Contrast-enhanced Transcranial Color-coded Sonography Research Articles

Application value of transcranial contrast-enhanced ultrasonography in evaluating middle cerebral artery stenosis.

To detect the display rate and flow velocity of intracranial circle of Willis (anterior, middle, and posterior cerebral arteries) with transcranial contrast-enhanced transcranial color-coded sonography (CE-TCCS), using digital subtraction angiography (DSA) as the golden diagnostic standard. We collected data from 104 patients with suspected stroke treated in our hospital between December 2019 and October 2021. The detection rate of the intracranial circle of Willis, anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) were analyzed based on routine TCCS and CE-TCCS data. Based on digital subtraction angiography (DSA) data, the degree of MCA stenosis was divided into mild stenosis (<50%), moderate stenosis (50-69%), severe stenosis (70-99%), and bilateral middle cerebral artery CE-TCCS examinations were performed. We evaluated MCA color blood flow on CE-TCCS, and recorded the peak systolic velocity (PSV), end-diastolic velocity (EDV), and mean flow velocity (MFV). The display rates of ACA, MCA, and PCA were significantly improved on the CE-TCCS, and the PSV, EDV and MFV of the MCA stenosis group were higher than those of the normal group. The flow velocity of each stenosis subgroup was increased compared to the normal group. The optimal cutoff values of normal and stenosis under the receiver operating characteristic (ROC) curve were PSV = 168.5 cm/s, EDV = 61.5 cm/s, and MFV = 110.5 cm/s. The optimal cutoff values for mild and moderate stenosis and for moderate and severe stenosis were PSV = 201.5 cm/s and 249.5 m/s, EDV = 95.2 cm/s and 141.5 cm/s, and MFV = 137.6 cm/s and 160.5 cm/s, respectively. PSV and MFV had the most significant sensitivity, specificity, and accuracy. Transcranial contrast-enhanced ultrasonography can improve the display rate of intracranial blood vessels and can accurately diagnose MCA stenosis.

Transcranial Color-Coded Sonography for the Detection of Cerebral Veins and Sinuses and Diagnosis of Cerebral Venous Sinus Thrombosis

This study aimed to determine the detection rate of transcranial color-coded sonography (TCCS) of cerebral veins and sinuses and to explore the diagnostic accuracy of TCCS for straight sinus (SS) and transverse sinus (TS) thromboses. The detection rates of cerebral veins and sinuses using TCCS and contrast-enhanced TCCS (CE-TCCS) were analyzed. The diagnostic accuracy of CE-TCCS was evaluated. Median time from symptoms to CE-TCCS was 10 (range, 1–150) d. The detection rate of bilateral basal veins of Rosenthal was 100% by CE-TCCS, followed by right TS (91.89%), SS (88.12%), left TS (74.59%) and vein of Galen (70.27%). Compared with magnetic resonance imaging/magnetic resonance venography, CE-TCCS showed 100% sensitivity and 96.3% specificity for SS thrombosis, 100% and 100% for right TS thrombosis and 100% and 94.4% for left TS thrombosis. In conclusion, CE-TCCS shows high identification rates of cerebral veins and sinuses and a high diagnostic accuracy for SS and TS thrombosis.

Preliminary application of contrast-enhanced transcranial color-coded sonography in subacute intracerebral hemorrhage

Objective To observe the ultrasonographic findings of patients with basal ganglia hemorrhage by transcranial color-code sonography (TCCS) and contrast-enhanced transcranial color-code sonography (CE-TCCS), and to evaluate the clinical value of TCCS and CE-TCCS in assessing the cerebral perfusion with basal ganglia hemorrhage. Methods Eighty-two patients with basal ganglia hemorrhage were selected, and hematoma was seen in 58 patients (70.7%). Forty-six cases of bilateral TCCS with clear display of basal ganglia through temporal window were selected. CE-TCCS was used to observe cerebral perfusion of edema zone, edema zone edge and peripheral brain parenchyma. Results The bilateral rate displayed by TCCS was 79.3%. Among 58 cases, 30 cases had ventricular compression, 14 cases had hematoma rupture into ventricle, 8 cases had midline displacement, and 10 cases had no complication change. The cerebral perfusion in edema areas around hematoma was reduced by CE-TCCS, but the degree of reduction was different. There were reduced in a step-like manner in the cerebral perfusion from edema zone and edema zone edge to peripheral brain tissue. Conclusions CE-TCCS is a new method for clinical diagnosis and monitoring the progress of treatments of cerebral hematoma. Key words: Ultrasonography, Doppler, transcranial; Contrast-enhanced ultrasound, transcranial; Cerebral hemorrhage

Diagnostic Transcranial Ultrasound Perfusion-Imaging at 2.5 MHz Does Not Affect the Blood-Brain Barrier

The purpose was to assess whether standard ultrasound (US) perfusion-imaging by means of contrast-enhanced transcranial color-coded sonography (TCCS) affects the blood-brain barrier (BBB) in patients with small-vessel disease (SVD). One week after a screening MRI to exclude a preexisting BBB disruption, unilateral TCCS phase inversion harmonic imaging (PIHI) was performed in an axial diencephalic plane after intravenous bolus application of 2.5 mL SonoVue (IGEA, Bracco, Italy). Magnetic resonance imaging (MRI) was performed immediately after US. In five patients, PIHI was performed applying a mean mechanical index (MI) of 0.7 ± 0.1 for a time period of 2.5 min. MRI was started 12 ± 2 min after US contrast injection. Comparisons of initial and post-US MRI by four blinded readers did not show any signs of BBB disruption. It is concluded that standard contrast-enhanced US perfusion imaging in patients with SVD did not lead to MRI-detectable BBB changes. This gives further evidence for safety of diagnostic US. Future investigations with larger sample sizes and higher-field MRI might give further insights into potential bioeffects of diagnostic, as well as therapeutic, contrast-enhanced transcranial US. (E-mail: jan.jungehuelsing@charite.de)

Assessment of Dural Arteriovenous Fistulae by Transcranial Color-Coded Duplex Sonography

To study hemodynamic changes and to determine the value of contrast-enhanced transcranial color-coded sonography (TCCS) for the evaluation of dural arteriovenous fistulae (DAVF) before and after transcatheter embolization. Twenty-four patients (mean age 61+/-11 years) with occipitally located DAVF were studied with contrast-enhanced TCCS using the transtemporal bone window in transverse-axial and coronal insonation planes. Blood flow velocity measurements of all depictable basal cerebral veins and sinuses were obtained before and after transcatheter embolization. Pretreatment and post-treatment flow velocity values were compared. Four of the 24 patients (17%) could not be studied because of an insufficient temporal bone window. In all remaining patients (n=20), draining veins/sinuses could be identified because of pathologically increased blood flow velocities with peak systolic flow velocities of >50 cm/s. Of the 27 draining vessels depicted by DSA, TCCS correctly identified 25 (93%): the basal vein (3 of 3), the straight sinus (3 of 3), the superior sagittal sinus (1 of 3), the transverse sinus (9), the sigmoid sinus (4), and the superior petrosal sinus (5/5). However, TCCS failed to depict supplementary drainage via cortical veins. After transcatheter embolization, mean reduction of blood flow velocity was 44+/-18% (P<0.01) compared with pretreatment values. Contrast-enhanced TCCS is a promising technique for monitoring embolization of DAVF, follow-up after complete fistula occlusion, and may even be useful as a screening tool in patients with pulsatile tinnitus.

Diagnosis of middle cerebral artery occlusive lesions with contrast-enhanced transcranial color-coded real-time sonography in acute stroke

It is useful to evaluate the occlusive lesions of middle cerebral artery (MCA) occlusion with transcranial color-coded real-time sonography (TCCS). However, TCCS criteria for locating the site of the MCA occlusion has, as yet, remained unclear. The aim of the present study was to establish TCCS criteria for MCA occlusive lesions. We prospectively performed contrast-enhanced TCCS (CE-TCCS) in 75 consecutive acute stroke patients within 24 h of digital subtraction angiography. Patients were divided into four groups: occlusion of the MCA stem (MO group, n=12); occlusion of the MCA branch (MBO group, n=10); stenosis of the MCA stem (MS group, n=9); and no occlusive or stenotic lesions (control group, n=44). The following parameters were measured: peak systolic velocity (PSV) and end diastolic velocity (EDV) of bilateral MCA stems, and ED-ratio (the side-to-side ratio of the EDV). We establish the CE-TCCS criteria for MCA occlusive lesions using the sensitivity-specificity curve analysis. A PSV of 170 cm/s distinguished MCA stenosis from other groups (positive and negative predictive values and the accuracies were 100%, 99.0% and 99.1%, respectively). An EDV of 26 cm/s differentiated MO or MBO from the other groups (positive and negative predictive values and the accuracies were 84.6%, 100% and 96.5%, respectively). An ED-ratio of 2.5 discriminated MO from the MBO group (positive and negative predictive values and the accuracies were 88.9%, 85.7% and 87.5%, respectively). Measurement of MCA stem flow velocity with CE-TCCS can identify MCA stem stenosis and occlusion, as well as MCA branch occlusion.

Transcranial color-coded sonography for vertebrobasilar disorders in end-stage renal disease

Because vertebrobasilar arterial disorders seem to be common in patients with end-stage renal disease, a neuroradiological evaluation of vertebrobasilar circulation is necessary for patients with possible vertebrobasilar insufficiency. In three patients on maintenance hemodialysis, contrast-enhanced transcranial color-coded real-time sonography (TCCS) through a suboccipital window delineated occlusion of bilateral vertebral arteries with reversal of the basilar artery, reversal of the left vertebral artery mimicking left subclavian steal phenomenon, and dolichoectasia of the basilar artery and bilateral vertebral arteries with signals of turbulent flow. TCCS has several advantages over computed tomographic angiography and magnetic resonance angiography, including the direction of blood flow, handy performance even during hemodialysis, and contrast agent free from nephrotoxicity. Thus, TCCS is useful in the evaluation of intracranial circulation in patients with end-stage renal disease.

Observation on the integrity of the blood-brain barrier after microbubble destruction by diagnostic transcranial color-coded sonography.

To investigate alteration of the blood-brain barrier from ultrasonic contrast agent destruction by diagnostic transcranial color-coded sonography using gadolinium-enhanced magnetic resonance imaging. Healthy male volunteers received 10 mL (400 mg/dL) of Levovist (SH U 508A; Schering AG, Berlin, Germany; n = 6) or 3 mL of Optison (FS069; Mallinckrodt Inc, St Louis, MO; n = 4) followed by 0.3 mmol/kg magnetic resonance imaging contrast agent (Magnevist; Schering) intravenously. Then transcranial color-coded sonography was performed with a conventional color duplex sonographic system, which insonated the brain in a slightly angulated axial plane with temporal average intensity of less than 700 mW/cm2 or acoustic pressure amplitude of less than 2.69 MPa, attenuated by the temporal bone. Before, immediately after, and 2 hours after insonation, T1-weighted axial magnetic resonance imaging was performed. All magnetic resonance images were individually assessed, and T1 signal intensities were measured in 2 regions of interest in both hemispheres at the 3 time points. No focal contrast enhancement or damage to the brain and no significant difference between T1 signal intensities in the right and left brain regions could be detected during early or late phases when either ultrasonic contrast agent was used. This bioeffects study gives further evidence of the safety of ultrasonic destruction of Levovist and Optison microbubbles by diagnostic transcranial color-coded sonography. However, more subtle local effects may have been missed by gadolinium-enhanced magnetic resonance imaging. Studies on diagnostic contrast-enhanced transcranial color-coded sonography as well as microbubble-based drug delivery strategies should consider ultrasonic contrast agent microbubble characteristics and concentration as well as ultrasound transmission power levels.

Contrast-enhanced transcranial color-coded sonography in acute hemispheric brain infarction.

The aim of the present study was to investigate the diagnostic potential of contrast-enhanced transcranial color-coded real-time sonography (CE-TCCS) in otherwise ultrasound-refractory acute stroke patients with an ischemia in the territory of the middle cerebral artery (MCA). Furthermore, correlations of CE-TCCS findings with clinical, angiographic, and CT results were investigated. In 90 acute stroke patients with inadequate insonation conditions in unenhanced transcranial color-coded real-time sonography (TCCS) examinations, CE-TCCS, clinical, angiographic, and CT examinations were performed within 12 hours, 36 hours (CE-TCCS only), and 1 week after onset of clinical symptoms. A CT angiography (CTA) as reference method was available in 39 individuals. After application of a galactose-based echo-enhancing agent, the portion of conclusive ultrasound examinations of the MCA, as manifested by an MCA occlusion, decreased or increased flow velocity (FV), and symmetrical MCA FV, was evaluated. CE-TCCS findings on admission and during follow-up were correlated with infarction size as demonstrated on follow-up CT, and clinical findings were assessed by use of the European Stroke Scale. Adequate diagnosis was achieved in 74 of 90 patients (82%) by the use of echo contrast agents. MCA occlusion or reduction of MCA FV was found in 20 and 27 patients, respectively. MCA occlusion was confirmed by CTA in 17 cases. In one individual, false-positive diagnosis of MCA occlusion was made according to ultrasound criteria. In 5 patients with MCA occlusion, vessel recanalization was observed during follow-up; 15 of 27 patients with decreased flow velocities showed normalization after the third examination that was associated with a significantly better clinical outcome (P<0.0001). Furthermore, MCA occlusion or decreased FV in the first 12 hours were associated with significantly larger infarctions in the MCA territory compared with normal CE-TCCS findings (P<0.0001). CE-TCCS enables adequate diagnosis in approximately 80% of acute hemispheric stroke patients with insufficient unenhanced TCCS examinations. It is a reliable diagnostic tool regarding MCA mainstem and branch occlusions. Because this method conveys useful information concerning cerebral tissue and clinical prognosis, it may be useful to identify those patients who benefit most from local or intra-arterial thrombolytic therapy.

Cerebral arteriovenous transit time (cTT): a sonographic assessment of cerebral microcirculation using ultrasound contrast agents

:— Transcranial color-coded sonography (TCCS) has been used to investigate major brain-supplying arteries, draining veins and brain parenchyma. Here, we describe a contrast-enhanced TCCS analysis of cerebral arteriovenous transit time (cTT) as a measure of cerebral microcirculation. We evaluate its reproducibility and its correlation with clinical impairment of brain function and neuropsychological tests. A total of 27 patients with cerebral microangiopathy and 30 healthy controls were examined. CTT is defined by the time an ultrasound contrast agent requires to pass from the P2-segment of the posterior cerebral artery to the vein of Galen. This was measured by comparison of power Doppler intensity in two off-line defined regions of interest. Serial intraindividual cTT measurements within several min showed a good reproducibility of this parameter. cTT was significantly longer in patients with cerebral microangiopathy than in controls (Mann–Whitney U test, p < 0.001) and related to cognitive impairment measured by the Mini-Mental-State examination. We conclude that it is a quick and reliable parameter related to increased vascular resistance of the microcirculation or a rarefaction of microvessels. Further studies are needed to show the sensitivity and specificity of cTT in the diagnosis of small vessel disease and the interference of important circulation factors, such as heart failure or blood viscosity.

Contrast-enhanced transcranial color-coded duplex sonography: efficiency and validity.

To evaluate the diagnostic efficiency and accuracy of contrast-enhanced transcranial color-coded sonography (CE-TCCS). TCCS is hampered by insufficient ultrasonic penetration in 20% of cerebrovascular patients. In 47 patients whose basal arteries could not be assessed adequately, 59 TCCS examinations were performed before and after administration of the ultrasonic contrast agent (CA) Levovist. The assessability of different basal cerebral arteries after CA administration was evaluated off-line. Angiographic records were available from 11 patients. Satisfactory investigation of the middle cerebral artery, the anterior cerebral artery, the P1 and P2 segments of the posterior cerebral artery, and the supraclinoid portion of the internal carotid artery siphon was possible in 5.1%, 28.8%, 35.6%, 55.9%, and 47.5% of patients before, and in 84.7%, 91.5%, 93.2%, 94.5%, and 93.2% of patients after contrast enhancement. Stenoses or occlusions of basal cerebral arteries were registered in 28 patients (60%). CE-TCCS diagnosis was confirmed by digital subtraction angiography or magnetic resonance angiography in 10 of the 11 patients, leading to positive and negative predictive values of 0.86 and 1.00. Contrast enhancement improves the diagnostic potential of TCCS significantly in patients with temporal bone window failure, and proved to be a reliable method for detecting middle cerebral artery and siphon occlusion.

Diagnosis and Monitoring of Middle Cerebral Artery Occlusion with Contrast-Enhanced Transcranial Color-Coded Real-Time Sonography in Patients with Inadequate Acoustic Bone Windows

Transcranial color-coded real-time sonography (TCCS) is an emerging diagnostic technique that allows noninvasive imaging of intracranial vessels within parenchymal structures. However, in some patients, transcranial ultrasound is particularly hindered by insufficient ultrasound penetration through the temporal bone. The present study evaluates whether or not application of an echo-contrast agent in ultrasound-refractory patients with middle cerebral artery (MCA) trunk occlusion enhances image acquisition enough to yield accurate diagnoses. Contrast-enhanced (CE) TCCS examinations, computed tomography scans and angiographic studies were performed in 20 patients with clinical symptoms suggestive of MCA occlusion within 12 h of the onset of symptoms. For comparison, 20 control persons without history or clinical signs for cerebrovascular diseases were examined using CE-TCCS. In none of the patients or control subjects did unenhanced TCCS investigations depict any color-coded vascular signal of an intracranial vessel. After application of 9 mL of 400 mg/mL galactose-based microbubbles, CE-TCCS was performed. In subjects with MCA occlusion, CE-TCCS examinations were repeated within 24 h, 48 h and 5 days after stroke. In stroke patients ( n = 20), CE-TCCS showed an occluded MCA main stem in 11 patients, and this vessel was clearly demonstrable on the unaffected side. On the affected side, the posterior cerebral artery (PCA) and anterior cerebral artery (ACA) could be visualized in 8 of 11 subjects; in 3 patients, at least 1 of these vessels was detectable. Angiographic studies confirmed the diagnosis of MCA trunk occlusion in all 11 individuals. In follow-up investigations, 3 stroke patients had angiographic and CE-TCCS examinations consistent with vessel reperfusion. Nine stroke patients had a patent MCA shown in angiographic and CE-TCCS examinations. In the control group, the MCA trunk could be visualized in all subjects by CE-TCCS. CE-TCCS is a sensitive and specific ultrasound method for the diagnosis of MCA trunk occlusion that overcomes the anatomical hindrance of inadequate acoustic bone window. This technique may help to identify patients suitable for thrombolytic therapies and monitor their response.

Insufficient and absent acoustic temporal bone window: Potential and limitations of transcranial contrast-enhanced color-coded sonography and contrast-enhanced power-based sonography

The aim of this study was to investigate the diagnostic potential of contrast-enhanced transcranial color-coded sonography (CE-TCCS) and contrast-enhanced transcranial power-based sonography (CE-TPS) in patients with insufficient or absent acoustic bone windows (IABW). Due to temporal bone thickness, the basal cerebral circulation could not be insonated in 21 of 172 patients using unenhanced transcranial color-coded real-time sonography (TCCS) and transcranial power-based sonography. Additional CE-TCCS and CE-TPS were performed after application of 400 mg/ml galactose microbubble suspension. In both modalities, the use of echo-contrast agents allowed visualisation of the first segment of the middle cerebral artery (MCA) in all patients. The A1 segment of the anterior cerebral artery (67% in CE-TCCS; 81% in CE-TPS), P1 segment of the posterior cerebral artery (71% in CE-TCCS; 76% in CE-TPS) and the basilar artery (48% in CE-TCCS; 67% in CE-TPS) were depictable in the majority of the examinations. The M3 (5% in CE-TCCS; 33% in CE-TPS; p < 0.05), P2 (24% in CE-TCCS; 71% in CE-TPS; p < 0.005), P3 segments (0% in CE-TCCS; 43% in CE-TPS; p < 0.005) and the posterior communicating artery (5% in CE-TCCS; 33% in CE-TPS; p < 0.05) were detected in a significantly greater proportion of subjects using power Doppler. In conclusion, CE-TCCS and CE-TPS appear to be sensitive ultrasonic tools that provide reliable data regarding the basal cerebral circulation in patients with IABW. Furthermore, CE-TPS offers advantages over CE-TSSC in the identification of small-caliber arteries and vessels that run at unfavorable angels to the ultrasound beam. Both methods can overcome hyperostosis of the skull that is a major hindrance in transcranial ultrasonography, and may be helpful in the diagnosis of occlusive diseases of intracranial vessels.

Transcranial Color‐Coded Real‐Time Sonography of Intracranial Veins

Sonographic findings in patients with superior sagittal sinus thrombosis were compared to those in healthy adults. Two patients with angiographically verified superior sagittal sinus thrombosis were examined by transcranial color-coded real-time sonography (TCCS) after intravenous application of a pulmonary stable ultrasound contrast agent. For comparison, 10 patients without venous pathology had contrast-enhanced TCCS; in addition, 30 healthy adults had plain TCCS to determine the identification rate for deep and superficial venous segments and to define normal values of venous blood flow velocities. The straight sinus was identified in 22 of 30 healthy subjects by plain TCCS, and in 9 of 10 patients by contrast-enhanced TCCS. The mean peak and angle-corrected blood flow velocity was 19.1 +/- 7.1 cm/sec. The superior and inferior sagittal sinuses were identified by contrast-enhanced TCCS in 2 and 1 subjects, respectively; they were never seen on plain TCCS. In the 2 patients with sagittal sinus thrombosis a distinct increase of blood flow velocity was recorded from the straight sinus (83 and 92 cm/sec), most likely reflecting collateral circulation. These preliminary data indicate that TCCS and particularly contrast-enhanced TCCS permit identification and blood flow measurements within the deep and occasionally, the superficial venous system. TCCS may contribute to an assessment of hemodynamic repercussions of venous thrombosis and may indicate the risk of venous infarction and hemorrhage.

Vascularization of Primary Central Nervous System Tumors: Detection with Contrast-Enhanced Transcranial Color-Coded Real-Time Sonography

Vascularization of Primary Central Nervous System Tumors: Detection with Contrast-Enhanced Transcranial Color-Coded Real-Time Sonography