter, bifurcation height, laterality, arterial dissection, and atherosclerotic plaques of the basilar artery (BA). Transcranial Doppler was used to measure the vertebrobasilar mean velocity (Vm), peak systolic velocity (Vs), end-diastolic velocity (Vd), and pulsatile index. Twenty-six patients with VBD were enrolled, of which 15 had IS and 11 did not. The incidence of classical vascular risk factors, including age, sex, hypertension, diabetes, and hypercholesterolemia, did not differ significantly between the two groups. The BA diameters of the stroke group were significantly higher than that of the nonstroke group (6.57 ± 1.00 mm vs. 5.06 ± 0.50 mm, p = 0.000). The height of the BA bifurcation in the stroke and nonstroke groups was statistically significant (p = 0.002). Compared with the nonstroke group, the Vm, Vs, and Vd of the BA in the stroke group were lower, but the difference was not significant. In the 16 patients with atherosclerotic stenosis, 30 atherosclerotic plaques were found in the BA, 18 (60%) in the greater curvature, and 12 (40%) in the lesser curvature. In addition, one artery dissection (on the lesser curvature) and two dissecting aneurysms (on the greater curvature) were found in the BA of three patients, respectively. The BA diameter and bifurcation height are factors related to IS in patients with VBD. The mechanism of stroke in patients with VBD may involve abnormal hemodynamics, artery dissection, and atherosclerosis. HR-MRI is a useful method for evaluating the risk and underlying mechanism of stroke in patients with VBD.

Study on the Correlation between different Levels of Patients with Vertebrobasilar Dolichoectasia and Posterior Circulation Blood Perfusion

OBJECTIVE

This study investigates the differences and changing trend of posterior circulation blood perfusion between different levels of vertebrobasilar dolichoectasia(VBD) patients. The relationship between the deviation of the basilar artery(BA) in different directions and the location of pontine infarction are also investigated.

METHODS

A cohort of 106 patients(74 males and 32 females) who satisfied the diagnostic criteria for VBD were recruited for this study and classified according to the bifurcation height and the deviation position of the BA, as well as the measured blood perfusion value of the pontine, which includes rCBF, rCBV, MTT, and TTP.

RESULTS

Out of the 106 patients, 19 cases were classified as Level 1, 74 cases were classified as Level 2, and 13 cases were classified as Level 3. The different levels between the VBD groups were statistically significant (P<0.05, P<0.01), and it was found that as the level increases, rCBF and rCBV gradually decreased, while MTT and TTP gradually increased. The statistic results of different perfusion parameters were also significant, when pairwise comparisons between Level 1 and Level 3, and Level 2 and Level 3 were performed. However, when comparing Level 1 and Level 2, only the TTP showed significant result. Among 106 patients, 22 cases had brainstem infarction, 13 cases had left brainstem infarction, 8 cases had right brainstem infarction, and 1 case had brainstem infarction on both sides. Brainstem infarction generally occurs on the opposite side of the direction of BA deviation(P<0.05). Regardless of the BA was deviated to the left or right, perfusion analysis showed that there was significant difference in blood perfusion on both sides of the pontine when BA is deviated(P<0.05, P<0.01). The rCBF and rCBV on the contralateral side of deviation were lower than those on the same side, and the MTT and TTP were longer than those on the same side. There were 37 cases with vertebral artery dominance(VAD), 16 cases with left VAD, and 21 cases with right VAD. Statistical analysis showed that BA was more likely to deflect to the opposite side of the dominant artery(P<0.05), and compared with non-VAD, there was no significant difference in pontine blood perfusion (p>0.05).

CONCLUSION

As VBD level increases, rCBF and rCBV will gradually decreases while MTT and TTP showed sign of increasing. The location of brainstem infarction is opposite to the direction of the BA deviation, and BA is more likely to deviate to the opposite side of the dominant artery.