Cervical carotid plaque evaluation using 3D T1-weighted black-blood magnetic resonance imaging: Comparison of turbo field-echo and turbo spin-echo sequences

Carotid and aortic plaque imaging using 3D gradient-echo imaging and the three-point Dixon method with improved motion-sensitized driven-equilibrium (iMSDE)

BACKGROUND

We devised a method that combines the 3D-Dixon-gradientecho (GRE) method with an improved motion-sensitized driven-equilibrium (iMSDE) to suppress blood flow signals.

PURPOSE

The purpose of this study was to evaluate the effectiveness of the new method we developed plaque imaging method (3D-Dixon-GRE with the iMSDE method).

STUDY TYPE

Retrospective cohort.

POPULATION

Thirty-nine patients who underwent cervical plaque imaging.

FIELD STRENGTH/SEQUENCE

3.0 T/3D-GRE.

ASSESSMENT

Signal intensities of the common carotid artery, aorta, plaque, muscle, and subcutaneous fat were measured through the VISTA and the 3D-Dixon-GRE with iMSDE methods, and each contrast was calculated.

STATISTICAL TEST

Used the Mann Whitney U test. P-values below 0.05 were considered statistically significant.

RESULTS

Plaque and muscle contrast estimated through the VISTA method and 3D-Dixon-GRE with iMSDE method was 1.60 ± 0.96 and 2.04 ± 1.06, respectively, (P < 0.05). The contrast between the flow (common carotid artery and Aorta) and muscle according to the VISTA method and 3D-Dixon-GRE with iMSDE method was 0.24 ± 0.11 and 0.40 ± 0.12, respectively (P < 0.001). Finally, the mean contrast for subcutaneous fat and muscle at six locations was 3.05 ± 1.25 and 0.81 ± 0.23 for the VISTA method and 3D-Dixon-GRE with the iMSDE method, respectively (P < 0.001).

DATA CONCLUSION

Compared to the conventional method (VISTA), the 3D-Dixon-GRE with iMSDE method is preferable in relation to the fat suppression effect, but it is disadvantageous regarding blood flow signal suppression. Therefore, the 3D-Dixon-GRE with the iMSDE method could be considered useful for plaque imaging.

High-resolution magnetic resonance vessel wall imaging in ischemic stroke and carotid artery atherosclerotic stenosis: A review

Ischemic stroke is a significant burden on human health worldwide. Carotid Atherosclerosis stenosis plays an important role in the comprehensive assessment and prevention of ischemic stroke patients. High-resolution vessel wall magnetic resonance imaging has emerged as a successful technique for assessing carotid atherosclerosis stenosis. This advanced imaging modality has shown promise in effectively displaying a wide range of characteristics associated with the condition, leading to a comprehensive evaluation. High-resolution vessel wall magnetic resonance imaging not only enables a comprehensive evaluation of the instability of carotid atherosclerosis stenosis plaques but also provides valuable information for understanding the pathogenesis and predicting the prognosis of ischemic stroke patients. The purpose of this article is to review the application of high-resolution magnetic resonance imaging in ischemic stroke and carotid atherosclerotic stenosis.

Usefulness of 3D T1-Turbo Spin Echo Imaging for the Evaluation of Intracranial Stent Placement

Objective

Evaluation of intracranial stent placement by MRI suffers the problems of signal artifacts during time-of-flight MRA (TOF-MRA). Therefore, angiographic examination is required for detailed intravascular assessment of the stent placement site. Recently, 3D T1-turbo spin echo (3D-TSE) has been developed for evaluation of carotid artery stent placement. We investigated the use of the 3D-TSE imaging method for the evaluation of intracranial vascular stent placement.

Methods

The subjects consisted of nine patients who underwent intracranial vascular stent placement between April 2015 and December 2019. Postoperatively, the lumens of the placed stents were measured by TOF-MRA, DSA, and 3D-TSE imaging. Analysis was performed by type of stent and placement site.

Results

The stents used were Neuroform Atlas (3 patients), LVIS (3 patients), LVIS Jr (2 patients), and Integrity (1 patient). TOF-MRA of the stent placement site showed defects in the image or poor visualization in all nine patients, whereas 3D-TSE imaging visualized the lumen at the stent indwelling site in all patients. The blood vessel diameter measured by the DSA and 3D-TSE imaging exhibited positive correlations regardless of the stent type and placement site.

Conclusion

3D-TSE imaging allows visualization of the lumen of the site of an intracranial vascular stent, regardless of the type of stent or the vessel. Thus, this method may be useful for evaluating the vascular lumen of a lesion.

Semiautomated Segmentation and Volume Measurements of Cervical Carotid High-Signal Plaques Using 3D Turbo Spin-Echo T1-Weighted Black-Blood Vessel Wall Imaging: A Preliminary Study

Unstable carotid plaques are visualized as high-signal plaques (HSPs) on 3D turbo spin-echo T1-weighted black-blood vessel wall imaging (3D TSE T1-BB VWI). The purpose of this study was to compare manual segmentation and semiautomated segmentation for the quantification of carotid HSPs using 3D TSE T1-BB VWI. Twenty cervical carotid plaque lesions in 19 patients with a plaque contrast ratio of > 1.3 compared to adjacent muscle were studied. Using the mean voxel value for the adjacent muscle multiplied by 1.3 as a threshold value, the semiautomated software exclusively segmented and measured the HSP volume. Manual and semiautomated HSP volumes were well correlated (r = 0.965). Regarding reproducibility, the inter-rater ICC was 0.959 (bias: 24.63, 95% limit of agreement: −96.07, 146.35) for the manual method and 0.998 (bias: 15.2, 95% limit of agreement: −17.83, 48.23) for the semiautomated method, indicating improved reproducibility by the semiautomated method compared to the manual method. The time required for semiautomated segmentation was significantly shorter than that of manual segmentation times (81.7 ± 7.8 s versus 189.5 ± 49.6 s; p < 0.01). The results obtained in this study demonstrate that the semiautomated segmentation method allows for reliable assessment of the HSP volume in patients with carotid plaque lesions, with reduced time and effort for the analysis.