scholarly journals Superb Microvascular Imaging Ultrasound for Cervical Carotid Artery Stenosis for Prediction of the Development of Microembolic Signals on Transcranial Doppler during Carotid Exposure in Endarterectomy

2021 ◽  
pp. 61-68
Author(s):  
Takayuki Chiba ◽  
Shunrou Fujiwara ◽  
Kazumasa Oura ◽  
Kohki Oikawa ◽  
Kokei Chida ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Transcranial Doppler ◽  
Carotid Artery Stenosis ◽  
Carotid Plaque ◽  
Carotid Arteries ◽  
Artery Stenosis ◽  
Neurological Deficits ◽  
Artery Embolism ◽  
Superb Microvascular Imaging ◽  
Microvascular Imaging

<b><i>Introduction:</i></b> During exposure of the carotid arteries, embolism from the surgical site is recognized as a primary cause of neurological deficits or new cerebral ischemic lesions following carotid endarterectomy (CEA), and associations have been reported between histological neovascularization in the carotid plaque and both plaque vulnerability and the development of artery-to-artery embolism. Superb microvascular imaging (SMI) enables accurate visualization of neovessels in the carotid plaque without the use of intravenous contrast. This study aimed to determine whether preoperative SMI ultrasound for cervical carotid artery stenosis predicts the development of microembolic signals (MES) on transcranial Doppler (TCD) during exposure of the carotid arteries in CEA. <b><i>Methods:</i></b> Preoperative cervical carotid artery SMI ultrasound followed by CEA under TCD monitoring of MES in the ipsilateral middle cerebral artery was conducted in 70 patients previously diagnosed with internal carotid artery stenosis (defined as ≥70%). First, observers visually identified intraplaque microvascular flow (IMVF) signals as moving enhancements located near the surface of the carotid plaque within the plaque on SMI ultrasonograms. Next, regions of interest (ROI) were manually placed at the identified IMVF signals (or at arbitrary places within the plaque when no IMVF signals were identified within the carotid plaque) and the carotid lumen, and time-intensity curves of the IMVF signal and lumen ROI were generated. Ten heartbeat cycles of both time-intensity curves were segmented into each heartbeat cycle based on gated electrocardiogram findings and averaged with respect to the IMVF signal and lumen ROI. The difference between the maximum and minimum intensities (ID) was calculated based on the averaged IMVF signal (ID<sub>IMVF</sub>) and lumen (ID<sub>l</sub>) curves. Finally, the ratio of ID<sub>IMVF</sub> to ID<sub>l</sub> was calculated. <b><i>Results:</i></b> MES during exposure of the carotid arteries were detected in 17 patients (24%). The incidence of identification of IMVF signals was significantly greater in patients with MES (94%) than in those without (57%; <i>p</i> = 0.0067). The ID<sub>IMVF</sub>/ID<sub>l</sub> ratio was significantly greater in patients with MES (0.108 ± 0.120) than in those without (0.017 ± 0.042; <i>p</i> &#x3c; 0.0001). The specificity and positive predictive value for the ID<sub>IMVF</sub>/ID<sub>l</sub> ratio for prediction of the development of MES were significantly higher than those for the identification of IMVF signals. Logistic regression analysis revealed that only the ID<sub>IMVF</sub>/ID<sub>l</sub> ratio was significantly associated with the development of MES (95% CI 101.1–3,628.9; <i>p</i> = 0.0048). <b><i>Conclusion:</i></b> Preoperative cervical carotid artery SMI ultrasound predicts the development of MES on TCD during exposure of the carotid arteries in CEA.

scholarly journals Carotid Artery Stenosis: Comparison of 3D Time-of-Flight MR Angiography and Contrast-Enhanced MR Angiography at 3T

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Ivan Platzek ◽  
Dominik Sieron ◽  
Philipp Wiggermann ◽  
Michael Laniado
Keyword(s):  
Carotid Artery ◽  
Carotid Artery Stenosis ◽  
Mr Angiography ◽  
Carotid Arteries ◽  
Time Of Flight ◽  
Internal Carotid Artery Stenosis ◽  
Artery Stenosis ◽  
Wilcoxon Test ◽  
Tof Mra ◽  
Contrast Enhanced

Purpose. The aim of this study was to assess the correlation of 3D time-of-flight MR angiography (TOF MRA) and contrast-enhanced MR angiography (CEMRA) for carotid artery stenosis evaluation at 3T.Material and Methods. Twenty-three patients (5 f, 18 m; mean age 61 y, age range 45–78 y) with internal carotid artery stenosis detected with ultrasonography were examined on a 3.0T MR system. The MR examination included both 3D TOF MRA and CEMRA of the carotid arteries. MR images were evaluated independently by two board-certified radiologists. Stenosis evaluation was based on a five-point scale. Stenosis grades determined by TOF and CEMRA were compared using Spearman’s rank correlation coefficient and the Wilcoxon test. Cohen’s Kappa was used to evaluate interrater reliability.Results. CEMRA detected stenosis in 24 (52%) of 46 carotids evaluated, while TOF detected stenosis in 27 (59%) of 46 carotids. TOF MRA yielded significantly higher results for stenosis grade in comparison to CEMRA (P=0.014). Interrater agreement was very good for both TOF MRA (κ=0.93) and CEMRA (κ=0.93).Conclusion. At 3T, 3D TOF MRA should not be used as replacement for contrast-enhanced MRA of the carotid arteries, as it results in significantly higher stenosis grades.

Transcranial Doppler Waveform Blunting in Severe Extracranial Carotid Artery Stenosis

2000 ◽  
Vol 10 (1) ◽  
pp. 33-38 ◽  
Author(s):  
A. Hartmann ◽  
H. Mast ◽  
J.L.P. Thompson ◽  
R.M. Sia ◽  
J.P. Mohr
Keyword(s):  
Carotid Artery ◽  
Transcranial Doppler ◽  
Carotid Artery Stenosis ◽  
Artery Stenosis ◽  
Extracranial Carotid Artery ◽  
Doppler Waveform

scholarly journals Plaque Contact Surface Area and Flow Lumen Volume Predict Stroke Risk in Extracranial Carotid Artery Stenosis

2021 ◽  
Author(s):  
Ryan Gedney ◽  
Ethan Kung ◽  
Veena Mehta ◽  
Adam Brown ◽  
Matthew Bridges ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Surface Area ◽  
Contact Surface ◽  
Carotid Artery Stenosis ◽  
Carotid Arteries ◽  
Stroke Risk ◽  
Artery Stenosis ◽  
Operating Characteristics ◽  
Contact Surface Area ◽  
Stroke Center

The standard indication for intervention in asymptomatic disease is currently percent stenosis in the internal carotid artery as measured by the NASCET method, which remains limited in discriminating power. CT angiography (CTA) is widely used to calculate NASCET stenosis but also offers the opportunity to analyze carotid artery plaques from a morphological perspective that has not been widely utilized. We aim to improve stroke risk stratification of patients with carotid artery stenosis using plaque 3D modeling and image analysis. Patients with CTAs appropriate for 3D reconstruction were identified from an NIH designated stroke center database, and carotid arteries were segmented and analyzed using software algorithms to calculate contact surface area between the plaque and blood flow (CSA), and volume of the flow lumen within the region of the plaque (FLV). These novel parameters factor in the 3D morphometry inherent to each carotid plaque. A total of 134 carotid arteries were analyzed, 33 of which were associated with an ipsilateral stroke. Plaques associated with stroke demonstrated statistically significant increases in average CSA and FLV when compared to those not associated with stroke. When compared to NASCET percent stenosis, CSA and FLV both demonstrated a larger area under the receiver operating characteristics curve (AUC) in predicting stroke risk in patients with carotid stenosis. The data presented here demonstrate morphological features of carotid plaques that are independent of NASCET criteria stratification and may present an improved method in assessing stroke risk in patients with carotid artery stenosis.

Abstract 125: Intravascular Ultrasound: A Clinically Useful Tool for Carotid Plaque Characterization

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Elizabeth Hitchner ◽  
Mohamed A Zayed ◽  
George Lee ◽  
Weesam Al-Khatib ◽  
Barton Lane ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Intravascular Ultrasound ◽  
Carotid Artery Stenosis ◽  
Carotid Plaque ◽  
Patient Characteristics ◽  
Carotid Stenting ◽  
Artery Stenosis ◽  
Plaque Morphology ◽  
Plaque Characterization ◽  
Plaque Area

OBJECTIVE: Virtual Histology Intravascular Ultrasound (VH™ IVUS) is valuable for estimating minimal lumen diameter (MLD) and plaque characterization. The clinical use of IVUS in the carotid arteries is not well characterized. To evaluate carotid plaque morphology, we performed VH™ IVUS in patients with known carotid artery stenosis. METHODS: From July 2010, patients were prospectively enrolled in an IRB approved study to undergo IVUS prior to an elective carotid stenting procedure. Hospital records were reviewed for co-morbidities, carotid/arch anatomy, preoperative carotid duplex velocity measurements, and incidence of postoperative microemboli. Comparison of pre- and postoperative diffusion-weighted MR images was used to identify microemboli. IVUS-derived MLD and vessel wall plaque characteristics were collected. Spearman correlation was performed between MLD and duplex estimated stenosis, and between plaque characteristics and frequency of postoperative microemboli. RESULTS: 14 patients were enrolled during the study period with carotid artery stenosis (average ICA/CCA ratio 5.5, 64.3% asymptomatic). Major co-morbidities included hyperlipidemia (79%), diabetes (71%), and angina (43%). 57% of patients had type 1 arches, and 50% of patients had heavily calcified irregular carotid plaques. MLD correlated with preoperative duplex ICA/CCA ratio (R2=-0.56,p=0.05), and carotid plaque area correlated with peak systolic and diastolic velocities (R2=-0.55,p=0.05). Although microembolic frequency did not correlate with preoperative patient characteristics, it correlated with IVUS-derived plaque necrotic core area (R2=0.53,p=0.05). CONCLUSION: We demonstrate that periprocedural carotid IVUS is clinically feasible and useful. Preoperative duplex measurements correlated with IVUS MLD confirming the fidelity of the technique. Moreover carotid IVUS demonstrates that patients with necrotic plaque cores have a higher frequency of postoperative microemboli. These findings suggest that carotid IVUS may be helpful to identify patients who are at higher risk of microemboli during carotid artery stenting.

Abstract TP137: The Association Between MRI-detected Carotid Vulnerable Plaque and Coronary Artery Stenosis

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Manabu Nagata ◽  
Kazumichi Yoshida ◽  
Kazumichi Yoshida ◽  
Ryu Fukumitsu ◽  
Yohei Takenobu ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Carotid Artery ◽  
Carotid Artery Stenosis ◽  
Carotid Plaque ◽  
Coronary Artery Stenosis ◽  
Coronary Intervention ◽  
Artery Stenosis ◽  
Vulnerable Plaques ◽  
Carotid Mri ◽  
History Of

It is now accepted that carotid artery stenosis should be treated as a part of systemic atherothrombosis. However, little is known about the association in atherosclerosis between the carotid and coronary arteries. We retrospectively investigated the association between carotid plaque vulnerability diagnosed on carotid magnetic resonance imaging (MRI) and coexisting coronary artery stenosis in patients scheduled for carotid endarterectomy (CEA) or carotid artery stenting (CAS). Eighty-nine consecutive cases that underwent carotid reconstruction for carotid artery stenosis at Kyoto University Hospital between 2010 and 2015 were enrolled in this study. Ten cases that received neither coronary angiography (CAG) nor coronary computed tomography angiography (CCTA) as preoperative examinations, 6 cases with restenosis after CEA or CAS, and 2 cases that did not undergo carotid MRI were excluded. We evaluated relative overall signal intensity (roSI) of the carotid plaque on T1-weighted imaging and coronary artery stenosis detected on CAG or CCTA in the remaining 71 cases. Carotid plaques with roSI >1.5 were defined as MRI-detected vulnerable plaques. Thirty-one cases had a history of previous coronary intervention (stenting or bypass surgery), of which 26 (84%) showed carotid vulnerable plaques. In the cases with no history of coronary intervention, coronary artery stenosis was newly detected in 21 cases, and was not demonstrated in the other 19 cases. Fifteen of the 21 cases with coronary artery stenosis (71%) also showed carotid vulnerable plaques. On the other hand, only 4 of the 19 cases without coronary artery stenosis (21%) had carotid vulnerable plaques, representing a significant difference (P<0.05). Among the cases with no history of coronary intervention, prevalence of coronary artery stenosis in cases with carotid vulnerable plaques was 79%, significantly higher than that in cases without carotid vulnerable plaques (29%). In conclusion, this study demonstrated that patients with carotid vulnerable plaques are more likely to have advanced coronary artery stenosis. Plaque characterization by carotid MRI is useful not only for treatment of carotid artery stenosis, but also for predicting coronary artery stenosis.

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