Clinical value of black-blood high-resolution magnetic resonance imaging for intracranial atherosclerotic plaques

Strong Contrast Stagnation of Unilateral Vertebral Artery on Three-Dimensional Black Blood-Enhanced MRI Predicts Acute Medulla Infarction

PURPOSE

This study aimed to evaluate angiographic and contrast enhancement (CE) patterns on three-dimensional (3D) black blood (BB) contrast-enhanced MRI in patients with acute medulla infarction.

MATERIALS AND METHODS

From January 2020 to August 2021, we retrospectively analyzed stroke 3D BB contrast-enhanced magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) findings of patients visiting the emergency room for symptom evaluation of acute medulla infarction. In total, 28 patients with acute medulla infarction were enrolled in this study. Four types of 3D BB contrast-enhanced MRI and MRA were classified as follows: 1=unilateral contrast-enhanced vertebral artery (VA)+no visualization of VA on MRA; 2=unilateral enhanced VA+hypoplastic VA; 3=no enhanced VA+unilateral complete occlusion of VA; 4=no enhanced VA+normal VA (including hypoplasia) on MRA.

RESULTS

Of the 28 patients with acute medulla infarction, 7 (25.0%) showed delayed positive findings after 24 hours on diffusion-weighted imaging (DWI). Of these patients, 19 (67.9%) showed CE of the unilateral VA on 3D BB contrast-enhanced MRI (type 1 and 2). Of the 19 patients with CE of VA on 3D BB contrast-enhanced MRI, 18 showed no visualization of enhanced VA on MRA (type 1), and 1 showed hypoplastic VA. Of the 7 patients with delayed positive findings on DWI, 5 showed CE of the unilateral VA and no visualization of the enhanced VA on MRA (type 1). Symptom onset to door time or initial MR check time was significantly shorter in the groups with delayed positive findings on DWI (P<0.05).

CONCLUSION

Unilateral CE on 3D BB contrast-enhanced MRI and no visualization of the VA on MRA are related to the recent occlusion of the distal VA. These findings suggest that the recent occlusion of the distal VA is related to acute medulla infarction, including delayed visualization on DWI.

Relationship Between Hypertension and Basilar Atherosclerosis in Chinese Han Population: A High-Resolution Magnetic Resonance Imaging Study

Objective

To investigate the relationship between hypertension and basilar atherosclerosis evaluated by high-resolution magnetic resonance imaging (HR-MRI) in the Chinese Han population.

Methods

High resolution-MRI vessel wall imaging was performed in selected 193 patients for various indications. Multivariable logistic regression models based on odds ratio (OR) with their associated 95% confidence interval (CI) were used to assess the relationship between hypertension and basilar artery (BA) plaque, moderate or severe stenosis of BA plaque, and vulnerable plaque. A linear regression model was used to assess the relationship between hypertension and BA plaque numbers.

Results

Patients with hypertension had a higher proportion of BA plaque and vulnerable plaque as well as more number of enhancements of BA plaque and serious plaque compared with normotensive patients (all values of p < 0.05). Multivariable logistic regression analysis indicated that patients with hypertension had an increased risk for and more number of enhancements of BA plaque (adjusted-OR: 4.32, 95% CI 1.89–9.88, p < 0.001; adjusted-β: 0.55, 95% CI 0.14–0.96, p = 0.009, respectively) and had a higher proportion of moderate or severe stenosis of BA plaque and vulnerable plaque (adjusted-OR: 3.08, 95% CI 0.77–12.32, p = 0.111; adjusted-OR: 4.52, 95% CI 1.50–13.64, p = 0.007, respectively) compared with the normotensive group. Moreover, there was a saturation effect of age on the prevalence of BA plaque and vulnerable plaque.

Conclusion

Hypertension was the independent risk factor of BA plaque and vulnerable plaque assessed by HR-MRI in the Chinese Han population.

Comparison of 3D T1-SPACE and DSA in evaluation of intracranial in-stent restenosis

OBJECTIVE

In-stent restenosis (ISR) after stenting for intracranial stenosis is a significant issue. This study aimed to evaluate the usefulness of the 3D T1-SPACE technique in the follow-up of patients after stent implantation.

METHODS

Fifteen patients with intracranial arterial stenosis were prospectively enrolled 6-8 months after stenting. Digital subtraction angiography (DSA) and 3D T1-SPACE imaging were performed to evaluate the degree of stenosis and the enhancement of the vessel wall. Bland-Altman plots were used to assess the agreement between the two imaging methods, and the Pearson correlation coefficient was calculated as a measure of the linear correlation.

RESULTS

Eight Enterprise stents and seven Wingspan stents were used in 15 patients. The follow-up DSA after 6-8 months showed that the degree of stenosis was 40% (range, 30-72%), and ISR occurred in 4 of 15 (26.7%) lesions. The degree of stenosis assessed using the 3D T1-SPACE imaging technique was 35% (range, 30-75%). All four patients with ISR demonstrated significant enhancement. The Pearson correlation coefficient between the two methods was 0.959 (p < 0.05), and the Bland-Altman plot showed that all data points were within the consistency limits ([Formula: see text] ± 1.96 s).

CONCLUSION

As a non-invasive imaging modality, 3D T1-SPACE showed great consistency with DSA in measuring the degree of stenosis after intracranial stenting. It may be used as an optional method for detecting ISR.

ADVANCES IN KNOWLEDGE

This study evaluated the usefulness of 3D T1-SPACE technique in the follow-up of patients after stent implantation, which could be used as an optional and non-invasive method in detection of in-stent restenosis.

Cerebral Perforating Artery Disease : Characteristics on High-Resolution Magnetic Resonance Imaging

PURPOSE

Our aims were to evaluate the feasibility of high-resolution magnetic resonance imaging (HR-MRI) for displaying the cerebral perforating arteries in normal subjects and to discuss the value of HR-MRI for detecting the causes of infarctions in the territory of the lenticulostriate artery (LSA).

METHODS

Included in this study were 31 healthy subjects and 28 patients who had infarctions in the territory supplied by the LSA. The T1-weighted imaging (T1WI), T2WI, diffusion-weighted imaging (DWI), and HR-MRI, including 3‑dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) and 3D fast spin-echo T1WI (namely CUBE T1 in GE Healthcare), were applied on a 3-Tesla scanner. The numbers and route of the perforating arteries on both sides were independently confirmed on HR-MRI by two physicians. The Wilcoxon test was used to compare the differences.

RESULTS

The numbers of perforating arteries in healthy subjects observed on 3D-TOF-MRA were as follows: numbers of the bilateral recurrent artery of Heubner (RAH) ranged from 0-3 (median 1), numbers of the left LSA ranged from 0-7 (median 3), numbers of the right LSA ranged from 0-5 (median 3), numbers of the bilateral anterior choroidal artery ranged from 1-2 (median 1) and the numbers of the bilateral thalamoperforating artery ranged from 1-2 (median 1). In the patients with lenticulostriate infarctions, the numbers of LSAs on the affected side were lower than on the opposite and ipsilateral sides in the healthy subjects. The results were statistically significant. An abnormality of the RAH may lead to a centrum semiovale infarct pattern, whereas an abnormality of the LSA is associated with a corona radiata infarct pattern.

CONCLUSION

The use of HR 3D-TOF-MRA and CUBE T1 had unique advantages in displaying the tiny perforating arteries in vivo. Moreover, effective recognition of the associated cerebral perforating artery and infarct patterns may enhance our understanding of the mechanism of stroke in patients with lenticulostriate infarctions.

Intracranial Vessel Wall Imaging with Magnetic Resonance Imaging: Current Techniques and Applications

Vessel wall magnetic resonance imaging (VW-MRI) is a modern imaging technique with expanding applications in the characterization of intracranial vessel wall pathology. VW-MRI provides added diagnostic capacity compared with conventional luminal imaging methods. This review explores the principles of VW-MRI and typical imaging features of various vessel wall pathologies, such as atherosclerosis, dissection, and vasculitis. Radiologists should be familiar with this important imaging technique, given its increasing use and future relevance to everyday practice.

Prognostic value of high-resolution magnetic resonance imaging in evaluating carotid atherosclerotic plaque in patients with ischemic stroke

BACKGROUND

Ischemic stroke (IS) is a devastating occurrence affecting millions worldwide. This study aimed to evaluate the prognostic value of high-resolution magnetic resonance imaging (HRMRI) in assessing carotid atherosclerotic plaque in IS patients.

METHODS

Between January 2013 and March 2015, 338 IS patients were recruited for the investigative purposes of the study. All participants of the study underwent an HRMRI inspection procedure after being admitted into the hospital. During this study, we systematically analyzed and measured various types of fibrous caps, lipid compositions, and plaque lipid ratios. Univariate and multivariate logistic regression analyses were performed for predicting prognosis of IS patients. A receiver-operating characteristic (ROC) curve was employed to determine the accuracy of the IS prognosis.

RESULTS

The percentage of type I fibrous caps exhibited significant decrease, while the percentage of type III fibrous caps, lipid compositions, and lipid ratios all displayed increase. The results of the univariate analysis indicated that age, hypertension, hyperlipidemia, treatment regimens, fibrous cap type, plaque type, lipid composition, and lipid ratio shared a correlation in regards to the poor prognosis of IS patients. Multivariate logistic regression analysis demonstrated that the prognosis of IS patients was not necessarily dependent on fibrous cap type, plaque type, or age. ROC curves revealed that the HRMRI possessed a strong predicative ability in relation to the identification of the prognosis of IS patients through factors such as type of plaque and fibrous caps determination.

CONCLUSION

Our study conclusively intimated the promise of HRMRI as an evaluative tool for the determination of carotid atherosclerotic plaques in patients with IS.