Carotid Artery Steno-occlusive Disease Research Articles

The Many Manifestations of Rhino-Orbital-Cerebral Mucormycosis: An Illustrative Case Report (P10-10.003)

<h3>Objective:</h3> To describe and illustrate with neuroimaging the progression of rhino-orbital-cerebral mucormycosis leading to orbital apex syndrome, cranial neuropathies, cavernous sinus thrombosis, and strokes from internal carotid artery steno-occlusive disease. <h3>Background:</h3> A 67-year old female with uncontrolled diabetes mellitus presented with progressive vision loss in the right eye and right sided facial weakness, associated with fatigue and fevers. She underwent intranasal debridement, and hematoxylin and eosin staining showed broad-based, branching, non-septate hyphae, consistent with mucormycosis. She was treated with antifungals. She sought care again 3 months later, at which point she had no vision in the right eye, and was unable to open or move the right eye. Her examination at this point was notable for no light perception in the right eye with mid-size, unreactive pupil; complete ptosis and ophthalmoplegia of the right eye; and right facial weakness in a lower motor neuron pattern. Magnetic resonance imaging of the brain demonstrated inflammation at the orbital apex, as well as thromboses of the right superior ophthalmic vein and right cavernous sinus. Despite treatment with systemic antifungals and anticoagulation, the patient later developed sudden-onset lethargy associated with a right gaze deviation. She was found to have severe stenosis of the bilateral intracranial internal carotid arteries on cerebral angiogram. Magnetic resonance imaging showed interval development of bilateral deep watershed territory infarcts. <h3>Design/Methods:</h3> NA <h3>Results:</h3> NA <h3>Conclusions:</h3> Mucormycosis is a rare but devastating fungal infection caused by mucormycetes, which are ubiquitous in nature. Most patients with invasive mucormycosis are immunocompromised, classically due to poorly controlled diabetes or hematologic malignancies. Mucormycosis spreads contiguously through the sinuses, and is also angioinvasive. Because the infection typically begins as a rhinosinusitis, the fungus spreads intracranially through direct invasion of the cavernous sinus. This case and the associated imaging illustrates the stepwise progression of mucormycosis due to contiguous spread intracranially. <b>Disclosure:</b> Dr. Trenz has nothing to disclose. Dr. Tetreault has nothing to disclose.

Abstract TP133: Assessment of Hemodynamic Compromise by Neuro-Parenchymal Blood-Volume System: Comparison With Acetazolamide Challenged Single Photon Emission Computed Tomography

Objective: To investigate whether Neuro-parenchymal blood-volume (PBV) measurements could be used instead of acetazolamide (ACZ)-challenged single-photon emission computed tomography (SPECT) to evaluate hemodynamic compromise in patients with cerebrovascular steno-occlusive disease. Methods: Thirteen patients with unilateral carotid artery steno-occlusive disease were enrolled from April 2018 to June 2019, and the severity of hemodynamic compromise was assessed by Neuro PBV system (syngo Neuro PBV IR, Siemens Medical Solutions, Erlangen, Germany) and acetazolamide-challenged SPECT of the brain. Cerebral blood volume (CBV) was measured using a C-arm flat detector angiographic system. The asymmetry ratio of CBV in the middle cerebral artery (MCA) territory (CBV AR ) was defined as the (CBV on the ipsilateral side / CBV on the contralateral side) х 100 (%). Cerebral blood flow (CBF) was quantified by SPECT using the quantitative SPECT/dual-table autoradiography method. Cerebrovascular reserve (CVR) in the MCA territory was defined as (CBF after ACZ challenge – CBF at rest) / CBF at rest х 100 (%) and classified as reduced (&lt;18.4%) or non-reduced (≥18.4%). Results: Five patients showed reduced CVR. The CBV AR was significantly lower in the reduced CVR group than in the non-reduced CVR group (71.6% vs. 110.0%, P = 0.003). The cut-off value of CBV AR for predicting reduced CVR obtained from analysis of the receiver operating characteristic curve was 99.0% (sensitivity 100% and specificity 87.5%), and the area under the curve was 0.975 (95% confidence interval: 0.906-1). Conclusion: This is the first report to evaluate the correlation between CBV AR measured using the Neuro PBV system and CVR assessed by SPECT. CBV AR is useful indicator for evaluating reduced CVR in the MCA territory, as an alternative to ACZ-challenged SPECT.

Cystatin C as a predictor for carotid artery steno-occlusive disease in non-cardioembolic ischemic stroke

BackgroundStroke is the third leading cause of death in developed nations. Ultrasonography (US) of the carotid arteries is the modality of choice for diagnosis and monitoring of cases of atheromatous disease. Cystatin C (CysC) is a risk factor for cerebrovascular and cardiovascular disease.ObjectivesTo detect the association of serum CysC levels with acute ischemic stroke, the correlation of its levels with stroke severity, and the association between CysC levels with extra- and intracranial stenosis.MethodsCase-control study was conducted on 66 subjects, 33 patients within the first week of stroke onset with age range from 40 to 75 years, and 33 control healthy subjects with matched age and sex. All subjects underwent complete neurological examination, Extra- and transcranial duplex, CT brain, routine laboratory work-up, and serum CysC.ResultsSerum CysC levels were significantly raised in patients with acute ischemic stroke compared to controls. CysC levels were higher in patients with extracranial stenosis than in those with intracranial stenosis. Moreover, extracranial stenosis > 50% has higher levels of CysC. Serum CysC level showed a significant correlation with National Institutes of Health Stroke Scale (NIHSS) and intima-media thickness (IMT).ConclusionSerum CysC can be used as a marker for acute atherosclerotic ischemic stroke and stroke severity. High-grade extracranial stenosis has the highest level of CysC.

Alterations of cerebral perfusion in asymptomatic internal carotid artery steno-occlusive disease

Patients with asymptomatic occlusion in the internal carotid arteries (ICA) have been shown to have a better preserved hemodynamic status of the brain as compared to patients with symptoms. This study was aimed to explore the cerebral perfusion alterations in asymptomatic patients using multi-parametric arterial spin-labeling (ASL) magnetic resonance (MR) imaging. Forty-two patients diagnosed with asymptomatic ICA stenosis/occlusion were prospectively included and divided into high-grade (ultrasonographic stenosis ≥70%, N = 20) and low-grade groups (N = 22). On a 3-Tesla clinical MR scanner, pseudo-continuous ASL was performed to measure cerebral blood flow CBF, arterial transit time ATT, and flow territory. Fisher’s exact test indicates that the high-grade group has higher frequency in asymmetric ATT (p < 10−3) and asymmetric flow territory (p < 10−3) as compared to the low-grade group. The between-group difference in CBF asymmetry is marginal (p = 0.062). Logistic regression further reveals that hemispherical asymmetry in ATT and flow territory is associated with the existence of high-grade ICA stenosis (odds ratio = 12 and 21, respectively), whereas hemispherical asymmetry in CBF is not. Our data suggest that ATT and flow territory may be better predictors of asymptomatic high-grade ICA stenosis diagnosed by carotid ultrasonography than CBF.

Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study.

Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0±10.5years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r=0.767, P<0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR)=2.459, 95% confidence interval (CI) 1.896-3.189, P<0.001]. Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA.

Abstract TMP32: Ultrasonography Grading of Internal Carotid Artery Disease: Multi-Parametric DEGUM versus SRU Consensus Criteria

Introduction: The novel multi-parametric ‘DEGUM’ duplex ultrasonography (DUS) criteria may improve accuracy of extracranial carotid artery grading but have not been compared with the established Society of Radiologists in Ultrasound (SRU) consensus criteria yet. We sought to investigate the diagnostic agreement between these two widely used DUS approaches for grading of carotid artery steno-occlusive disease. Methods: This was a sub-analysis of the complete dataset from a prospective multicenter study, where a total of 120 patients underwent both DUS and catheter angiography for validation of the multi-parametric DEGUM ultrasound approach. In this analysis, two ultrasonography experts independently interpreted documented B-image, color-flow and Doppler spectra findings utilizing DEGUM and SRU criteria. Carotid arteries were categorized into clinically relevant NASCET strata: moderate (50-69%), severe (70-99%) and occlusion. On angiography, ICA was graded using the NASCET approach. Inter-rater and between-methods reliability was assessed through weighted Cohen’s kappa. Overall accuracy for both ultrasound approaches was computed using catheter angiography as the gold standard. Results: We analyzed a total of 162 carotid artery pairs on catheter angiography and DUS. There was almost perfect agreement between both ultrasonography diagnostic approaches in describing all clinically relevant grades of the disease (k w 0.91, CI95%: 0.89-0.94). Inter-rater reliability was found to be comparably high for both the DEGUM (k w 0.97, CI95%: 0.94-0.98) and the SRU (k w 0.98, CI95%: 0.97-0.99) ultrasonography approaches. Compared with catheter angiography, overall accuracy for moderate and severe stenosis ranges did not differ between the DEGUM (73% and 73%, respectively) and the SRU (73% and 70%, respectively) approaches. There was also no difference for detection of carotid artery occlusion (96% and 96%, respectively). Conclusions: Our analysis showed almost perfect diagnostic agreement between the DEGUM and the SRU approaches for ultrasonography grading of carotid artery steno-occlusive disease. Therefore, our data do not support superiority of one approach over the other in the evaluation of clinically relevant grades of the disease.

Higher Levels of Cystatin C Are Associated with Extracranial Carotid Artery Steno-Occlusive Disease in Patients with Noncardioembolic Ischemic Stroke

Background: Large artery atherosclerosis is a major cause of ischemic stroke worldwide. Differential biomarker profiles associated with extra- and intracranial atherosclerosis are a topic of considerable interest. Cystatin C (CysC), a marker of renal function, is a risk factor for cardiovascular disease. Aim: We sought to determine whether CysC levels were associated with extra- and intracranial large artery stenosis (LAS) in patients with acute ischemic stroke. Methods: We retrospectively analyzed data of acute noncardioembolic ischemic stroke patients who were admitted to our stroke center within 5 days from symptom onset. Serum CysC levels were measured using latex agglutination turbidimetric immunoassay. Extra- and intracranial LAS were defined as ≥50% diameter stenosis or occlusion of the relevant internal carotid artery (ICA) and/or middle cerebral artery (MCA) using carotid echography and volume rendering on magnetic resonance angiography. Multivariate logistic analyses were used to assess the association between CysC levels and LAS after adjustment for potential confounders. Results: Of 205 patients (mean age 70.2 years), 76 (37.1%) had LAS. The distribution of LAS was 29 extracranial ICA, 34 intracranial ICA/MCA (8 ICA only, 25 MCA only, 1 ICA+MCA) and 13 tandem stenosis (both extracranial ICA and intracranial ICA/MCA). Levels of CysC were higher in patients with extracranial ICA stenosis than in those with intracranial ICA/MCA stenosis (1.23 ± 0.33 vs. 0.97 ± 0.21 mg/l, p < 0.001). In multivariate analysis, the highest CysC tertile (>1.04 mg/l) was significantly associated with extracranial ICA stenosis (adjusted odds ratio [OR] 5.01, 95% confidence interval [CI] 1.51-16.63, p = 0.009) after adjustment for age, sex, diabetes, chronic kidney disease, current smoking, systolic blood pressure, HDL cholesterol, high-sensitivity C-reactive protein (hs-CRP) and premorbid lipid-lowering drugs use. When CysC was considered as a continuous variable, 1 SD increase in CysC was significantly associated with extracranial ICA stenosis (adjusted OR 3.01, 95% CI 1.58-5.72, p = 0.001). However, there were no significant associations between CysC levels and intracranial ICA/MCA stenosis. In addition, CysC levels showed a weak but statistically significant correlation with hs-CRP levels (r = 0.195, p = 0.021). Using receiver operating characteristic curve analysis, CysC value displayed good performance in discriminating extracranial ICA stenosis (c-statistic 0.79, 95% CI 0.69-0.89, p < 0.001). Conclusions: This preliminary study suggests that higher levels of CysC were independently associated with symptomatic extracranial ICA stenosis, but not with intracranial ICA/MCA stenosis in patients with noncardioembolic stroke. Our findings provide new insights into the link between serum CysC and carotid atherosclerosis.

Collateral circulation via the circle of Willis in patients with carotid artery steno-occlusive disease: evaluation on 3-T 4D MRA using arterial spin labelling

To evaluate whether 3-T four-dimensional (4D) arterial spin-labelling (ASL) -based magnetic resonance angiography (MRA) is useful for assessing the collateral circulation via the circle of Willis in patients with carotid artery steno-occlusive disease. Institutional review board approval and prior written informed consent from all patients were obtained. The inclusion criteria were fulfilled by 13 patients with carotid artery steno-occlusive disease. All underwent 4D-ASL MRA at 3T and digital subtraction angiography (DSA). The flow-sensitive alternating inversion recovery (FAIR) preparation scheme with look-locker sampling was used for spin labeling. At 300-ms intervals seven dynamic scans were obtained with a spatial resolution of 0.5×0.5×0.6mm(3). The collateral flow via the circle of Willis was read on 4D-ASL MRA and DSA images by two sets of two independent readers each. κ statistics were used to assess interobserver and intermodality agreement. On DSA, collateral flow via the anterior communicating artery (AcomA) was observed in six patients, via the posterior communicating artery (PcomA) in four patients, and via both the AcomA and PcomA in three patients. With respect to the qualitative evaluation of 4D-ASL MRA images, interobserver agreement was excellent for all items (κ=1). 4D-ASL MRA and DSA consensus readings agreed on the type of collateral flow pattern in 10 of the 13 patients (77%). Intermodality agreement was good (κ=0.606; 95% confidence interval (CI): 0.215-0.997). 3T 4D-ASL MRA may be a useful tool for the evaluation of the collateral circulation in patients with carotid artery steno-occlusive disease.

Evaluation of hemodynamic outcomes after carotid artery stenting using cerebral perfusion CT

Objective To evaluate 1-week and 1-year outcomes of carotid artery stenting (CAS)using cerebral perfusion CT(PCT). Methods The clinical database of 20 patients with unilateral carotid artery stenosis( ≥60% ) who underwent CAS were retrospectively reviewed. Relative cerebral blood volume (rCBV), relative cerebral blood flow(rCBF) and relative mean transit time( rMTT) were measured by using cerebral PCT within one week before CAS and at one week and at one year after CAS. Cerebral MRI was performed within one week before CAS. The noncontrast CT was performed within one week before CAS and immediately after CAS. The arteriography was performed at one year after CAS. The variance analysis was performed to determine whether there were significant differences of rCBV, rCBF, rMTT in anterior cerebral artery area( ACA area), middle cerebral artery area( MCA area), posterior cerebral artery area( PCA area),basal ganglia area, front and back cortical watershed area( CWS area) and internal watershed area( IWS area) among the different time points. Results In the three measures, there was no significant difference of rCBV in all areas among the three time points( P ＞ 0. 05 ) , and there was no significant difference of rCBF and rMTT in PCA area( P ＞ 0. 05 ), but there were significant differences of rCBF and rMTT in all other areas among the three time ponits(P ＜0. 01). In one week before CAS, at one week and at one year after CAS, rCBF of 20 patients is 0. 86 ±0. 06, 0. 95 ±0. 04, 0. 98 ±0. 07 in ACA area, 0. 81 ±0. 04, 1.06 ±0. 04, 1.03 ±0.07 in MCA area, 0. 84 ±0. 06, 0. 97 ±0. 04, 0. 96 ±0. 04 in basal ganglia, 0. 78 ±0. 03,0. 97 ±0. 03, 0. 96 ±0. 02 in front CWS area, 0. 77 ±0. 03, 1.00 ±0. 02, 0. 98 ±0. 03 in back CWS area,and 0. 80 ± 0. 04, 0. 94 ± 0. 03, 0. 93 ± 0. 04 in IWS area ( F = 18. 95, 146. 41,63.03,540. 85,415.97,164.19, P＜0. 01). rMTT is 1.17 ±0.05, 1.04±0.04, 1.01 ±0.06 in ACA area, 1.41±0.06, 1.08±0.04, 1.07±0.04 in MCA area, 1.20±0.06, 1.06±0.04, 1.05±0.04 in basal ganglia, 1.41 ±0.05,1.10 ±0. 05, 1.09 ±0. 04 in front CWS area, 1.43 ±0. 10, 1.07 ±0. 06, 1.08 ±0. 06 in back CWS area,1.29±0.10, 1.09 ±0.05, 1.11 ±0.07 in IWS area (F=51.74, 248. 89, 70.08, 381.68, 288.94,41.53, P ＜0. 01 ). There were significant differences of rCBF and rMTT between those measured one week before CAS and one week or one year after CAS ( P ＜ 0. 01 ), but there were no significant differences of rCBF or rMTT in any area measured between those at 1 week after CAS and those measured at 1 year after CAS(P＞0.05). Conclusions Hemodynamic outcome at one year after CAS is good in the absence of contralateral carotid artery steno-occlusive disease. In addition, the coherence of results between 1-week and 1-year indicates that the outcome of one week after CAS could predict long-term hemodynamic outcome. Key words: Tomography, X-ray computed; Perfusion; Stent; Outcome

Brain Temperature Measured by Using Proton MR Spectroscopy Predicts Cerebral Hyperperfusion after Carotid Endarterectomy

To determine whether brain temperature measured by using preoperative proton magnetic resonance (MR) spectroscopy could help identify patients at risk for cerebral hyperperfusion after carotid endarterectomy (CEA). Institutional review board approval and informed consent were obtained. Acquisition of proton MR spectroscopic data by using point-resolved spectroscopy without water suppression was performed before CEA in the bilateral cerebral hemispheres of 84 patients with unilateral internal carotid artery stenosis (> or =70%) and without contralateral internal carotid artery steno-occlusive disease. Brain temperature was calculated from the chemical shift difference between water and N-acetylaspartate signals at proton MR spectroscopy. Cerebral blood flow (CBF) was also measured by using single photon emission computed tomography and N-isopropyl-p-[(123)I]-iodoamphetamine before and immediately after CEA and on the 3rd postoperative day. The relationship between each variable and the development of post-CEA hyperperfusion (CBF increase > or = 100% compared with preoperative values) was evaluated with univariate statistical analysis followed by multivariate analysis. A linear correlation was observed between preoperative brain temperature difference (the value in the affected hemisphere minus the value in the contralateral hemisphere) and increases in CBF immediately after CEA (r = 0.763 and P < .001) when the preoperative brain temperature difference was greater than 0. Cerebral hyperperfusion immediately after CEA was observed in nine patients (11%). Elevated preoperative brain temperature difference was the only significant independent predictor of post-CEA hyperperfusion. When elevated brain temperature difference was defined as a marker of hemodynamic impairment in the affected cerebral hemisphere, use of preoperative brain temperature difference resulted in 100% sensitivity and 87% specificity, with a 47% positive predictive value and a 100% negative predictive value for the prediction of post-CEA hyperperfusion. Hyperperfusion syndrome developed on the 3rd and 4th postoperative days in two of the nine patients who exhibited hyperperfusion immediately after CEA. Brain temperature measured by using preoperative proton MR spectroscopy may help identify patients at risk for post-CEA cerebral hyperperfusion.

Computed Tomography Angiography of the Carotid and Cerebral Circulation

As a result of the development of multidetector row computed tomography (CT) technology, multidetector CT angiography is rapidly becoming the preferred examination for the initial evaluation of an increasing number of clinical neurovascular applications such as carotid artery steno-occlusive disease, acute ischemic and hemorrhagic stroke, subarachnoid hemorrhage, and cerebral vasospasm. This article reviews the most recent literature on these topics, provides the reader with useful clinical tips for performing and interpreting these increasingly complex diagnostic examinations, presents illustrative cases, and looks at future developments in this vibrant area of neuroradiology research.

The Cart and The Horse

Endarterectomy is recommended in current clinical guidelines for selected patients with a significant symptomatic or asymptomatic extracranial carotid artery stenosis, provided that the operation can be performed with acceptable safety.1–3 These recommendations are based on the results of several controlled trials in which those randomized to have the operation had better clinical outcomes compared with those who did not, on a background of what at the time was considered to constitute best medical therapy. The advent of angioplasty/stenting offers the promise of a less invasive means of directly treating carotid artery steno-occlusive disease compared with endarterectomy. Unlike surgical procedures, however, pharmaceuticals, biologicals, and devices are subject to regulatory approval in the United States by the Food and Drug Administration. Placement of a carotid artery stent system was first approved by the Food and Drug Administration in 2004 for the treatment of patients deemed “at high risk for adverse events from carotid endarterectomy who require carotid revascularization [who have] neurological symptoms and ≥50% stenosis of the common or internal carotid artery by ultrasound or angiogram, or in patients without neurological symptoms and ≥80% stenosis of the common or internal carotid artery by ultrasound or angiogram” (http://www.fda.gov/cdrh/pdf4/p040012a.pdf). Article see p 159 Registries were developed to help assess the safety of stent systems as used in larger populations, in part to help identify risks that might not have been apparent based on the smaller numbers of subjects included in the randomized trial that compared stenting with endarterectomy in patients at high risk of postendarterectomy complications.4 In that trial, the postprocedural 30-day rate of stroke, myocardial infarction, or death was 2.1% with stenting versus 9.3% with endarterectomy ( P =0.18) for symptomatic patients; for those with an asymptomatic carotid artery stenosis, the periprocedural rates were 5.4% versus 10.2% ( P =0.20), …