Color-coded Sonography Research Articles

TCD/TCCSによる脳血管攣縮の評価

TCD/TCCSによる脳血管攣縮の評価

Evaluation of Interventional Therapy for Patients with Intracranial Vertebral Artery Stenosis by Transcranial Color-Coded Sonography

The aim of this study was to evaluate the efficacy of stenting for patients with intra-cranial vertebral artery stenosis by trans-cranial color-coded sonography and to analyze the risk factors of in-stent restenosis (ISR). In total, 121 patients with intra-cranial vertebral artery stenosis stents were included. The follow-up time was 3–12 mo (mean: 9.9 mo). The success rate was 92.6%. Peak systolic velocity and end-diastolic velocity decreased from 261 ± 63 to 109 ± 41 cm/s and from 133 ± 44 to 47 ± 18 cm/s, respectively (both p < 0.001). Peak systolic velocity (245 ± 47 cm/s) and end-diastolic velocity (121 ± 31 cm/s) of patients with ISR (18.9%, 20/106) were higher than those of patients without ISR (101 ± 38 and 44 ± 17 cm/s, respectively) at 12 mo post-procedure (p < 0.05). The length of the stent and residual stenosis were related to ISR. In conclusion, stenting is a feasible treatment method for intra-cranial vertebral artery stenosis. Trans-cranial color-coded sonography can be used for monitoring patients to identify ISR.

Factors Associated with No or Insufficient Temporal Bone Window Using Transcranial Color-coded Sonography

PurposeTranscranial color-coded sonography (TCCS) noninvasively assesses physiologic and pathologic intracranial blood flow especially in non-Caucasians who have high prevalence of intracranial steno-occlusive arterial disease. However, a higher temporal bone window failure (WF) rate is found in non-Caucasians and thus limits the utilization of TCCS. This study was performed to explore the associated factors of temporal bone WF in Taiwanese patients. MethodsBetween January 2014 and June 2014, 355 consecutive patients who received TCCS examination during their hospitalization at neurological ward were enrolled in this study, including 218 men and 137 women. Patients were classified into two groups, one with no or insufficient temporal bone window and the other with good temporal bone window for identification of middle, anterior, and posterior cerebral arteries via transtemporal approach. Age, sex, and conventional vascular risk factors in each group were compared. ResultsIt was found that 28.8% of the patients had no or insufficient temporal bone window. Among them, 20.3% had complete bilateral temporal bone WF. For all factors studied, older age and female sex were significantly associated with no or insufficient temporal bone window. ConclusionThe failure rate of temporal bone window was considered high as compared to Western countries but, not surprisingly, age and sex remained the significant factors. Introducing echo contrast agents during the TCCS examination might help to increase the success rate of TCCS examination and provide useful information to clinicians.

Clinical Outcomes of Carotid Endarterectomy in Symptomatic and Asymptomatic Patients with Ipsilateral Intracranial Stenosis.

The risk of perioperative stroke and the benefits of carotid endarterectomy (CEA) remain uncertain in the case of an ipsilateral intracranial stenosis. The aim of this observational study was to analyze the early and late outcomes of CEA in patients with a carotid tandem lesion (CTL), defined as a severe stenosis at the bifurcation with any concomitant lesion ≥50 % involving the intracranial portion of the ipsilateral internal carotid artery or the main trunk of the anterior or middle cerebral artery. From 2000 to 2009, 1143 patients underwent CEA for symptomatic or asymptomatic extracranial carotid stenosis according to the NASCET and ACAS recommendations, respectively. CTLs were diagnosed in 219 patients (19.2 %) by extracranial and transcranial color-coded Doppler sonography combined with noninvasive brain imaging studies. The primary endpoints of the study were perioperative (30-day) stroke and death, and any ipsilateral ischemic adverse events during the follow-up, which ranged from 0.1 to 10 years (mean 4.9 ± 3.3 years). The rates of the primary endpoints were compared between patients with (group I) and without CTL (group II). Overall, 219 CEAs were performed in group I and 924 in group II. Nearly two in three of the carotid lesions (777 of 1143, 68 %) were symptomatic at presentation (62.1 % in group I vs 69.4 % in group II; p = 0.03), with a 23.8 % rate of stroke (21.9 % in group I vs 24.2 % in group II; p = 0.85). There were 2 (0.9 %) perioperative ipsilateral strokes in group I and 5 (0.5 %) in group II (p = 0.62), and no deaths. The 5-year ipsilateral stroke-free, any stroke-free, and overall survival rates did not differ significantly between patients with and without CTL. This study has shown that patients with and without CTL who underwent CEA had a similar occurrence of perioperative adverse events (probably due to the extremely low incidence of perioperative complications) and comparable late outcomes, suggesting that the presence of CTL does not justify refusing CEA for patients who could benefit from it.

Prediction of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage Using Cerebral Blood Flow Velocities and Cerebral Autoregulation Assessment.

The risk of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) is associated with large cerebral artery vasospasm, but vasospasm is not a strong predictor for DCI. Assessment of cerebral autoregulation with transcranial Doppler (TCD) may improve the prediction of DCI. The aim of this prospective study was to assess the value of TCD-derived variables to be used alone or in combination for prediction of DCI. We included consecutive patients with low-grade aneurysmal SAH within 4 days of aneurysm rupture. Cerebral autoregulation was evaluated using the moving correlation coefficient Mx calculated from spontaneous fluctuations of cerebral blood flow velocities and arterial blood pressure. Transcranial color-coded sonography was performed to assess large artery vasospasm. Thirty patients (19 women and 11 men; mean age ± SD 44.7 ± 12.1 years) were included. Twenty (66.7%) patients had vasospasm. DCI occurred in six (20%) patients after a median delay of 10 days (range 8-13 days). Cerebral autoregulation was impaired at baseline and at day 7 and then returned to normal at day 14. Neither cerebral autoregulation impairment nor large artery vasospasm alone was associated with DCI. In contrast, the combination of large artery vasospasm with worsening impairment of cerebral autoregulation from baseline to day 7 was significantly correlated to subsequent DCI (p = 0.007). Early deterioration of cerebral autoregulation was strongly predictive of DCI in patients with large artery vasospasm after low-grade SAH. Our results suggest that consideration to both cerebral blood flow velocities and cerebral autoregulation may improve the prediction of DCI.

CAS 後過灌流症候群の発症予測に関する研究

CAS 後過灌流症候群の発症予測に関する研究

The level of circulating endothelial progenitor cell is associated with cerebral vasoreactivity: a pilot study.

Endothelial progenitor cell is known to be able to repair injured vessels. We assessed the hypothesis that endothelial progenitor cell also modulates cerebral endothelial function in healthy status. We used transcranial color-coded sonography to measure middle cerebral arterial vasoreactivity to CO2 (breath-holding index) in healthy subjects and observed its relationship with the number of circulating CD34CD133+ cells. To detect significant correlations between each characteristic and breath-holding index of middle cerebral artery, we used univariate and multivariate regression analyses. 22 young healthy subjects were included in the present study (6 men, 16 women; mean age: 28.45 ± 3.98 years, range: 22–34 years). The mean breath-holding index and CD45lowCD34+CD133+ cells number were 0.95 ± 0.48% and 0.52 ± 0.26, respectively. The level of CD34CD133+ cells was independently associated with middle cerebral artery's vasoreactivity (r = 0.439, P = 0.04). Our results suggest that endothelial progenitor cell also modulates healthy cerebral vessels' endothelial function. This ability of endothelial progenitor cell could be potentially applied therapeutically and for prevention in conditions with cerebral endothelial dysfunction and cerebral ischemia.

Absence of Doppler signal in transcranial color-coded ultrasonography may be confirmatory for brain death: A case report

Absence of Doppler signal in transcranial color-coded ultrasonography may be confirmatory for brain death: A case report

Asymptomatic intracranial arterial stenosis and metabolic syndrome: the APAC study.

PurposeThe metabolic syndrome (MetS) is a major risk factor for cardiovascular diseases. We investigated potential associations between MetS and asymptomatic intracranial arterial stenosis (ICAS) in a general population.MethodsThe community-based “Asymptomatic Polyvascular Abnormalities in Community Study” examined asymptomatic polyvascular abnormalities in a Chinese population aged 40+ years without history of stroke and coronary heart disease. MetS was defined by the International Diabetes Federation criteria. Asymptomatic ICAS was diagnosed by transcranial color-coded Doppler sonography.ResultsOut of 5393 study participants, asymptomatic ICAS was detected in 713 (13.2%) participants, and MetS in 1323 (24.5%) individuals. Prevalence of asymptomatic ICAS increased significantly from 7.5% to 24.2% with increasing number of MetS components. After adjusting for age, gender, physical activity, body mass index, low-density lipoprotein cholesterol and high-sensitivity C-reactive protein, MetS was significantly associated with asymptomatic ICAS (OR: 1.50; 95%CI: 1.23,1.83). Compared with the subgroup without MetS, the ORs for asymptomatic ICAS increased (P<0.0001) for each of 5 components of MetS from 1.71 (95%CI: 1.27,2.30), to 2.20 (95%CI: 1.63,2.98), 2.79 (95CI: 2.01,3.88), 3.08 (95%CI: 2.11,4.51) and 4.27 (95%CI: 2.22,8.20).ConclusionsIn multivariate analysis, MetS was an independent and additional factor associated with asymptomatic ICAS. Study participants with 5 MetS components had a 4 times higher risk of asymptomatic ICAS than participants with no MetS component.

Reduced circulating endothelial progenitor cells in reversible cerebral vasoconstriction syndrome.

BackgroundThe pathophysiology of reversible cerebral vasoconstriction syndrome (RCVS) remains elusive. Endothelial dysfunction might play a role, but direct evidence is lacking. This study aimed to explore whether patients with RCVS have a reduced level of circulating circulating endothelial progenitor cells (EPCs) to repair the dysfunctional endothelial vasomotor control.MethodsWe prospectively recruited 24 patients with RCVS within one month of disease onset and 24 healthy age- and sex-matched controls. Flow cytometry was used to quantify the numbers of circulating EPCs, defined as KDR+CD133+, CD34+CD133+, and CD34+KDR+ double-positive mononuclear cells. The Lindegaard index, an index of vasoconstriction, was calculated by measuring the mean flow velocity of middle cerebral arteries and distal extracranial internal carotid arteries via color-coded sonography on the same day as blood drawing. A Lindegaard index of 2 was chosen as the cutoff value for significant vasoconstriction of middle cerebral arteries based on our previous study.ResultsPatients with RCVS had a reduced number of CD34+KDR+ cells (0.009 ± 0.006% vs. 0.014 ± 0.010%, p = 0.031) but not KDR+CD133+ cells or CD34+CD133+ EPCs, in comparison with controls. The number of CD34+KDR+ cells was inversely correlated with the Lindegaard index (rs = -0.418, p = 0.047). Of note, compared to controls, patients with a Lindegaard index > 2 (n = 13) had a reduced number of CD34+KDR+ cells (0.007 ± 0.005% vs. 0.014 ± 0.010%, p = 0.010), but those with a Lindegaard index ≤ 2 did not.ConclusionsPatients with RCVS had reduced circulating CD34+KDR+ EPCs, which were correlated with the severity of vasoconstriction. Endothelial dysfunction might contribute to the pathogenesis of RCVS.

Transcranial Direct Current Stimulation and Cerebral Vasomotor Reserve: A Study in Healthy Subjects.

Cerebral vasomotor reserve (VMR) is the capability of cerebral arterioles to change their diameter in response to various stimuli, such hypercapnia. Changes of VMR due to transcranial direct current stimulation (tDCS) have been poorly studied. Twenty-five healthy subjects underwent anodal/cathodal and sham tDCS on right primary motor area. Before and after tDCS, we assessed VMR by Transcranial Color-Coded Sonography (TCCS) calculating trought Breath Holding Index (BHI) and Heart Rate Variability (HRV), in particular after Valsalva manouver. A-tDCS decreased VMR and BHI (p < 0.05), whereas C-tDCS increased VMR, and BHI (p < 0.05); Sham doesn't provide statistically significant of both VMR, BHI and HRV (p > 0.05). Our study confirms that tDCS induces a modification of bilateral VMR with a polarity-specific effect; based on this bilateral MFV and BHI modifications, we can speculate an involvement of the SNS in the VMR regulation.

Development of a new clot formation protocol for standardized in vitro investigations of sonothrombolysis.

Agreement about the most suitable clot formation protocol for sonothrombolysis investigations is lacking. Lysis rates vary strongly owing to different test conditions and, thus, cannot be compared. We aim to establish a simple but physiologically grounded protocol for in vitro coagulation to enable standardized sonothrombolysis investigations. Clots were generated from platelet-rich plasma (PRP) obtained by centrifugation (10 min, 180 × g) of human venous blood (VB). PRP was mixed with the boundary layer formed between the supernatant and the erythrocyte layer. To achieve clots with different platelet counts, PRP was gradually substituted with platelet-free plasma (PFP), harvested from the supernatant of VB after centrifugation (10 min, 2570 × g). Clot types were examined for histological appearance, hydrodynamic resistance under physiological flows, and lysis rate measured by weight loss after a 2-h treatment with recombinant tissue plasminogen activator (rt-PA) (60 kU/ml). Lysis rates of the most suitable clot were measured after a 1-h treatment with rt-PA (60 kU/ml), and combined treatment with rt-PA and 2-MHz transcranial color-coded sonography (TCCS) (0.179 W/cm(2)) or 2-MHz transcranial Doppler (TCD) (0.457 W/cm(2)). With increased platelet count, the hydrodynamic resistance of the artificial clots increased, their histological appearance became more physiological, and lysis rates decreased. The most suitable clots consisted of 1.5-ml PRP, 2.0-ml PFP, and 0.5-ml boundary layer. Their lysis rates were 36.7 ± 7.8% (rt-PA), 40.8 ± 8.6% (rt-PA+TCCS), and 40.4 ± 8.3% (rt-PA+TCD). These systemic investigations were conducted for the first time. This protocol should be used for standardized sonothrombolysis investigations.

Endovascular treatment of chronic mesenteric ischemia.

Data regarding endovascular treatment of chronic mesenteric ischemia (CMI) are sparse. Angioplasty is often accompanied by early restenosis and the need of further interventions. Thus we present our own patients' data and review the recent literature. We retrospectively reviewed all endovascular CMI treatments performed from 2008 to 2012 (27 patients, 14 females, mean age 70 ± 9 years). Patients' data were retrieved from electronic health records. Patients' follow-up included routinely performed color-coded ultrasonography, and, if performed for other clinical reasons, computed tomography or angiography. In addition, data extracted from 11 studies focusing on endovascular CMI treatment were analyzed. Procedures were performed without clinical complications in all patients. Seven patients received pure angioplasty and 20 patients stent-assisted angioplasties using bare metal stents, respectively. Three patients died 3, 5 and 32 months after the intervention. Five patients underwent re-intervention (one early restenosis at day 4 after pure angioplasty with stent placement and four because of in-stent restenosis, 5 to 23 months after placement). Another patient was treated surgically because of stent occlusion and reoccurring abdominal angina 15 months after the intervention. The 11 studies found in the literature included 429 cases with 196 treatments of the coeliac trunk (truncus coeliacus = TC), 319 of the superior mesenteric artery (SMA) and 42 of the inferior mesenteric artery (IMA). Patency rates in the more recent studies were high with up to 80% within 1 year. Data of earlier studies report longer follow-up periods and indicate low patency rates after three years. Our 2-year patency rate of 50% is within the range of reported patency data. The presented data show that endovascular SMA treatment is a suitable and safe procedure in patients suffering from CMI, but long-term results are limited.

Morphological, hemodynamic, and clinical independent risk factors for anterior communicating artery aneurysms.

The pathogenesis of cerebral aneurysms still raises some controversies. The aim of this study was to identify morphological, hemodynamic, and clinical independent risk factors for anterior communicating artery (ACoA) aneurysm development. Computed tomography angiography and transcranial color-coded sonography were performed in 77 patients with a nonbleeding ACoA aneurysm and in 73 controls. Symmetry of A1 segments of the anterior cerebral arteries, angles between A1 and A2 segments, tortuosity, diameter, mean velocity (Vm), pulsatility index, and volume flow rate in both A1 segments were determined. Moreover, all study participants completed a survey on their medical history. Multivariate backward stepwise logistic regression analysis was performed to identify independent risk factors for ACoA aneurysm development. Smoking, hypertension, asymmetry of A1 segments, the angle between A1 and A2 segments, A1 segment diameter, Vm, pulsatility index, and volume flow rate turned out to be associated with the occurrence of ACoA aneurysms on univariate analysis. Multivariate analysis identified smoking (odds ratio, 2.036; 95% confidence interval, 1.277-3.245), asymmetry of A1 segments>40% (odds ratio, 2.524; 95% confidence interval, 1.275-4.996), pulsatility index (odds ratio, 0.004; 95% confidence interval, 0.000-0.124), and the angle between A1 and A2 segments≤100° (odds ratio, 4.665; 95% confidence interval, 2.247-9.687) as independent strong risk factors for ACoA aneurysm development. The risk of ACoA aneurysm formation is determined by several independent clinical, morphological, and hemodynamic factors. The strongest independent risk factors include smoking, asymmetry of A1 segments>40%, low blood flow pulsatility, and the angle between A1 and A2 segments≤100°.

Contrast-enhanced ultrasound and real-time elastography for the diagnosis of benign Leydig cell tumors of the testis - a single center report on 13 cases.

To describe sonomorphological features in testicular Leydig cell tumors (LCTs) with a special focus on contrast-enhanced ultrasonography (CEUS) and real-time elastography (RTE). In a series of 186 patients with testicular surgery for neoplastic disease, 13 benign LCTs (in 12 patients) were histopathologically diagnosed. Preoperatively, all patients had been examined with a standardized protocol (high-resolution grayscale and color-coded ultrasonography, CEUS). 5 patients underwent RTE. In CEUS, the filling time of the lesion was compared to that of 14 size-matched germ cell tumors (GCT). 10/13 LCTs had a size of < 10 mm, and a sharply demarcated hypoechoic appearance was typical (10/13). Color-coded ultrasonography detected signals in 8 lesions, while CEUS showed clear hypervascularization in all. LCTs had a significantly shorter filling time than GCTs (p < 0.0005), with 9/13 LCTs being completely filled within 4 s. In RTE, all 5 examined lesions were clearly "harder" than the surrounding testicular tissue. Contrary to some earlier reports, we could demonstrate marked hypervascularization in LCTs. This feature clearly allows for the differentiation of a small LCT from focal scars. However, it may only be visible on CEUS. In CEUS, LCT is suggested by the findings of a short filling time or by a circumferential vessel with a rapid centripetal filling, combined with a "harder" appearance in RTE. These features along with the findings of a small and peripherally situated hypoechoic tumor would justify an operative strategy with frozen section examination and possibly organ sparing surgery instead of orchiectomy.

Bilateral steno-occlusive disease of the middle cerebral artery: a case report with clinical-hemodynamic mismatch

Case report: A 37-year-old man was admitted for a right MCA transient ischaemic attack. He was smoker, obese, dyslipidaemic, with previous history of heroin addiction and cured B and C hepatitis virus infections. Brain magnetic resonance and cardiac evaluation were normal. Transcranial color-coded sonography (TCCS) showed >50% proximal right MCA stenosis and distal left MCA occlusion. Treatment with aspirin and statin was started. Three months later, TCCS revealed >70% right MCA stenosis and left MCA occlusion. Selective angiography confirmed the steno-occlusive disease. Cerebrospinal fluid analysis revealed increased protein levels and a normal cell count. Corticotherapy was started, but the patient did not complied. Bilateral occlusion of MCA was noticed on TCCS, one month later, being the patient asymptomatic. Pulsed arterial spin labelling (PASL) revealed a severe decrease of cerebral blood flow in the distal part of both MCA territories.

Transcranial color coded sonography: advanced approach using ultrasound fusion imaging

Background: Transcranial color-coded sonography (TCCS) is a well established method to study intracranial parenchymal and vascular structures. It is, however, limited by the need to insonate through available bone windows, resulting in oblique imaging planes, which can hinder easy allocation, particularly within the brain parenchyma and limit the opportunity for direct comparison with other imaging techniques. The objective of this study was to analyze the diagnostic yield of the ultrasound fusion imaging (UFI) technique using standard diagnostic approaches.

Prevalence of Intracranial Atherosclerosis among Patients with Coronary Artery Disease: A 1-Year Hospital-Based Study

Background: There are limited data on the prevalence of intracranial atherosclerotic disease (ICAD) in patients with coronary artery disease (CAD) worldwide and especially among Egyptians. The purpose of the present study was to determine the prevalence and correlates of ICAD in patients with CAD. Methods: From January 1, 2012 to January 1, 2013, we recruited 118 consecutive patients who had ischemic heart disease. All patients were assessed for vascular risk factors and the existence of stroke or transient ischemic attack (TIA) and were evaluated by extracranial and transcranial color-coded sonography. All patients underwent coronary angiography. Clinical, echocardiographic and angiographic variables were tested by univariate and multivariate analysis. Results: Out of 118 consecutive patients with CAD, intracranial disease was detected in 14 patients (11.9%). Eight patients (6.8%) had stenosis >50%, while 6 patients (5.1%) had stenosis <50%. The univariate analysis showed that the strongest variables associated with ICAD were the presence of recent or old stroke or TIA, followed by moderate or severe extracranial stenosis, and multivessel or left main CAD. Conclusion: We observed low prevalence (6.8%) of high-grade ICAD among Egyptian patients with CAD. Multivessel or left main CAD and moderate-to-severe extracranial carotid stenosis were the strongest predictors for the existence of ICAD among CAD patients.

Prevalence of Intracranial Stenosis in a Norwegian Ischemic Stroke Population

There is no data about prevalence of intracranial stenosis (IS) in Northern Europe. This study aimed to investigate the prevalence of symptomatic and asymptomatic IS in a Norwegian, community-based ischemic stroke population. In a prospective study, all ischemic stroke or transient ischemic attack (TIA) patients were screened for IS by transcranial color-coded sonography, magnetic resonance angiography, and/or computed tomography angiography. Patients with IS and any cardiac arrhythmia or other possible causes of IS than atherosclerosis were excluded. IS was defined as symptomatic if the infarct/symptoms were related to the territory of the stenotic artery. Risk factors for cerebrovascular disease were registered on admission. During an 18-month study period, 607 patients had an ischemic stroke or a TIA. Out of 69 patients with IS (11.4%), 7 patients were excluded because having atrial fibrillation, and IS of possible atherosclerotic etiology was therefore diagnosed in 62 patients (10.2%). IS was symptomatic in 45 patients (7.4%). Diabetes mellitus was the only risk factor significantly associated with symptomatic IS (odds ratio 2.39, 95% confidence interval [CI] 1.03-5.54, P=.04). IS occurs in approximately 10% and is symptomatic in about 7% of a Norwegian ischemic stroke/TIA population. Diabetes mellitus appears to be the major risk factor for IS.

Ocular Color-Coded Sonography – A Promising Tool for Neurologists and Intensive Care Physicians

Ocular color-coded duplex sonography (OCCS), when performed within the safety limits of diagnostic ultrasonography, is an easy noninvasive technique with high potential for diagnosis and therapy in diseases with raised intracranial pressure and vascular diseases affecting the eye. Despite the capabilities of modern ultrasound systems and its scientific validation, OCCS has not gained widespread use in neurological practice. In this review, the authors describe the technique and main parameter settings of OCCS systems toreduce potential risks as thermal or cavitational effects for sensitive orbital structures. Applications of OCCS are the determination of intracranial pressure in emergency medicine, and follow-up evaluations of idiopathic intracranial hypertension and ventricular shunting by measuring the optic nerve sheath diameter. A diameter of 5.7 - 6.0 mm corresponds well with symptomatically increased intracranial pressure (> 20 cmH2O). OCCS also helps to discriminate between different etiologies of central retinal artery occlusion - by visualization of a "spot sign" and Doppler flow analysis of the central retinal artery - and aids the differential diagnosis of papilledema. At the end perspectives are illustrated that combine established ultrasound methods such as transcranial color-coded sonography with OCCS.