Contrast-enhanced Transcranial Color-coded Duplex Sonography Research Articles

Evaluation of Contrast-enhanced Transcranial Color-coded Duplex Sonography (CE-TCCD) Applied in Stroke Patients with Intracranial Collateral Circulation.

CE-TCCD was applied to 70 patients (51 males and 19 females) who presented with ischemic symptoms, to detect the openness of the anterior communicating artery (ACoA) and posterior communicating artery (PCoA) of the Willis ring before Computed Tomography angiography (CTA) or Magnetic Resonance Angiography (MRA) examination. The results from CETCCD is used to compare with CTA/MRA result to verify the diagnostic efficacy. Forty-one communicating artery openings were detected by CE-TCCD, among which 37 were PCoA and 4 were ACoA. Among the 70 patients, 23 of 70 patients indicated severe stenosis within intracranial and/or extracranial arteries. Eighteen out of the 23 patients showed collateral circulation, accounting for 78.3% (18/23). Moderate stenosis were 23 cases in total, in which 7 cases showed collateral circulation, accounting for 30.4% (7/23). Slight stenosis were 24 cases in total, none of which showed collateral circulation. In the stroke patients with limited bone windows, CE-TCCD can evaluate intracranial collateral circulation.

Contrast‐Enhanced Transcranial Color‐Coded Duplex Sonography Criteria for Basilar Artery Stenosis

The aim of this study is to assess contrast-enhanced transcranial color-coded duplex sonography (CE-TCCS) diagnosis of basilar artery (BA) stenosis. CE-TCCS and cerebral angiography were performed in 120 consecutive patients. The patients were angiographically divided into five groups: (1) intracranial arteries (ICA) stenosis but no BA stenosis as intracranial stenosis (ICS) group, (2) both ICA and BA stenoses as internal carotid arteay and basilar arteay stenoses (IBS) group, (3) BA stenosis as basilar artery stenosis (BAS) group, (4) BA occlusion as basilar artery occlusion (BAO) group, and (5) no arterial lesions as Control group. We compared the peak systolic flow velocity (PSV) of BA using CE-TCCS. PSV was highest in the BAS group (n= 9, 206.1 +/- 118.6 cm/sec), followed by the ICS (n= 27, 74.9 +/- 36.1 cm/sec) and Control (n= 70, 58.2 +/- 17.3 cm/sec) groups. IBS group had two patients (PSV: 102 cm/sec and 167 cm/sec). Sensitivity-specificity curve analysis revealed a cutoff PSV of 120 cm/sec to distinguish the BAS group from other groups, and then we calculated sensitivity of 100%, specificity of 95%, positive predictive value of 64%, negative predictive value of 100%, and accuracy of 95%. Measurement of PSV of the BA using CE-TCCS is useful for the identification of BA stenosis.

Contrast-Enhanced Transcranial Color-Coded Duplex Sonography Versus Computed Tomography and Magnetic Resonance Angiography in the Follow-up of Basilar Stenting

The annual risk of stroke in patients with basilar artery stenosis is 2.5% to 11%, and even despite aggressive medical treatment, the prognosis of basilar artery thrombosis is fatal. For these reasons, invasive therapeutic approaches have been developed for cases of stroke due to vertebrobasilar circulation stenosis and occlusion. 1 In specialized centers, both intra-arterial thrombolysis performed in cases of basilar occlusion and intracranial stenting nowadays are becoming available suitable procedures to restore vascularization in cases of vertebrobasilar stenosis. 2,3 Nonetheless, restenosis is the major complication, with rates of 30% to 41% and an overall annual periprocedural complication rate of 6.6%. 4,5 It is therefore important to perform an accurate postprocedural follow-up to determine stent lumen patency. Conventional digital subtraction angiography (DSA) is still the most sensitive technique for visualizing the residual lumen after stenting, but it is invasive and not free of complications. Postprocedural follow-up is then usually performed by computed tomographic angiography (CTA) or magnetic resonance angiography (MRA). These techniques are both expensive and have limitations due to stent-induced artifacts, which may hide the residual lumen. 2 Transcranial color-coded duplex sonography (TCCD) has been a well-established diagnostic tool for visualization of the basal cerebral arteries since the early 1990s, although it is limited by the quality of the temporal acoustic bone window.6 With the introduction of sonographic contrast agents, vessel visualization has become easier and feasible in daily practice, at the bedside of the patient, with low costs and excellent results. 7 We report a case of a patient with a stroke and basilar artery stenosis who underwent a stenting procedure and follow-up studies with MRA, CTA, DSA, and TCCD.

Intracranial Aneurysms Treated With Endovascular Coils

Because neck recurrence after endovascular treatment of intracranial aneurysms (IAs) is not uncommon, surveillance to assess long-term stability of occlusion is clearly important. This study evaluated unenhanced and contrast-enhanced transcranial color-coded duplex sonography (TCCS) in detecting refilling of IAs treated with detachable coils. Patients with coiled IAs were imaged before and after contrast enhancement. The results were compared with those of a surveillance digital subtraction angiogram (DSA). The operator was blinded to the results of the DSA. Aneurysms were classed as either occluded or with residual flow and quantified as minor, moderate, or extensive. There were 208 studies performed in 4 neurosurgical centers. Of those, 141 studies received ultrasonic contrast enhancement with Levovist, and 68 had an additional enhanced study with SonoVue. We excluded 44 studies. Of the 164 unenhanced studies, TCCS correctly identified 52 of 67 cases defined as completely occluded by DSA (sensitivity 78%; specificity 77%), 13 of 50 aneurysms with minor refilling (sensitivity 26%; specificity 88%), 15 of 27 aneurysms with moderate refilling (sensitivity 56%; specificity 95%), and 9 of 20 aneurysms with extensive refilling (sensitivity 45%; specificity 100%). TCCS correctly identified an additional 10 aneurysms with minor refilling after Levovist enhancement and 3 with SonoVue. Both SonoVue and Levovist enhancement identified an additional 1 aneurysm with moderate refilling and 3 with extensive refilling. TCCS could be used to selectively monitor IAs, which would reduce the requirement for long-term invasive monitoring. The detection of neck refilling is improved with contrast enhancement.

Noninvasive Assessment of the Circle of Willis in Cerebral Ischemia: The Potential of CT Angiography and Contrast-Enhanced Transcranial Color-Coded Duplexsonography

Thirty-four patients with acute hemispheric ischemic strokes underwent both CT angiography and contrast-enhanced transcranial color-coded duplexsonography (TCCD) to study the effectiveness of the combined noninvasive techniques for evaluation of the circle of Willis. In 3/34 patients, CT angiography and contrast-enhanced TCCD demonstrated middle cerebral artery (MCA) occlusion, in 5 others MCA stenosis. A severe posterior cerebral artery stenosis was missed by CT angiography. In 8 patients, contrast-enhanced TCCD failed because of poor bone windows. In these patients, CT angiography was normal. CT angiography and contrast-enhanced TCCD are complementary noninvasive diagnostic tools. Disagreements between the diagnostic findings of these methods still need further evaluation by digital subtraction angiography.

Transcranial color-coded duplex sonography.

Transcranial color-coded duplex sonography (TCCS) enables the reliable assessment of intracranial stenoses, occlusions, and cross-flow through the circle of Willis without using potentially hazardous compression tests. Transpulmonary ultrasound contrast agents (UCAs) increase the number of conclusive TCCS investigations, which suggests that UCAs may provide the conclusive evaluation of intracranial arteries in most patients with ischemic cerebrovascular disease. Further, contrast-enhanced TCCS may become an important tool both for the management of acute ischemic stroke by assessing intracranial hemodynamics and the displacement and diameter changes in supratentorial ventricles. TCCS is useful for the detection and monitoring of intracranial vasospasm, may visualize larger supratentorial hematomas with subcortical location and hemorrhagic transformation of ischemic infarcts, and provides the incidental detection of cerebral aneurysms and arteriovenous malformations. Second-generation UCAs and new ultrasound machines are very likely to further increase the frequency of conclusive TCCS studies. Power-based three-dimensional, contrast-enhanced TCCS is an important further development, which would make the method much less operator dependent. Site-targeted UCAs appear to provide a new and exciting method for ultrasonic diagnosis and management of patients with ischemic cerebrovascular disease.

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.

Assessment of intracranial venous hemodynamics in normal individuals and patients with cerebral venous thrombosis.

Despite ongoing improvements in noninvasive imaging techniques, transcranial color-coded duplex sonography (TCCS) has so far been used only on a limited basis in patients with cerebral venous thrombosis. We evaluated the diagnostic value of both noncontrast and contrast-enhanced TCCS by comparing normal volunteers and patients with acute cerebral venous thrombosis. In 75 healthy volunteers (aged 45.8+/-17.4 years), normal values for the deep cerebral veins (DCVs) and the posterior fossa sinuses were established by transtemporal insonation. Eight patients with cerebral venous thrombosis were assessed by TCCS, through which the hemodynamics of the DCVs were measured, and the patients were followed-up over a period of between 33 and 387 days after examination. MR angiography served as the "gold standard" technique for confirming the venous status in all 8 patients. No side differences in flow velocities were detected in the paired venous structures in normal volunteers. As indirect signs of (and diagnostic criteria for) cerebral venous thrombosis, pathologically increased flow velocities or significant side differences in the DCVs were registered in 5 of the 8 patients; the other patients showed nonsignificant increases in flow velocity which decreased over time. During follow-up, the status of the posterior fossa sinuses could be diagnosed correctly in seven patients after contrast enhancement when these results were compared with those of venous MR angiography. In 1 patient, a partial recanalization was mistakenly diagnosed as an occlusion. TCCS allows a reliable evaluation of the major DCVs and posterior fossa sinuses. The anterior and mid portions of the superior sagittal sinus and cortical veins cannot be assessed. Increased venous blood flow velocity can be used as an indirect criterion for indicating a cerebral venous thrombosis. Clinical recovery coincided with decreases in blood flow velocity in the series of patients investigated in this study.

Diagnostic impact and prognostic relevance of early contrast-enhanced transcranial color-coded duplex sonography in acute stroke

Diagnostic impact and prognostic relevance of early contrast-enhanced transcranial color-coded duplex sonography in acute stroke

Power-based versus conventional transcranial color-coded duplex sonography in the assessment of the vertebrobasilar-posterior system

Power Doppler (PD) is a new ultrasonic technique that allows improved visualization of vascular structures. The aim of our study was to compare the ability of power-based transcranial color-coded duplex sonography (p-TCCS) to conventional transcranial color-coded duplex sonography (TCCS) and contrast-enhanced transcranial color-coded duplex sonography (CE-TCCS) in the visualization of the vertebrobasilar system. In 41 patients without cerebrovascular diseases, we evaluated and compared identification rates of major vessels of the vertebrobasilar system and branches using both ultrasound (US) techniques. In 9 patients we performed additional CE-TCCS studies. Furthermore, the possibility of visualization of the basilar artery (BA) and the vertebral arteries (VA) over the long course was investigated. TCCS and p-TCCS were equally effective at showing the VAs (74 of 82 v 80 of 82), proximal segments of the BA (37 of 41 v 41 of 41) and P1 segments of the posterior cerebral artery (PCA) (72 of 82 v 82 of 82). However, the diagnostic sensitivity of p-TCCS was significantly better for peripheral segments of the PCA (34 of 82 v 68 of 82 for P2 and 2 of 82 v 24 of 82 for P3 segments, P<.001), distal parts of the BA (25 of 41 v 38 of 41, P<.01), the anterior inferior cerebellar artery (AICA) (0 of 82 v 8 of 82, P<.0001) and the posterior inferior cerebellar artery (PICA) (13 of 82 v 34 of 82, P<.001). Furthermore, using transtemporal coronal sections, p-TCCS allowed visualization of the BA over the complete course in connection with one or both VAs in half of the patients. Except P2 and P3 segments, CE-TCCS did not increase resolution compared with p-TCCS. PD offers significant advantages over color-coded sonography in imaging the BA and small-calibre vessels like the PICA, AICA, and peripheral segments of the PCA. P-TCCS in combination with TCCS increases the diagnostic sensitivity to identify vascular structures of the vertebrobasilar system.