Color-coded Sonography Research Articles

Possibilities of transcranial color-coded sonography in pathology of deep brain veins in children

A study in children with headaches associated mainly with venous hemodynamic disturbances has been performed. The role of cerebral venous disturbances has been defined in children with structural cerebral abnormalities: craniovertebral junction anomalies (Chiari abnormalities I) and hypoplasia of cerebral venous sinuses. Disturbances of cerebral hemodynamics revealed by ultrasonic methods determine the management of patients with different cerebral venous abnormalities.

Ipsilateral evaluation of the transverse sinus: Transcranial color-coded sonography approach in comparison with magnetic resonance venography

The ultrasound examination of intracranial venous structures by transcranial color-coded sonography (TCCS) is a validated and standardized application. Similarly some intracranial venous sinuses are known for their relatively low insonation rate, as straight sinus (SRS) and transverse sinus (TS), ranging from 35% to 73%. The relatively high frequency of hypoplasia of TS can partially take account for these data. The aim of this study is to evaluate the feasibility of this approach in a standard TCCS examination, in comparison with magnetic resonance (MR) findings by using the Virtual Navigator system. The standardized approach to the TS was a contralateral insonation, starting to the SRS plane and angulating downwards the probe. In this way it is possible to insonate the proximal segment of the contralateral TS. We proposed a new approach with an extreme downwards tilting and a slow opposite angulation of the probe for examining the ispilateral TS. Forty consecutive subjects were chosen among patients who underwent standard TCCS examinations at our lab and had a suitable temporal acoustic window, and a recently performed MR venography. The contralateral TS insonation rate was compared with the ipsilateral one. The insonation rate was 61/80 (76.25%) for the contralateral TS and 75/80 (93.75%) for the ipsilateral approach. Two of 5 not detectable TS were aplasic in MR venography and the others were not identified by a poor acoustic window. The ipsilateral approach could be associated to the contralateral standard study for insonating the TS.

Perfusion status of the stroke-like lesion at the hyperacute stage in MELAS

Hypoperfusion on single-photon emission computed tomography (SPECT) of the stroke-like lesion (SLL) at the hyperacute stage of mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) is considered to be a supportive evidence of the mitochondrial angiopathy theory. Our objectives were to examine whether other neuroimages, especially transcranial color-coded sonography (TCCS), done at the hyperacute stage of stroke-like episode (SLE) is consistent with hypoperfusion of the SLL. We reviewed the magnetic resonance imaging (MRI), SPECT, cerebral angiography, and TCCS of a patient with MELAS syndrome, all of which were performed at the hyperacute stage of one SLE. MRI on the 1st day post SLE showed right temporoparietal lesion with vasogenic edema. SPECT on the 2nd day showed focal decreased uptake of technetium-99m hexamethylpropyleneamine oxime (99mTc-HMPAO) in the same region, but cerebral angiography and TCCS on the 3rd day showed increased regional cerebral blood flow (rCBF) and distal arteriole dilation in the same region. TCCS can delineate increased rCBF of the SLL at the hyperacute stage of SLE. We propose that the discrepancy between the decreased 99mTc-HMPAO uptake and increased rCBF might be caused by mitochondrial dysfunction. The phenomenon of “hypoperfusion” on SPECT might be caused by cell dysfunction but not decreased rCBF. We suggest that SPECT can be complemented by angiography and TCCS in future studies to delineate the perfusion status of SLLs.

The retrobulbar spot sign in sudden blindness – Sufficient to rule out vasculitis?

Summary Introduction Sudden retinal blindness is a common complication of temporal arteritis (TA). Another common cause is embolic occlusion of the central retinal artery (CRA). The aim of this prospective study was to examine the diagnostic value of hyperechoic material in the CRA for exclusion of vasculitis as a cause. The authors used orbital color-coded sonography (OCCS) for the detection of hyperechoic material. Materials and methods Twenty-four patients with sudden visual loss were included in the study after opthalmoscopic exclusion of other causes (e.g. vitreous bleeding, retinal detachment). Parallel to routine diagnostic workup OCCS was performed in all patients. Results 7 patients with the diagnosis of TA presented with different degrees of hypoperfusion in the CRA without hyperechoic material (referred to as a “spot sign”) detected by OCCS. Diagnostic workup in the remaining 17 patients did not reveal any signs of TA. The hyperechoic spot sign was visible in 10 of 12 patients (83%) with embolic CRA occlusion. Altogether the frequency of the spot sign in this group was 59%. Detection of embolic CRAO using the spot sign had a sensitivity of 83% and a specificity of 100%. The missing spot sign in patients with TA was a highly specific finding (p-value 0.01). Conclusions The “spot sign” is a highly specific finding, and its detection excludes the diagnosis of temporal arteritis in patients with sudden blindness. The finding of a spot sign helps prevent patients from receiving long-term steroid treatment, or an invasive temporal artery biopsy, with its immanent risks.

Chronic cerebrospinal venous insufficiency in patients with multiple sclerosis: A case-control study from Iran

Chronic cerebrospinal venous insufficiency (CCSVI) is a newly suggested cause for multiple sclerosis (MS) detected by color-coded Doppler sonography. Our aim was to evaluate the relationship between CCSVI and MS compared to the control group. The study was performed on 84 MS patients and 115 healthy subjects. The presence of at least two of the extra- and/or intra-cranial Zamboni's criteria was considered positive for evidence of CCSVI. Although the total number of MS patients with any detectable CCSVI criterion was significantly higher than the controls (22.6% vs. 10.4%, P = 0.019), only one out of 84 patients fulfilled the Zamboni's criteria (1.2% vs. none, P = 0.422). Our results do not support the presence of a relationship between MS and CCSVI criteria defined by Zamboni.

Evaluation of very early recanalization after tPA administration monitoring by transcranial color-coded sonography

Summary Background/aims Cerebrovascular ultrasonography was useful clinically for evaluating cerebral hemodynamics rapidly and in real-time for patients with acute ischemic stroke. We analyzed if the patients had early recanalization or not using transcranial color-coded sonography (TCCS) in order to evaluate the usefulness of real-time monitoring in systemic thrombolysis. Methods Subjects were patients who had acute ischemic stroke with intravenous tissue plasminogen activator (tPA) within 3 h from onset. We evaluated occlusion of intracranial arteries from transtemporal or suboccipital window by TC-CFI with Thrombolysis in Brain Ischemia (TIBI) flow-grading system and monitored residual flow in real-time every 15 min until 120 min after the t-PA bolus. Results We could monitor residual flow in 5 patients who had good echo windows (4 male, mean age; 60.8 ± 6.4 years). Two patients had proximal occlusion of the middle cerebral artery (MCA), one patient had distal occlusion of MCA, one patient had M2 occlusion and one patient had distal occlusion of unilateral vertebral artery. Four patients had early complete recanalization within 60 min after the t-PA bolus (two patients within 60 min and other two patients within 30 min), however, occlusion persisted during 120 min monitoring in one patient with proximal occlusion of MCA. NIH Stroke Scale of two patients with very early recanalization was 0 at the end of the treatment. There was no symptomatic and asymptomatic intracranial hemorrhage in 4 patients except for the patients without recanalization. Conclusions It is anticipated that real-time ultrasound monitoring is useful for evaluating a very early thrombolytic effect of tPA connected with early clinical recovery.

Visibility of the Lesser Sphenoid Wing Is an Important Indicator for Detecting the Middle Cerebral Artery on Transcranial Color-Coded Sonography

Background: Failure to detect the sphenoidal segment of the middle cerebral artery (M1) on transcranial color-coded sonography (TCCS) results from either M1 occlusion or an insufficient temporal bone window (TBW). We sought to identify a simple indicator on B mode images for M1 evaluation. Methods: Consecutive acute ischemic stroke patients with an intact M1 segment underwent prospective TCCS evaluation. Visibilities of the contralateral temporal bone (CTB), midbrain (MB) and lesser sphenoid wing (LSW) on B mode images were defined as follows: ‘invisible’, ‘poor’ if the contour was less than 50% visible, ‘fair’ if more than 50% visible and ‘good’ if totally visible. M1 detectability on color Doppler images was defined as follows: ‘INVISIBLE’, ‘POOR’ if the M1 was detected as color dots, ‘FAIR’ if linearly but discontinuously detectable, and ‘GOOD’ if linearly and continuously detectable. The relationship between each structure’s visibility and M1 detectability was assessed. Results: Seventy-six patients with 152 TBWs were evaluated. The CTB was ‘invisible’ in 2%, ‘poor’ in 22%, ‘fair’ in 36% and ‘good’ in 40%. Visibility of the MB was 36, 24, 26 and 14%, respectively. Visibility of the LSW was 16, 22, 29 and 32%, respectively. The M1 was ‘INVISIBLE’ in 51%, ‘POOR’ in 7%, ‘FAIR’ in 7% and ‘GOOD’ in 35%. Spearman’s rank correlation coefficient between each structure’s visibility and M1 detectability was 0.68 for the CTB, 0.66 for the MB and 0.80 for the LSW, respectively (p < 0.001 for all). Conclusion: Visibility of the LSW on B mode appears to be a better indicator than other structures for M1 evaluation.

Transcranial Ultrasound from Diagnosis to Early Stroke Treatment – Part 2: Prehospital Neurosonography in Patients with Acute Stroke – The Regensburg Stroke Mobile Project

Background and Purpose: The primary aim of this study was to investigate the diagnostic accuracy and time frames for neurological and transcranial color-coded sonography (TCCS) assessments in a prehospital ‘911’ emergency stroke situation by using portable duplex ultrasound devices to visualize the bilateral middle cerebral arteries (MCAs). Methods: This study was conducted between May 2010 and January 2011. Patients who had sustained strokes in the city of Regensburg and the surrounding area in Bavaria, Germany, were enrolled in the study. After a ‘911 stroke code’ call had been dispatched, stroke neurologists with expertise in ultrasonography rendezvoused with the paramedic team at the site of the emergency. After a brief neurological assessment had been completed, the patients underwent TCCS with optional administration of an ultrasound contrast agent in cases of insufficient temporal bone windows or if the agent had acute therapeutic relevance. The ultrasound studies were performed at the site of the emergency or in the ambulance during patient transport to the admitting hospital. Relevant timelines, such as the time from the stroke alarm to patient arrival at the hospital and the duration of the TCCS, were documented, and positive and negative predictive values for the diagnosis of major MCA occlusion were assessed. Results: A total of 113 patients were enrolled in the study. MCA occlusion was diagnosed in 10 patients. In 9 of these 10 patients, MCA occlusion could be visualized using contrast-enhanced or non-contrast-enhanced TCCS during patient transport and was later confirmed using computed tomography or magnetic resonance angiography. One MCA occlusion was missed by TCCS and 1 atypical hemorrhage was misdiagnosed. Overall, the sensitivity of a ‘field diagnosis’ of MCA occlusion was 90% [95% confidence interval (CI) 55.5–99.75%] and the specificity was 98% (95% CI 92.89–99.97%). The positive predictive value was 90% (95% CI 55.5–99.75%) and the negative predictive value was 98% (95% CI 92.89–99.97%). The mean time (standard deviation) from ambulance dispatch to arrival at the patient was 12.3 min (7.09); the mean time for the TCCS examination was 5.6 min (2.2); and the overall mean transport time to the hospital was 53 min (18). Conclusion: Prehospital diagnosis of MCA occlusion in stroke patients is feasible using portable duplex ultrasonography with or without administration of a microbubble contrast agent. Prehospital neurological as well as transcranial vascular assessments during patient transport can be performed by a trained neurologist with high sensitivity and specificity, perhaps opening an additional therapeutic window for sonothrombolysis or neuroprotective strategies.

Accuracy of transcranial colour-coded sonography in the diagnosis of anterior cerebral artery vasospasm

Background and purposeTranscranial colour-coded sonography (TCCS) has been proven to be a method of high performance in the diagnosis of spasm of the middle cerebral artery (MCA). Relevant data concerning the anterior cerebral artery (ACA) varies amongst studies. The aim of this study was to assess the performance of TCCS in the diagnosis of spasm affecting the ACA. Material and methodsNinety-two patients (39 women and 53 men, age 51 ± 12.1 years) were examined using TCCS before cerebral angiography. Of 184 examined ACAs, only 133 arteries could be visualized due to insufficiency of the temporal acoustic window. Therefore, only 15 out of 25 arteries in which vasospasm was diagnosed with angiography (by two neuroradiologists not informed about the sonographic findings) could be included in the analysis. Receiver operating characteristic (ROC) curves were constructed for specific blood flow velocities: peak systolic (PSV), mean (M) and end-diastolic (EDV). The area under the ROC curve was used to measure the overall diagnostic performance of TCCS. ResultsThe area under the ROC curve for PSV was 0.83, which indicates good performance. The PSV threshold of 98 cm/s corresponded to maximum accuracy and was associated with 71% sensitivity vs. 88% specificity. Average systolic blood flow velocity in the vessels with vasospasm was 129 cm/s, whereas in unaffected vessels it was 76 cm/s. ConclusionsThe accuracy of TCCS in the diagnosis of ACA spasm is relatively high – the value of the area under the ROC amounts to 0.83. PSV performs best and the threshold of 98 cm/s is associated with an optimal trade-off between sensitivity and specificity.

Time course of cerebral hemodynamics in aneurysmal subarachnoid hemorrhage

Vascular complications are important causes of neurologic sequelae among survivors of aneurysmal subarachnoid hemorrhage (SAH). However, little is known about the time course of cerebral hemodynamics and outcome in patients with and without angiographically confirmed cerebral vasospasm. Serial transcranial color-coded sonography (TCCS), angiography, and MRI studies were performed to measure cerebrovascular hemodynamics and assess complications following aneurysmal SAH. Eighteen aneurysmal SAH patients were enrolled. Angiographically confirmed cerebral vasospasm occurred in 14 patients (77.8%), 5 of whom (35.7%) were asymptomatic. The mean blood flow velocity (V(mean) ) of the middle cerebral artery increased significantly as compared with healthy volunteers from day 1 to day 15, and substantially decreased thereafter. The V(mean) of middle cerebral artery was significantly higher in patients with than in patients without angiographically confirmed cerebral vasospasm from day 3 to day 12. Compared to angiography, TCCS detected cerebral vasospasm with 85.7% sensitivity, 100% specificity, 100% positive predictive value, and 66.7% negative predictive value. MRI-evidenced cerebral infarctions occurred in nine patients (50%), three of whom (33.3%) were asymptomatic. This study demonstrated that approximately one-third of acute phase aneurysmal SAH patients have asymptomatic delayed cerebral infarction, which was undetected by TCCS in one-third of them. This may explain why the accuracy of TCCS to predict clinical symptomatic cerebral vasospasm is suboptimal.

“The seagull cry” in internal carotid artery dissection

A 47-year-old man with left Horner syndrome due to left internal carotid artery dissection (figure, A) underwent transcranial color-coded sonography. Microembolic signals were detected in the left middle cerebral artery (figure, B). Doppler spectral analysis of the left intracranial carotid bifurcation displayed mirror-image …

Extracranial venous hemodynamics in multiple sclerosis

A chronic state of impaired cerebral and cervical venous drainage, termed chronic cerebrospinal venous insufficiency (CCSVI), has recently been implicated in the pathogenesis of multiple sclerosis (MS). We performed a color-coded Doppler sonography case-control study to externally validate the CCSVI criteria. We prospectively evaluated consecutive patients with clinically definite MS and healthy volunteers using extracranial and transcranial color-coded Doppler sonography. The recently developed neurosonology criteria for CCSVI detection were used for interpretation of ultrasound assessments. The presence of venous reflux in cervical veins was assessed both in the sitting and upright position during a short period of apnea and after Valsalva maneuver. We recruited 42 patients with MS (mean age 39 ± 11 years, 17 men) and 43 control individuals (mean age 38 ± 12 years, 16 men). Very good/excellent intrarater and interrater agreement (κ values 0.82-1.00) was documented in 3 out of 5 CCSVI criteria. There was no evidence of stenosis or nondetectable Doppler flow in cervical veins in patients and controls. Reflux in internal jugular vein (IJV) was documented in 1 patient (2%) and 1 control subject (2%), both in sitting and supine posture during apnea. After performing Valsalva maneuver, we documented the presence of IJV valve incompetence in 3 patients with MS (7%) and 4 healthy volunteers (9%; p > 0.999). With established reproducibility of venous ultrasound testing, our data argue against CCSVI as the underlying mechanism of MS. Without further independent validation of CCSVI, potentially dangerous endovascular procedures, proposed as novel therapy for MS, should not be performed outside controlled clinical trials.

Detection of Intracranial Arterial Stenosis Using Transcranial Color-Coded Duplex Sonography, Computed Tomographic Angiography, and Digital Subtraction Angiography

The aim of this retrospective study was to compare intracranial arterial stenosis in patients with stroke using 3 different methods: transcranial color-coded duplex sonography, computed tomographic (CT) angiography, and digital subtraction angiography in a common clinical practice. Sixty-seven patients (47 male and 20 female; age range, 23-79 years; mean age ± SD, 62.0 ± 9.5 years) were enrolled in this study over 40 months. All patients underwent examinations of the intracranial arteries using transcranial color-coded sonography, CT angiography, and digital subtraction angiography. Findings were divided into 4 groups: normal, mild stenosis (<50%), severe stenosis (50%-99%), and occlusion. Because of technical reasons or an insufficient bone window, 465 of 536 arterial segments in 67 patients were evaluated; 12 stenotic and 15 occluded segments were detected using digital subtraction angiography. The sensitivity, specificity, positive predictive value, and negative predictive value of transcranial color-coded sonography and CT angiography in comparison with digital subtraction angiography as a reference standard were 88.9%, 94.8%, 51.1%, and 99.3% and 81.5%, 98.7%, 78.6%, and 98.6%, respectively. The agreement between transcranial color-coded sonography and CT angiography was 93.8% (κ = 0.559); between transcranial color-coded sonography and digital subtraction angiography, it was 93.9% (κ = 0.588); and between CT angiography and digital subtraction angiography, it was 96.6% (κ = 0.697). Moderate agreement was found between CT angiography, transcranial color-coded sonography, and digital subtraction angiography in the evaluation of intracranial stenosis. Computed tomographic angiography and digital subtraction angiography are sufficient for assessment of the diagnosis.

Value of B-Mode and Colour Coded Sonography in Pneumonia

Value of B-Mode and Colour Coded Sonography in Pneumonia

Noninvasive detection of elevated intracranial pressure using a portable ultrasound system

ObjectiveThe aim of this study is to prospectively compare the accuracies of transcranial color-coded sonography (TCCS) and transcranial Doppler (TCD) in the diagnosis of elevated intracranial pressure. MethodsA prospective, blinded, head-to-head comparison of TCD and TCCS methods using intracranial pressure (ICP) measured continuously via an intraparenchymal catheter as the reference standard in 2 groups of 20 neurocritical care patients each: high ICP (group 1) and normal ICP (group 2). Middle cerebral artery (MCA) pulsatility index (PI) recordings from all patients' sonographic reports were selected based on the highest left or right recorded MCA PI. Transcranial Doppler was performed using a dedicated TCD device, and TCCS was performed using a portable ultrasound system. ResultsThe PI values obtained did not differ significantly between the 2 methods (group 1, P = .46; group 2, P = .11). Linear regression analysis identified a significant relationship between PI obtained with both methods (r = 0.897; P < .0001). The duration of PI measurement was statistically longer with TCCS than TCD (group 1, P < .01; group 2, P < .01). Diagnostic accuracies were good and similar for both methods (TCD area under curve, 0.901; TCCS area under curve 0.870; P = .69). ConclusionsThis work is a pilot study comparing TCCS and TCD in the detection of elevated ICP. This study suggests that a bedside portable ultrasound system may be useful to determine MCA PI with accuracy similar to that of a dedicated TCD device.

Value of Ultrasound (US)-Guided Percutaneous Needle Biopsy of Detected Pathological Gastrointestinal (GI) Tract Lesions but Negative or Incomplete Endoscopy

The study aim was to investigate the diagnostic value of US-guided percutaneous needle biopsy in the case of suspicious tumor lesion of the GI tract revealed by abdominal US but without detection with endoscopy or with incomplete or no possible endoscopy. Over a defined time period, all consecutive patients with no appropriate endoscopic diagnostic specimen or finding were registered. The patient, diagnostic, and periinterventional characteristics were documented. In total, 16 patients (7 males; mean age, 63.2 [range, 43 - 90] years) were enrolled in this study representing a rare but possible constellation from endoscopic practice characterized by no detectable intraluminal tumor growth and a suspicious tumor lesion revealed with abdominal US as found in each case (n = 16) from 01 / 01 / 2003 - 12 / 31 / 2006. The main indications for needle biopsy were pathological colonic cockades (n = 7) and tumor lesions of the stomach and small intestine (n = 9). The first needle biopsy attempt was successful in all subjects (technical success rate: 100 %) using the color-coded US mode in each case (100 %). There were no postinterventional complications (rate: 0 %). Percutaneous US-guided needle biopsy can be considered a safe diagnostic tool for clarifying the differential diagnosis of suspicious tumor lesions of the GI tract (revealed originally only by abdominal US) as the next favorable diagnostic step in the rare situation that endoscopy cannot provide appropriate information, in order to shorten the diagnostic course, to achieve a therapeutic decision and to decrease effort and costs.

Imaging of spontaneous intracerebral hemorrhages by means of transcranial color-coded sonography

Transcranial color-coded sonography (TCCS) allows the visualization of cerebral structures and enables monitoring of circulatory disorders occurring within the circle of Willis. To verify whether TCCS is a reliable method in imaging intracerebral hemorrhages (ICHs) and to what degree its results are consistent with these by means of computed tomography (CT). This study included 39 patients with spontaneous ICHs of supratentorial and infratentorial locations. Initial TCCS was done not later than 12h after initial CT. Clinical findings and the measurements of hemorrhagic foci and midline shift (MLS) were compared between these two methods. TCCS revealed ICHs in 34 patients, including 29 and 5 with supra- and infratentorial localization, respectively. Moreover, it showed 12 cases (35.3%) of intraventricular hemorrhage (IVH) and 16 cases of a midline shift (MLS). No significant differences were found between the measurements of hemorrhagic foci or MLS obtained by TCCS and CT. There was a significant correlation between the volumes of hemorrhagic foci or MLS values measured by both methods analyzed (R = 0.99 or R = 0.98, respectively). Additionally, MLS was shown to increase significantly with the volume of hemorrhagic foci (R = 0.90). The high correlation between TCCS and CT in imaging spontaneous ICHs introduces the possibility of applying TCCS in everyday clinical practice.

Brain-Derived Neurotrophic Factor Gene Val66Met Polymorphism Modulates Reversible Cerebral Vasoconstriction Syndromes

BackgroundReversible cerebral vasoconstriction syndrome (RCVS) could be complicated by cerebral ischemic events. Hypothetical mechanisms of RCVS involve endothelial dysfunction and sympathetic overactivity, both of which were reported to be related to brain-derived neurotrophic factor (BDNF). The study investigated the association between functional BDNF Val66Met polymorphism and RCVS.MethodsPatients with RCVS and controls were prospectively recruited and genotyped for the BDNF Val66Met polymorphism. Magnetic resonance angiography (MRA) and transcranial color-coded Doppler sonography were employed to evaluate cerebral vasoconstriction. Genotyping results, clinical parameters, vasoconstriction scores, mean flow velocities of the middle cerebral artery (VMCA), and Lindegaard indices were analyzed. Split-sample approach was employed to internally validate the data.Principal FindingsNinety Taiwanese patients with RCVS and 180 age- and gender-matched normal controls of the same ethnicity completed the study. The genotype frequencies did not differ between patients and controls. Compared to patients with Met/Met homozygosity, patients with Val allele had higher mean vasoconstriction scores of all arterial segments (1.60±0.72 vs. 0.87±0.39, p<0.001), VMCA values (116.7±36.2 vs. 82.7±17.9 cm/s, p<0.001), and LI (2.41±0.91 vs. 1.89±0.41, p = 0.001). None of the Met/Met homozygotes, but 38.9% of the Val carriers, had VMCA values of >120 cm/s (p<0.001). Split-sample validation by randomization, age, entry time or residence of patients demonstrated concordant findings.ConclusionsOur findings link BDNF Val66Met polymorphism with the severity of RCVS for the first time and implicate possible pathogenic mechanisms for vasoconstriction in RCVS.

Predictors of Hyperperfusion Syndrome Before and Immediately After Carotid Artery Stenting in Single-Photon Emission Computed Tomography and Transcranial Color-Coded Real-Time Sonography Studies

Hyperperfusion syndrome (HPS) is a critical complication after carotid artery stenting (CAS) and carotid endarterectomy (CEA). To identify predictors of HPS before and immediately after CAS. We analyzed patients who underwent elective CAS from 2005 to 2008, and underwent single-photon emission computed tomography (SPECT) and transcranial color-coded real-time sonography before and immediately after CAS. HPS was defined as post-CAS deteriorating neurological conditions with headache not secondary to cerebral ischemia. We assessed the measures of blood flow between the two cortical hemispheres by taking the ratio of cerebral blood flow (CBF) of the affected to unaffected hemisphere excluding any ischemic/infarcted areas (asymmetry index); the measures of blood flow within each cortical hemisphere by comparing the CBF in the affected cortical hemispheric area to the CBF in the ipsilateral cerebellar hemisphere (middle cerebral artery [MCA]-to-cerebellar activity ratio); cerebral vasoreactivity (CVR); MCA mean blood flow velocity in the affected hemisphere; and MCA mean blood flow velocity ratio (preoperative to postoperative). Sixty-four patients were analyzed retrospectively. Nine patients presented with HPS. Logistic regression analysis showed that CVR (P<.01) and MCA mean blood flow velocity (P<.05) were the significant predictors among the pre-CAS variables, and that MCA mean blood flow velocity ratio (P<.05) and MCA-to-cerebellar activity ratio change (P<.05) were significant predictors among the post-CAS variables. SPECT and transcranial color-coded real-time sonography studies are useful in predicting HPS.

Quantitative Morphometry of Peripheral Arteries by use of Color Coded Ultrasound (CCU) as Compared to Angiography: Results of the PeriQuant Registry Study

Quantitative Morphometry of Peripheral Arteries by use of Color Coded Ultrasound (CCU) as Compared to Angiography: Results of the PeriQuant Registry Study