Surveillance Duplex Ultrasonography of Stent Grafts for Popliteal Aneurysms.

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Pineda, Danielle M; Troutman, Douglas A; Dougherty, Matthew J; Calligaro, Keith D

2016-05-01

Stent grafts, also known as covered stents, have become an increasingly acceptable treatment for popliteal artery aneurysms. However, endovascular exclusion confers lower primary patency compared to traditional open bypass and exclusion. The purpose of this study was to evaluate whether duplex ultrasonography (DU) can reliably diagnose failing stent grafts placed for popliteal artery aneurysms prior to occlusion. Between June 5, 2007, and March 11, 2014, 21 stent grafts (Viabahn; Gore, Flagstaff, Arizona) were placed in 19 patients for popliteal artery aneurysms. All patients had at least 1 follow-up duplex scan postoperatively. Mean follow-up was 28.9 months (9-93 months). Postoperative DU surveillance was performed in our Intersocietal Accreditation Commission noninvasive vascular laboratory at 1 week postprocedure and every 6 months thereafter. Duplex ultrasonography measured peak systolic velocities (PSVs) and ratio of adjacent PSVs (Vr) every 5 cm within the stent graft and adjacent arteries. We retrospectively classified the following factors as "abnormal DU findings": focal PSV > 300 cm/s, uniform PSVs 3.0. These DU criteria were derived from laboratory-specific data that we previously published on failing stent grafts placed for lower extremity occlusive disease. Four of the 21 stent grafts presented with symptomatic graft thrombosis within 6 months of a normal DU. Three of these 4 patients presented with rest pain and underwent thrombectomy (2) or vein bypass (1), and 1 elected for nonintervention for claudication. Our results suggest that surveillance DU using criteria established for grafts placed for occlusive disease may not be useful for predicting stent graft failure in popliteal artery aneurysms. © The Author(s) 2016.

Development of a Duplex Ultrasound Simulator and Preliminary Validation of Velocity Measurements in Carotid Artery Models.

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Zierler, R Eugene; Leotta, Daniel F; Sansom, Kurt; Aliseda, Alberto; Anderson, Mark D; Sheehan, Florence H

2016-07-01

Duplex ultrasound scanning with B-mode imaging and both color Doppler and Doppler spectral waveforms is relied upon for diagnosis of vascular pathology and selection of patients for further evaluation and treatment. In most duplex ultrasound applications, classification of disease severity is based primarily on alterations in blood flow velocities, particularly the peak systolic velocity (PSV) obtained from Doppler spectral waveforms. We developed a duplex ultrasound simulator for training and assessment of scanning skills. Duplex ultrasound cases were prepared from 2-dimensional (2D) images of normal and stenotic carotid arteries by reconstructing the common carotid, internal carotid, and external carotid arteries in 3 dimensions and computationally simulating blood flow velocity fields within the lumen. The simulator displays a 2D B-mode image corresponding to transducer position on a mannequin, overlaid by color coding of velocity data. A spectral waveform is generated according to examiner-defined settings (depth and size of the Doppler sample volume, beam steering, Doppler beam angle, and pulse repetition frequency or scale). The accuracy of the simulator was assessed by comparing the PSV measured from the spectral waveforms with the true PSV which was derived from the computational flow model based on the size and location of the sample volume within the artery. Three expert examiners made a total of 36 carotid artery PSV measurements based on the simulated cases. The PSV measured by the examiners deviated from true PSV by 8% ± 5% (N = 36). The deviation in PSV did not differ significantly between artery segments, normal and stenotic arteries, or examiners. To our knowledge, this is the first simulation of duplex ultrasound that can create and display real-time color Doppler images and Doppler spectral waveforms. The results demonstrate that an examiner can measure PSV from the spectral waveforms using the settings on the simulator with a mean absolute error

The inter-observer agreement in the assessment of carotid plaque neovascularization by contrast-enhanced ultrasonography: The impact of plaque thickness.

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Chen, Jian; Zhang, Yan-Ming; Song, Ze-Zhou; Fu, Yan-Fei; Geng, Yu

2018-04-10

The interobserver agreement in the assessment of the grade of carotid plaque neovascularization by contrast-enhanced ultrasonography is poorly established. We examined 140 carotid plaques in 66 patients (all patients had bilateral plaques, and 8 patients had 2 plaques on one side). We performed conventional and contrast-enhanced ultrasonography to analyze the presence of carotid plaque neovascularization, which was graded by two independent observers whose interobserver agreement (κ) was evaluated according to the thickness of carotid plaque. For all carotid plaques, the mean κ was 0.689 (95% confidence interval 0.604-0.774). It was 0.689 (0.569-0.808), 0.637 (0.487-0.787), and 0.740 (0.585-0.896), respectively for carotid plaques with maximal thickness 3 mm. The interobserver agreement for assessing carotid plaque neovascularization by using contrast-enhanced ultrasonography is substantial and acceptable for research purposes, regardless of the maximal thickness of the plaque. © 2018 Wiley Periodicals, Inc.

Validation of a basic neurosonology laboratory for detecting cervical carotid artery stenosis.

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de la Cruz Cosme, C; Dawid Milner, M S; Ojeda Burgos, G; Gallardo Tur, A; Márquez Martínez, M; Segura, T

2017-03-24

Most of the cases of ischaemic stroke in our setting are of atherothrombotic origin. Detecting intracranial and cervical carotid artery stenosis in patients with ischaemic stroke is therefore essential. Ultrasonography has become the tool of choice for diagnosing carotid artery stenosis because it is both readily accessibility and reliable. However, use of this technique must be validated in each laboratory. The purpose of this study is to validate Doppler ultrasound in our laboratory as a means of detecting severe carotid artery stenosis. We conducted an observational descriptive study to evaluate diagnostic tests. The results from transcranial and cervical carotid Doppler ultrasound scans conducted by neurologists were compared to those from carotid duplex scans performed by radiologists in patients diagnosed with stroke. Arteriography was considered the gold standard (MR angiography, CT angiography, or conventional arteriography). Our sample included 228 patients. Transcranial and cervical carotid Doppler ultrasound showed a sensitivity of 95% and specificity of 100% for detection of carotid artery stenosis > 70%, whereas carotid duplex displayed a sensitivity of 87% and a specificity of 94%. Transcranial carotid Doppler ultrasound achieved a sensitivity of 78% and a specificity of 98% for detection of intracranial stenosis. Doppler ultrasound in our neurosonology laboratory was found to be a useful diagnostic tool for detecting cervical carotid artery stenosis and demonstrated superiority to carotid duplex despite the lack of B-mode. Furthermore, this technique was found to be useful for detecting intracranial stenosis. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

The value and economic analysis of routine postoperative carotid duplex ultrasound surveillance after carotid endarterectomy.

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AbuRahma, Ali F; Srivastava, Mohit; AbuRahma, Zachary; Jackson, Will; Mousa, Albeir; Stone, Patrick A; Dean, L Scott; Green, Jason

2015-08-01

Several studies have reported on the role of postoperative duplex ultrasound surveillance after carotid endarterectomy (CEA) with varying results. Most of these studies had a small sample size or did not analyze cost-effectiveness. We analyzed 489 of 501 CEA patients with patch closure. All patients had immediate postoperative duplex ultrasound examination and were routinely followed up both clinically and with duplex ultrasound at regular intervals of 1 month, 6 months, 12 months, and every 12 months thereafter. A Kaplan-Meier analysis was used to estimate the rate of ≥50% and ≥80% post-CEA restenosis over time and the time frame of progression from normal to ≥50% or ≥80% restenosis. The cost of post-CEA duplex surveillance was also estimated. Overall, 489 patients with a mean age of 68.5 years were analyzed. Ten of these had residual postoperative ≥50% stenosis, and 37 did not undergo a second duplex ultrasound examination and therefore were not included in the final analysis. The mean follow-up was 20.4 months (range, 1-63 months), with a mean number of duplex ultrasound examinations of 3.6 (range, 1-7). Eleven of 397 patients (2.8%) with a normal finding on immediate postoperative duplex ultrasound vs 4 of 45 (8.9%) with mild stenosis on immediate postoperative duplex ultrasound progressed to ≥50% restenosis (P = .055). Overall, 15 patients (3.1%) had ≥50% restenosis, 9 with 50% to duplex ultrasound), which equals $1,408,320, to detect only four patients with ≥80% to 99% restenosis who may have been potential candidates for reintervention. This study shows that the value of routine postoperative duplex ultrasound surveillance after CEA with patch closure may be limited, particularly if the finding on immediate postoperative duplex ultrasound is normal or shows minimal disease. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Reproducibility of duplex ultrasonography and air plethysmography used for the evaluation of chronic venous insufficiency.

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Asbeutah, Akram Mahmoud; Riha, Andrea Zdena; Cameron, James Donald; McGrath, Barry Patrick

2005-04-01

The purpose of this study was to determine the reproducibility of measurements on duplex ultrasonography (DU) and air plethysmography (APG) in subjects with post-thrombotic syndrome. Duplex ultrasonography and APG were used to measure indices of lower limb venous reflux in 15 limbs with a history of deep vein thrombosis and evidence of venous insufficiency as diagnosed by ultrasonography. Three limbs were in class 0; 4 were in classes 1 to 3; and 8 were in classes 4 to 6, according to clinical, etiologic, anatomic, and pathophysiologic clinical classification. Duplex ultrasonography was performed 3 times on the same day, and venous diameter, area, peak reflux velocity, reflux flow volume, and reflux duration measurements were obtained. Air plethysmography was performed on 2 days, 7 to 10 days apart, with 1 measurement on the first day and 2 measurements on the second day. Values obtained from APG included outflow fraction, venous filling index, ejection fraction, and residual volume fraction. The measurements were performed by a vascular technologist blinded to the previous test results. One-way analysis of variance, the Student paired t test, and Bland-Altman plots were used to examine the statistical differences of the DU and APG parameters for all measurements. The mean coefficient of variation for within-subject measurements of all DU and APG parameters measured was less than 10%. Bland-Altman plots showed that there were no apparent trends with increasing values over a wide range for any of the DU parameters, nor were there any for the APG parameters. Under ideal conditions, when measured by a highly trained technologist, both DU and APG showed satisfactory reproducibility.

The value of 3D-CT angiography and duplex sonography in comparison to arteriography in carotid artery stenoses

International Nuclear Information System (INIS)

Link, J.; Mueller-Huelsbeck, S.; Wesner, F.; Hoepfner, M.; Schwarzenberg, H.; Heller, M.

1997-01-01

To determine the value of 3D-CT angiography, duplex sonography in comparison to selective digital subtraction angiography for evaluation of carotid artery stenoses. Methods: 30 patients with 51 stenoses of carotid artery underwent 3D-CT angiography, duplex sonography and angiography. Quantification of stenosis was determined according to the NASCET study and categorized into mild (0-29%), moderate (30-69%), severe (70-99%) and occluded (100%). Results: The agreement of 3D-CT angiography with intraarterial digital subtraction angiography (DSA) was 62% (r=0.89; p [de

Carotid Consensus Panel duplex criteria can replace modified University of Washington criteria without affecting accuracy.

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Kim, Ann H; Augustin, Gener; Shevitz, Andrew; Kim, Hannah; Trivonovich, Michael R; Powell, Alexis R; Kumins, Norman; Tarr, Robert; Kashyap, Vikram S

2018-04-01

The decision to intervene for internal carotid stenosis often depends on the degree of stenosis seen on duplex ultrasound (US). The aim of this study is to compare the diagnostic accuracy of two criteria: modified University of Washington (UW) and 2003 Carotid Consensus Panel (CCP). All patients undergoing US in an accredited (IAC) vascular laboratory from January 2010 to June 2015 were reviewed ( n=18,772 US exams). Patients receiving a neck computed tomography angiography (CTA) within 6 months of the US were included in the study ( n=254). The degree of stenosis was determined by UW/CCP criteria and confirmed on CTA images using North American Symptomatic Carotid Endarterectomy Trial (NASCET)/European Carotid Surgery Trial (ECST) schema. Kappa analysis with 95% confidence intervals (CIs) were utilized to determine duplex-CTA agreement. A total of 417 carotid arteries from 221 patients were assessed in this study. The modified UW criteria accurately classified 266 (63.9%, kappa = 0.321, 95% CI 0.255 to 0.386) cases according to NASCET-derived measurements. The sensitivity, specificity, and accuracy at ≥ 60% stenosis were 65.7%, 81.3%, and 81.9%. The CCP criteria resulted in 296 (70.9%) accurate diagnoses (kappa = 0.359, 95% CI 0.280 to 0.437). At ≥ 70% stenosis, the sensitivity, specificity and accuracy were 38.8%, 91.6%, and 87.1% for NASCET. Comparison of the duplex results to ECST-derived CTA measurements revealed a similar trend (UW 53.1%, κ = 0.301 vs CCP 62.1%, κ = 0.315). The CCP criteria demonstrate a higher concordance rate with measurements taken from CTAs. The CCP criteria may be more sensitive in classifying clinically significant degrees of stenosis without a loss in diagnostic accuracy.

Internal carotid artery occlusion or subocclusion: Contemporary diagnostic challenges: Case report

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Popov Petar

2009-01-01

Full Text Available Introduction. Measurement of vessel stenosis using ultrasonography or magnetic resonance is still the principal method for determining the severity of carotid atherosclerosis and need for endarterectomy. Case Outline. A 56-year-old male was admitted to the Cardiovascular Institute 'Dedinje' due to a clinically asymptomatic restenosis of the operated left internal carotid artery (ICA. Angiography and magnetic resonance angiography (MRA in previous hospitalization had revealed occluded right ICA. However, routine duplex ultrasonography revealed a highgrade restenosis (85% of the left ICA and subocclusion of the right ICA by an ulcerated plaque (confirmed on repeated MRA. Conclusion. Selective arteriography examination could misrepresent the degree of stenosis especially in patents with the ICA that seems to be occluded. MRA is considered the method of choice for identifying pseudo-occlusions of ICA.

Screen for intracranial dural arteriovenous fistulae with carotid duplex sonography.

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Tsai, L-K; Yeh, S-J; Chen, Y-C; Liu, H-M; Jeng, J-S

2009-11-01

Early diagnosis and management of intracranial dural arteriovenous fistulae (DAVF) may prevent the occurrence of stroke. This study aimed to identify the best carotid duplex sonography (CDS) parameters for screening DAVF. 63 DAVF patients and 170 non-DAVF patients received both CDS and conventional angiography. The use of seven CDS haemodynamic parameter sets related to the resistance index (RI) of the external carotid artery (ECA) for the diagnosis of DAVF was validated and the applicability of the best CDS parameter set in 20 400 patients was tested. The CDS parameter set (ECA RI (cut-off point = 0.7) and internal carotid artery (ICA) to ECA RI ratio (cut-off point = 0.9)) had the highest specificity (99%) for diagnosis of DAVF with moderate sensitivity (51%). Location of the DAVF was a significant determinant of sensitivity of detection, which was 70% for non-cavernous DAVF and 0% for cavernous sinus DAVF (pdetected abnormality in 92 of 20 400 patients. These abnormalities included DAVF (n = 25), carotid stenosis (n = 32), vertebral artery stenosis (n = 7), intracranial arterial stenosis (n = 6), head and neck tumour (n = 3) and unknown aetiology (n = 19). Combined CDS parameters of ECA RI and ICA to ECA RI ratio can be used as a screening tool for the diagnosis of DAVF.

Carotid duplex ultrasound and transcranial Doppler findings in commercial divers and pilots.

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Dormanesh, Banafshe; Vosoughi, Kia; Akhoundi, Fahimeh H; Mehrpour, Masoud; Fereshtehnejad, Seyed-Mohammad; Esmaeili, Setareh; Sabet, Azin Shafiee

2016-12-01

The risky working environments of divers and pilots, and the possible role of extreme ambient pressure in carotid stenosis, make ischemic stroke an important occupational concern among these professionals. In this study, we aimed to evaluate the association of being exposed to hyperbaric or hypobaric conditions with carotid artery stenosis by comparing common carotid intima-media thickness (CCIMT) and blood flow velocities of cerebral arteries in divers and pilots using carotid duplex ultrasound (CDUS) and transcranial Doppler (TCD). CDUS and transtemporal TCD were performed in 29 divers, 36 pilots and 30 control participants. Medical history, blood pressure, lipid profile and blood sugar were recorded to control the previously well-known risk factors of atherosclerosis. Findings of the CDUS and TCD [including: CCIMT and blood flow velocities of internal carotid artery (ICA), common carotid artery (CCA), and middle cerebral artery (MCA)] of divers and pilots were compared with those of the control group using regression analysis models. Both right and left side CCIMT were significantly higher in divers (P < 0.05) and pilots (P < 0.05) in comparison with the control group. Carotid index [peak systolic velocity (PSV) of ICA/PSV of CCA) of divers and pilots were also higher than the control group. TCD findings were not significantly different between divers, pilots, and the control group. Increased CCIMT and carotid index in diver and pilot groups appear to be suggestive of accelerated atherosclerosis of carotid artery in these occupational groups.

Transvaginal duplex ultrasonography appears to be the gold standard investigation for the haemodynamic evaluation of pelvic venous reflux in the ovarian and internal iliac veins in women.

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Whiteley, M S; Dos Santos, S J; Harrison, C C; Holdstock, J M; Lopez, A J

2015-12-01

To assess the suitability of transvaginal duplex ultrasonography to identify pathological reflux in the ovarian and internal iliac veins in women. A retrospective study of patients treated in 2011 and 2012 was performed in a specialised vein clinic. Diagnostic transvaginal duplex ultrasonography in women presenting with symptoms or signs of pelvic vein reflux were compared with the outcomes of treatment from pelvic vein embolisation. A repeat transvaginal duplex ultrasonography was performed 6 weeks later by a blinded observer and any residual reflux was identified. Results from 100 sequential patients were analysed. Mean age 44.2 years (32-69) with mode average parity of 3 (0-5 deliveries). Pre-treatment, 289/400 veins were refluxing (ovarian - 29 right, 81 left; internal iliac - 93 right, 86 left). Coil embolisation was successful in 86/100 patients and failed partially in 14/100 - 5 due to failure to cannulate the target vein. One false-positive diagnosis was made. Currently there is no accepted gold standard for pelvic vein incompetence. Comparing transvaginal duplex ultrasonography with the outcome from selectively treating the veins identified as having pathological reflux with coil embolisation, there were no false-negative diagnoses and only one false-positive. This study suggests that transvaginal duplex ultrasonography could be the gold standard in assessing pelvic vein reflux. © The Author(s) 2014.

Summary receiver operating characteristic curves as a technique for meta-analysis of the diagnostic performance of duplex ultrasonography in peripheral arterial disease

NARCIS (Netherlands)

deVries, SO; Hunink, MGM; Polak, JF

Rationale and Objectives. We summarized and compared the diagnostic performance of duplex and color-guided duplex ultrasonography in the evaluation of peripheral arterial disease. We present our research as an example of the use of summary receiver operating characteristic (ROC) curves in a

Duplex-assisted carotid artery stenting without administration of contrast medium for patients with chronic kidney disease or allergic reaction.

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Mizowaki, Takashi; Fujita, Atsushi; Imahori, Taichiro; Uyama, Atsushi; Inoue, Satoshi; Kohta, Masaaki; Hamaguchi, Hirotoshi; Sasayama, Takashi; Hosoda, Kohkichi; Kohmura, Eiji

2016-07-01

We aimed to investigate the safety and feasibility of duplex-assisted carotid artery stenting (CAS) without administration of contrast medium for the prevention of adverse reactions. Fifteen patients (9 % of all CASs) with severe carotid stenosis (≥70 %) associated with chronic kidney disease (CKD) (stage ≥3) or allergy to contrast medium underwent duplex-assisted CAS without administration of contrast medium over 4 years. The procedural success rate and perioperative complication rates were compared between the duplex-assisted CAS (n = 15) and conventional CAS (n = 153) groups. The technical success rate was 100 % in both groups. Combined stroke or death rates during the post-procedural period did not differ significantly between the duplex-assisted CAS group (0/15, 0 %) and conventional CAS group (4/153, 2.6 %). None of the 14 patients with CKD in the duplex-assisted CAS group experienced further deterioration of renal function. The mean surface radiation dose of participants in the duplex-assisted CAS group (n = 13, 312 ± 131 mGy) was significantly lower than that of the conventional CAS group (n = 31, 1036 ± 571 mGy) (p duplex-assisted CAS group (156 ± 39.7 min) and the conventional CAS group (156 ± 37.4 min). Duplex-assisted CAS without administration of contrast medium could be an alternative option in selected patients deemed to be at high risk for renal failure from nephrotoxic contrast medium or who have an allergy to contrast medium.

Incidentally diagnosed Takayasu arteritis on thyroid ultrasonography showing prominent collateral vessels of thyroidal arteries and common carotid artery occlusion

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Nam, Se Jin; Kim, Eun Kyung [Dept. of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2014-10-15

We report a case of middle-aged woman incidentally diagnosed with Takayasu arteritis during the ultrasonography of a thyroid gland nodule. Prominent collaterals of the thyroidal arteries and a thin common carotid artery with mural thickening and deficient intraluminal flow signals were initially depicted on the ultrasonography with color Doppler. Subsequent magnetic resonance angiography and computed tomography aortography confirmed the diagnosis with the imaging features of a bilateral long segment common carotid artery occlusion and segmental stenosis of the left subclavian artery in addition to the suggestive physical findings.

Duplex ultrasound: A diagnostic tool for carotid stenosis management in type 2 diabetes mellitus

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Yogan Kisten

2013-07-01

Full Text Available Background: Diabetic patients are at increased risk of developing cardiac events and stroke, and prevention of diabetes mellitus is therefore desirable. Marked geographical and ethnic variation in the prevalence of diabetes caused by urbanisation, demographic and epidemiological transitions has rendered this one of the major non-communicable diseases in South Africa. Duplex ultrasound (DUS plays an important role in primary health care in early detection of carotid atherosclerotic disease and the degree of carotid stenosis present. It is a reliable, cost-effective and non-invasive diagnostic tool. The purpose of this study was to determine the role of ultrasound in carotid stenosis management in type 2 diabetes mellitus (T2DM. Objectives: To determine the prevalence of carotid stenosis in a selected T2DM population using DUS and to correlate these findings with other predisposing atherosclerotic risk factors. Methods: The study setting was at an academic hospital in the Western Cape using carotid DUS reports of 103 diabetic subjects ≥ 35 years old. Predisposing risk factors were correlated with degree of carotid stenosis present. Data were analysed using the Fischer exact test, Chisquare and Student t-test. Results: Carotid DUS reports of 63 out of 103 T2DM patients revealed no evidence of a carotid stenosis, thereby lowering the risk profile. Forty patients were identified as having carotidstenosis; 22 symptomatic patients had a > 70% carotid stenosis which warranted surgicalintervention. A greater prevalence of stenosis in the Caucasian group, in both the male (p =0.0411 and female (p = 0.0458 cohorts, was noted. The overall trend suggested a relationship between T2DM and lifestyle, and a statistically significant relationship (p = 0.0063 between smoking and carotid stenosis was observed. Conclusion: T2DM and predisposing atherosclerotic risk factors significantly increased thepossibility of carotid stenosis development.

Renal duplex doppler ultrasonography in patients with recurrent urinary tract infection

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Soliman Neveen

2009-01-01

Full Text Available Renal hemodynamics were studied using duplex Doppler ultrasonography in forty (33 females and 7 males; mean age: 12.1 ± 5.3 years normotensive patients with recurrent urinary tract infection and with no evidence of obstructive uropathy and age matched control group of 24 healthy children and adolescents. Resistivity index (RI and pulsatility index (PI in both arcuate (AA and interlobar (IA arteries were significantly higher in patients as compared to controls (P= 0.001, 0.01 respectively. Diastolic/systolic ratio (D/S at the same levels of renal vasculature (AA and IA was significantly lower in study patients as compared to their controls (P= 0.01, 0.001 respectively. Moreover, scarred renal units had higher RI and PI values as well as lower D/S ratio as compared to non scarred units (p= 0.01, 0.001, 0.001 respectively.. In conclusion, intra renal vascular resistivity is significantly increased in recurrent UTI patients particularly in those sus-taining renal scarring. Further follow up studies are recommended to determine if duplex assess-ment of intrarenal vasculature could be useful as an ancillary diagnostic and/or prognostic technique in the evaluation and follow up of recurrent UTI.

Internal Carotid Artery Aneurysm Mimicking Peritonsillar Abscess

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Jacek Brzost

2015-01-01

Full Text Available The extracranial internal carotid artery aneurysm (EICAA is an uncommon arterial lesion. Patients typically present with neurologic symptoms resulting from impaired cerebral perfusion and compression symptoms of cranial nerves. Often EICAA presents as a pulsatile neck mass, which is otherwise asymptomatic. We present a case of an 84-year-old female, who was initially referred to the Emergency Department for Otolaryngology with suspected peritonsillar abscess. The patient had a history of recent upper airway infection and cardiovascular comorbidities, including hypertension and ischaemic stroke complicated by extensive neurologic deficits. Physical examination revealed a compact, nonpulsatile mass in the lateral parapharyngeal space and local erythema of the mucosa. Duplex Doppler Ultrasonography and Computed Tomography revealed an atherosclerotic aneurysm of the right internal carotid artery, measuring 63×55×88 mm, stretching from the skull base to the angle of the mandible.

A historical prospective cohort study of carotid artery stenosis after radiotherapy for head and neck malignancies

International Nuclear Information System (INIS)

Brown, Paul D.; Foote, Robert L.; McLaughlin, Mark P.; Halyard, Michele Y.; Ballman, Karla V.; Collie, A. Craig; Miller, Robert C.; Flemming, Kelly D.; Hallett, John W.

2005-01-01

Purpose: To determine carotid artery stenosis incidence after radiotherapy for head-and-neck neoplasms. Methods and Materials: This historical prospective cohort study comprised 44 head-and-neck cancer survivors who received unilateral neck radiotherapy between 1974 and 1999. They underwent bilateral carotid duplex ultrasonography to detect carotid artery stenosis. Results: The incidence of significant carotid stenosis (8 of 44 [18%]) in the irradiated neck was higher than that in the contralateral unirradiated neck (3 of 44 [7%]), although this difference was not statistically significant (p = 0.13). The rate of significant carotid stenosis events increased as the time after radiotherapy increased. The risk of ipsilateral carotid artery stenosis was higher in patients who had undergone a neck dissection vs. those who had not. Patients with significant ipsilateral stenosis also tended to be older than those without significant stenosis. No other patient or treatment variables correlated with risk of carotid artery stenosis. Conclusions: For long-term survivors after neck dissection and irradiation, especially those who are symptomatic, ultrasonographic carotid artery screening should be considered

Relationship Between Carotid Intima-Media Thickness Using Ultrasonography and Diagnostic Indices of Metabolic Syndrome

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Ko, Kyung Sun; Heo, Kyung Hwa; Won, Yong Lim; Kim, Ki Woong [Center for Occupational Disease Reserach, Occupational Safety and Health Research Insurance, KOSHA, Incheon (Korea, Republic of)

2009-09-15

The aim of the present study was undertaken to investigate the association between diagnostic indices of metabolic syndrome(MetS) with carotid intima-media thickness using ultrasonography. The participants in the study were 315 male employees without carotid atherosclerosis and other cardiovascular disease. This study was approved by the Institutional Review Board of Occupational Safety and Health Research Institute. Written informed consent for the participants in this study was obtained from all individuals. Anthropometric parameters and biochemical characteristics were done using each specific equipment and the NCEP-ATP III criteria were used to define MetS. They were examined by B-mode ultrasound to measure the carotid intima-media thickness(carotid IMT) at the near and far walls of common carotid and bifurcation(bulb). The mean carotid IMT was 0.739{+-}0.137 mm and it's thickness significantly increased with the increase in age. Also, amounts of systolic and diastolic blood pressure, triglyceride and fasting glucose were significantly increased with the increase in age. Carotid IMT were significantly correlated with BMI(r=0.170, p=0.004), systolic(r=0.148, p=0.011) and diastolic blood pressure(r=0.123, p=0.036) and HDL-cholesterol(r=-0.164, p=0.005). On multiple logistic regression analysis for the diagnostic indices of MetS, carotid IMT were significantly associated with blood pressure(OR=4.220, p<0.01) and MetS(OR=1.301, p<0.05). The results indicate that blood pressure and MetS are important risk factors for carotid atherosclerosis.

Subclinical thyroid dysfunction and risk of carotid atherosclerosis.

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Hosu Kim

Full Text Available The effect of subclinical thyroid dysfunction on vascular atherosclerosis remains uncertain. The objective of this study was to elucidate the association between sustained subclinical thyroid dysfunction and carotid plaques, which are an early surrogate marker of systemic atherosclerosis.The study included 21,342 adults with consistent thyroid hormonal status on serial thyroid function tests (TFTs and carotid artery duplex ultrasonography at a health screening center between 2007 and 2014. The effect of subclinical thyroid dysfunction on baseline carotid plaques and newly developed carotid plaques during 5-year follow-up was determined by logistic regression analyses and GEE (Generalized Estimating Equations, respectively.Carotid plaques were more common in the subclinical hypothyroidism (55.6% than the euthyroidism (47.8% at baseline. However, in multivariable analysis, thyroid status was not a significant risk for the carotid plaques at baseline. Instead, traditional cardiovascular risk factors, such as age (P <0.001, systolic blood pressure (P = 0.023, fasting blood glucose (P = 0.030, and creatinine (P = 0.012 were associated with baseline carotid plaques in subclinical hypothyroidism. In longitudinal analyses of subjects who were followed up for more than 5 years, there was no significant difference in the cumulative incidence of new carotid plaques according to time between subjects with subclinical hypothyroidism and those with euthyroidism (P = 0.392.Sustained subclinical thyroid dysfunction did not affect the baseline or development of carotid plaques in healthy individuals.

[Can TOF MRA replace duplex and Doppler sonography in preoperative assessment of the carotid arteries? A prospective comparison and review of the literature].

Science.gov (United States)

Krappel, F A; Bauer, E; Harland, U

2002-01-01

To examine the quality and usefulness of time-of-flight MR-angiography and duplex-doppler sonography, respectively, in assessment of the extracranial arteries before cervical spine operations. Patients scheduled for operations of the cervical spine had an MRI plus TOF as well as a duplex and Doppler scan. At the time of the examination the radiologist and the neurologist in charge were blinded for the study. Endpoints were not only the accuracy of the procedures but more so which method improved the preoperative process most. Twenty patients were examined so far. Only in one case did the result differ when a complete occlusion diagnosed sonographically was judged as a severe stenosis on MRA. One patient did not tolerate the MRA for the extra 5 minutes necessary, therefore a contrast-enhanced MRA was performed. MRA eased the preoperative process as imaging of the pathology and the carotids were realised in one step. The costs were slightly higher for MRA than for duplex-doppler sonography. TOF-MRA can replace the duplex-doppler examination in the preoperative assessment of the carotids and has the potential to streamline the preoperative time schedule. Similar to duplex and doppler, in order to be accurate enough the method requires a high degree of expertise from the radiologist.

Carotid artery ultrasonographic assessment in patients from the Fremantle Diabetes Study Phase II with carotid bruits detected by electronic auscultation.

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Knapp, Arthur; Cetrullo, Violetta; Sillars, Brett A; Lenzo, Nat; Davis, Wendy A; Davis, Timothy M E

2014-09-01

Electronic auscultation appears superior to acoustic auscultation for identifying hemodynamic abnormalities. The aim of this study was to determine whether carotid bruits detected by electronic stethoscope in patients with diabetes are associated with stenoses and increased carotid intima-medial thickness (CIMT). Fifty Fremantle Diabetes Study patients (mean±SD age, 73.7±10.0 years; 38.0% males) with a bruit found by electronic auscultation and 50 age- and sex-matched patients with normal carotid sounds were studied. The degree of stenosis and CIMT were assessed from duplex ultrasonography. Patients with a bruit were more likely to have stenosis of ≥50% and CIMT of >1.0 mm than those without (odds ratios [95% confidence intervals]=14.0 [1.8-106.5] and 5.3 [1.8-15.3], respectively; both P=0.001). For the six patients with stenosis of ≥70%, five had a bruit, and one (with a known total occlusion) did not (odds ratio=5.0 [0.6-42.8]; P=0.22). The sensitivity and specificity of carotid bruit for stenoses of ≥50% were 88% and 58%, respectively; respective values for stenoses of ≥70% were 83% and 52%. The equivalent negative predictive values were 96% and 98%, and positive predictive values were 30% and 10%, respectively. Electronic recording of carotid sounds for later interpretation is convenient and reliable. Most patients with stenoses had an overlying bruit. Most bruits were false positives, but ultrasonography is justified to document extent of disease; CIMT measurement will identify increased vascular risk in most of these patients. The absence of a bruit was rarely a false-negative finding, suggesting that these patients can usually be reassured that they do not have hemodynamically important stenosis.

Extracranial Carotid Artery Stenting in Surgically High-Risk Patients Using the Carotid Wallstent Endoprosthesis:Midterm Clinical and Ultrasound Follow-Up Results

International Nuclear Information System (INIS)

Maleux, Geert; Bernaerts, Pauwel; Thijs, Vincent; Daenens, Kim; Vaninbroukx, Johan; Fourneau, Inge; Nevelsteen, Andre

2003-01-01

The purpose of this study was to evaluate the feasibility, safety and midterm outcome of elective implantation of the Carotid Wallstent (registered) in patients considered to be at high surgical risk. In a prospective study, 54 carotid artery stenoses in 51 patients were stented over a 24-month period. Three patients underwent bilateral carotid artery stenting. Institutional inclusion criteria for invasive treatment of carotid occlusive disease (carotid endarterectomy or carotid artery stenting) are patients presenting with a 70% or more symptomatic stenosis and those with an 80% or more asymptomatic stenosis having a life-expectancy of more than 1 year. All patients treated by carotid artery stenting were considered at high risk for carotid endarterectomy because of a hostile neck (17 patients-31.5%) or because of severe comorbidities (37 patients-68.5%). No cerebral protection device was used. Of the 54 lesions, 33 (61.1%) were symptomatic and 21 (38.8%) were asymptomatic. Follow-up was performed by physical examination and by duplex ultrasonography at 1 month, 6 months, 1 year and 2 years after the procedure. All 54 lesions could be stented successfully without periprocedural stroke. Advert events during follow-up (mean 13.9 ± 5.7 months) were non-stroke-related death in 6 patients (11.1%), minor stroke in 4 stented hemispheres(7.4%), transient ipsilateral facial pain in 1 patient (1.8%),infection of the stented surgical patch in 1 patient (1.8%) and asymptomatic in stent restenosis in 4 patients (7.4%). The percutaneous implantation of the Carotid Wallstent (registered) , even without cerebral protection device, appears to be a safe procedure with acceptable clinical and ultrasonographic follow-up results in patients at high surgical risk. But some late adverse events such as ipsilateral recurrence of non-disabling (minor) stroke or in stent restenosis still remain real challenging problems

Evaluation of a new carotid intima-media thickness measurement by B-mode ultrasonography using an innovative measurement software, intimascope.

Science.gov (United States)

Yanase, Toshihiko; Nasu, Shigeru; Mukuta, Yoshihiro; Shimizu, Yutaka; Nishihara, Tetsu; Okabe, Taijiro; Nomura, Masatoshi; Inoguchi, Toyoshi; Nawata, Hajime

2006-12-01

Carotid intima-media thickness (IMT), an indicator of atherosclerosis and coronary heart disease (CHD) is usually evaluated by eye measurement under B-scope carotid artery ultrasonography. However, the axial resolution of this system is >/=0.1 mm, which causes difficulties in respect to accuracy and reproducibility. We evaluated a newly developed B-scope carotid artery ultrasonography programmed by an innovative measurement software, Intimascope (Media Cross Co. Ltd., Tokyo, Japan), which measures IMT with 10 times higher axial resolution at an estimated scale of 0.01 mm. Intraobserver or interobserver coefficient of variation (CV) of the computer-based average IMT (aver-IMT) value and 3-point IMT value were much smaller than the corresponding value by conventional eye-measurement method (3-point value). We measured IMT of 427 asymptomatic subjects undergoing medical checkups (243 men and 184 women, 23 to 73 years of age). Although the mean values of aver-IMT and 3-point IMT of 427 subjects were comparable with that of the eye measurement method, the aver-IMT showed the smallest SD (standard deviation) and CV values. In both men and women, multivariate regression analysis revealed significant contributions of age and LDL-C to the aver-IMT value. Univariate regression analysis revealed that the aver-IMT value of total subjects showed the highest correlation coefficient values with most risk factors and risk assessment score, Framingham Risk Assessment, or Prospective Cardiovascular Munster study (PROCAM) Risk Score. These results may suggest superiority of computer-based aver-IMT over 3-point IMT by either computer-based or eye measurement method. Carotid aver-IMT measurement using the new Intimascope software may provide a more precise and reproducible index of atherosclerosis than does conventional IMT measurement.

Reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications

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Vilson Lacerda Brasileiro Junior

2014-02-01

Full Text Available Objective The present study evaluated the reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications. Materials and Methods Thirty-five patients under high-risk for development of carotid artery calcifications who had digital panoramic radiography were referred to undergo ultrasonography. Thus, 70 arteries were assessed by both methods. The main parameters utilized to evaluate the panoramic radiography reliability in the diagnosis of carotid artery calcifications were accuracy, sensitivity, specificity and positive predictive value of this method as compared with ultrasonography. Additionally, the McNemar's test was utilized to verify whether there was a statistically significant difference between digital panoramic radiography and ultrasonography. Results Ultrasonography demonstrated carotid artery calcifications in 17 (48.57% patients. Such individuals presented with a total of 29 (41.43% carotid arteries affected by calcification. Radiography was accurate in 71.43% (n = 50 of cases evaluated. The degree of sensitivity of this method was 37.93%, specificity of 95.12% and positive predictive value of 84.61%. A statistically significant difference (p < 0.001 was observed between the methods evaluated in their capacity to diagnose carotid artery calcifications. Conclusion Digital panoramic radiography should not be indicated as a method of choice in the investigation of carotid artery calcifications.

Restenosis after carotid artery stenting and endarterectomy: a secondary analysis of CREST, a randomised controlled trial.

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Lal, Brajesh K; Beach, Kirk W; Roubin, Gary S; Lutsep, Helmi L; Moore, Wesley S; Malas, Mahmoud B; Chiu, David; Gonzales, Nicole R; Burke, J Lee; Rinaldi, Michael; Elmore, James R; Weaver, Fred A; Narins, Craig R; Foster, Malcolm; Hodgson, Kim J; Shepard, Alexander D; Meschia, James F; Bergelin, Robert O; Voeks, Jenifer H; Howard, George; Brott, Thomas G

2012-09-01

In the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST), the composite primary endpoint of stroke, myocardial infarction, or death during the periprocedural period or ipsilateral stroke thereafter did not differ between carotid artery stenting and carotid endarterectomy for symptomatic or asymptomatic carotid stenosis. A secondary aim of this randomised trial was to compare the composite endpoint of restenosis or occlusion. Patients with stenosis of the carotid artery who were asymptomatic or had had a transient ischaemic attack, amaurosis fugax, or a minor stroke were eligible for CREST and were enrolled at 117 clinical centres in the USA and Canada between Dec 21, 2000, and July 18, 2008. In this secondary analysis, the main endpoint was a composite of restenosis or occlusion at 2 years. Restenosis and occlusion were assessed by duplex ultrasonography at 1, 6, 12, 24, and 48 months and were defined as a reduction in diameter of the target artery of at least 70%, diagnosed by a peak systolic velocity of at least 3·0 m/s. Studies were done in CREST-certified laboratories and interpreted at the Ultrasound Core Laboratory (University of Washington). The frequency of restenosis was calculated by Kaplan-Meier survival estimates and was compared during a 2-year follow-up period. We used proportional hazards models to assess the association between baseline characteristics and risk of restenosis. Analyses were per protocol. CREST is registered with ClinicalTrials.gov, number NCT00004732. 2191 patients received their assigned treatment within 30 days of randomisation and had eligible ultrasonography (1086 who had carotid artery stenting, 1105 who had carotid endarterectomy). In 2 years, 58 patients who underwent carotid artery stenting (Kaplan-Meier rate 6·0%) and 62 who had carotid endarterectomy (6·3%) had restenosis or occlusion (hazard ratio [HR] 0·90, 95% CI 0·63-1·29; p=0·58). Female sex (1·79, 1·25-2·56), diabetes (2·31, 1·61-3·31

Preoperative Duplex Scanning is a Helpful Diagnostic Tool in Neurogenic Thoracic Outlet Syndrome.

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Orlando, Megan S; Likes, Kendall C; Mirza, Serene; Cao, Yue; Cohen, Anne; Lum, Ying Wei; Freischlag, Julie A

2016-01-01

To evaluate the diagnostic role of venous and arterial duplex scanning in neurogenic thoracic outlet syndrome (NTOS). Retrospective review of patients who underwent duplex ultrasonography prior to first rib resection and scalenectomy (FRRS) for NTOS from 2005 to 2013. Abnormal scans included ipsilateral compression (IC) with abduction of the symptomatic extremity (>50% change in subclavian vessel flow), contralateral (asymptomatic side) compression (CC) or bilateral compression (BC). A total of 143 patients (76% female, average age 34, range 13-59) underwent bilateral preoperative duplex scanning. Ipsilateral compression was seen in 44 (31%), CC in 12 (8%), and BC in 14 (10%). Seventy-three (51%) patients demonstrated no compression. Patients with IC more often experienced intraoperative pneumothoraces (49% vs. 25%, P duplex ultrasonography can assist in NTOS diagnosis. Ipsilateral compression on abduction often correlates with Adson testing. © The Author(s) 2016.

Analysis of the population at high risk of stroke detected with carotid artery ultrasonography in Tianjin urban communities

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Wei YUE

2015-04-01

Full Text Available Objective To investigate the features of carotid atherosclerosis in a population at high risk of stroke in urban communities of Tianjin, so as to provide inspiration for carotid ultrasonography to play a greater role in the prevention and control of stroke.  Methods A total of 956 residents at high risk of stroke were selected from 4 urban communities in Tianjin using cluster random sampling method. Doppler ultrasound screening was performed in bilateral common carotid artery (CCA, internal carotid artery (ICA, external carotid artery (ECA, vertebral artery (VA, subclavian artery (SCA and innominate artery of the population. The intima-media thickness (IMT, atherosclerotic plaque formation and its location and size, vascular stenosis or occlusion, and flow spectrum were detected. The results and features of carotid ultrasound screening were analyzed and compared among different gender and age groups.  Results 1 The detection rate of carotid atherosclerosis was 71.55% (684/956, and the detection rate in males was significantly higher than that in females (79.08% vs 65.87%; χ2 = 20.067, P = 0.000. 2 Among the population with carotid atherosclerosis, the most common manifestation was the formation of atherosclerotic plaques (81.58%, 558/684, secondly intima-media thickening (13.01%, 89/684, followed by moderate to severe stenosis or occlusion (5.41%, 37/684. The proportion of intima-media thickening in males was lower than that in females (7.08% vs 18.38%; χ2 = 19.269, P = 0.000. The proportion of carotid atherosclerotic plaque formation in males was higher than that in females (86.46% vs 77.16%; χ2 = 9.824, P = 0.002. The median rating of carotid atherosclerosis was 1.79, with males higher than females [1.98 (0.70, 3.26 vs 1.52 (0.20, 2.84; Z = 2.304, P = 0.042]. The site of plaque formation was most commonly located in carotid bulb (36.61%, secondly SCA (22.18%. Of the type of carotid stenosis, ICA stenosis was detected in 30 cases, VA

Asymptomatic carotid artery stenosis in patients with severe peripheral vascular diseases

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Rasoul Mirsharifi

2009-04-01

Full Text Available

• BACKGROUND: The prevalence of carotid artery stenosis (CAS in the  eneral population is not high enough to justify screening programs. This study was done to determine the prevalence of asymptomatic carotid artery stenosis (ACAS among patients with severe peripheral vascular disease (PVD.
• METHODS: Between March 2005 and February 2006, 54 consecutive  atients with severe PVD admitted at a vascular surgery unit and underwent carotid duplex scanning in a prospective study. A  uestionnaire was used to collect data concerning known risk factors. Significant CAS was defined as a stenosis of 70% or greater.
• RESULTS: The mean age was 62.5 years (51-72. Out of 54 patients, 2 (3.7% had an occluded internal carotid artery. Significant CAS was found in 9 (16.7% and its presence was correlated with diabetes, hypertension, hypercholesterolemia, hypertriglyceridemia, coronary artery disease, severity of symptoms, ankle-brachial index, and carotid bruit. On multivariate analysis, only hypercholesterolemia and carotid bruit seemed to have independent influence.
• CONCLUSION: The prevalence of significant ACAS is higher among  atients with severe PVD. This patient population may indicate a  uitable subgroup for screening of ACAS, especially when hypercholesterolemia and carotid bruit are present.
• KEYWORDS: Carotid artery stenosis, duplex ultrasound scanning, peripheral vascular disease, carotid endarterectomy,
• cerebrovascular accident.

Multi-parametric ultrasound criteria for internal carotid artery disease - comparison with CT angiography

International Nuclear Information System (INIS)

Barlinn, Kristian; Kepplinger, Jessica; Siepmann, Timo; Pallesen, Lars-Peder; Bodechtel, Ulf; Reichmann, Heinz; Puetz, Volker; Floegel, Thomas; Kitzler, Hagen H.; Alexandrov, Andrei V.

2016-01-01

The German Society of Ultrasound in Medicine (known by its acronym DEGUM) recently proposed a novel multi-parametric ultrasound approach for comprehensive and accurate assessment of extracranial internal carotid artery (ICA) steno-occlusive disease. We determined the agreement between duplex ultrasonography (DUS) interpreted by the DEGUM criteria and CT angiography (CTA) for grading of extracranial ICA steno-occlusive disease. Consecutive patients with acute cerebral ischemia underwent DUS and CTA. Internal carotid artery stenosis was graded according to the DEGUM-recommended criteria for DUS. Independent readers manually performed North American Symptomatic Carotid Endarterectomy Trial-type measurements on axial CTA source images. Both modalities were compared using Spearman's correlation and Bland-Altman analyses. A total of 303 acute cerebral ischemia patients (mean age, 72 ± 12 years; 58 % men; median baseline National Institutes of Health Stroke Scale score, 4 [interquartile range 7]) provided 593 DUS and CTA vessel pairs for comparison. There was a positive correlation between DUS and CTA (r s = 0.783, p < 0.001) with mean difference in degree of stenosis measurement of 3.57 %. Bland-Altman analysis further revealed widely varying differences (95 % limits of agreement -29.26 to 22.84) between the two modalities. Although the novel DEGUM criteria showed overall good agreement between DUS and CTA across all stenosis ranges, potential for wide incongruence with CTA underscores the need for local laboratory validation to avoid false screening results. (orig.)

Multi-parametric ultrasound criteria for internal carotid artery disease - comparison with CT angiography

Energy Technology Data Exchange (ETDEWEB)

Barlinn, Kristian; Kepplinger, Jessica; Siepmann, Timo; Pallesen, Lars-Peder; Bodechtel, Ulf; Reichmann, Heinz; Puetz, Volker [Carl Gustav Carus University Hospital, Technische Universitaet Dresden, Department of Neurology, Dresden (Germany); Floegel, Thomas [Carl Gustav Carus University Hospital, Technische Universitaet Dresden, Department of Neurology, Dresden (Germany); Carl Gustav Carus University Hospital, Technische Universitaet Dresden, Department of Neuroradiology, Dresden (Germany); Kitzler, Hagen H. [Carl Gustav Carus University Hospital, Technische Universitaet Dresden, Department of Neuroradiology, Dresden (Germany); Alexandrov, Andrei V. [The University of Tennessee Health Science Center, Department of Neurology, Memphis, TN (United States)

2016-09-15

The German Society of Ultrasound in Medicine (known by its acronym DEGUM) recently proposed a novel multi-parametric ultrasound approach for comprehensive and accurate assessment of extracranial internal carotid artery (ICA) steno-occlusive disease. We determined the agreement between duplex ultrasonography (DUS) interpreted by the DEGUM criteria and CT angiography (CTA) for grading of extracranial ICA steno-occlusive disease. Consecutive patients with acute cerebral ischemia underwent DUS and CTA. Internal carotid artery stenosis was graded according to the DEGUM-recommended criteria for DUS. Independent readers manually performed North American Symptomatic Carotid Endarterectomy Trial-type measurements on axial CTA source images. Both modalities were compared using Spearman's correlation and Bland-Altman analyses. A total of 303 acute cerebral ischemia patients (mean age, 72 ± 12 years; 58 % men; median baseline National Institutes of Health Stroke Scale score, 4 [interquartile range 7]) provided 593 DUS and CTA vessel pairs for comparison. There was a positive correlation between DUS and CTA (r{sub s} = 0.783, p < 0.001) with mean difference in degree of stenosis measurement of 3.57 %. Bland-Altman analysis further revealed widely varying differences (95 % limits of agreement -29.26 to 22.84) between the two modalities. Although the novel DEGUM criteria showed overall good agreement between DUS and CTA across all stenosis ranges, potential for wide incongruence with CTA underscores the need for local laboratory validation to avoid false screening results. (orig.)

Predictors of diagnostic success with renal artery duplex ultrasonography.

Science.gov (United States)

Hedayati, Nasim; Del Pizzo, David J; Harris, Sean E; Kuskowski, Michael; Pevec, William C; Lee, Eugene S; Pifer, Christy; Dawson, David L

2011-05-01

Renal artery duplex ultrasonography (RA-DUS) is commonly used for the evaluation and follow-up of renal artery atherosclerotic disease. In a complete study, renal artery flow is evaluated from the vessel origin to the intraparenchymal branches. The quality of RA-DUS is in part technologist-dependent, but many factors may affect the ability to complete a diagnostic examination. This study evaluated the clinical and technical factors that predict the ability to obtain a complete RA-DUS examination. A prospective evaluation of all patients undergoing RA-DUS between July 2008 and February 2009 was performed. Factors such as patient age, gender, body mass index, technologists' years of experience, patient care setting (inpatient vs. outpatient), bedside examination, smoking before the examination, fasting status, and recent abdominal surgery were all recorded. Multivariate logistic regression analysis was performed. A p value of ≤ 0.05 was considered significant. During the study period, 250 patients underwent RA-DUS (mean age: 59.9 ± 17.8 years, 57% [143] female). A total of 87 (35%) examinations were incomplete. This included nondiagnostic examinations which did not exhibit any segment of the renal artery. Factors that were associated with an incomplete examination included technologists' years of experience (OR = 0.92, p = 0.042), bedside examination (OR = 4.17, p = 0.016), and recent abdominal surgery (OR = 3.45, p = 0.047). Body mass index, fasting status, and smoking before the examination did not affect the ability to obtain a complete study. One-third of the RA-DUS studies were classified as incomplete by the strict criteria used in this prospective study. An experienced ultrasound technologist is more likely to obtain a complete RA-DUS examination. Recent abdominal surgery and bedside examinations were predictive of a limited examination as well. Vascular laboratories should consider these factors when scheduling examinations so as to obtain complete RA

Experiences with carotid endarterectomy at Sree Chitra Tirunal Institute

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Unnikrishnan Madathipat

2008-01-01

Full Text Available Background: Atherosclerotic carotid artery disease poses a grave threat to cerebral circulation, leading to a stroke with its devastating sequelae, if left untreated. Carotid endarterectomy has a proven track record with compelling evidence in stroke prevention. Objectives: aTo confirm that carotid endarterectomy (CEA is safe and effective in preventing stroke at both short and long term. b to demonstrate long term patency of internal carotid artery when arteriotomy repair is performed using autologous saphenous vein patch. Materials and Methods: During ten years, from September 1997 to February 2008, thirty nine patients who underwent consecutive carotid endarterectomy at our institute, form the basis of this report. Their age ranged from thirty to seventy eight years, with a mean age of 56. There were four women in this cohort. Thirty seven patients were symptomatic with> 70% stenosis and two were asymptomatic with> 80% stenosis, incidentally detected. Imaging included Duplex scan and MRA for carotid territory and brain, and non-invasive cardiac assessment. Co-morbidities included smoking, hypertension, diabetes, and coronary artery disease. Carotid Endarterectomy was performed under general anaesthesia, using carotid shunt and vein patch arteriotomy repair. Results: All the patients made satisfactory recovery, without major adverse cerebral events in this series. Morbidities included Transient Ischemic Attack (TIA in two, needing only medications in one, and carotid stenting in the other. Minor morbidities included neck hematoma in two and transient hypoglossal paresis in three patients. Yearly follow-up included duplex scan assessment for all the patients. Two patients died of contralateral stroke, two of myocardial events and two were lost to follow up. Thirty three patients are well and free of the disease during the follow up of three to 120 months. Conclusion: Carotid endarterectomy provided near total freedom from adverse cerebral

Association between Carotid Intima Media Thickness and Heart Rate Variability in Adults at Increased Cardiovascular Risk

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Ovidiu C. Baltatu

2017-04-01

Full Text Available Background: Atherosclerotic carotid intima-media thickness (IMT may be associated with alterations in the sensitivity of carotid baroreceptors. The aim of this study was to investigate the association between carotid IMT and the autonomic modulation of heart rate variability (HRV.Methods: A total of 101 subjects were enrolled in this prospective observational study. The carotid IMT was determined by duplex ultrasonography. The cardiac autonomic function was determined through HRV measures during the Deep Breathing Test. Linear regression models, adjusted for demographics, comorbidities, body mass index, waist-hip-ratio, and left ventricular ejection fraction were used to evaluate the association between HRV parameters and carotid IMT.Results: Participants had a mean age of 60.4 ± 13.4 years and an estimated 10-year atherosclerotic cardiovascular disease (ASCVD risk score (using the Pooled Cohort Equations of 16.4 ± 17. The mean carotid media thickness was highest (0.90 ± 0.19 mm in the first quartile of the standard deviation of all RR intervals (SDNN (19.7 ± 5.1 ms and progressively declined in each subsequent quartile to 0.82 ± 0.21 mm, 0.81 ± 0.16 mm, and 0.68 ± 0.19 in quartiles 2 (36.5 ± 5.9 ms, 3 (57.7 ± 6.2 ms and 4 (100.9 ± 22.2 ms, respectively. In multivariable adjusted models, there was a statistical significant association between SDNN and carotid IMT (OR −0.002; 95%CI −0.003 to −0.001, p = 0.005. The same significant association was found between carotid IMT and other measures of HRV, including coefficient of variation of RR intervals (CV and dispersion of points along the line of identity (SD2.Conclusions: In a cohort of individuals at increased cardiovascular risk, carotid IMT as a marker of subclinical atherosclerosis was associated with alterations of HRV indicating an impaired cardiac autonomic control, independently of other cardiovascular risk factors.

Implementation of real-time duplex synthetic aperture ultrasonography

DEFF Research Database (Denmark)

Hemmsen, Martin Christian; Larsen, Lee; Kjeldsen, Thomas

2015-01-01

This paper presents a real-time duplex synthetic aperture imaging system, implemented on a commercially available tablet. This includes real-time wireless reception of ultrasound signals and GPU processing for B-mode and Color Flow Imaging (CFM). The objective of the work is to investigate the im...... and that the required bandwidth between the probe and processing unit is within the current Wi-Fi standards....

Quantitative assessment of changes in carotid plaques during cilostazol administration using three-dimensional ultrasonography and non-gated magnetic resonance plaque imaging

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Yamaguchi, Mao; Ohba, Hideki; Mori, Kiyofumi; Narumi, Shinsuke; Katsura, Noriyuki; Ohura, Kazumasa; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto; Kudo, Kohsuke [Iwate Medical University, Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Morioka (Japan)

2012-09-15

Cilostazol, an antiplatelet agent, is reported to induce the regression of atherosclerotic changes. However, its effects on carotid plaques are unknown. Hence, we quantitatively investigated the changes that occur within carotid plaques during cilostazol administration using three-dimensional (3D) ultrasonography (US) and non-gated magnetic resonance (MR) plaque imaging. We prospectively examined 16 consecutive patients with carotid stenosis. 3D-US and T1-weighted MR plaque imaging were performed at baseline and 6 months after initiating cilostazol therapy (200 mg/day). We measured the volume and grayscale median (GSM) of the plaques from 3D-US data. We also calculated the contrast ratio (CR) of the carotid plaque against the adjacent muscle and areas of the intraplaque components: fibrous tissue, lipid, and hemorrhage components. The plaque volume on US decreased significantly (median at baseline and 6 months, 0.23 and 0.21 cm{sup 3}, respectively; p = 0.03). In the group exhibiting a plaque volume reduction of more than 10%, GSM on US increased significantly (24.8 and 71.5, respectively; p = 0.04) and CR on MRI decreased significantly (1.13 and 1.04, respectively; p = 0.02). In this group, in addition, the percent area of the fibrous component on MRI increased significantly (68.6% and 79.4%, respectively; p = 0.02), while those of the lipid and hemorrhagic components decreased (24.9% and 20.5%, respectively; p = 0.12) (1.0% and 0.0%, respectively; p = 0.04). There were no substantial changes in intraplaque characteristics in either US or MRI in the other group. 3D-US and MR plaque imaging can quantitatively detect changes in the size and composition of carotid plaques during cilostazol therapy. (orig.)

Urinary arsenic methylation capability and carotid atherosclerosis risk in subjects living in arsenicosis-hyperendemic areas in southwestern Taiwan

Energy Technology Data Exchange (ETDEWEB)

Huang, Y.-L. [Department of Public Health, School of Medicine, Taipei Medical University, Taipei, Taiwan (China); Hsueh, Y.-M. [Department of Public Health, School of Medicine, Taipei Medical University, Taipei, Taiwan (China)], E-mail: ymhsueh@tmu.edu.tw; Huang, Y.-K. [Graduate Institute of Medical Sciences, School of Medicine, Taipei Medical University, Taipei, Taiwan (China); Yip, P.-K. [Department of Neurology, College of Medicine, National Taiwan University, Taiwan (China); Yang, M.-H. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu, Taiwan (China); Chen, C.-J. [Genomics Research Center, Academia Sinica, Taipei, Taiwan (China); Graduate Institute of Epidemiology, College of Public Health, National Taiwan University Taipei, Taiwan (China)

2009-04-01

Long-term exposure to inorganic arsenic from artesian drinking well water is associated with carotid atherosclerosis in the Blackfoot Disease (BFD)-hyperendemic area in Taiwan. The current study examined the arsenic methylation capacity and its risk on carotid atherosclerosis. A total of 304 adults (158 men and 146 women) residing in the BFD-hyperendemic area were included. The extent of carotid atherosclerosis was assessed by duplex ultrasonography. Chronic arsenic exposure was estimated by an index of cumulative arsenic exposure (CAE) and the duration of artesian well water consumption. Urinary levels of inorganic arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)] were determined by high performance liquid chromatography linked on-line to a hydride generator and atomic absorption spectrometry (HPLC-HG-AAS). The percentage of arsenic species, primary methylation index [PMI = MMA(V) / (As(III) + As(V)] and secondary methylation index [SMI = DMA(V) / MMA(V)] were calculated and employed as indicators of arsenic methylation capacity. Results showed that women and younger subjects had a more efficient arsenic methylation capacity than did men and the elderly. Carotid atherosclerosis cases had a significantly greater percentage of MMA(V) [%MMA(V)] and a lower percentage of DMA [%DMA (V)] compared to controls. Subjects in the highest two tertiles of PMI with a median of CAE > 0 mg/L-year had an odds ratio (OR) and a 95% confidence interval (CI) of carotid atherosclerosis of 2.61 and 0.98-6.90 compared to those in the highest two tertiles of PMI with a CAE = 0 mg/L-year. We conclude that individuals with greater exposure to arsenic and lower capacity to methylate inorganic arsenic may be at a higher risk to carotid atherosclerosis.

Urinary arsenic methylation capability and carotid atherosclerosis risk in subjects living in arsenicosis-hyperendemic areas in southwestern Taiwan

International Nuclear Information System (INIS)

Huang, Y.-L.; Hsueh, Y.-M.; Huang, Y.-K.; Yip, P.-K.; Yang, M.-H.; Chen, C.-J.

2009-01-01

Long-term exposure to inorganic arsenic from artesian drinking well water is associated with carotid atherosclerosis in the Blackfoot Disease (BFD)-hyperendemic area in Taiwan. The current study examined the arsenic methylation capacity and its risk on carotid atherosclerosis. A total of 304 adults (158 men and 146 women) residing in the BFD-hyperendemic area were included. The extent of carotid atherosclerosis was assessed by duplex ultrasonography. Chronic arsenic exposure was estimated by an index of cumulative arsenic exposure (CAE) and the duration of artesian well water consumption. Urinary levels of inorganic arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)] were determined by high performance liquid chromatography linked on-line to a hydride generator and atomic absorption spectrometry (HPLC-HG-AAS). The percentage of arsenic species, primary methylation index [PMI = MMA(V) / (As(III) + As(V)] and secondary methylation index [SMI = DMA(V) / MMA(V)] were calculated and employed as indicators of arsenic methylation capacity. Results showed that women and younger subjects had a more efficient arsenic methylation capacity than did men and the elderly. Carotid atherosclerosis cases had a significantly greater percentage of MMA(V) [%MMA(V)] and a lower percentage of DMA [%DMA (V)] compared to controls. Subjects in the highest two tertiles of PMI with a median of CAE > 0 mg/L-year had an odds ratio (OR) and a 95% confidence interval (CI) of carotid atherosclerosis of 2.61 and 0.98-6.90 compared to those in the highest two tertiles of PMI with a CAE = 0 mg/L-year. We conclude that individuals with greater exposure to arsenic and lower capacity to methylate inorganic arsenic may be at a higher risk to carotid atherosclerosis

Renal function and carotid atherosclerosis in adults with no known kidney disease.

Science.gov (United States)

Buscemi, S; Geraci, G; Massenti, F M; Buscemi, C; Costa, F; D'Orio, C; Rosafio, G; Buscemi, C; Maniaci, V; Parrinello, G

2017-03-01

A high prevalence of atherosclerotic lesions characterizes patients with chronic kidney disease, though there is little data on the relationship between kidney function and atherosclerotic changes in the healthy population or in people with no known renal impairment. The aim of our study was to analyze, in a comprehensive general population with no known kidney disease, the relationship between renal function and subclinical carotid atherosclerotic damage. A general real-life population of 611 participants (233 males and 378 females; age ≥18 years) with no known kidney failure was selected for the study. The glomerular filtration rate (GFR) was estimated according to the CKD-EPI equation. Carotid intima-media thickness (c-IMT) and plaques were assessed by duplex Doppler ultrasonography of the carotid vessels. The main laboratory and metabolic parameters were evaluated in all participants. When we divided the overall study population into tertiles according to GFR values (I tertile 99 ml/min/1.73 m 2 ), the c-IMT mean values and the prevalence of carotid plaques decreased with the increasing tertile of GFR. On univariate analysis, c-IMT was significantly correlated with eGFR (r = -0.33; p < 0.001), serum creatinine (r = 0.17; p < 0.001), and other variables such as age, systolic blood pressure, waist circumference, fasting or random glycemia, and glycated hemoglobin (HbA 1 c). On multiple regression analysis, serum creatinine was associated with c-IMT (β = 0.069; p = 0.017), independent of other covariates. Our study seems to suggest the importance of early identification of people with near normal or mildly decreased renal function due to its association with carotid atherosclerosis. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights

Carotid free-floating thrombus causing stroke in a young woman with lupus anticoagulant: A case report and review of the literature.

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Afsharfard, Abolfazl; Gholizadeh, Barmak; Abdolalian, Younes; Hosseini, Seyed Masoud

2017-01-01

In young adults Stroke is a challenging condition and various tests are needed to diagnose and manage its underlying problems. Free floating thrombosis of internal carotid artery (FFT-ICA) is one of the rare problems among carotid artery diseases which can lead to stroke in adults. Owing to limited cases of FFT-ICA there is not a worldwide accepted consensus on management of FFT-ICA, but some recurrences after medical management have been reported in the literature. A-25-year old woman was referred to hospital with sudden onset aphasia and right sided hemiparesis. Carotid duplex ultrasonography showed an iso-echogenic thrombus ranged about 5×10mm partially attached to arterial wall of the right internal carotid artery. It was floating in accordance with the heartbeat. Anticoagulation therapy was initiated and subsequently she underwent an urgent operation. To explore the etiology of her problem, various lab tests were carried out; the results showed markedly elevated levels of lupus anticoagulant. She was discharged from hospital after an uneventful recovery showing gradual improvement of symptoms in follow-up visits. FFT-ICA is one of the scarce disorders of carotid artery. Less than 150 cases have been reported in the literature indicating its common occurrence in old men. Hence the etiology of this case (FFT in a young patient with high levels of lupus anticoagulant antibody) may be the first of its type. In this case we chose surgical treatment resulting in complete resolution of symptoms and non-recurrence within 6 month follow-up. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Indium-111 platelet scintigraphy in carotid disease

International Nuclear Information System (INIS)

Branchereau, A.; Bernard, P.J.; Ciosi, G.; Bazan, M.; de Laforte, C.; Elias, A.; Bouvier, J.L.

1988-01-01

Forty-five patients (35 men, 10 women) undergoing carotid surgery had Indium-111 platelet scintigraphy as part of their preoperative work-up. Imaging was performed within three hours after injection of the Indium-111. A second series of views was obtained 24 hours later and repeated at 24 hour intervals for two days. Of 54 scintigrams, 22 were positive and 32 negative. Positive results were defined as a twofold or more increase in local activity on a visualized carotid after 24 hours. The sensitivity of the method was 41%, intraoperatively, and the specificity, 100%. The low sensitivity places this method behind sonography and duplex-scanning for screening patients for surgery. We believe that indications for platelet scintigraphy are limited to: 1. Repeated transient ischemic attacks in the same territory with minimal lesions on arteriography and non-homogeneous plaque on duplex scan; 2. Symptomatic patients being treated medically as a possible argument for surgery; 3. Determining therapeutic policy for patients having experienced a transient ischemic attack with a coexisting intracardiac thrombus

Diagnosing erectile dysfunction: the penile dynamic colour duplex ultrasound revisited.

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Aversa, A; Bruzziches, R; Spera, G

2005-12-01

A number of disease processes of the penis including Peyronie's disease, priapism, penile fractures and tumors are clearly visualized with ultrasound. Diagnostic evaluation of erectile dysfunction (ED) by penile dynamic colour-duplex Doppler ultrasonography (D-CDDU) is actually considered a second level approach to ED patients because of the fact that intracavernous injections test IV with prostaglandin-E(1) may provide important information about the patients' erectile capacity. However, no direct vascular imaging and a high percentage of false negative diagnoses of vasculogenic ED are its major pitfalls and subsequent treatment decisions remain quite limited. The occurrence of ED and its sentinel relationship to cardiovascular disease has prompted more accurate vascular screening in all patients even in the absence of cardiovascular risk factors. The sonographic evaluation of the intima-media thickness of the carotid arteries may sometimes represent an early manifestation of diffuse atherosclerotic disease and endothelial damage. This latter finding is often the cause of failure to oral agents, i.e. phosphodiesterase inhibitors, because of inability of the dysfunctional endothelium to release nitric oxide. D-CDDU represents an accurate tool to investigate cavernous artery inflow and venous leakage when compared with more invasive diagnostic techniques i.e. selective arteriography and dynamic infusion cavernosometry along with cavernosography.

Duplex evaluation following femoropopliteal angioplasty and stenting: criteria and utility of surveillance.

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Baril, Donald T; Marone, Luke K

2012-07-01

Surveillance following lower extremity bypass, carotid endarterectomy, and endovascular aortic aneurysm repair has become the standard of care at most institutions. Conversely, surveillance following lower extremity endovascular interventions is performed somewhat sporadically in part because the duplex criteria for recurrent stenoses have been ill defined. It appears that duplex surveillance after peripheral endovascular interventions, as with conventional bypass, is beneficial in identifying recurrent lesions which may preclude failure and occlusion. In-stent stenosis following superficial femoral artery angioplasty and stenting can be predicted by both peak systolic velocity and velocity ratio data as measured by duplex ultrasound. Duplex criteria have been defined to determine both ≥50% in-stent stenosis and ≥80% in-stent stenosis. Although not yet well studied, it appears that applying these criteria during routine surveillance may assist in preventing failure of endovascular interventions.

Carotid angioplasty and stenting for symptomatic carotid kinking combined with stenosis

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JIANG Xue-li

2013-03-01

Full Text Available Background Carotid endarterectomy (CEA is currently the preferred treatment for severe carotid kinking and stenosis. Kinking is generally believed to be a relative contraindication for endovascular stent placement. This article aims to study the necessity, feasibility and security of carotid angioplasty and stenting (CAS for symptomatic carotid kinking combined with stenosis, and summarize clinical experience of this disease according to therapeutic results. Methods Twenty-two cases with symptomatic carotid kinking and high-grade stenosis demonstrated by digital subtraction angiography (DSA were performed CAS. Their clinical manifestations, imaging features, procedure safety and follow-up data were collected and retrospectively analyzed. All patients understood CEA and voluntarily received CAS. Results Twenty-two cases with carotid kinking and stenosis were all successfully performed CAS (the success rate was 100% without stent-related disability or mortality. Twenty-four self-expandable stents were implanted. The mean degree of stenosis was reduced from 85.63%before stenting to 11.25% after stenting and the angles of kinking were improved from 120° (Metz' category. During the period of hospitalization, no transient ischemic attack (TIA or cerebral infarction occurred, and the clinical symptoms and signs of ischemia, such as dizziness and headache, were improved or disappeared. Besides, no permenant complications or deaths happened. All cases were followed up from 6 to 72 months, among whom 1 patient experienced contralateral carotid TIA, and 2 patients experienced ipsilateral carotid TIA (one indicated aspirin resistance in platelet aggregation test and the other showed restenosis in DSA. Computed tomography angiography (CTA of 10 patients and Duplex scan of 7 patients during the follow-up demonstrated carotid in good morphology and fluent blood flow, without kinking or restenosis. Conclusion CAS is a feasible and safe therapeutic method and

A new approach for the screening of carotid lesions: a 'fast-track' method with the use of new generation hand-held ultrasound devices.

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Aboyans, V; Lacroix, P; Jeannicot, A; Guilloux, J; Bertin, F; Laskar, M

2004-09-01

We assessed the usefulness of fast-track neck sonography with a new-generation hand-held ultrasound scanner in the detection of > or =60% carotid stenosis. Patients with a past history of atherosclerotic disease or presence of risk factors were enrolled. All had fast-track carotid screening with a hand-held ultrasound scanner. Initial assessment was performed with our quick imaging protocol. A second examiner performed a conventional complete carotid duplex as gold-standard. We enrolled 197 consecutive patients with a mean age of 67 years (range 35-94). A carotid stenosis >60% was detected in 13 cases (6%). The sensitivity, specificity, positive and negative predictive value of fast-track sonography was 100%, 64%, 17% and 100%, respectively. Concomitant power Doppler imaging during the fast-track method did not improve accuracy. The use of a fast-track method with a hand-held ultrasound device can reduce the number of unnecessary carotid Duplex and enhance the screening efficiency without missing significant carotid stenoses.

An assessment of the vulnerability of carotid plaques: a comparative study between intraplaque neovascularization and plaque echogenicity

International Nuclear Information System (INIS)

Zhou, Yangyang; Li, Yan; Bai, Yang; Chen, Ying; Sun, Xiaofeng; Zhu, Yingqiao; Wu, Jiang

2013-01-01

Carotid plaque echolucency as detected by Color Doppler ultrasonography (CDUS) has been used as a potential marker of plaque vulnerability. However, contrast-enhanced ultrasound (CEUS) has recently been shown to be a valuable method to evaluate the vulnerability and neovascularization within carotid atherosclerotic plaques. The aim of this study was to compare CEUS and CDUS in the assessment of plaque vulnerability using transcranial color Doppler (TCD) monitoring of microembolic signals (MES) as a reference technique. A total of 46 subjects with arterial stenosis (≥ 50%) underwent a carotid duplex ultrasound, TCD monitoring of MES and CEUS (SonoVue doses of 2.0 mL) within a span of 3 days. The agreement between the CEUS, CDUS, and MES findings was assessed with a chi-square test. A p-value less than 0.05 was considered statistically significant. Neovascularization was observed in 30 lesions (44.4%). The vascular risk factors for stroke were similar and there were no age or gender differences between the 2 groups. Using CEUS, MES were identified in 2 patients (12.5%) within class 1 (non-neovascularization) as opposed to 15 patients (50.0%) within class 2 (neovascularization) (p = 0.023). CDUS revealed no significant differences in the appearance of the MES between the 2 groups (hyperechoic and hypoechoic) (p = 0.237). This study provides preliminary evidence to suggest that intraplaque neovascularization detected by CEUS is associated with the presence of MESs, where as plaque echogenicity on traditional CDUS does not. These findings argue that CEUS may better identify high-risk plaques

Efficacy of patient selection strategies for carotid endarterectomy by contrast-enhanced MRA on a 1 T machine and duplex ultrasound in a regional hospital

International Nuclear Information System (INIS)

Korteweg, M.A.; Kerkhoff, H.; Bakker, J.; Elgersma, O.E.H.

2008-01-01

Aim: To investigate whether contrast-enhanced magnetic resonance angiography (CE-MRA) and duplex ultrasound (DUS) could replace digital subtraction angiography (DSA) for diagnosing internal carotid artery (ICA) stenosis in regional centres with less specialized technicians and equipment, such as a 1 Tesla MRI machine. Materials and methods: Sixty-six consecutive, symptomatic patients with ICA stenosis, as evidenced using DSA, were included. In the first 34 patients DUS was validated and cut-off criteria were established. Data were analysed by receiver operating characteristic curve and logistic regression. Two observers analysed the DUS and CE-MRA results of 32 patients. Stenoses were categorized in accordance with North American Symptomatic Endarterectomy Trial (NASCET) measurement criteria. Results: Peak systolic velocity (PSV) in the ICA was defined as a better parameter for defining stenosis than end diastolic velocity and the PSV ICA:common carotid artery ratio. The optimal PSV threshold was 230 cm/s. Four ICAs were not interpretable on DUS, and one on CE-MRA. Two patients did not undergo CE-MRA. The sensitivities and specificities were calculated: for DUS these were 100% and 68% respectively; for observer 1 on CE-MRA these were 93% and 89%, respectively; for observer 2 these were 92% and 87%, respectively. The sensitivity and specificity for combined DUS/CE-MRA were 100% and 85%, respectively. Seventy-eight percent of CE-MRA and DUS correlated. The weighted Kappa for CE-MRA and DSA were 0.8 and 0.9, respectively. Conclusion: DUS and CE-MRA are effective non-invasive methods for selecting patients with ICA stenosis for carotid endarterectomy in non-specialized centres using a 1 T machine. The present results suggest that no referrals to more specialized centres for non-invasive diagnostic work-up for carotid artery stenoses will be necessary

Urinary tract infection in children: Role of ultrasonography

International Nuclear Information System (INIS)

Lee, Hye Won; Lee, Sun Wha; Ko, Young Tae; Lim, Joo Won

1994-01-01

To evaluate diagnostic usefulness of ultrasonography(US) in pediatric patient with urinary tract infection. Fifty-five children with urinary tract infection underwent renal ultrasonography and voiding cystourethrography(VCUG). The imaging findings were analyzed retrospectively. Renal sonograms were normal in 34 of 55 children(62%). Five of 34 patients with normal sonogram had vesicoureteral reflux of grade I and III on VCUG. Renal sonograms were abnormal in 21 of 55 children(38%). Sonographic findings included hydronephrosis, hyperechoic kidney, nephromegaly, altrophic kidney, renal abscess, and duplex ureter. Eleven of 21 patient with abnormal sonogram had vesicoureteral reflux of grade I to IV on VCUG. Ultrasonography is an useful and reliable initial screening examination in the investigation of children with UTI. Unfortunately US is neither sufficiently sensitive nor specific for detecting VUR. VCUG provides confirmative and valuable information about vesicoureteral reflux, and VCUG should be considered as a next modality for UTI. The combined use of sonography and VCUG provides more valuable information in urinary tract infection

Pre-operative Duplex Ultrasonography in Arteriovenous Fistula Creation: Intra- and Inter-observer Agreement.

Science.gov (United States)

Zonnebeld, Niek; Maas, Tommy M G; Huberts, Wouter; van Loon, Magda M; Delhaas, Tammo; Tordoir, Jan H M

2017-11-01

Although clinical guidelines on arteriovenous fistula (AVF) creation advocate minimum luminal arterial and venous diameters, assessed by duplex ultrasonography (DUS), the clinical value of routine DUS examination is under debate. DUS might be an insufficiently repeatable and/or reproducible imaging modality because of its operator dependency. The present study aimed to assess intra- and inter-observer agreement of DUS examination in support of AVF surgery planning. Ten end stage renal disease patients were included, to assess intra- and inter-observer agreement of pre-operative DUS measurements. All measurements were performed by two trained and experienced vascular technicians, blinded to measurement readings. From the routine DUS protocol, representative measurements (venous diameters, and arterial diameters and volume flow in the upper arm and forearm) were selected. For intra-observer agreement the measurements were performed in triplicate, with the probe released from the skin between each. Intraclass correlation coefficients were calculated for intra- and inter-observer agreement, and Bland-Altman plots used to graphically display mean measurement differences and limits of agreement. Ten patients (6 male, 59.4±19.7 years) consented to participate, and all predefined measurements were obtained. Intraclass correlation coefficients for intra-observer agreement of diameter measurements were at least 0.90 (95% CI 0.74-0.97; radial artery). Inter-observer agreement was at least 0.83 (0.46-0.96; lateral diameter upper arm cephalic vein). The Bland-Altman plots showed acceptable mean measurement differences and limits of agreement. In experienced hands, excellent intra- and inter-observer agreement can be reached for the discrete pre-operative DUS measurements advocated in clinical guidelines. DUS is therefore a reliable imaging modality to support AVF surgery planning. The content of DUS protocols, however, needs further standardisation. Copyright © 2017 European

Clinical utility of carotid and transcranial ultrasound in cerebrovascular diseases

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Figueiredo L

2014-08-01

Full Text Available Lívia Figueiredo, Viviane F Zétola, Marcos C Lange Neurology Division, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil Abstract: Carotid and transcranial (CTU ultrasound is a useful tool in a number of clinical settings, particularly in cerebrovascular diseases. CTU is the only method that provides real-time determination of velocity and the spectral waveform of blood flow in the extracranial and basal intracranial arteries, and is effective in the detection of stenosis and occlusion. When transcranial ultrasound is considered, CTU is the only method that allows visualization of microembolic signals in the intracranial arteries. CTU makes a rapid differential diagnosis possible, improving therapeutic decision-making in acute stroke and determining the risk of recurrence and prognosis based on its findings. It is also the standard of care in children with sickle cell disease, when selecting patients for chronic blood transfusion, and for reducing the risk of ischemic stroke in these patients. CTU has some advantages, ie, relative simplicity in terms of interpretation and performance, and affordability, noninvasiveness, and portability. The main concern with ultrasound is that it is an operator-dependent tool and requires a high level of expertise and knowledge of three-dimensional cerebrovascular anatomy for correct interpretation of sonograms. The most significant limitation of intracranial evaluation by transcranial ultrasound is the absence of a suitable bone window in approximately 10% of patients. This paper gives an overview of the current utility and importance of CTU in the prevention and evaluation of ischemic cerebrovascular disease. Keywords: transcranial Doppler ultrasonography, Doppler ultrasonography duplex, cerebrovascular disorders, stroke

[Measurements of blood velocities using duplex sonography in carotid artery stents: analysis of reliability in an in-vitro model and computational fluid dynamics (CFD)].

Science.gov (United States)

Schönwald, U G; Jorczyk, U; Kipfmüller, B

2011-01-01

Stents are commonly used for the treatment of occlusive artery diseases in carotid arteries. Today, there is a controversial discussion as to whether duplex sonography (DS) displays blood velocities (BV) that are too high in stented areas. The goal of this study was to evaluate the effect of stenting on DS with respect to BV in artificial carotid arteries. The results of computational fluid dynamics (CFD) were also used for the comparison. To analyze BV using DS, a phantom with a constant flow (70 cm/s) was created. Three different types of stents for carotid arteries were selected. The phantom fluid consisted of 67 % water and 33 % glycerol. All BV measurements were carried out on the last third of the stents. Furthermore, all test runs were simulated using CFD. All measurements were statistically analyzed. DS-derived BV values increased significantly after the placement of the Palmaz Genesis stent (77.6 ± 4.92 cm/sec, p = 0.03). A higher increase in BV values was registered when using the Precise RX stent (80.1 ± 2.01 cm/sec, p CFD simulations showed similar results. Stents have a significant impact on BV, but no effect on DS. The main factor of the blood flow acceleration is the material thickness of the stents. Therefore, different stents need different velocity criteria. Furthermore, the results of computational fluid dynamics prove that CFD can be used to simulate BV in stented silicone tubes. © Georg Thieme Verlag KG Stuttgart · New York.

Duplex ultrasonography in the hemorrhagic fever with renal syndrome; Correlation with laboratory findings

International Nuclear Information System (INIS)

Han, Chun Hee; Cho, K. S.; Auh, Y. h.; Park, C. S.; Park, S. K.; Kim, S. B.

1994-01-01

Assuming that the duplex Doppler sonography might be useful in predicting the disease evolution of hemorrhagic fever with renal syndrome, we compared the resistive index (RI) with the clinical and laboratory findings in 18 patients. We underwent 30 duplex Doppler examinations in 18 patients: one examination in nine, two examinations in six, and three examinations in three patients. Duplex Dopper waveforms were obtained from the main, segmental,interlobar, and arcuate arteries of both kidneys, and the RI was calculated for each study. In oliguric phase, the mean RI was high (average, 0.94), and the serum BUN(averate, 92.3mg/dl) and creatinine(average, 10.4mg/dl) levels were elevated. In diuretic phase the mean RI was normalized (average, 0.7), and the serum BUN(average, 31.1mg/dl)and serum creatinine (average, 2.9mg/dl) levels were low. There was statistically significant correlation between the mean RI and the serum levels of BUN and creatinine and 24 hour urine output (P<0.001). We conclude that the mean RI is a useful indicator in predicting the disease evolution in patients with hemorrhagic fever with renal syndrome

Association between plasma homocysteine concentrations and extracranial carotid stenosis

International Nuclear Information System (INIS)

Mousavi, Seyed Ali; Ghasemi, M.; Hoseini, T.

2006-01-01

Increasing epidemiologic data support a relationship between elevated plasma total homocysteine levels and an increased risk for vascular disease. Higher plasma total homocysteine (tHcy) levels have been associated with extracranial carotid atherosclerosis and cerebral infarction in whites. However, data regarding such associations are limited for Asians. This study examined the association between tHcy level and carotid stenosis in Iranian subjects. In this retrospective study, the subjects were 158 patients with ischemic stroke, including 105 with a normal tHcy level and 53 with a high tHcy level. We investigated the extracranial carotid arteries by ultrasonography and measured serum tHcy by ELISA method in these two groups. We found no meaningful association between a high tHcy level and carotid stenosis. The lack of any meaningful difference in carotid stenosis between patients with normal and elevated tHcy levels is probably due to the low frequency of extracranial diseases in the Asian population and to the nature of homocysteine atherosclerosis. (author)

Prevalence of significant carotid artery stenosis in Iranian patients with peripheral arterial disease

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Ghabili K

2011-10-01

Full Text Available Abolhassan Shakeri Bavil1, Kamyar Ghabili2, Seyed Ebrahim Daneshmand3, Masoud Nemati3, Moslem Shakeri Bavil4, Hossein Namdar5, Sheyda Shaafi61Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 2Medical Philosophy and History Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 3Department of Radiology, Tabriz University of Medical Sciences, Tabriz, Iran; 4Department of Neurosurgery, Tabriz University of Medical Sciences, Tabriz, Iran; 5Department of Cardiology, Tabriz University of Medical Sciences, Tabriz, Iran; 6Neuroscience Research Center, Tabriz University of Medical Sciences, Tabriz, IranBackground: Generalized screening for carotid artery stenosis with carotid duplex ultrasonography in patients with peripheral arterial disease is controversial.Objectives: The aim of the present study was to determine the prevalence of significant internal carotid artery (ICA stenosis in a group of Iranian patients with peripheral arterial disease.Methods: We prospectively screened 120 patients with a known diagnosis of peripheral vascular disease for carotid artery stenosis. Based on the angiographic assessment of abdominal aorta and arteries of the lower extremities, patients with stenosis greater than 70% in the lower extremity arteries were included. A group of healthy individuals aged ≥50 years was recruited as a control. Risk factors for atherosclerosis including smoking, diabetes mellitus, hyperlipidemia, ischemic heart disease, and cerebrovascular disease were recorded. Common carotid arteries (CCAs and the origins of the internal and external arteries were scanned with B-mode ultrasonogaphy. Significant ICA stenosis, >70% ICA stenosis but less than near occlusion of the ICA, was diagnosed when the ICA/CCA peak systolic velocity ratio was ≥3.5.Results: Ninety-five patients, with a mean age of 58.52 ± 11.04 years, were studied. Twenty-five patients had a history of smoking, six

The role of contrast-enhanced ultrasound in risk assessment of carotid atheroma

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Silviu Stanciu

2016-07-01

Full Text Available Background and objective: Contrast-enhanced ultrasound, used to assess atherosclerotic carotid plaques, improves visualization of vessel wall irregularities and depicts intraplaque neovascularization. This article illustrates the use of contrast-enhanced ultrasound in the risk assessment of carotid atherosclerotic lesions, especially in challenging plaques evaluation. Materials and methods: For 23 patients with difficult duplex ultrasound examination due to carotid tortuosity or calcifications we assessed plaque morphology (contour, echogenicity and stenosis degree using contrast substance (Sonovue, Braco with dedicated vascular low mechanical index CPC software. Conclusion: Contrast-enhanced ultrasound is a new, noninvasive, and safe procedure for imaging carotid atherosclerotic lesions. It is a valuable tool for evaluating the vulnerable plaque at risk for rupture and for the diagnostic of the development and severity of systemic atherosclerotic disease

A Novel Carotid Device for Embolic Diversion: Lessons Learned from a “First in Man” Trial in Patients with Atrial Fibrillation

International Nuclear Information System (INIS)

Sievert, Horst; Franke, Jennifer; Grad, Ygael; Nishri, Boaz; Assaf, Yaron; Yodfat, Ofer; Römer, Albrecht; Robertson, Greg C.; Stone, Gregg W.

2012-01-01

Purpose: This study was designed to investigate a novel device that was developed to direct emboli away from the internal carotid artery to the external carotid artery to prevent embolic stroke while avoiding the necessity for anticoagulation with warfarin. Methods: A stent-like, self-expandable filter was developed consisting of fine cobalt alloy mesh. After promising preclinical animal testing, the device was implanted into the common carotid artery extending into the external carotid artery in three patients with atrial fibrillation, each of whom were at high-risk for cerebral emboli and were suboptimal candidates for anticoagulation. Follow-up was performed clinically and with carotid duplex ultrasound. Results: The implantation was successful in all three patients. Unrestricted flow through the filter was demonstrated in each patient at 6 months by duplex sonography. However, at 7 months ultrasound demonstrated occlusion of the internal carotid artery filter in one patient, which was subsequently confirmed by angiography. Subtotal filter occlusion occurred in a second patient at 14 months. Neither patient had clinical symptoms. Both internal carotid arteries were successfully recanalized using standard angioplasty techniques without complication. The third patient had completely normal carotid blood flow at 29 months follow-up. Conclusions: Implantation of a novel device intended to divert emboli away from the internal carotid artery was feasible, but resulted in occlusive neointimal proliferation in two of three patients. These results demonstrate a discrepancy from the findings of preclinical animal studies and human investigation.

Association Between Macrominerals Intake and Changes in Internal Carotid Artery-Intima Media Thickness in POST Ischemic Stroke Patients

Science.gov (United States)

Pudjonarko, Dwi; Tugasworo, Dodik; Silaen, Rumintang

2017-02-01

Carotid Intima Media Thickness (C-IMT) has been widely used as marker for atherosclerosis. Previous studies on minerals intake and its association with C-IMT revealed various. Most of the studies showed inconsistent results. The aim of this study is to determine wether macro minerals intake is related to internal carotid-intima media thickness (IC-IMT). This is a longitudinal study, pre test post test design conducted in Neurology clinic, Kariadi hospital, Semarang from June to December 2014. Subjects were 22 post ischemic stroke patients. Minerals intake and IC-IMT was measured using Food Frequency Questionnaire and Duplex Carotid Ultrasonography. Statistical analysis was performed using Chi-Square, Fisher Exact and Logistic Regression test. Subjects included in this study were 17 male subjects (77.3%) and 5 female subjects (22.7%). Mean of IC-IMT in female subjects was found to be higher than in male. Mean of total IC-IMT was increased after a period of six months (0.96±0.80 to 0.97±0.21 mm). There were significant association between calcium as well as sodium intakes and IC-IMT. In contrast, there were no association between magnesium as well as potassium intake and IC-IMT. Multivariate analysis suggest that sodium intake (OR=26.828) was the most influencing factor for IC-IMT, followed by calcium intake (OR=0.042). Calcium as well as potassium intake were independently associated with IC-IMT. Magnecium as well as sodium intake were not independently associated with IC-IMT changes. Sodium intake was the most influencing variable to IC-IMT changes, followed by calcium intake.

Color coded duplex sonography. Interdisciplinary vascular ultrasonography; Farbkodierte Duplexsonographie. Interdisziplinaerer vaskulaerer Ultraschall

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Kubale, R. [Institut fuer Radiologie, Sonographie und Nuklearmedizin, Pirmasens (Germany); Stiegler, H. [Staedtisches Krankenhaus Schwabing, Muenchen (Germany). 7. Medizinische Abt.

2002-07-01

An interdisciplinary team of experts impart the state of the art in color coded duplex sonography applied for examination of all anatomic areas. Detailed information is given for every vascular area, describing the examination procedure, possible origins of mistakes or faults, and means to avoid them. In addition to the classical applications, eg. for examination of the extra- and intracranial vessels, vessels of the limbs, visceral vessels and the vessels of liver and kidney, there are chapters devoted to: haemodialysis shunts, arteriovenous malformations, duplex sonography of the penis, tumor vascularisation. (orig./CB) [German] Ein interdisziplinaeres Autorenteam vermittelt Ihnen den State of the Art der FKDS fuer alle anatomischen Regionen. Fuer jede der Gefaessregionen werden detaillierte Angaben zum Untersuchungsablauf, zu moeglichen Fehlerquellen und zu deren Vermeidung geboten. Neben den klassischen Anwendungen bei der Untersuchung - der extra- und intrakraniellen Gefaesse, - der Extremitaetengefaesse, - der viszeralen Gefaesse sowie der Gefaesse von Niere und Leber finden Sie Kapitel zu den Themen: Haemodialyseshunt, arteriovenoese Malformationen, Duplexsonographie des Penis und Tumorvaskularisation. (orig./AJ)

Cone pathway function in relation to asymmetric carotid artery stenosis

DEFF Research Database (Denmark)

Kofoed, Peter Kristian; Munch, Inger Christine; Holfort, Stig K

2013-01-01

Purpose:  To examine retinal function in relation to retinal perfusion pressure in patients with carotid artery stenosis. Methods:  Thirteen patients with carotid artery stenosis without clinical eye disease underwent assessment of ophthalmic artery systolic blood pressure (OSP) by ocular...... pneumoplethysmography, carotid artery obstructive disease by ultrasonography, intraocular pressure by applanation tonometry, retinal perfusion by fluorescein angiography and retinal function by multifocal electroretinography (mfERG). Data analysis compared the eye on the most stenotic side with the fellow eye...... pressure (p = 0.0028, 0.011, 0.041 for N1, P1, N2 implicit times, respectively, and p = 0.0086, 0.016, 0.040 for N1, P1, N2 for amplitudes, respectively, corrected for OSP). Conclusion:  Cone function deviation was observed in clinically healthy eyes on the side with highest degree of carotid artery...

Carotid Artery Stenting Successfully Prevents Progressive Stroke Due to Mobile Plaque

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Masahiro Oomura

2015-05-01

Full Text Available We report a case of progressive ischemic stroke due to a mobile plaque, in which carotid artery stenting successfully prevented further infarctions. A 78-year-old man developed acute multiple infarcts in the right hemisphere, and a duplex ultrasound showed a mobile plaque involving the bifurcation of the left common carotid artery. Maximal medical therapy failed to prevent further infarcts, and the number of infarcts increased with his neurological deterioration. Our present case suggests that the deployment of a closed-cell stent is effective to prevent the progression of the ischemic stroke due to the mobile plaque.

Approach To Unstable Plaque In Carotid Disease

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Mojdeh Ghabaee

2017-02-01

Full Text Available Risk of cerebral infarction due to thrombo emboli originating  from carotid artery disease estimated to be near 15%, and this risk  is closely associated with the severity of luminal stenosis. But at the same time characteristics  of the plaque should be taken into account for therapeutic planning when the patient is asymptomatic and the diameter of the stenosis does not reach the threshold of 70%. Search for markers of plaque vulnerability, instability, or thromboembolic potential as complementary to the degree of the luminal stenosis in stroke risk prediction should be considered .These morphologic features of carotid plaques are increasingly believed to be one of those markers that could carry further prognostic information, and early recognition of these plaques features may identify a high-risk subgroup of patients who might particularly benefit from aggressive interventions with aggressive medical treatment. Color and duplex Doppler sonography  evaluates both  morphologic and hemodynamic   abnormalitie of carotid. Echogensity, degree of stenosis and plaque surface features are essential parameters of morphological abnormality.

Doppler color flow mapping of peripheral vessels: Comparison of angiodynography with conventional duplex US

International Nuclear Information System (INIS)

Merritt, C.R.B.; Bluth, E.I.; Sullivan, M.A.

1986-01-01

A new Doppler color flow imager was compared to duplex US in the evaluation of carotid and peripheral vessels in 50 patients. A 7.5-MHz transducer permitted simultaneous high-resolution real-time imaging of Doppler flow and tissue. The system was found to have excellent image quality and Doppler sensitivity. Flow characteristics and velocity measurements obtained with this system correlated well with those obtained using the duplex scanner and were obtained more quickly than with the conventional system, allowing more complete assessment of flow characteristics. Color Doppler flow imaging appears to be an extremely promising method for the rapid and effective evaluation of peripheral vascular flow

Carotid endarterectomy in cervical block anesthesia in patients with occluded contralateral internal carotid artery

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Ilijevski Nenad

2006-01-01

Full Text Available Introduction: The goal of modern carotid surgery is relief of symptoms, stroke prevention, improvement in quality of life, prevention of vascular dementia, and prolongation of lifetime. OBJECTIVE: The objective of this paper was to compare the outcome of carotid endarterectomy in cervical block vs. general anesthesia in patients with occluded contralateral internal carotid artery (ICA. METHOD: One hundred patients (76 male, 24 female, mean age 60.81 years with occluded contralateral ICA were operated from 1997-2000. Neurological symptomatology, deficiency and stroke incidence were preoperatively analyzed in two groups. Duplex-scanning, angiograms and CT-scan confirmed the diagnosis. Risk factors analysis included hypertension, diabetes, lipid metabolism disorders, smoking and history of CAD, CABG and PAOD. Morbidity and mortality were used to compare the outcome of surgery in two groups. RESULTS There was no difference of age, gender and symptomatology between the groups. Paresis, TIA and dysphasia were most frequent. 70%-90% of ICA stenosis was seen in the majority of patients. Hypertension and smoking were dominant risk factors in these two groups. Eversion carotid end arterectomy was the most frequent technique used. In three cases out of nine that were operated under cervical block, the neurological symptoms developed just after clamping, so the intra-luminal shunt was placed. Postoperative morbidity was 12% and mortality was 8%. Conclusion: There was no difference of preoperative parameters, surgical technique and outcome in these two groups. Without other intraoperative monitoring, cervical block anesthesia might be an option in patients with the occlusion of the contralateral ICA. However, prospective studies involving more patients are needed.

Embolic Stroke due to Carotidynia Potentially Associated with Moving Carotid Artery Caused by Swallowing.

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Yamaguchi, Yoshitaka; Hayakawa, Mikito; Kinoshita, Naoto; Yokota, Chiaki; Ishihara, Toshiya; Toyoda, Kazunori

2018-03-01

A 63-year-old woman with end-stage renal disease on maintenance hemodialysis discontinued her medication for rheumatoid arthritis with prednisolone and azathioprine. One month later, she was admitted because of consciousness disturbance and right hemiparesis. Diffusion-weighted brain magnetic resonance imaging (MRI) revealed multiple hyperintensities in her left frontal and parietal lobes. She also developed high fever and left neck pain. Carotid ultrasonography showed calcified plaque with vessel wall swelling at the bifurcation of the left common carotid artery (LCCA) and surrounding hypoechoic soft tissue. The tissue was identified as an isodense lesion on noncontrast computed tomography (CT) and as a high-intensity lesion on fat-saturated T2-weighted MRI. From her symptoms and radiological findings, she was diagnosed with carotidynia. Cervical MRI also showed that the LCCA was transposed to a retropharyngeal location, suggesting a moving carotid artery. Carotid ultrasonography revealed that the LCCA moved to and from the retropharyngeal position with swallowing and was thus being compressed by the hyoid bone. After corticosteroid therapy was initiated with 30 mg of prednisolone, her symptoms and radiological findings improved. To our knowledge, this is the first report of a case of cerebral embolism due to carotidynia. The repetitive compressions by the hyoid bone during swallowing were presumed to have provoked shear stress and inflammation of the carotid vessel wall, which was aggravated by discontinuation of steroid therapy in our case. These mechanical and inflammatory stresses might cause dysfunction of endothelial cells, hypercoagulation, platelet hyperaggregation, and vulnerability and rupture of carotid plaques, and may subsequently result in embolic strokes. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Carotid artery calcification in ischemic stroke patients detected in standard dental panoramic radiographs - a preliminary study

International Nuclear Information System (INIS)

Christou, P.; Kiliaridis, S.; Leemann, B.; Schimmel, M.; Muller, F.

2010-01-01

Purpose: Examine the prevalence of carotid artery calcifications in standard dental panoramic radiographs (OPT), their association to gender, medical history and oral status. Assess the predictive value of a dental OPT in early diagnosis of carotid artery calcifications. Material and Methods: Fourteen patients admitted to Geneva University Hospital for recent ischemic stroke and stenosis of the carotid artery confirmed by Duplex sonography. All OPTs were digitised and subsequently assessed independently by two operators. Results: From 21 carotid artery calcifications detected with Doppler sonography 15 were visible on the corresponding OPT, most of them on the right side (n=11). No correlation was found between the side of calcification and cerebral lesion. Hypertension and periodontal disease were the most prevalent cardiovascular risk factors. Conclusions: Dentists who either detect carotid artery calcifications in OPTs or see patients with severe periodontitis should consider a prophylactic specialist examination. (authors)

[Carotid artery injury: value of Doppler screening in head injured patients].

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Terminassian, A; Bonnet, F; Guerrini, P; Ricolfi, F; Delaunay, F; Beydon, L; Catoire, P

1992-01-01

A case is reported of a patient with a traumatic aneurysm of the intracranial part of the carotid artery occurring after a traffic accident. The patient was admitted in coma (Glasgow score 5), and presented with a depressed fracture of the frontal and parietal bones, a fracture of the left petrous pyramid and of the left anterior clinoid process, as well as of the right tympanic bone and temporomandibular joint. The borders of the left carotid canal seemed unaltered. Despite the lack of localised neurological signs, cervical and transcranial Doppler ultrasonography was carried out. Intracranial carotid blood flow was found to be altered on both sides. Angiography showed a false carotid aneurysm on the left side (carotid siphon portion C3), and a moderate irregular stenosis of the C2 part on the right. There were no brain lesions on the CT scan. Prophylactic treatment with heparin was started. The patient recovered normal consciousness within a fortnight. The false aneurysm increased in volume and was treated by embolisation. Flow speeds in the carotid siphons also returned to normal. The usefulness of routine screening of patients with petrous bone fractures with Doppler ultrasound is discussed.

Compression ultrasonography of the lower extremity with portable vascular ultrasonography can accurately detect deep venous thrombosis in the emergency department.

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Crisp, Jonathan G; Lovato, Luis M; Jang, Timothy B

2010-12-01

Compression ultrasonography of the lower extremity is an established method of detecting proximal lower extremity deep venous thrombosis when performed by a certified operator in a vascular laboratory. Our objective is to determine the sensitivity and specificity of bedside 2-point compression ultrasonography performed in the emergency department (ED) with portable vascular ultrasonography for the detection of proximal lower extremity deep venous thrombosis. We did this by directly comparing emergency physician-performed ultrasonography to lower extremity duplex ultrasonography performed by the Department of Radiology. This was a prospective, cross-sectional study and diagnostic test assessment of a convenience sample of ED patients with a suspected lower extremity deep venous thrombosis, conducted at a single-center, urban, academic ED. All physicians had a 10-minute training session before enrolling patients. ED compression ultrasonography occurred before Department of Radiology ultrasonography and involved identification of 2 specific points: the common femoral and popliteal vessels, with subsequent compression of the common femoral and popliteal veins. The study result was considered positive for proximal lower extremity deep venous thrombosis if either vein was incompressible or a thrombus was visualized. Sensitivity and specificity were calculated with the final radiologist interpretation of the Department of Radiology ultrasonography as the criterion standard. A total of 47 physicians performed 199 2-point compression ultrasonographic examinations in the ED. Median number of examinations per physician was 2 (range 1 to 29 examinations; interquartile range 1 to 5 examinations). There were 45 proximal lower extremity deep venous thromboses observed on Department of Radiology evaluation, all correctly identified by ED 2-point compression ultrasonography. The 153 patients without proximal lower extremity deep venous thrombosis all had a negative ED compression

Unusual case of stroke related to Kocuria Kristinae endocarditis treated with surgical procedure.

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Aleksic, D; Miletic-Drakulic, S; Boskovic-Matic, T; Simovic, S; Toncev, G

2016-01-01

We report the case of a 35-year-old man with stroke related to infective endocarditis (IE) caused by Kocuria kristinae . The patient with chronic hepatitis C virus infection and a former intravenous drug user developed a stroke suddenly, after three months duration of fever and malaise. Duplex ultrasonography of the carotid arteries (zero level diastolic flow, diastolic reversed flow) focused attention to cardiac valve pathology and endocarditis (definite confirmation was made by transesophageal echocardiography). Kocuria kristinae was grown from the blood culture and antibiotic therapy administered, according to the antibiogram, did not cure the infection and the patient underwent an aortic valve replacement with a mechanical prosthesis and debridement of the mitral valve. One year after the surgery, the patient had no subjective problems and neurological findings were normal.  Conclusion: To our knowledge, this is the first case of IE caused by Kocuria kristinae , which was diagnosed after the development of stroke, where IE was suspected based on Duplex ultrasonography of the carotid arteries.  This is the second case of infection by this bacterium which could not be cured by antibiotics only and had to be submitted to surgical intervention. Hippokratia 2016, 20(3): 231-234.

Quantification of cerebral blood flow via Duplex sonography

International Nuclear Information System (INIS)

Vogl, G.; Pohl, P.; Willeit, J.; Aichner, F.

1987-01-01

An attempt was made to measure quantitatively the total cerebral blood flow by means of Duplex sonography. In a group of healthy young subjects a median value for total cerebral blood flow was obtained amounting to 469 ml/min ± 30%, repeat measurements yielded a maximum deviation of ± 11%. In three patients the values obtained after severe apoplectic insult due to occlusion of the internal carotid artery were definitely below the value of the group of healthy subjects, whereas the value for the total blood flow was in the upper range of normal values in a patient with occlusion of the a. cerebri media. Comparative measurements of the regional cerebral blood flow with xenon 13 yielded in those patients with occlusion of the internal carotid artery a markedly reduced mean flow and in the patient with occlusion of the a. cerebri media a less markedly reduced mean flow. Regionally reduced perfusion was seen in all the four patients in the range of the clinically and computer tomographically well-known ischaemia zone. Thanks to the simplicity of this sonographic examination method it could be a useful decision parameter in determining the indication for a reconstruction of the carotid artery, especially in asymptotic patients. (orig.) [de

Outcome of Carotid Artery Stenting for Radiation-Induced Stenosis

International Nuclear Information System (INIS)

Dorresteijn, Lucille; Vogels, Oscar; Leeuw, Frank-Erik de; Vos, Jan-Albert; Christiaans, Marleen H.; Ackerstaff, Rob; Kappelle, Arnoud C.

2010-01-01

Purpose: Patients who have been irradiated at the neck have an increased risk of symptomatic stenosis of the carotid artery during follow-up. Carotid angioplasty and stenting (CAS) can be a preferable alternative treatment to carotid endarterectomy, which is associated with increased operative risks in these patients. Methods and Materials: We performed a prospective cohort study of 24 previously irradiated patients who underwent CAS for symptomatic carotid stenosis. We assessed periprocedural and nonprocedural events including transient ischemic attack (TIA), nondisabling stroke, disabling stoke, and death. Patency rates were evaluated on duplex ultrasound scans. Restenosis was defined as a stenosis of >50% at the stent location. Results: Periprocedural TIA rate was 8%, and periprocedural stroke (nondisabling) occurred in 4% of patients. After a mean follow-up of 3.3 years (range, 0.3-11.0 years), only one ipsilateral incident event (TIA) had occurred (4%). In 12% of patients, a contralateral incident event was present: one TIA (4%) and two strokes (12%, two disabling strokes). Restenosis was apparent in 17%, 33%, and 42% at 3, 12, and 24 months, respectively, although none of the patients with restenosed vessels became symptomatic. The length of the irradiation to CAS interval proved the only significant risk factor for restenosis. Conclusions: The results of CAS for radiation-induced carotid stenosis are favorable in terms of recurrence of cerebrovascular events at the CAS site.

Non invasive techniques for the study of the extracranial carotid arterial system

International Nuclear Information System (INIS)

Ameneiro Perez, Santiago; Alvarez Sanchez, Jose Antonio; Aldama Figueroa, Alfredo

2000-01-01

A review of the noninvasive diagnostic techniques that have been historically used to detect the stenoocclussive lesions of the extracranial carotid arterial system is made. The technological development and the new therapeutic criteria to prevent strokes caused by these lesions have encouraged research in this field. A review of the most used techniques at present: mode B ultrasound, duplex ultrasound and color duplex ultrasound, as well as of the advantages and disadvantages of each one is made. Nowadays, there are hemodynamic criteria together with these techniques that evaluate the stenosis degrees and the characteristics of the lesions with accuracy enough to substitute in most of the cases the invasive and more expensive diagnostic angiographic methods

Prediction of cerebrovascular reserve by the MRI and doppler ultrasonography

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Lee, Hui Joong; Kim, Yong Sun [Kyungpook National University Hospital, Daegu (Korea, Republic of)

2005-07-15

We investigated acute stroke patterns on diffusion weighted images and with doppler ultrasonography studies of ICA and MCA steno-occlusive diseases in order to predict the cerbrovascular reserve (CVR), as was measured by acetazolamide (ACZ)-challenged Tc-99m ECD brain perfusion SPECT. A retrospective analysis was performed of 76 patients who underwent MRI/MRA, ACZ-challenged Tc-99m ECD brain perfusion SPECT, and carotid and vertebral artery Doppler sonography. After dividing these patients into four groups-MCA and ICA ateno-occlusions, we analyzed the relationship between the CVR and topologic MR patterns and the flow volume, as was measured by Doppler sonography. The CVRs were preserved in 26 of 76 patients. The CVRs were impaired in those cases of occlusion that were detected on MRA and also by the pattern of the territorial involvement on the diffusion weighted image ({rho} < 0.05, x{sup 2} test). Yet in cases of preserved CVRs, the flow volume of the contralateral ICA, the anterior circulation, and the total cerebral flow volume were increased, as was checked by Doppler sonography ({rho} < 0.05, t-test). As calculated by logistic regression analysis, the accuracy for predicting the preserved CVR by using the statistically significant variables was 78%. We believe that the MRI-SPECT correlation study was helpful for understanding the hemodynamics and topographic patterns of ischemia in patients with ICA and MCA steno-occlusive disease, and that the flow volume measurement, which was done by using duplex US, was useful for predicting the CVR.

Measurement of carotid bifurcation pressure gradients using the Bernoulli principle.

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Illig, K A; Ouriel, K; DeWeese, J A; Holen, J; Green, R M

1996-04-01

Current randomized prospective studies suggest that the degree of carotid stenosis is a critical element in deciding whether surgical or medical treatment is appropriate. Of potential interest is the actual pressure drop caused by the blockage, but no direct non-invasive means of quantifying the hemodynamic consequences of carotid artery stenoses currently exists. The present prospective study examined whether preoperative pulsed-Doppler duplex ultrasonographic velocity (v) measurements could be used to predict pressure gradients (delta P) caused by carotid artery stenoses, and whether such measurements could be used to predict angiographic percent diameter reduction. Preoperative Doppler velocity and intraoperative direct pressure measurements were obtained, and per cent diameter angiographic stenosis measured in 76 consecutive patients who underwent 77 elective carotid endarterectomies. Using the Bernoulli principle (delta P = 4v(2), pressure gradients across the stenoses were calculated. The predicted delta P, as well as absolute velocities and internal carotid artery/common carotid velocity ratios were compared with the actual delta P measured intraoperatively and with preoperative angiography and oculopneumoplethysmography (OPG) results. An end-diastolic velocity of > or = 1 m/s and an end-diastolic internal carotid artery/common carotid artery velocity ratio of > or = 10 predicted a 50% diameter angiographic stenosis with 100% specificity. Although statistical significance was reached, preoperative pressure gradients derived from the Bernoulli equation could not predict actual individual intraoperative pressure gradients with enough accuracy to allow decision making on an individual basis. Velocity measurements were as specific and more sensitive than OPG results. Delta P as predicted by the Bernoulli equation is not sufficiently accurate at the carotid bifurcation to be useful for clinical decision making on an individual basis. However, end

Mildly Elevated Serum Bilirubin Levels Are Negatively Associated with Carotid Atherosclerosis among Elderly Persons

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Kawamoto, Ryuichi; Ninomiya, Daisuke; Hasegawa, Yoichi; Kasai, Yoshihisa; Kusunoki, Tomo; Ohtsuka, Nobuyuki; Kumagi, Teru; Abe, Masanori

2014-01-01

Serum bilirubin may have a beneficial role in preventing oxidative changes in atherosclerosis. Limited information is available on whether serum total bilirubin is an independent confounding factor for carotid atherosclerosis {for example, intima-media thickness (IMT), plaque} measured noninvasively by B-mode ultrasonography only among elderly persons. The study subjects were 325 men aged 79±8 (mean ± standard deviation) years and 509 women aged 81±8 years that were enrolled consecutively from patients aged ≥60 years in the medical department. Carotid IMT and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that in men age (β = 0.199, p = 0.002), smoking status (β = 0.154, p = 0.006), GGT (β = -0.139, p = 0.039), and GGT (β = -0.133, p = 0.022) were significantly and independently associated with carotid IMT, and in women age (β = 0.186, pbilirubin (β = -0.119, p = 0.006), and prevalence of cardiovascular disease (CVD) (β = 0.103, p = 0.017) were also independently associated with carotid IMT. The odds ratios (ORs) {95% confidence interval (CI)} of increasing serum bilirubin category were negatively associated with carotid IMT ≥1.0 mm and plaque in both genders. Compared to subjects with a serum bilirubin of Quartile-1, the multivariate-OR (95% CI) of carotid plaque was 0.25 (0.11–0.57) in the Quartile-4 male group, and 0.41 (0.21–0.78) in the Quartile-2 female group, 0.51 (0.26–0.98) in the Quartile-3 female group, and 0.46 (0.24–0.89) in the Quartile-4 female group. Our data demonstrated an independently negative association between serum bilirubin and carotid atherosclerosis in both genders. PMID:25479598

Vertebrocarotid collateral in extracranial carotid artery occlusions: digital subtraction angiography findings

International Nuclear Information System (INIS)

Oguzkurt, Levent; Kizilkilic, Osman; Tercan, Fahri; Tuerkoez, Riza; Yildirim, Tuelin

2005-01-01

The internal and external carotid arteries are usually considered occluded distal to a common carotid artery occlusion but some collateral vessels may provide blood keeping the internal and external carotid arteries patent distal to the occlusion. Most common communication in such a case is diversion of blood from muscular branches of the vertebral artery to occipital branch of the external carotid artery which in turn could maintain blood flow into the internal carotid artery, a condition called carotid steal. We encountered vertebrocarotid anastomoses maintaining the patency of carotid circulation in six patients. Patients were four females and two males, ages ranging from 40 to 67 (mean age: 56) years. Five of the patients had ischemic cerebral symptoms. The origin of the external carotid artery was occluded in two and the whole common carotid artery in the remaining four patients. Two patients had double steal, carotid and subclavian at the same time. There was also severe stenosis or occlusion of at least one other major extracranial cerebral artery in all the cases. This concomitant involvement of the second extracranial cerebral artery was thought to be the main reason for the development of vertebrocarotid collateral. In contrast to most of the previously published reports claiming the inadequacy of angiography when compared with colour Doppler ultrasonography, angiography finely depicted the distal patency of the carotid circulation and all the collaterals in detail in every case. Selective injection of the vertebral artery ipsilateral to the occlusion, is the key to demonstrate distal patency of the carotid circulation in cases of proximal carotid occlusion. Demonstration of patency of the distal circulation is very important because some of the patients might get benefit from a reconstructive surgery

Vertebrocarotid collateral in extracranial carotid artery occlusions: digital subtraction angiography findings

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Oguzkurt, Levent; Kizilkilic, Osman; Tercan, Fahri; Tuerkoez, Riza; Yildirim, Tuelin

2005-02-01

The internal and external carotid arteries are usually considered occluded distal to a common carotid artery occlusion but some collateral vessels may provide blood keeping the internal and external carotid arteries patent distal to the occlusion. Most common communication in such a case is diversion of blood from muscular branches of the vertebral artery to occipital branch of the external carotid artery which in turn could maintain blood flow into the internal carotid artery, a condition called carotid steal. We encountered vertebrocarotid anastomoses maintaining the patency of carotid circulation in six patients. Patients were four females and two males, ages ranging from 40 to 67 (mean age: 56) years. Five of the patients had ischemic cerebral symptoms. The origin of the external carotid artery was occluded in two and the whole common carotid artery in the remaining four patients. Two patients had double steal, carotid and subclavian at the same time. There was also severe stenosis or occlusion of at least one other major extracranial cerebral artery in all the cases. This concomitant involvement of the second extracranial cerebral artery was thought to be the main reason for the development of vertebrocarotid collateral. In contrast to most of the previously published reports claiming the inadequacy of angiography when compared with colour Doppler ultrasonography, angiography finely depicted the distal patency of the carotid circulation and all the collaterals in detail in every case. Selective injection of the vertebral artery ipsilateral to the occlusion, is the key to demonstrate distal patency of the carotid circulation in cases of proximal carotid occlusion. Demonstration of patency of the distal circulation is very important because some of the patients might get benefit from a reconstructive surgery.

Imaging diagnosis of dural and direct cavernous carotid fistulae

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Santos, Daniela dos; Monsignore, Lucas Moretti; Nakiri, Guilherme Seizem; Cruz, Antonio Augusto Velasco e; Colli, Benedicto Oscar; Abud, Daniel Giansante, E-mail: danisantos2404@gmail.com [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas

2014-07-15

Arteriovenous fistulae of the cavernous sinus are rare and difficult to diagnose. They are classified into dural cavernous sinus fistulae or direct carotid-cavernous fistulae. Despite the similarity of symptoms between both types, a precise diagnosis is essential since the treatment is specific for each type of fistula. Imaging findings are remarkably similar in both dural cavernous sinus fistulae and carotid-cavernous fistulae, but it is possible to differentiate one type from the other. Amongst the available imaging methods (Doppler ultrasonography, computed tomography, magnetic resonance imaging and digital subtraction angiography), angiography is considered the gold standard for the diagnosis and classification of cavernous sinus arteriovenous fistulae. The present essay is aimed at didactically presenting the classification and imaging findings of cavernous sinus arteriovenous fistulae. (author)

[Doppler ultrasonography of the renal artery: Guidelines and predictive factors for the presence of a tight stenosis. Retrospective analysis of 450 consecutive examinations].

Science.gov (United States)

Dejerome, C; Grange, C; De Laforcade, L; Bonin, O; Laville, M; Lermusiaux, P; Long, A

2018-05-01

Duplex ultrasonography screening for renal artery stenosis has been the object of guidelines published by four societies designed to optimize the cost-effectiveness of the examination. To determine how well guideline indications for ultrasonography matched with requests and results in our university hospital; to determine whether compliance with guidelines was predictive of renal artery stenosis; to identify guidelines predictive of presence of stenosis; and to determine whether other predictive factors can be recognized. Requests and results of 450 Duplex ultrasonography examinations of the renal arteries performed from January 1st 2014 to December 31st 2015 were compared with published guidelines. At least one guideline indication was identified for 212 of the 450 examinations performed (47.1%). Among these examinations, renal artery stenosis≥70% was identified in 18 patients (8.0%). No case of stenosis was identified during examinations performed outside guideline indications. Factors predictive of stenosis were: compliance with guidelines (OR=21.86 [2.88; 165.8]). Predictive guidelines were: resistant hypertension in spite of appropriate treatment (OR=3.85, [1.44; 10.33], P=0.011), accelerated hypertension (OR=7.30, [1.40; 37.99], P=0.049), sudden unexplained pulmonary edema (OR=7.30, [1.40; 37.99], P=0.049), unexplained renal insufficiency (OR=3.58, [1.37; 9.37], P=0.011), unexplained renal hypotrophy (OR=16.69, [4.38; 63.69], P<0.001), renal asymmetry (OR=4.32, [1.45; 12.85], P<0.016). No other factor was predictive of renal stenosis. These examinations had therapeutic consequences in only 50% of patients. This study confirms the relevance of published guidelines. The diagnostic-effectiveness of Duplex ultrasonography examinations to search for renal artery stenosis depends upon compliance with these guidelines. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Invasive treatment for carotid fibromuscular dysplasia

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Maciejewski, Damian R.; Dzierwa, Karolina; Kabłak-Ziembicka, Anna; Michalski, Michał; Wójcik-Pędziwiatr, Magdalena; Brzychczy, Andrzej; Moczulski, Zbigniew; Żmudka, Krzysztof; Pieniążek, Piotr

2015-01-01

Introduction Fibromuscular dysplasia (FMD) is an infrequent non-inflamatory disease of unknown etiology that affects mainly medium-size arteries. The prevalence of FMD among patients scheduled for endovascular treatment of carotid artery stenosis is unknown. Aim To evaluate the prevalence and treatment options of carotid FMD in patients scheduled for carotid artery stenting (CAS). Material and methods Between Jan 2001 and Dec 2013, 2012 CAS procedures were performed in 1809 patients (66.1% men; age 65.3 ±8.4 years, 49.2% symptomatic). In case of FMD suspicion in Doppler-duplex ultrasound (DUS), computed tomography angiography was performed for aortic arch and extracranial and intracranial artery imaging. For invasive treatment of FMD carotid stenosis, balloon angioplasty was considered first. If the result of balloon angioplasty was not satisfactory (> 30% residual stenosis, dissection), stent placement was scheduled. All patients underwent follow-up DUS and neurological examination 3, 6 and 12 months after angioplasty, then annually. Results There were 7 (0.4%) (4 symptomatic) cases of FMD. The FMD group was younger (47.9 ±7.5 years vs. 67.2 ±8.9 years, p = 0.0001), with higher prevalence of women (71.4% vs. 32.7%, p = 0.0422), a higher rate of dissected lesions (57.1% vs. 4.6%, p = 0.0002) and less severe stenosis (73.4% vs. 83.9%, p = 0.0070) as compared to the non-FMD group. In the non-FMD group the prevalence of coronary artery disease was higher (65.1% vs. 14.3% in FMD group, p = 0.009). All FMD patients underwent successful carotid artery angioplasty with the use of neuroprotection devices. In 4 cases angioplasty was supported by stent implantation. Conclusions Fibromuscular dysplasia is rare among patients referred for CAS. In case of significant FMD carotid stenosis, it may be treated with balloon angioplasty (stent supported if necessary) with optimal immediate and long-term results. PMID:26161104

Contemporary carotid imaging: from degree of stenosis to plaque vulnerability.

Science.gov (United States)

Brinjikji, Waleed; Huston, John; Rabinstein, Alejandro A; Kim, Gyeong-Moon; Lerman, Amir; Lanzino, Giuseppe

2016-01-01

Carotid artery stenosis is a well-established risk factor of ischemic stroke, contributing to up to 10%-20% of strokes or transient ischemic attacks. Many clinical trials over the last 20 years have used measurements of carotid artery stenosis as a means to risk stratify patients. However, with improvements in vascular imaging techniques such as CT angiography and MR angiography, ultrasonography, and PET/CT, it is now possible to risk stratify patients, not just on the degree of carotid artery stenosis but also on how vulnerable the plaque is to rupture, resulting in ischemic stroke. These imaging techniques are ushering in an emerging paradigm shift that allows for risk stratifications based on the presence of imaging features such as intraplaque hemorrhage (IPH), plaque ulceration, plaque neovascularity, fibrous cap thickness, and presence of a lipid-rich necrotic core (LRNC). It is important for the neurosurgeon to be aware of these new imaging techniques that allow for improved patient risk stratification and outcomes. For example, a patient with a low-grade stenosis but an ulcerated plaque may benefit more from a revascularization procedure than a patient with a stable 70% asymptomatic stenosis with a thick fibrous cap. This review summarizes the current state-of-the-art advances in carotid plaque imaging. Currently, MRI is the gold standard in carotid plaque imaging, with its high resolution and high sensitivity for identifying IPH, ulceration, LRNC, and inflammation. However, MRI is limited due to time constraints. CT also allows for high-resolution imaging and can accurately detect ulceration and calcification, but cannot reliably differentiate LRNC from IPH. PET/CT is an effective technique to identify active inflammation within the plaque, but it does not allow for assessment of anatomy, ulceration, IPH, or LRNC. Ultrasonography, with the aid of contrast enhancement, is a cost-effective technique to assess plaque morphology and characteristics, but it is

The prevalence of carotid artery stenosis in patients undergoing aortic reconstruction.

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Cahan, M A; Killewich, L A; Kolodner, L; Powell, C C; Metz, M; Sawyer, R; Lilly, M P; Benjamin, M E; Flinn, W R

1999-09-01

Coronary artery disease occurs frequently in patients undergoing aortic reconstruction, and it has been presumed that internal carotid artery occlusive disease is also common. This has led to the practice of screening for and repairing significant carotid lesions in asymptomatic patients prior to aortic reconstruction. The purpose of this study was to determine the true prevalence of internal carotid artery disease in these patients. The records of 240 patients who underwent duplex ultrasound screening for carotid artery disease prior to aortic reconstruction were reviewed. Surgery was performed for aortic aneurysm (AA) or aorto-iliac occlusive disease (AO). The prevalence of hyperlipidemia and coronary artery disease was similar between the two groups, but tobacco use, hypertension, and diabetes mellitus differed. Internal carotid artery stenosis > or = 50% occurred in 26.7% of the total group (64 of 240 cases). Stenosis > or = 50% was more common in the AO group (40 of 101 cases, 39.6%) than the AA group (24 of 139 cases, 17.3%, P = 0.0001). Severe disease (70% to 99%) was also more common in the AO group than the AA group (9.9% versus 3.6%, P = 0.0464). Internal carotid artery disease occurs commonly in patients undergoing aortic reconstruction, and screening is worthwhile. Significant disease is more common in patients with aorto-iliac occlusive disease than in those with aortic aneurysm, although atherosclerotic risk factors occur with varying frequency in the two groups. These findings suggest that additional factors may contribute to the higher prevalence of internal carotid artery stenosis in aorto-iliac occlusive disease.

Clinical features of 10 patients with spontaneous cervical internal carotid artery dissection

International Nuclear Information System (INIS)

Nagoya, Harumitsu; Takeda, Hidetaka; Dembo, Tomohisa; Kato, Yuzi; Deguchi, Ichiro; Fukuoka, Takuya; Maruyama, Hazime; Horiuchi, Yohsuke; Tanahashi, Norio

2011-01-01

We clinically investigated 10 patients with spontaneous cervical internal carotid artery dissections (age range 36-70, mean 52±12 years; 8 male and 2 female) who were admitted to our university hospital between August 2002 and 2009. Cervical internal carotid artery dissection was diagnosed using findings from MRI, MR angiography (MRA), 3D-CTA, cerebral angiography, and carotid artery ultrasonography according to the diagnostic criteria of brain artery dissociation defined by the brain artery dissociation working group of the Strategies Against Stroke Study for Young Adults in Japan. The initial symptoms were stroke in eight patients, only neck pain in another, and no symptoms in the last. Four patients (40%) had neck pain or headache at onset. Five of the 10 patients had radiological improvements within three months after onset. The outcomes at three months were relatively good, with seven and three patients scoring 1 and 2, respectively, on the modified Rankin Scale. Disease did not recur in any patients during an average of 17.2 months of follow up. Spontaneous cervical internal carotid artery dissection is not rare in Japan. This condition should be considered when patients present with internal carotid artery occlusion or stenosis. (author)

[CHANGES OF CAROTID AND VERTEBRAL ARTERIES IN PATENTS WITH ARTERIAL HYPERTENSION AND HEPATOBILIARY PATHOLOGY].

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Polyakov, V Ya; Nikolaev, Yu A; Pegova, S V; Matsievskaya, T R; Obukhov, I V

2016-01-01

The study included 1172 patients (410 men and 762 women) at the mean age of 60.3 ± 10.4 years with grade I-II (stage I-II) arterial hypertension (AH) admitted to the clinic of Institute of Experimental Medicine. The patients were divided into 2 groups based on the results of clinical and laboratory diagnostics. Group 1 (n = 525) included patients with AH and hepatobiliary system (HBS) diseases, group 2 (n = 647) patients with AH without HBS diseases. The patients group 1 had a thicker intima-media complex of carotid arteries, higher peak systolic bloodflow rate in the internal and vertebral carotid arteries, more pronounced coiling of internal carotid arteries than patients of group 2. Patients with AH and HBS diseases exhibited correlation between bloodflow rate in external carotid arteries and atherogenicity coefficient. Duplex scanning of neck vessels of in patients with AH without HBS diseases revealed peculiar changes of the intima-media thickness and hemodynamically significant changes of the blood flow in the internal carotid arteries that may be of prognostic value in this nosological syntropy and require the personified approach to diagnostics, treatment, and prevention of these conditions.

Comparison of common carotid artery intima-media thickness between Brazilian Euro-descendants and Afro-descendants with atherosclerosis risk factors.

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Casella, Ivan Benaduce; Sotelo, Fabio José Bonafé; Yamazaki, Yumiko; Presti, Calógero; Vassoler, Alecxander; Melo, Henry Augusto Hoffmann

2009-01-01

To compare common carotid intima-media thickness (IMT) between the two major Brazilian ethnic groups (those of African descent and those of European descent) among individuals with one or more risk factors for atherosclerotic disease. Two hundred and six patients with one or more risk factors for atherosclerotic disease were evaluated in a cross-sectional study in which their clinical, ethnic and Demographic characteristics were collected. All patients underwent duplex ultrasound examination of their carotid vessels to obtain IMT measurements. One hundred and fifty-three patients (74.3%) had a carotid IMT greater than 1.0 mm at one or more point of measurement in at least one common carotid artery. There was a significant correlation between older age and mean carotid wall thickness (R=0.479 / PBrazilian individuals are similar to those in previously described populations. No differences were observed between the two main Brazilian ethnic groups. Longitudinal studies are required for a better evaluation of the incidence, etiologic factors and evolution of carotid intimomedial thickening in this population.

Uniaxial Tensile Properties of Atherosclerotic Carotid Artery After Mobilization of Pushing on Qiao-Gong: A Safety Study Using an Animal Model of Carotid Atherosclerosis.

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Qi, Ji; Zhang, Shaoqun; Zhang, Lei; Ping, Ruiyue; Ping, Kaike; Ye, Da; Shen, Honggui; Chen, Yili; Li, Yikai

2018-02-01

This study aimed to preliminarily explore the effects of the soft tissue mobilization of pushing on Qiao-Gong (MPQ) on biomechanical properties of the carotid artery using an animal model of carotid atherosclerosis (CAS). Fifty rabbits were randomly divided into 4 groups: animals with CAS treated with MPQ (CAS-MPQ [n = 15]); animals with CAS treated without MPQ (CAS [n = 15]); normal animals treated with MPQ (normal-MPQ [n = 10]); and a blank control group (n = 10). The MPQ procedure consisted of soft tissue mobilization of the Qiao-Gong acupoint on the front edge of the sternocleidomastoid muscle applied from top to bottom, by flat pushing with the thumb repeatedly for 20 times. Disease in the CAS models was induced by carotid artery balloon injury combined with a high-fat diet for 12 weeks. At the end of modeling, carotid color Doppler ultrasonography examination was performed to confirm which animal models were successfully induced with CAS, excluding model rabbits without typical CAS at the same time. Then, MPQ was applied on rabbits in the CAS-MPQ and the normal-MPQ groups for 3 weeks. By contrast, rabbits in the other 2 groups were fed normally without MPQ. Uniaxial failure tests were later performed on carotid arteries in all 4 groups, and at the end of the study, a 2-way factorial analysis of variance of the results was conducted. (1) At the end of modeling, 10 rabbits in the CAS-MPQ group and 9 in the CAS group were included with typical carotid atherosclerotic characteristics. (2) Young's elastic modulus of the rabbit carotid artery increased more significantly in the CAS-MPQ group than the CAS group. (3) Compared with normal rabbit carotid arteries, atherosclerotic carotid arteries had lower levels of ultimate stress and ultimate strain but higher levels of ultimate load. The uniaxial tensile mechanical properties of the rabbit atherosclerotic carotid artery were impaired after MPQ. Copyright © 2018. Published by Elsevier Inc.

Appraisal of different ultrasonography indices in patients with carotid artery atherosclerosis

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Rafati, Mehravar; Havaee, Elham; Moladoust, Hassan; Sehhati, Mohammadreza

2017-01-01

In this study a semi-automated image-processing based method was designed in which the parameters such as intima-media thickness (IMT), resistive index (RI), pulsatility index (PI), dicrotic notch index (DNI), and mean wavelet entropy (MWE) were evaluated in B-mode and Doppler ultrasound in patients presenting with carotid artery atherosclerosis. In a cross-sectional design, 144 men were divided into four groups of control, mild, moderate and severe stenosis subjects. In all individuals, far ...

Immediate Catheter Directed Thrombolysis for Thromboembolic Stroke During Carotid Endarterectomy

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E. Fletcher

Full Text Available : Background: Carotid artery endarterectomy (CEA is a common procedure undertaken by vascular surgeons with over 5,000 procedures performed annually worldwide. Published rates of perioperative stroke range from 1.3% to 6.3%. Case report: A case is presented in which on-table intra-cranial angiography and catheter directed thrombolysis were used for a thromboembolic occlusion of the distal internal carotid artery (ICA and proximal middle cerebral artery (MCA. An 83-year-old lady developed a dense right hemiparesis while undergoing a CEA under local anaesthetic (LA. Immediate re-exploration of the endarterectomy did not reveal technical error. Intraoperative duplex scanning of the internal carotid artery revealed no detectable diastolic flow. On-table angiogram showed complete occlusion of the distal ICA and proximal MCA. Catheter directed administration of TPA was undertaken. The entire ICA and MCA were completely clear on a completion angiogram. The patient made a full neurological recovery. Discussion and conclusion: Prompt diagnosis and treatment with intraoperative catheter directed thrombolysis can resolve thromboembolic occlusion of the ICA/MCA. It is argued that performing CEA under LA is useful for immediate recognition of perioperative stroke. Furthermore, the advantage is highlighted of vascular surgeons having both the resources and skillset to perform on-table angiography and thrombolysis. Keywords: Carotid endarterectomy, Stroke, Thrombolysis, Thromboembolus, Local anaesthetic

Impact of Hypertriglyceridemia on Carotid Stenosis Progression under Normal Low-Density Lipoprotein Cholesterol Levels.

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Kitagami, Masayuki; Yasuda, Ryuta; Toma, Naoki; Shiba, Masato; Nampei, Mai; Yamamoto, Yoko; Nakatsuka, Yoshinari; Sakaida, Hiroshi; Suzuki, Hidenori

2017-08-01

Dyslipidemia is a well-known risk factor for carotid stenosis progression, but triglycerides have attracted little attention. The aim of this study was to assess if serum triglycerides affect progression of carotid stenosis in patients with well-controlled low-density lipoprotein cholesterol (LDL-C) levels. This is a retrospective study in a single hospital consisting of 71 Japanese patients with internal carotid artery stenosis greater than or equal to 50% and normal serum LDL-C levels who underwent angiographic examination with or without the resultant carotid artery stenting or endarterectomy from 2007 to 2011, and were subsequently followed up for 4 years. Clinical factors including fasting serum triglyceride values were compared between the progression (≥10% increase in degree of carotid stenosis on ultrasonography) and the nonprogression groups. During 4 years, 15 patients (21.1%) had carotid stenosis progression on either side. Cox regression analysis demonstrated that symptomatic cases (hazard ratio [HR], 4.327; P = .019), coexisting intracranial arteriosclerotic stenosis (HR, 5.341; P = .005), and hypertriglyceridemia (HR, 6.228; P = .011) were associated with subsequent progression of carotid stenosis. Kaplan-Meier plots demonstrated that the progression-free survival rate was significantly higher in patients without hypertriglyceridemia and intracranial arteriosclerotic stenosis at baseline. Among patients with moderate to severe carotid stenosis and well-controlled LDL-C, hypertriglyceridemia was an important risk factor for progression of carotid stenosis irrespective of surgical treatments. It would be worthwhile to test if triglyceride-lowering medications suppress carotid stenosis progression. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Probabilistic Medium Access Control for Full-Duplex Networks with Half-Duplex Clients

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Chen, Shih-Ying; Huang, Ting-Feng; Lin, Kate Ching-Ju; Hong, H. -W. Peter; Sabharwal, Ashutosh

2016-01-01

The feasibility of practical in-band full-duplex radios has recently been demonstrated experimentally. One way to leverage full-duplex in a network setting is to enable three-node full-duplex, where a full- duplex access point (AP) transmits data to one node yet simultaneously receives data from another node. Such three-node full-duplex communication however introduces inter-client interference, directly impacting the full-duplex gain. It hence may not always be beneficial to enable three-nod...

The relationship of flow velocities to vessel diameters differs between extracranial carotid and vertebral arteries of stroke patients.

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Owolabi, Mayowa O; Agunloye, Atinuke M; Ogunniyi, Adesola

2014-01-01

Chronic changes in flow rate through arteries produce adjustment of arterial diameters. We compared the relationship between flow velocity and diameter in the carotid and in the vertebral arteries of stroke patients. Using triplex ultrasonography, the internal diameter and flow velocities of the common carotid, internal carotid, and vertebral arteries of 176 consecutive stroke patients were measured. Correlations were examined with Pearson's statistics at an alpha level of 0.05. Mean age of the patients was 59.3 ± 12 years, and 66% had cerebral infarcts. Diameter and blood flow velocities showed significant negative correlations (-0.115 ≥ r ≥ -0.382) in the carotid arteries on both sides, but positive correlations (0.211 ≤ r ≤ 0.320) in the vertebral arteries, even after controlling for age, gender, and blood pressure. Our study demonstrated different diameter/flow relationships in the carotid and the vertebral arteries of stroke patients, which may suggest pathologic changes in the adaptive processes governing vessel diameter and growth, especially in the carotid arteries. Copyright © 2013 Wiley Periodicals, Inc.

Association of glycated hemoglobin with carotid intimal medial thickness in Asian Indians with normal glucose tolerance.

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Venkataraman, Vijayachandrika; Amutha, Anandakumar; Anbalagan, Viknesh Prabu; Deepa, Mohan; Anjana, Ranjit Mohan; Unnikrishnan, Ranjit; Vamsi, Mamilla; Mohan, Viswananthan

2012-01-01

To assess the association of glycated hemoglobin (HbA1c) levels with carotid intimal medial thickness (CIMT) in Asian Indians with normal glucose tolerance (NGT). Subjects with NGT were recruited from the Chennai Urban Rural Epidemiology Study carried out on a representative population of Chennai, South India. All subjects had fasting plasma glucose right common carotid artery using high-resolution B-mode ultrasonography. The study group included 1383 NGT subjects, of whom 760 (54.9%) were women. The mean CIMT value in the 1st quartile of HbA1c (5.8) (prights reserved.

Assessing carotid atherosclerosis by fiber-optic multispectral photoacoustic tomography

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Hui, Jie; Li, Rui; Wang, Pu; Phillips, Evan; Bruning, Rebecca; Liao, Chien-Sheng; Sturek, Michael; Goergen, Craig J.; Cheng, Ji-Xin

2015-03-01

Atherosclerotic plaque at the carotid bifurcation is the underlying cause of the majority of ischemic strokes. Noninvasive imaging and quantification of the compositional changes preceding gross anatomic changes within the arterial wall is essential for diagnosis of disease. Current imaging modalities such as duplex ultrasound, computed tomography, positron emission tomography are limited by the lack of compositional contrast and the detection of flow-limiting lesions. Although high-resolution magnetic resonance imaging has been developed to characterize atherosclerotic plaque composition, its accessibility for wide clinical use is limited. Here, we demonstrate a fiber-based multispectral photoacoustic tomography system for excitation of lipids and external acoustic detection of the generated ultrasound. Using sequential ultrasound imaging of ex vivo preparations we achieved ~2 cm imaging depth and chemical selectivity for assessment of human arterial plaques. A multivariate curve resolution alternating least squares analysis method was applied to resolve the major chemical components, including intravascular lipid, intramuscular fat, and blood. These results show the promise of detecting carotid plaque in vivo through esophageal fiber-optic excitation of lipids and external acoustic detection of the generated ultrasound. This imaging system has great potential for serving as a point-ofcare device for early diagnosis of carotid artery disease in the clinic.

Carotid angioplasty and stenting in the elderly

International Nuclear Information System (INIS)

Kadkhodayan, Yasha; Cross, DeWitte T.; Moran, Christopher J.; Derdeyn, Colin P.

2007-01-01

To investigate the technical success rate as well as the procedural and mid-term complication rates of carotid angioplasty and stenting in elderly patients, a group excluded from large randomized endarterectomy trials given their perceived high surgical risk. Of 200 consecutive carotid angioplasty and/or stenting procedures performed between March 1996 and March 2005, 21 procedures were performed without cerebral protection devices in 20 patients over the age of 79 years (mean age: 83 years, 12 men, eight women). These patients' medical records were retrospectively reviewed for vascular imaging reports and available clinical follow-up. Procedural and mid-term complication rates were calculated and compared to a previously published cohort of 133 consecutive patients ≤79 years of age who also underwent endovascular treatment at our institution. Carotid stenosis was reduced from a mean of 82% to no significant stenosis in all procedures. The procedural stroke rate was zero of 21 procedures. The procedural transient ischemic attack rate (TIA) was one of 21 procedures (4.8%). Mean follow-up was 24.6 months (range: 1.0-79.5 months) with at least a 30-day follow-up for 20 of the 21 procedures (95.2%). There were no new strokes. There was one recurrent ipsilateral TIA at 1.9 months. In five cases with follow-up carotid ultrasonography, no hemodynamically significant restenosis had occurred. There were three myocardial infarctions (MI) occurring at 0.5, 2.1, and 15.2 months, of which the last MI was fatal. The composite 30-day stroke and death rate was zero of 21 procedures (95% confidence interval: 0-14%). No significant difference was found in the 30-day rate of stroke, TIA, MI, or death between the elderly and younger patients. Carotid angioplasty and stenting in elderly patients can be performed successfully with acceptable procedural and mid-term complication rates comparable to younger patients. (orig.)

Influence of arterial wave reflection on carotid blood pressure and intima-media thickness in older endurance trained men and women with pre-hypertension.

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Heffernan, Kevin S; Jae, Sae Young; Tomayko, Emily; Ishaque, Muhammad R; Fernhall, Bo; Wilund, Kenneth R

2009-05-01

Increased carotid intima-media thickness (IMT) with aging is a significant predictor of mortality. Older endurance trained (ET) individuals have lower carotid artery stiffness but similar carotid IMT when compared to sedentary (SED) age-matched peers. The purpose of this study was to examine the contribution of arterial wave reflections to carotid hemodynamics and IMT in older ET and SED with pre-hypertension. Subjects consisted of endurance-trained master athletes and age-matched sedentary controls (mean age 67 years). Carotid artery Beta-stiffness index and IMT was assessed with ultrasonography. Carotid pressure and augmented pressure from wave reflections (obtained from pulse contour analysis) was measured with applanation tonometry. Carotid systolic blood pressure (SBP) and IMT were not different between groups (P>0.05). Carotid stiffness was significantly lower in ET versus SED (7.3 +/- 0.8 versus 9.9 +/- 0.6, Phypertension have reduced carotid artery stiffness, but similar carotid SBP and carotid IMT when compared to SED. The lack of change in carotid SBP and IMT in older ET may be related to the inability of chronic exercise training to reduce bradycardia-related augmented pressure from wave reflections with aging.

Carotid stenosis and cognitive impairment amongst older Chinese adults living in a rural area: a population-based study.

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Yan, Z; Liang, Y; Shi, J; Cai, C; Jiang, H; Song, A; Qiu, C

2016-01-01

The possible association between carotid stenosis and cognitive impairment in the Chinese population has been rarely investigated. The association between the severity of carotid stenosis and cognitive impairment amongst older Chinese people living in a rural area was assessed. This cross-sectional study included 1375 participants (age ≥60 years) from the Confucius Hometown Aging Project in Shandong. In 2010-2011, data were collected through interviews and clinical examinations. Carotid stenosis was assessed using ultrasonography. Cognitive impairment was defined according to the education-specific cutoff scores of the Mini-Mental State Examination. Data were analyzed using multinomial logistic models. The overall prevalence was 7.0% for moderate carotid stenosis, 2.0% for severe stenosis and 6.0% for cognitive impairment. The multi-adjusted odds ratio of cognitive impairment was 1.43 (95% confidence interval 0.63-3.22) for moderate carotid stenosis and 3.75 (1.24-11.40) for severe carotid stenosis (P(trend) = 0.023). Similar results were obtained in people without a history of cerebrovascular disease. Severe carotid stenosis, even asymptomatic, is associated with cognitive impairment independent of atherosclerotic risk factors and disorders amongst older Chinese people. © 2015 EAN.

Mean blood velocities and flow impedance in the fetal descending thoracic aortic and common carotid artery in normal pregnancy.

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Bilardo, C M; Campbell, S; Nicolaides, K H

1988-12-01

A linear array pulsed Doppler duplex scanner was used to establish reference ranges for mean blood velocities and flow impedance (Pulsatility Index = PI) in the descending thoracic aorta and in the common carotid artery from 70 fetuses in normal pregnancies at 17-42 weeks' gestation. The aortic velocity increased with gestation up to 32 weeks, then remained constant until term, when it decreased. In contrast, the velocity in the common carotid artery increased throughout pregnancy. The PI in the aorta remained constant throughout pregnancy, while in the common carotid artery it fell steeply after 32 weeks. These results suggest that with advancing gestation there is a redistribution of the fetal circulation with decreased impedance to flow to the fetal brain, presumably to compensate for the progressive decrease in fetal blood PO2.

Artificial neural network aided non-invasive grading evaluation of hepatic fibrosis by duplex ultrasonography

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Zhang Li

2012-06-01

Full Text Available Abstract Background Artificial neural networks (ANNs are widely studied for evaluating diseases. This paper discusses the intelligence mode of an ANN in grading the diagnosis of liver fibrosis by duplex ultrasonogaphy. Methods 239 patients who were confirmed as having liver fibrosis or cirrhosis by ultrasound guided liver biopsy were investigated in this study. We quantified ultrasonographic parameters as significant parameters using a data optimization procedure applied to an ANN. 179 patients were typed at random as the training group; 60 additional patients were consequently enrolled as the validating group. Performance of the ANN was evaluated according to accuracy, sensitivity, specificity, Youden’s index and receiver operating characteristic (ROC analysis. Results 5 ultrasonographic parameters; i.e., the liver parenchyma, thickness of spleen, hepatic vein (HV waveform, hepatic artery pulsatile index (HAPI and HV damping index (HVDI, were enrolled as the input neurons in the ANN model. The sensitivity, specificity and accuracy of the ANN model for quantitative diagnosis of liver fibrosis were 95.0%, 85.0% and 88.3%, respectively. The Youden’s index (YI was 0.80. Conclusions The established ANN model had good sensitivity and specificity in quantitative diagnosis of hepatic fibrosis or liver cirrhosis. Our study suggests that the ANN model based on duplex ultrasound may help non-invasive grading diagnosis of liver fibrosis in clinical practice.

Analysis of haemodynamic disturbance in the atherosclerotic carotid artery using computational fluid dynamics

International Nuclear Information System (INIS)

Birchall, Daniel; Zaman, Azfar; Hacker, Jacob; Davies, Gavin; Mendelow, David

2006-01-01

Computational fluid dynamics (CFD) provides a means for the quantitative analysis of haemodynamic disturbances in vivo, but most work has used phantoms or idealised geometry. Our purpose was to use CFD to analyse flow in carotid atherosclerosis using patient-specific geometry and flow data. Eight atherosclerotic carotid arteries and one healthy control artery were imaged with magnetic resonance angiography (MRA) and duplex ultrasound, and the data used to construct patient-specific computational models used for CFD and wall shear stress (WSS) analysis. There is a progressive change in three-dimensional (3-D) velocity profile and WSS profile with increasing severity of stenosis, characterised by increasing restriction of areas of low WSS, change in oscillation patterns, and progressive rise in WSS within stenoses and downstream jets. Areas of turbulent, retrograde flow and of low WSS are demonstrated in the lee of the stenoses. This study presents the largest CFD analysis of abnormal haemodynamics at the atheromatous carotid bifurcation using patient-specific data and provides the basis for further investigation of causal links between haemodynamic variables and atherogenesis and formation of unstable plaque. We propose that this provides a means for the prospective assessment of relative stroke risk in patients with carotid atherosclerosis. (orig.)

Carotid disease in diabetic patients undergoing coronary artery bypass grafting

International Nuclear Information System (INIS)

Shahid, M.; Abid, A.R.; Dar, M.A.; Noeman, A.; Amin, S.; Azhar, M.

2012-01-01

Objective: To compare the severity of carotid artery disease in diabetic and non-diabetic patients undergoing coronary artery bypass grafting. Methods: From January to June 2008, 379 patients undergoing elective coronary artery bypass surgery were preoperatively evaluated for the presence of carotid stenoses by duplex scanning. Patients were divided into two groups, Group I, 156 (41.2%) diabetic patients and Group II, 223 (58.8%) non-diabetic patients. Results: There were 314 (82.8%) males and 65 (17.2%) females with a mean age of 57.2+-9.1 years. In diabetic group there were 125 (80.1%) males and 31 (19.9%) females with a mean age of 56.3+-8.9 years. Left main stem stenosis was present in 59 (37.8%) diabetics and 45 (20.2%) non-diabetics (p 70% stenosis was present in 20 (5.3%) with 13 (8.3%) diabetics and 7 (3.1%) non-diabetics (p<0.025). Stenosis of 50-70% was observed in 30 (7.9%) of which 17 (10.9%) were diabetics and 13 (5.8%) were non-diabetics. Conclusion: Presence of diabetes mellitus is associated with diffuse coronary artery disease and significant carotid artery disease in patients undergoing coronary artery bypass grafting. (author)

Early evaluation of renal hemodynamic alterations in type I diabetes mellitus with duplex ultrasound

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Saif Aasem

2010-01-01

Full Text Available To evaluate the role of renal duplex ultrasonography in the detection of early alte-ration of renal blood flow in type I diabetic patients, we studied with duplex ultrasound 32 patients with type I diabetes mellitus (19 males, 13 females, age range 8-19 years and 35 age and sex-matched controls. The resistivity indices (RIs and pulsatility indices (PIs of the main renal as well as intra-renal arteries were calculated. Compared with the healthy control subjects, diabetic patients had significantly higher resistivity indices (RIs in the intrarenal (segmental, arcuate and interlobar ar-teries (P= 0.001. The study, also revealed a significantly positive correlation between the RIs in the intrarenal arteries in diabetics and the albumin/creatinine ratio (r= 0.54, 0.52 and 0.51 respectively, glycated hemoglobin (r= 0.61, 0.59 and 0.63 respectively, as well as the estimated GFR (e-GFR (r= 0.53, 0.51 and 0.57 respectively. We conclude that the current study documented early intra-renal hemodynamic alterations in the form of pathologically elevated intrarenal RIs. This denotes the potential usefulness of duplex evaluation of the intrarenal arteries, as a noninvasive procedure, for monitoring type 1 diabetic patients to predict those at risk of diabetic nephropathy.

Lack of Association between ABO, PPAP2B, ADAMST7, PIK3CG, and EDNRA and Carotid Intima-Media Thickness, Carotid Plaques, and Cardiovascular Disease in Patients with Rheumatoid Arthritis

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Raquel López-Mejías

2014-01-01

Full Text Available Introduction. Rheumatoid arthritis (RA is a polygenic disease associated with accelerated atherosclerosis and increased cardiovascular (CV mortality. Recent studies have identified the ABO rs579459, PPAP2B rs17114036, and ADAMTS7 rs3825807 polymorphisms as genetic variants associated with coronary artery disease and the PIK3CG rs17398575 and EDNRA rs1878406 polymorphisms as the most significant signals related to the presence of carotid plaque in nonrheumatic Caucasian individuals. Accordingly, we evaluated the potential relationship between these 5 polymorphisms and subclinical atherosclerosis (assessed by carotid intima-media thickness (cIMT and presence/absence of carotid plaques and CV disease in RA. Material and Methods. 2140 Spanish RA patients were genotyped for the 5 polymorphisms by TaqMan assays. Subclinical atherosclerosis was evaluated in 620 of these patients by carotid ultrasonography technology. Results. No statistically significant differences were found when each polymorphism was assessed according to cIMT values and presence/absence of carotid plaques in RA, after adjusting the results for potential confounders. Moreover, no significant differences were obtained when RA patients were stratified according to the presence/absence of CV disease after adjusting for potential confounders. Conclusion. Our results do not confirm association between ABO rs579459, PPAP2B rs17114036, ADAMTS7 rs3825807, PIK3CG rs17398575, and EDNRA rs1878406 and subclinical atherosclerosis and CV disease in RA.

Association between triglyceride/HDL cholesterol ratio and carotid atherosclerosis in postmenopausal middle-aged women.

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Masson, Walter; Siniawski, Daniel; Lobo, Martín; Molinero, Graciela; Huerín, Melina

2016-01-01

The triglyceride/HDL cholesterol ratio, as a surrogate marker of insulin resistance, may be associated to presence of subclinical carotid atherosclerosis in postmenopausal women. The aim of this study was to explore this association. Women (last menstrual period≥2 years) in primary prevention up to 65 years of age were recruited. Association between the triglyceride/HDL cholesterol (HDL-C) ratio and presence of carotid plaque, assessed by ultrasonography, was analyzed. ROC analysis was performed, determining the precision of this ratio to detect carotid plaque. A total of 332 women (age 57±5 years) were recruited. Triglyceride/HDL-C ratio was 2.35±1.6. Prevalence of carotid plaque was 29%. Women with carotid plaque had higher triglyceride/HDL-C ratios (3.33±1.96 vs. 2.1±1.2, P<.001) than women with no carotid plaque. A positive relationship was seen between quintiles of this ratio and prevalence of carotid plaque (p<.001). Regardless of other risk factors, women with higher triglyceride/HDL-C ratios were more likely to have carotid plaque (odds ratio 1.47, 95% confidence interval 1.20-1.79, P<.001). The area under the curve of the triglyceride/HDL-C ratio to detect carotid plaque was .71 (95% confidence interval .65 to .76), and the optimal cut-off point was 2.04. In postmenopausal women in primary prevention, insulin resistance, estimated from the triglyceride/HDL-C ratio, was independently associated to a greater probability of carotid plaque. A value of such ratio greater than 2 may be used for assessing cardiovascular risk in this particular group of women. Copyright © 2016 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Association between HbA1c and carotid atherosclerosis among elderly Koreans with normal fasting glucose.

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Seung Won Lee

Full Text Available We examined whether glycated haemoglobin (HbA1c is associated to carotid atherosclerosis in an elderly Korean population with normal fasting glucose.Using data from the Korean Urban Rural Elderly study, we conducted a cross-sectional analysis of 1,133 participants (335 men and 798 women with a mean age of 71.8 years. All participants had fasting blood glucose less than 100mg/dL (5.6 mmol/L and HbA1c level below 6.5% (48 mmol/mol. They were also free from a history of cardiovascular disease, known type 2 diabetes mellitus or use of anti-diabetes medications. Carotid atherosclerosis was assessed by intima-media thickness (IMT using ultrasonography. The association between HbA1c and carotid IMT was investigated using multivariable linear regression analysis.HbA1c levels were independently and positively associated with carotid IMT (β = 0.020, p = 0.045 after adjusting for sex, age, body mass index, systolic blood pressure, diastolic blood pressure, triglyceride, LDL cholesterol, smoking and alcohol intake. However, fasting insulin and glucose levels were not associated with carotid IMT.HbA1c levels were positively associated with carotid atherosclerosis, as assessed by carotid IMT, in an elderly population with normoglycemia. Our study suggested that higher HbA1c level is an effective and informative marker of carotid atherosclerosis in an elderly population.

The effect of a simulation training package on skill acquisition for duplex arterial stenosis detection.

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Jaffer, Usman; Normahani, Pasha; Singh, Prashant; Aslam, Mohammed; Standfield, Nigel J

2015-01-01

In vascular surgery, duplex ultrasonography is a valuable diagnostic tool in patients with peripheral vascular disease, and there is increasing demand for vascular surgeons to be able to perform duplex scanning. This study evaluates the role of a novel simulation training package on vascular ultrasound (US) skill acquisition. A total of 19 novices measured predefined stenosis in a simulated pulsatile vessel using both peak systolic velocity ratio (PSVR) and diameter reduction (DR) methods before and after a short period of training using a simulated training package. The training package consisted of a simulated pulsatile vessel phantom, a set of instructional videos, duplex ultrasound objective structured assessment of technical skills (DUOSATS) tool, and a portable US scanner. Quantitative metrics (procedure time, percentage error using PSVR and DR methods, DUOSAT scores, and global rating scores) before and after training were compared. Subjects spent a median time of 144 mins (IQR: 60-195) training using the simulation package. Subjects exhibited statistically significant improvements when comparing pretraining and posttraining DUOSAT scores (pretraining = 17 [16-19.3] vs posttraining = 30 [27.8-31.8]; p duplex images in a pulsatile simulated phantom following a short period of goal direct training using a simulation training package. A simulation training package may be a valuable tool for integration into a vascular training program. However, further work is needed to explore whether these newly attained skills are translated into clinical assessment. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

The benign course of carotid-cavernous fistula in a child

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Kurul, Semra E-mail: skurul@hotmail.com; Cakmakci, Handan; Kovanlikaya, Arzu; Dirik, Eray

2001-08-01

Carotid-cavernous fistulas (CCF) are reported very rarely in childhood and their clinical course and prognosis are uncertain. We report a 9-year-old boy presented with left eye swelling, neck pain and headache. The MRI findings suggested a CCF with enlarged left superior ophthalmic vein. Ocular Doppler ultrasonography revealed enlarged left superior ophthalmic vein, and arterialization of Doppler wave form. The cerebral angiogram showed normal anatomy. Control Doppler examination findings supported the diagnosis of closure of fistula. The clinical and radiological findings of this unusual presentation are discussed.

The benign course of carotid-cavernous fistula in a child

International Nuclear Information System (INIS)

Kurul, Semra; Cakmakci, Handan; Kovanlikaya, Arzu; Dirik, Eray

2001-01-01

Carotid-cavernous fistulas (CCF) are reported very rarely in childhood and their clinical course and prognosis are uncertain. We report a 9-year-old boy presented with left eye swelling, neck pain and headache. The MRI findings suggested a CCF with enlarged left superior ophthalmic vein. Ocular Doppler ultrasonography revealed enlarged left superior ophthalmic vein, and arterialization of Doppler wave form. The cerebral angiogram showed normal anatomy. Control Doppler examination findings supported the diagnosis of closure of fistula. The clinical and radiological findings of this unusual presentation are discussed

Triaging TIA/minor stroke patients using the ABCD2 score does not predict those with significant carotid disease.

Science.gov (United States)

Walker, J; Isherwood, J; Eveson, D; Naylor, A R

2012-05-01

'Rapid Access' TIA Clinics use the ABCD(2) score to triage patients as it is not possible to see everyone with a suspected TIA TIA/minor stroke or 'carotid territory' TIA/minor stroke. Between 1.10.2008 and 31.04.2011, 2452 patients were referred to the Leicester Rapid Access TIA Service. After Stroke Physician review, 1273 (52%) were thought to have suffered a minor stroke/TIA. Of these, both FD/ED referrer and Specialist Stroke Consultant ABCD(2) scores and carotid Duplex ultrasound studies were available for 843 (66%). The yield for identifying a ≥50% stenosis or carotid occlusion was 109/843 (12.9%) in patients with 'any territory' TIA/minor stroke and 101/740 (13.6%) in those with a clinical diagnosis of 'carotid territory' TIA/minor stroke. There was no association between ABCD(2) score and the likelihood of encountering significant carotid disease and analyses of the area under the receiver operating characteristic curve (AUC) for FD/ED referrer and stroke specialist ABCD(2) scores showed no prediction of carotid stenosis (FD/ED: AUC 0.50 (95%CI 0.44-0.55, p = 0.9), Specialist: AUC 0.51 (95%CI 0.45-0.57, p = 0.78). The ABCD(2) score was unable to identify TIA/minor stroke patients with a higher prevalence of clinically important ipsilateral carotid disease. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Arterial function of carotid and brachial arteries in postmenopausal vegetarians

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Su T

2011-08-01

Full Text Available Ta-Chen Su1, Pao-Ling Torng2, Jiann-Shing Jeng3, Ming-Fong Chen1, Chiau-Suong Liau1,41Division of Cardiology, Department of Internal Medicine, 2Department of Obstetrics and Gynecology, 3Department of Neurology, National Taiwan University Hospital, National Taiwan University College of Medicine, 4Cardiovascular Center, Taipei Buddist Tzu-Chi Hospital, Hsin-Dian, Taipei, TaiwanBackground: Vegetarianism is associated with a lower risk of cardiovascular disease. However, studies of arterial function in vegetarians are limited.Methods: This study investigated arterial function in vegetarianism by comparing 49 healthy postmenopausal vegetarians with 41 age-matched omnivores. The arterial function of the common carotid artery was assessed by carotid duplex, while the pulse dynamics method was used to measure brachial artery distensibility (BAD, compliance (BAC, and resistance (BAR. Fasting blood levels of glucose, lipids, lipoprotein (a, high-sensitivity C-reactive protein, homocysteine, and vitamin B12 were also measured.Results: Vegetarians had significantly lower serum cholesterol, high-density and low-density lipoprotein, and glucose compared with omnivores. They also had lower vitamin B12 but higher homocysteine levels. Serum levels of lipoprotein (a and high-sensitivity C-reactive protein were no different between the two groups. There were no significant differences in carotid beta stiffness index, BAC, and BAD between the two groups even after adjustment for associated covariates. However, BAR was significantly lower in vegetarians than in omnivores. Multiple linear regression analysis revealed that age and pulse pressure were two important determinants of carotid beta stiffness index and BAD. Vegetarianism is not associated with better arterial elasticity.Conclusion: Apparently healthy postmenopausal vegetarians are not significantly better in terms of carotid beta stiffness index, BAC, and BAD, but have significantly decreased BAR than

The relationship between AGT gene polymorphism and carotid ultrasound changes in elderly patients with hypertension and type-2 diabetes mellitus

International Nuclear Information System (INIS)

Pu Jianhong; Li Jianzhong; Wu Xiuying; Qian Huiying; Liu Jian

2012-01-01

Objective: To observe the relation between angiotensinogen (AGT) gene polymorphism and carotid ultrasound change in the elderly hypertensive patients with type 2 diabetes mellitus (T2DM). Methods: Two hundred and three cases of hospitalization of the elderly were divided into three groups, 105 cases of elderly patients with hypertension; 38 cases of elderly hypertensive patients with T2DM; 60 cases of healthy elderly subjects (the control group) and lipids were measured after admission and carotid ultrasonography were performed. The M235T polymorphism detection was carried out by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. Results: (1) TT genotype of AGT gene and elderly hypertensive with T2DM group carotid ultrasound abnormal rate increased and multi vessel disease was the main occurrence. (2) Multiple vessel disease of the carotid artery ultrasound and their blood lipid level were significantly increased. Conclusion: Hypertension and T2DM in elderly patients, carotid artery ultrasound abnormalities are significantly increased, while the elevated lipid levels and the TT genotype of the AGT gene artery atherosclerosis is further enhanced. (authors)

Tensile and compressive properties of fresh human carotid atherosclerotic plaques.

LENUS (Irish Health Repository)

Maher, Eoghan

2009-12-11

Accurate characterisation of the mechanical properties of human atherosclerotic plaque is important for our understanding of the role of vascular mechanics in the development and treatment of atherosclerosis. The majority of previous studies investigating the mechanical properties of human plaque are based on tests of plaque tissue removed following autopsy. This study aims to characterise the mechanical behaviour of fresh human carotid plaques removed during endarterectomy and tested within 2h. A total of 50 radial compressive and 17 circumferential tensile uniaxial tests were performed on samples taken from 14 carotid plaques. The clinical classification of each plaque, as determined by duplex ultrasound is also reported. Plaques were classified as calcified, mixed or echolucent. Experimental data indicated that plaques were highly inhomogeneous; with variations seen in the mechanical properties of plaque obtained from individual donors and between donors. The mean behaviour of samples for each classification indicated that calcified plaques had the stiffest response, while echolucent plaques were the least stiff. Results also indicated that there may be a difference in behaviour of samples taken from different anatomical locations (common, internal and external carotid), however the large variability indicates that more testing is needed to reach significant conclusions. This work represents a step towards a better understanding of the in vivo mechanical behaviour of human atherosclerotic plaque.

Current recommendations for the study of carotid stenosis by doppler ultrasound and other imaging techniques

International Nuclear Information System (INIS)

Perez Matamoros, Angelica

2012-01-01

Ischemic cerebrovascular disease has been one of the most frequent causes of death from chronic disease, as well as cause of long-term disabilities, in both the United States, and in Latin American countries during recent years. It is therefore, important to know about it. An updated review of international recommendations to the Costa Rican health system is performed for carotid imaging study in patients at risk of accidents and ischemic cerebrovascular disease; with special emphasis on carotid Doppler ultrasonography, due to its wide availability in the medical field Costa Rican. Furthermore, certain relevant concepts of other imaging techniques currently available are listed to determine the appropriate choice of each method according to the individual patient's condition, such as conventional angiography and tomographic angiography [es

Non-thrombotic Abnormalities on Lower Extremity Venous Duplex Ultrasound Examinations

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Adhikari, Srikar

2015-03-01

Full Text Available Introduction: Emergency physician-performed compression ultrasonography focuses primarily on the evaluation of the proximal veins of the lower extremity in patients with suspected deep venous thrombosis (DVT. A detailed sonographic evaluation of lower extremity is not performed. The objective of this study was to determine the prevalence of non-thrombotic findings on comprehensive lower extremity venous duplex ultrasound (US examinations performed on emergency department (ED patients. Methods: We performed a retrospective six-year review of an academic ED’s records of adult patients who underwent a comprehensive lower extremity duplex venous US examination for the evaluation of DVT. The entire US report was thoroughly reviewed for non-thrombotic findings. Results: We detected non-thrombotic findings in 263 (11%, 95% CI [9.5-11.9%] patients. Among the non-thrombotic findings, venous valvular incompetence (81, 30% was the most frequent, followed by cyst/mass (41, 15%, lymphadenopathy (33, 12%, phlebitis (12, 4.5%, hematoma (8, 3%, cellulitis (1, 0.3% and other (6, 2.2%. Conclusion: In our study, we detected a variety of non-thrombotic abnormalities on comprehensive lower extremity venous duplex US examinations performed on ED patients. Some of these abnormalities could be clinically significant and potentially be detected with point-of-care lower extremity US examinations if the symptomatic region is evaluated. In addition to assessment of the proximal veins for DVT, we recommend sonographic evaluation of the symptomatic area in the lower extremity when performing point-of-care ultrasound examinations to identify non-thrombotic abnormalities that may require immediate intervention or close follow up. [West J Emerg Med. 2015;16(2:250–254.

Deep vein thrombosis of lower extremity: What is the most important finding in duplex Doppler sonography

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Kim, Yong Soo; Koh, Byung Hee; Cho, On Koo; Rhim, Hyun Chul; Seo, Heung Suk; Hahm, Chang Kok; Kwak, Jin Young [Hanyang University College of Medicine, Seoul (Korea, Republic of)

1993-12-15

The positive findings of deep vein thrombosis on duplex Doppler ultrasonography such as intraluminal clot,non-compressibility of the venous lumen and abnormal or absent Doppler shift signal are well known. However, relatively hypoechoic thrombus is not always seen in sonography, and the vein is frequently compressible in partial thrombosis. In order to evaluate the most common and important findings of deep vein thrombosis, we analysed the findings at duplex Doppler ultrasound in 19 patients and compared the results with those of contrast venography in 11 patients. Duplex Doppler ultrasound examination of the common femoral and popliteal veins was performed for one extremity in 14 patients, and for both extremities in 5 (total 24 extremities). Contrast venography was performed for one extremity in 7 patients, and for both sides in 4 (total 15 extremities).Thrombosis was seen in 45.8%, non-compressibility of lumen in 75%, absent or decreased Doppler signal from common femoral vein in 95.8%. Thrombosis was seen in 41.7%, non-compressibility of lumen in 70.8%, absent or decreased Doppler shift signal from popliteal vein in 95.8%. We conclude that abnormal or absent Doppler shift signal is the most sensitive and important finding of the deep vein thrombosis

The use of intraoperative monitoring and treatment of symptomatic microemboli in carotid artery stenting: case report and discussion

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Rangi, P.S.; Clifton, A. [St Georges Hospital, Department of Neuroradiology, Atkinson Morley Wing, Tooting, London (United Kingdom); Markus, H.S.; Punter, M.N.M. [St Georges University of London, Centre for Clinical Neuroscience, Cranmer Terrace, London (United Kingdom)

2007-03-15

Carotid artery stenting is a recently introduced treatment in symptomatic atherosclerotic carotid artery disease with acceptable complication rates. The major risk is perioperative embolic stroke. Transcranial Doppler ultrasonography (TCD) can be used to identify embolic signals and guide therapy. We present a case of symptomatic embolization in a 72-year-old female following carotid stent deployment complicated by haemodynamic changes. Despite concurrent dual antiplatelet medication significant symptomatic embolization occurred even after restoration of the blood pressure, and modulation of the rate of embolization was achieved using dextran-40 guided by TCD monitoring. The patient recovered from an initially profound hemiparesis and dysphasia to minor sensory changes. Microemboli are common following carotid artery stenting and there appears to be a threshold phenomenon associated with prolonged embolization and progression to cerebral infarction. TCD can be used to detect particulate microemboli and therefore may be useful in guiding antithrombotic therapy in this setting. Dextran-40 has been shown to reduce the embolic load following carotid endarterectomy and was used to good effect in this patient in terms of both embolic load and clinical outcome. This is the first case of embolization following carotid stenting successfully treated with dextran-40, and offers a further option for therapeutic intervention in microembolism detected by TCD and stresses the importance of perioperative monitoring of embolic load for postoperative stroke risk. (orig.)

Markers of insulin resistance and carotid atherosclerosis. A comparison of the homeostasis model assessment and triglyceride glucose index.

Science.gov (United States)

Irace, C; Carallo, C; Scavelli, F B; De Franceschi, M S; Esposito, T; Tripolino, C; Gnasso, A

2013-07-01

The present investigation was designed to test the association between carotid atherosclerosis and two simple markers of insulin resistance, i.e. HOMA-Index and TyG-Index. The study was performed in two different cohorts. In the first cohort, 330 individuals were enrolled. Blood pressure, lipids, glucose, waist and cigarette smoking were evaluated. HOMA-IR and TyG-Index were calculated as markers of prevalent hepatic and muscular insulin resistance respectively. Carotid atherosclerosis was assessed by Doppler ultrasonography. The association between cardiovascular risk factors, markers of insulin resistance and carotid atherosclerosis was assessed by multiple logistic regression analyses. In the second cohort, limited to the evaluation of TyG-Index, 1432 subjects were studied. In the first cohort, TyG-Index was significantly associated with carotid atherosclerosis in a model including age, sex, diabetes, cigarette smoking and LDL cholesterol, while HOMA-IR was not. When components of metabolic syndrome were added to the model as dichotomous variables (absent/present), TyG-Index retained its predictive power. The same result was obtained when the metabolic syndrome was added to the model (absence/presence). The association between TyG-Index and carotid atherosclerosis was confirmed in the second cohort. The present findings suggest that TyG-Index is better associated with carotid atherosclerosis than HOMA-IR. © 2013 John Wiley & Sons Ltd.

Carotid plaque is a new risk factor for peripheral vestibular disorder: a retrospective cohort study.

Science.gov (United States)

Wada, Masaoki; Takeshima, Taro; Nakamura, Yosikazu; Nagasaka, Shoichiro; Kamesaki, Toyomi; Kajii, Eiji

2016-08-01

Many chronic diseases are associated with dizziness or vertigo, as is peripheral vestibular disorder (PVD). Although carotid plaque development is linked to atherosclerosis, it is unclear whether such plaques can lead to the development of PVD. We therefore conducted this study to investigate the presence of an association between carotid plaque and new PVD events.In this retrospective study, we consecutively enrolled 393 patients ≥20 years old who had been treated for chronic diseases such as hypertension, dyslipidemia, and diabetes mellitus for ≥6 months at a primary care clinic (Oki Clinic, Japan) between November 2011 and March 2013. Carotid plaque presence was measured with high-resolution ultrasonography for all patients. During a 1-year follow-up period, an otorhinolaryngologist diagnosed and reported any new PVD events (the main end point). Hazard ratios (HRs) and 95% confidence intervals (CIs) for new PVD occurrence were estimated using the Cox proportional hazard regression model.The mean age of the participants was 65.5 years; 33.8% were men, and 12.7%, 82.4%, and 93.1% had diabetes mellitus, hypertension, and dyslipidemia, respectively. There were 76 new PVD events; patients with carotid plaque had a greater risk of such events (crude HR: 3.25; 95% CI: 1.62-6.52) compared to those without carotid plaque. This risk was even higher after adjusting for traditional risk factors for atherosclerosis (adjusted HR: 4.41; 95% CI: 1.75-11.14).Carotid plaques are associated with an increased risk of new PVD events.

Vesicoureteral Reflux and Duplex Systems

OpenAIRE

Thomas, John C.

2008-01-01

Vesicoureteral reflux (VUR) is the most common anomaly associated with duplex systems. In addition to an uncomplicated duplex system, reflux can also be secondary in the presence of an ectopic ureterocele with duplex systems. Controversy exists in regard to the initial and most definitive management of these anomalies when they coexist. This paper will highlight what is currently known about duplex systems and VUR, and will attempt to provide evidence supporting the various surgical approa...

Clinical implications of internal carotid artery tortuosity, kinking and coiling: a systematic review

Directory of Open Access Journals (Sweden)

Zenteno M.

2014-03-01

Full Text Available Anatomical variations of the internal carotid artery are diverse. Abnormalities in their geometry and paths are commonly identified by ultrasonography and angiography. The surgical correction of symptomatic CAs is better in preventing stroke compared with best medical therapy, as well as it completely eliminates the symptoms in patients with nonhemispheric symptoms. The ICA anomalies may be dangerous and represent a risk factor for massive bleeding. Suture ligatures can penetrate and occlude torn vessels, scalpels or biting instruments can lacerate vessels, and indirectly conducted electric cauterization can burn the soft of bony tissues

Type-1 diabetes mellitus, nephrotic syndrome, and vur with ace gene polymorphism

International Nuclear Information System (INIS)

Kiani, I.G.; Mansoor, Q.; Ismail, M.; Khan, A.N.; Butt, G.

2012-01-01

Objectives: To determine sensitivity, specificity and other operating characteristics of bedside three-point compression ultrasonography performed in emergency department by emergency physicians in comparison with duplex ultrasonography. Methods: The cross-sectional study at Rasoul-e-Akram Hospital in Tehran, Iran, prospectively evaluated 81 suspected patients of lower extremity deep vein thrombosis between March 2006 and March 2007. A trained second-year resident and one attending physician of emergency medicine evaluated the veins of all the patients with through compression ultrasonography. Then, a second-year resident of radiology assessed the patients with duplex ultrasonography. Finally, data were compared and quantitative and categorical variables were worked out along with other statistical analysis through SPSS version 16. Results: The mean age of the patients was 47.2 +- 18.6 years. When cases who lost the compressibility of at least one of their femoral or popliteal veins were considered to be positive, there were 80.2% diagnosed by compression ultrasonography and 79% by the duplex variety. Sensitivity, specificity and accuracy of the former in comparison with the latter were 85.9%, 41.2% and 84.6% respectively. Conclusion: Compression ultrasonography has relatively an acceptable sensitivity and accuracy level, but has low specificity in the diagnosis of deep vein thrombosis in the hands of Iranian emergency physicians. It is better to implement duplex ultrasonography whenever accessible. Otherwise, compression ultrasonography results should be compared with the results of duplex ultrasonography as soon as possible. (author)

Diagnosis Of The Risk For Carotid Artery Stenos Based On Thermal Model In Infrared Images

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Fatemeh Valipoori Goodarzi

2017-02-01

Full Text Available Background and purpose: Ischemic stroke is the third leading cause of death and a common cause of hospitalization in the United States of America and is also an important factor for Inability of patients and carotid stenos is one of the most important factors in creating it. Now, Imaging studies include: Angiography, MRI, CT scan and Doppler ultrasonography , are used to detect carotid artery stenos that is one of the most important causes of ischemic stroke. However, each method has unique advantages and disadvantages, that many of them will have a compromise between performance and accuracy versus easy usage and cost considerations. In contrast, in this paper, thermography is used as a non-invasive and cost effective to detect carotid artery Stenos and thus the risk of stroke. Materials and methods: This study is done on a series of thermal images obtained from the Clinical Center in California. In this imaging, the automatic detection of carotid artery stenos and thus Risk for stroke was done, based on: (1 the difference of average temperature between the right and left carotid arteries in the neck (2 The presence or absence of internal and external carotid arteries. Results: In this study, with the survey conducted by a specialist brain of patients had been previously, the accuracy of this work is confirmed. the techniques and points that are Experimental and  scientifically based  and obtained in this study, can help to doctors for Early detection of Artery disease, based on analysis of thermal images . Conclusion: The method presented in this paper is considered as a non-invasive and cost-effective method that automatically operates to detect the carotid arteries and prevent the Risk for stroke.

Association between hyperhomocysteinemia and metabolic syndrome with early carotid artery atherosclerosis: A cross-sectional study in middle-aged Chinese population.

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Liu, Chengguo; Sun, Xiaohui; Lin, Hanli; Zheng, Ruizhi; Ruan, Liansheng; Sun, Zhanhang; Zhu, Yimin

2018-03-21

Homocysteine is a modifiable, independent risk factor for cardiovascular disease. The association between hyperhomocysteinemia and metabolic syndrome with the presence of early carotid artery atherosclerosis remains unknown in middle-aged Chinese adults. Chinese adults (n = 1607) of Han ethnicity, age 35 to 65 y, and living in their communities >2 y were surveyed. Hyperhomocysteinemia was defined as homocysteine concentrations >15 µmol/L. Carotid intima-media thickness and carotid plaque were examined by ultrasonography. All participants were classified into four groups by hyperhomocysteinemia and metabolic syndrome status. Participants with both hyperhomocysteinemia and metabolic syndrome had the highest levels of waist circumference and systolic blood pressure compared with the three other groups. The highest proportion of increased carotid intima-media thickness (61.3%) was in the subgroup of both hyperhomocysteinemia and metabolic syndrome. After adjustments for the covariates, the risk of increased carotid intima-media thickness was only significantly higher in the group with metabolic syndrome but without hyperhomocysteinemia (odds ratio: 1.47; 95% confidence interval, 1.13-1.93) compared with people without hyperhomocysteinemia and metabolic syndrome. Furthermore, statistically significant variances of prevalence of plaque among the four subgroups were not discovered. Our study demonstrated that metabolic syndrome had a strong effect on carotid intima-media thickness However, the increased homocysteine levels were not significantly associated with early carotid artery atherosclerosis in middle-aged Chinese people. Copyright © 2018 Elsevier Inc. All rights reserved.

Carotid Artery Stenosis: Comparison of 3D Time-of-Flight MR Angiography and Contrast-Enhanced MR Angiography at 3T

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Ivan Platzek

2014-01-01

Full Text Available Purpose. The aim of this study was to assess the correlation of 3D time-of-flight MR angiography (TOF MRA and contrast-enhanced MR angiography (CEMRA for carotid artery stenosis evaluation at 3T. Material and Methods. Twenty-three patients (5 f, 18 m; mean age 61 y, age range 45–78 y with internal carotid artery stenosis detected with ultrasonography were examined on a 3.0T MR system. The MR examination included both 3D TOF MRA and CEMRA of the carotid arteries. MR images were evaluated independently by two board-certified radiologists. Stenosis evaluation was based on a five-point scale. Stenosis grades determined by TOF and CEMRA were compared using Spearman’s rank correlation coefficient and the Wilcoxon test. Cohen’s Kappa was used to evaluate interrater reliability. Results. CEMRA detected stenosis in 24 (52% of 46 carotids evaluated, while TOF detected stenosis in 27 (59% of 46 carotids. TOF MRA yielded significantly higher results for stenosis grade in comparison to CEMRA (P=0.014. Interrater agreement was very good for both TOF MRA (κ=0.93 and CEMRA (κ=0.93. Conclusion. At 3T, 3D TOF MRA should not be used as replacement for contrast-enhanced MRA of the carotid arteries, as it results in significantly higher stenosis grades.

Welding of duplex and super-duplex stainless steels

International Nuclear Information System (INIS)

Van Nassau, L.; Meelker, H.; Hilkes, J.

1994-01-01

After a recall of the commercial designation of duplex or super-duplex steels (22-27% Cr, 4-8% Ni, 0.1-0.3% N with or without Mo (1.5-4%)) and of some metallurgical properties (phase diagrams, microstructure, ferrite determination, heat treatment and aging), welding technologies are synthetically presented (advantages-disadvantages of each process, metals filler, parameters of the welding processes, heat treatments after welding, cleaning, passivation, properties (mechanical, corrosion resistance) of the welded pieces). (A.B.). 28 refs. 5 figs., 15 tabs., 1 annexe

Evaluation of the carotid and vertebral arteries: comparison of 3D SCTA and IA-DSA-work in progress

International Nuclear Information System (INIS)

Seemann, M.D.; Minx, C.; Heuck, A.; Reiser, M.F.; Englmeier, K.H.; Schuhmann, D.R.G.; Fuerst, H.

1999-01-01

Objective: The purpose of this study was to develop a method for three-dimensional (3D) visualization of the whole vascular system of the carotid and vertebral arteries using spiral computed tomographic angiography (SCTA), that allows accurate, qualitative and quantitative evaluation, of anatomical abnormalities, including detection of additional lesions, and estimation of degree of stenosis. Materials and methods: Fifteen patients with anatomical and pathological abnormalities of the arterial vascular system detected by color-coded duplex ultrasound were studied using intraarterial digital subtraction angiography (IA-DSA) with aortic arch injection, and SCTA. The carotid and vertebral arteries were segmented using an interactive threshold interval density volume-growing method and visualized with a color-coded shaded-surface display (SSD) rendering method. The adjacent bone structures were visualized using a transparent volume rendering method. Results: In all cases, the entire volume of the vascular system of the carotid and vertebral arteries could be visualized on SCTA, and the anatomical and pathological abnormalities on 3D SCTA correlated well with that seen on IA-DSA. Conclusion: Results of 3D SCTA had a high degree of correlation with results of IA-DSA in the evaluation of the vascular system of the carotid and vertebral arteries. The 3D SCTA with a subsecond spiral CT scanner is useful for the visualization of anatomical and pathological abnormalities in the circulation in the carotid and vertebral arteries and offer a promising minimally invasive alternative compared with other diagnostic procedures. (orig.) (orig.)

Carotid ultrasonographic and brain computerized tomographic findings in patients with vascular ocular syndromes

Energy Technology Data Exchange (ETDEWEB)

Iwamoto, Toshihiko; Matsushima, Chikage; Shimizu, Souichirou; Takasaki, Masaru; Iwasaki, Takuya; Usui, Masahiko [Tokyo Medical Coll. (Japan)

2002-02-01

To clarify the characteristics of cerebrovascular lesions in subtypes of vascular ocular syndrome, including amaurosis fugax (AF), retinal artery occlusion (RAO), and retinal vein occlusion (RVO), 93 patients with vascular ocular syndrome were studied by means of carotid ultrasonography (US) and brain computerized tomography (CT). The subjects comprised 21 patients with AF, 37 with RAO, and 35 with RVO who were sequentially given these diagnoses by the department of ophthalmology. On the basis of US findings, carotid lesions were defined as the presence of plaque or stenotic changes. CT findings were assessed for the presence and distribution of low-density areas (LDAs). Mean age was similar in each group, ranging from 64.5 to 67.4 years. The RAO group had high rates of men, hypertension, and smokers. US showed that the prevalence of carotid lesions ipsilateral to the affected eye was high in the RAO group and that severe stenosis and ulcerated plaque were present in 28.6% of the AF group and 45.9% of the RAO group. On CT examination, cerebral infarctions appeared as LDAs in about 10% of the patients in each group, and the incidence and distribution of LDAs were similar. Of 13 patients with cerebral infarction, only 2 were presumably due to carotid lesions; the others had a variety of causes. The discrepancy between US and CT findings was attributed to the small number of patients with cerebral infarction, since most patients had visual defects as an initial symptom. Our results suggest that extracranial carotid lesions, considered to be a major risk factor for stroke, should be carefully assessed in patients with AF or RAO to prevent further stroke. (author)

Carotid artery surgery

Science.gov (United States)

Carotid endarterectomy; CAS surgery; Carotid artery stenosis - surgery; Endarterectomy - carotid artery ... through the catheter around the blocked area during surgery. Your carotid artery is opened. The surgeon removes ...

Backbone conformation affects duplex initiation and duplex propagation in hybridisation of synthetic H-bonding oligomers.

Science.gov (United States)

Iadevaia, Giulia; Núñez-Villanueva, Diego; Stross, Alexander E; Hunter, Christopher A

2018-06-06

Synthetic oligomers equipped with complementary H-bond donor and acceptor side chains form multiply H-bonded duplexes in organic solvents. Comparison of the duplex forming properties of four families of oligomers with different backbones shows that formation of an extended duplex with three or four inter-strand H-bonds is more challenging than formation of complexes that make only two H-bonds. The stabilities of 1 : 1 complexes formed between length complementary homo-oligomers equipped with either phosphine oxide or phenol recognition modules were measured in toluene. When the backbone is very flexible (pentane-1,5-diyl thioether), the stability increases uniformly by an order of magnitude for each additional base-pair added to the duplex: the effective molarities for formation of the first intramolecular H-bond (duplex initiation) and subsequent intramolecular H-bonds (duplex propagation) are similar. This flexible system is compared with three more rigid backbones that are isomeric combinations of an aromatic ring and methylene groups. One of the rigid systems behaves in exactly the same way as the flexible backbone, but the other two do not. For these systems, the effective molarity for formation of the first intramolecular H-bond is the same as that found for the other two backbones, but additional H-bonds are not formed between the longer oligomers. The effective molarities are too low for duplex propagation in these systems, because the oligomer backbones cannot adopt conformations compatible with formation of an extended duplex.

The Influence of Various Morphologic and Hemodynamic Carotid Plaque Characteristics on Neurological Events Onset and Deaths

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Milan D. Brajovic

2009-01-01

Full Text Available A group of 72 patients with 111 asymptomatic carotid stenoses (ACS, mean age 65.42 ± 9.21, and a group of 36 patients with 58 symptomatic carotid stenoses (SCS, mean age 67.63 ± 8.79, were analyzed prospectively during a 3-year follow-up period. All patients underwent color duplex scan sonography (CDS, carotid arteriography, computed tomography (CT scan, and neurological examination. The aim of the study was to analyze the correlation between echo plaque morphology (degree and plaque quality, local hemodynamic plaque characteristics, ischemic CT findings, and onset of new neurological events and deaths. The results analysis showed significantly more ACS in the group of 30–49% stenosis (p < 0.001, but significantly more SCS in the group of 70–89% (p < 0.0001 and ≥90% stenosis (p < 0.05. Fibrous plaque was more frequent in the ACS group (p < 0.001, while ulcerated and mixed plaques were more frequent in the SCS group (both p < 0.0001. In the SCS group, a significantly higher frequency of increased peak systolic and end diastolic velocities was noted at the beginning and end of the study (both p < 0.01, as well as for contralateral common (CCA or internal carotid artery (ICA occlusion (p < 0.05 and p < 0.01, respectively, but reduced carotid blood flow volume (p < 0.05 only at the end of the study. In the ACS group, the best correlation with new neurological events and deaths was shown with positive CT findings, peak systolic flow velocity over 210 cm/sec, end diastolic flow velocity over 110 cm/sec, plaque stenosis ≥70%, plaque ulceration, mixed plaque (all p < 0.0001; stenosis ≥50% (p < 0.001; and reduced carotid blood flow volume (p < 0.05.

Mildly elevated serum total bilirubin levels are negatively associated with carotid atherosclerosis among elderly persons with type 2 diabetes.

Science.gov (United States)

Kawamoto, Ryuichi; Ninomiya, Daisuke; Hasegawa, Yoichi; Kasai, Yoshihisa; Kusunoki, Tomo; Ohtsuka, Nobuyuki; Kumagi, Teru; Abe, Masanori

2016-01-01

Diabetes is strongly associated with several mechanisms of tissue damage such as oxidative stress. Serum bilirubin may have a beneficial role in preventing oxidative changes in cardiovascular disease (CVD). Limited information is available on whether serum bilirubin is an independent confounding factor for carotid atherosclerosis among elderly persons with type 2 diabetes. The study subjects were 169 men aged 79 ± 8 (mean ± SD) years and 205 women aged 81 ± 8 years that were enrolled consecutively from patients in the medical department. Carotid intima-media thickness (IMT) and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that serum total bilirubin (β = -0.160) was significantly associated with carotid IMT. Compared to subjects with a serum total bilirubin of tertile-1 (0.13-0.58 mg/dL), the multivariate-adjusted odds ratio (95% confidence interval) of carotid IMT ≥1.0 mm including plaque and carotid plaque was 0.46 (0.23-0.93) and 0.32 (0.17-0.60) in the Tertile-3 group (0.87-1.93 mg/dL), respectively. Next, data were further stratified by gender, age, smoking status, medication and prevalence of CVD. There were no significant differences in serum total bilirubin levels between selected subgroups. Our data demonstrated a negative association between serum total bilirubin and carotid atherosclerosis among elderly persons with type 2 diabetes.

Full Duplex Emulation via Spatial Separation of Half Duplex Nodes in a Planar Cellular Network

DEFF Research Database (Denmark)

Thomsen, Henning; Kim, Dong Min; Popovski, Petar

2016-01-01

A Full Duplex Base Station (FD-BS) can be used to serve simultaneously two Half-Duplex (HD) Mobile Stations (MSs), one working in the uplink and one in the downlink, respectively. The same functionality can be realized by having two interconnected and spatially separated Half Duplex Base Stations...... (HD-BSs), which is a scheme termed CoMPflex (CoMP for In-Band Wireless Full Duplex). A FD-BS can be seen as a special case of CoMPflex with separation distance zero. In this paper we study the performance of CoMPflex in a two-dimensional cellular scenario using stochastic geometry and compare...

Plaque Characteristics of Patients with Symptomatic Mild Carotid Artery Stenosis.

Science.gov (United States)

Takai, Hiroki; Uemura, Juniti; Yagita, Yoshiki; Ogawa, Yukari; Kinoshita, Keita; Hirai, Satoshi; Ishihara, Manabu; Hara, Keijirou; Toi, Hiroyuki; Matsubara, Shunji; Nishimura, Hirotake; Uno, Masaaki

2018-03-20

Carotid revascularization may be considered for severe stenosis, but its use for symptomatic mild stenosis (<50%) with vulnerable plaque or ulcer remains uncertain. The characteristics of patients with symptomatic mild stenosis who underwent revascularization are reviewed. The subjects of this study were 18 patients with symptomatic mild stenosis (<50%) on angiography from among 175 patients who underwent revascularization in our department. The plaques were evaluated by black-blood magnetic resonance imaging (BB-MRI) and ultrasonography (US) and classified into 2 types: type 1 (n = 15), a lesion with an ulcer or mobile plaque or thrombosis on angiography or US; and type 2 (n = 3), a lesion without any of the above. Fourteen patients underwent carotid endarterectomy (CEA), and 4 patients underwent carotid artery stenting. The stenosis on angiography was 27.2% ± 10.7 (5%-41%), and the area carotid artery stenosis rate on US was 69.8 ± 14.5% (44.5%-97%). The stenosis rate of these 2 methods was not at all correlated. In type 1 plaque that underwent CEA, 10 of 11 patients had vulnerable plaque by histopathology, and 1 patient had thrombus on the plaque by operative findings. In type 2 plaque that underwent CEA, all patients had vulnerable plaque by histopathology. During the follow-up period, none of the patients had restenosis or stroke. The findings of US and BB-MRI in patients with symptomatic mild stenosis (<50%) on angiography are important for determining treatment. If BB-MRI or US shows the findings of vulnerable plaque in mild stenosis, surgical treatment may be considered for these patients. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Harvesting full-duplex rate gains in cellular networks with half-duplex user terminals

KAUST Repository

Alammouri, Ahmad; Elsawy, Hesham; Alouini, Mohamed-Slim

2016-01-01

Full-Duplex (FD) transceivers may be expensive in terms of complexity, power consumption, and price to be implemented in all user terminals. Therefore, techniques to exploit in-band full-duplex communication with FD base stations (BSs) and half

Zotarolimus-eluting stent for the treatment of recurrent, severe carotid artery in-stent stenosis in the TARGET-CAS population.

Science.gov (United States)

Tekieli, Lukasz; Pieniazek, Piotr; Musialek, Piotr; Kablak-Ziembicka, Anna; Przewlocki, Tadeusz; Trystula, Mariusz; Moczulski, Zbigniew; Dzierwa, Karolina; Paluszek, Piotr; Podolec, Piotr

2012-06-01

To evaluate the safety and efficacy of a balloon-mounted drug-eluting stent (DES) for recurrent carotid in-stent stenosis (ISS). As part of our targeted carotid artery stenting (TARGET-CAS) protocol, neurological and ultrasound evaluations have been performed at 3, 6, and 12 months and then annually since 2001 in all carotid stent patients. For angiographically-confirmed >70% ISS, balloon angioplasty was performed as a first-line treatment. Recurrent ISS was treated with a 4.0-mm zotarolimus-eluting coronary stent (ZES) that was postdilated according to intravascular ultrasound imaging. Among the 1350 neuroprotected CAS procedures performed between January 2001 and March 2011, there were 7 (0.52%) patients (5 men; ages 51-72 years), all neurologically asymptomatic, with >70% recurrent ISS that occurred at 5 to 11 months after the initial balloon angioplasty treatment for ISS. ZES implantation under distal embolic protection was technically successful and uncomplicated. Angiographic stenosis was reduced from 84.6%±7.5% to 10.7%±3.6% (p<0.01). In 5 patients with ZES implanted fully within the self-expanding carotid stent, duplex ultrasound follow-up (mean 17 months, range 6-36) revealed no evidence of restenosis or stent fracture/deformation. In the 2 other patients, the ZES had been implanted for distal edge ISS such that the ZES protruded beyond the original carotid stent. This protruding segment of the ZES demonstrated deformation/kinking in both; in one, this led to symptomatic stent occlusion. The use of coronary ZES in the treatment of recurrent carotid ISS is feasible and appears effective provided the ZES is placed entirely within the original stent. Placement of a coronary ZES outside the carotid stent scaffold should be avoided.

Carotid Stenting with Distal Protection in High-Surgical-Risk Patients: One-Year Results of the ASTI Trial

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Bosiers, Marc, E-mail: marc.bosiers@telenet.be [A.Z. Sint-Blasius, Department of Vascular Surgery (Belgium); Scheinert, Dierk, E-mail: dierk.scheinert@gmx.de [Park Hospital, Center for Vascular Medicine-Angiology and Vascular Surgery (Germany); Mathias, Klaus, E-mail: k.mathias@asklepios.com [Klinikum Dortmund GmbH (Germany); Langhoff, Ralf, E-mail: ralf.langhoff@sankt-gertrauden.de [Sankt Gertrauden-Krankenhaus (Germany); Mudra, Harald, E-mail: haraldmudra@aol.com [Klinikum Neuperlach (Germany); Diaz-Cartelle, Juan, E-mail: juan.diazcartelle@bostonscientific.com [One Boston Scientific Place, Boston Scientific Corporation (United States)

2015-04-15

PurposeThis prospective, multicenter, nonrandomized study evaluated the periprocedural and 1-year outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Adapt Carotid Stent plus FilterWire EZ distal protection catheter (Boston Scientific Corporation, Natick, MA).Materials and MethodsThe study enrolled 100 patients (32 symptomatic, 63 asymptomatic, 5 unknown) at high risk for carotid endarterectomy due to prespecified anatomical criteria and/or medical comorbidities. Thirty-day and 1-year follow-up included clinical evaluation, carotid duplex ultrasound, and independent neurologic and NIH stroke scale assessments. One-year endpoints included the composite rate of major adverse events (MAE), defined as death, stroke, and myocardial infarction (MI) and the rates of late ipsilateral stroke (31–365 days), target lesion revascularization, and in-stent restenosis.ResultsOf the 100 enrolled patients, technical success was achieved in 90.9 % (90/99). The 30-day MAE rate (5.1 %) consisted of major stroke (2.0 %) and minor stroke (3.1 %); no deaths or MIs occurred. The 1-year MAE rate (12.2 %) consisted of death, MI, and stroke rates of 4.4, 3.3, and 8.9 %, respectively. Late ipsilateral stroke (31–365 days) rate was 1.1 %. Symptomatic patients had higher rates of death (11.1 vs. 1.7 %) and MI (7.4 vs. 1.7 %), but lower rates of major (7.4 vs. 10.0 %) and minor stroke (0.0 vs. 6.7 %), compared with asymptomatic patients.ConclusionResults through 1 year postprocedure demonstrated that carotid artery stenting with Adapt Carotid Stent and FilterWire EZ is safe and effective in high-risk-surgical patients.

Carotid Stenting with Distal Protection in High-Surgical-Risk Patients: One-Year Results of the ASTI Trial

International Nuclear Information System (INIS)

Bosiers, Marc; Scheinert, Dierk; Mathias, Klaus; Langhoff, Ralf; Mudra, Harald; Diaz-Cartelle, Juan

2015-01-01

PurposeThis prospective, multicenter, nonrandomized study evaluated the periprocedural and 1-year outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Adapt Carotid Stent plus FilterWire EZ distal protection catheter (Boston Scientific Corporation, Natick, MA).Materials and MethodsThe study enrolled 100 patients (32 symptomatic, 63 asymptomatic, 5 unknown) at high risk for carotid endarterectomy due to prespecified anatomical criteria and/or medical comorbidities. Thirty-day and 1-year follow-up included clinical evaluation, carotid duplex ultrasound, and independent neurologic and NIH stroke scale assessments. One-year endpoints included the composite rate of major adverse events (MAE), defined as death, stroke, and myocardial infarction (MI) and the rates of late ipsilateral stroke (31–365 days), target lesion revascularization, and in-stent restenosis.ResultsOf the 100 enrolled patients, technical success was achieved in 90.9 % (90/99). The 30-day MAE rate (5.1 %) consisted of major stroke (2.0 %) and minor stroke (3.1 %); no deaths or MIs occurred. The 1-year MAE rate (12.2 %) consisted of death, MI, and stroke rates of 4.4, 3.3, and 8.9 %, respectively. Late ipsilateral stroke (31–365 days) rate was 1.1 %. Symptomatic patients had higher rates of death (11.1 vs. 1.7 %) and MI (7.4 vs. 1.7 %), but lower rates of major (7.4 vs. 10.0 %) and minor stroke (0.0 vs. 6.7 %), compared with asymptomatic patients.ConclusionResults through 1 year postprocedure demonstrated that carotid artery stenting with Adapt Carotid Stent and FilterWire EZ is safe and effective in high-risk-surgical patients

Achieving single channel, full duplex wireless communication

KAUST Repository

Choi, Jung Il; Jain, Mayank; Srinivasan, Kannan; Levis, Phil; Katti, Sachin

2010-01-01

This paper discusses the design of a single channel full-duplex wireless transceiver. The design uses a combination of RF and baseband techniques to achieve full-duplexing with minimal effect on link reliability. Experiments on real nodes show the full-duplex prototype achieves median performance that is within 8% of an ideal full-duplexing system. This paper presents Antenna Cancellation, a novel technique for self-interference cancellation. In conjunction with existing RF interference cancellation and digital baseband interference cancellation, antenna cancellation achieves the amount of self-interference cancellation required for full-duplex operation. The paper also discusses potential MAC and network gains with full-duplexing. It suggests ways in which a full-duplex system can solve some important problems with existing wireless systems including hidden terminals, loss of throughput due to congestion, and large end-to-end delays. Copyright 2010 ACM.

Diagnostic nerve ultrasonography

International Nuclear Information System (INIS)

Baeumer, T.; Grimm, A.; Schelle, T.

2017-01-01

For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. Using ultrasonography for peripheral nerve diagnostics. With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves. (orig.) [de

Structural Properties of G,T-Parallel Duplexes

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Anna Aviñó

2010-01-01

Full Text Available The structure of G,T-parallel-stranded duplexes of DNA carrying similar amounts of adenine and guanine residues is studied by means of molecular dynamics (MD simulations and UV- and CD spectroscopies. In addition the impact of the substitution of adenine by 8-aminoadenine and guanine by 8-aminoguanine is analyzed. The presence of 8-aminoadenine and 8-aminoguanine stabilizes the parallel duplex structure. Binding of these oligonucleotides to their target polypyrimidine sequences to form the corresponding G,T-parallel triplex was not observed. Instead, when unmodified parallel-stranded duplexes were mixed with their polypyrimidine target, an interstrand Watson-Crick duplex was formed. As predicted by theoretical calculations parallel-stranded duplexes carrying 8-aminopurines did not bind to their target. The preference for the parallel-duplex over the Watson-Crick antiparallel duplex is attributed to the strong stabilization of the parallel duplex produced by the 8-aminopurines. Theoretical studies show that the isomorphism of the triads is crucial for the stability of the parallel triplex.

Ultrasonography versus intravenous urography

International Nuclear Information System (INIS)

Aslaksen, A.

1991-01-01

The present study was performed to compare the clinical value of urography and ultrasonography in a non-selected group of patients referred for urography to a university hospital. The conslusions and clinical implications of the study are as follows: Intravenous urography remains the cornerstone imaging examination in the evaluation of ureteral calculi. Ultrasonography is a valuable adjunct in cases of non- visualization of the kidneys, in distal obstruction and known contrast media allergy. When women with recurrent urinary tract infection are referred for imaging of the urinary tract, ultrasonography should be used. Ultrasonography should replace urography for screening of non-acute hydronephrosis like in female genital cancer and benign prostate hyperplasia. There is good correlation between urography and ultrasonography in assessing the degree of hydronephrosis. However, more researh on the relationship between hydronephrosis and obstruction is necessary. Ultrasonography should be used as the only imaging method of the upper urinary tract in patients with microscopic hematuria. In patients less than 50 years with macroscopic hematuria, ultrasonography should be used as the only imaging of the upper urinary tract, and an examination of the urinary bladder should be included. In patients over 50 years, urography supplied with ultrasonography should be used, but more research is necessary on the subject of imaging method and age. 158 refs

Severe ipsilateral carotid stenosis and middle cerebral artery disease in lacunar ischaemic stroke: innocent bystanders?

Science.gov (United States)

Mead, G E; Lewis, S C; Wardlaw, J M; Dennis, M S; Warlow, C P

2002-03-01

Lacunar infarcts are thought to be mostly due to intracranial small vessel disease. Therefore, when a stroke patient with a relevant lacunar infarct does have severe ipsilateral internal carotid artery (ICA) or middle cerebral artery (MCA) disease, it is unclear whether the arterial disease is causative or coincidental. If causative, we would expect ICA/MCA disease to be more severe on the symptomatic side than on the asymptomatic side. Therefore, our aim was to compare the severity of ipsilateral with contralateral ICA and MCA disease in patients with lacunar ischaemic stroke. We studied 259 inpatients and outpatients with a recent lacunar ischaemic stroke and no other prior stroke. We used carotid Duplex ultrasound and transcranial Doppler (TCD) ultrasound to identify ICA and MCA disease, and compared our results with previously published data. In our study, there was no difference between the severity of ipsilateral and contralateral ICA stenosis within individuals (median difference 0%, Wilcoxon paired data p=0.24, comparing severity of ipsilateral and contralateral stenosis). The overall prevalence of severe ipsilateral stenosis was 5%, and the prevalence of severe contralateral stenosis was 4% (OR 1.6, 95% CI 0.6, 4.8). There was no difference in the prevalence of ipsilateral and contralateral MCA disease. A systematic review of the other available studies strengthened this conclusion. Carotid stenosis in patients with a lacunar ischaemic stroke may be coincidental. Further studies are required to elucidate the causes of lacunar stroke, and to evaluate the role of carotid endarterectomy.

Long-term effects on carotid intima-media thickness after radiotherapy in patients with nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Huang, Tai-Lin; Huang, Chi-Ren; Tsai, Nai-Wen; Kung, Chia-Te; Wang, Hung-Chen; Lin, Wei-Che; Cheng, Ben-Chung; Su, Yu-Jih; Chang, Ya-Ting; Chang, Chuang-Rung; Tan, Teng-Yeow; Hsu, Hsuan-Chih; Lu, Cheng-Hsien; Chen, Hui-Chun; Lin, Hsin-Ching; Chien, Chih-Yen; Fang, Fu-Min; Huang, Chih-Cheng; Chang, Hsueh-Wen; Chang, Wen-Neng

2013-01-01

Vascular abnormalities are the predominant histologic changes associated with radiation in nasopharyngeal carcinoma (NPC). This study examined if the duration after radiotherapy correlates with the progression of carotid intima-media thickness (IMT) and investigated its relationship with inflammatory markers. One hundred and five NPC patients post-radiotherapy for more than one year and 25 healthy control subjects were examined by B-mode ultrasound for IMT measurement at the far wall of the common carotid artery (CCA). Surrogate markers including lipid profile, HbA1c, and high sensitive C-reactive protein (hs-CRP) were assessed. The IMT of CCA was significantly increased in NPC patients and carotid plaque was detected in 38 NPC patients (38/105, 36.2%). Significant risk factors for carotid plaques included age, duration after radiotherapy, and HbA1c levels. Age, duration after radiotherapy, hs-CRP, HbA1c, and platelet count positively correlated with IMT. The cut-off value of age and duration after radiotherapy for the presence of plaque was 52.5 years and 42.5 months, respectively. In NPC subjects, multiple linear regression analysis revealed that age, gender, duration after radiotherapy and platelet counts were independently associated with CCA IMT. After adjustments for age, gender and platelet counts, IMT increased in a linear manner with duration after radiotherapy. Radiation-induced vasculopathy is a dynamic and progressive process due to late radiation effects. Extra-cranial color-coded duplex sonography can be part of routine follow-up in NPC patients aged ≥50 years at 40 months post-radiotherapy

Duplex gall bladder: bystander or culprit.

Science.gov (United States)

Kumar, Jogender; Yadav, Arushi

2017-08-30

Gall bladder (GB) duplication is a rare anatomical malformation, which can be detected by preoperative imaging study. We present a case of duplex gall bladder in a 14-year-old boy who presented with abdominal pain. On ultrasound, he had right nephrolithiasis and duplex gall bladder. Duplex gall bladder was confirmed on MR cholangiopancreatography. There was a dilemma for surgical management of duplex gall bladder; however, he became asymptomatic after conservative treatment. Prophylactic surgery is not recommended for asymptomatic incidentally detected duplex gall bladder. Radiologists and paediatric surgeons should be sensitised about the exact anatomy of this entity. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Overall performance of the duplex Stirling refrigerator

International Nuclear Information System (INIS)

Erbay, L. Berrin; Ozturk, M. Mete; Doğan, Bahadır

2017-01-01

Highlights: • Overall performance coefficient of duplex Stirling refrigerator was investigated. • A definite region for the coefficient of performance of the refrigerator in duplex Stirling is identified. • A definite region for the thermal efficiency of the heat engine in duplex Stirling is identified. • Benchmark values and design bounds of the duplex Stirling refrigerator were obtained. - Abstract: The duplex Stirling refrigerator is an integrated refrigerator consists of Stirling cycle engine and Stirling cycle refrigerator used for cooling. The equality of the work generation of the heat engine to the work consumption of the refrigerator is the primary constraint of the duplex Stirling. The duplex Stirling refrigerator is investigated thermodynamically by considering the effects of constructional and operational parameters which are namely the temperature ratios for heat engine and refrigerator, and the compression ratios for both sides. The primary concern is given to the parametric effects on the overall coefficient of performance of the duplex Stirling refrigerator. The given diagrams provide a design bounds and benchmark results that allows seeing the big picture about the cooling load and heat input relation. Moreover they ease to determine the corresponding work rate to the target cooling load. As regard to the obtained results, a definite region for coefficient of performance of the refrigerator and a definite region for the thermal efficiency of the heat engine of the duplex Stirling are identified.

Effect of fosinopril on progression of the asymptomatic carotid atherosclerosis and left ventricular hypertrophy in hypertensive patients

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Tasić Ivan

2006-01-01

Full Text Available INTRODUCTION The cardiovascular changes (vascular structure changes, hypertrophy of the left ventricle contribute to both the increased cardiovascular morbidity and the mortality of essential hypertension. Therefore, modern treatment strategies should not only target blood pressure (BP reduction but also normalize cardiovascular structure and function. OBJECTIVE Aim of the study was to determine the effect of the ACE inhibitor Fosinopril on the Intima-media thickness of the common carotid artery and on the left ventricle mass after 9-month treatment of hypertensive patients. METHOD The study included 40 patients with the arterial hypertension and the left ventricle hypertrophy verified by echocardiography. The patients were randomized on A ACE-inhibitor - Fosinopril and 6 without ACE inhibitor - atenolol, and they were followed up 9 months. The groups were not different by age, sex, and metabolic status. Color Duplex ultrasonography of the carotid arteries was performed by Acuson Sequia C236 with high-frequency linear probe of 8 MHz. The Intima-media thickness of the common carotids on the left and the right was measured in diastole at 1.5. cm from the highest point of bifurcation under maximal magnification. Using the same device, the left ventricle mass and other parameters of the left ventricle were determined in M-mode and by means of 2D image. RESULTS After 9 months, BP In both groups Was reduced In similar range (group A: systolic BP from 158 to 137 mmHg, and diastolic BP from 94 to 85 mmHg, and group B; systolic BP from 164 to 137 mmHg, and diastolic BP from 87 to 84 mmHg. The thickness of the intimomedial complex in patients using Fosinopril was decreased by 0.0278 ± 0.03 mm, while in the group of patients that did not use the ACE-inhibitor, it was increased by 0.078 ±0.13 mm. The left ventricle mass in patients using Fosinopril was decreased by 5 grams (312 ± 72 g vs. 307 ± 77 g, while in group B patients, it was increased by 15

Assessment of intracranial vessels in association with carotid atherosclerosis and brain vascular lesions in rheumatoid arthritis.

Science.gov (United States)

Oláh, Csaba; Kardos, Zsófia; Sepsi, Mariann; Sas, Attila; Kostyál, László; Bhattoa, Harjit Pal; Hodosi, Katalin; Kerekes, György; Tamási, László; Valikovics, Attila; Bereczki, Dániel; Szekanecz, Zoltán

2017-09-26

Stroke has been associated with rheumatoid arthritis (RA). We assessed patients with RA and healthy control subjects by transcranial Doppler (TCD), carotid ultrasonography and brain magnetic resonance imaging (MRI). Altogether, 41 female patients with RA undergoing methotrexate (MTX) or biologic treatment and 60 age-matched control subjects underwent TCD assessment of the middle cerebral artery (MCA) and basilar artery. Pulsatility index (PI), resistivity (resistance) index (RI) and circulatory reserve capacity (CRC) were determined at rest (r) and after apnoea (a) and hyperventilation (h). The presence of carotid plaques and carotid intima-media thickness (cIMT) were also determined. Intracerebral vascular lesions were investigated by brain MRI. MCA PI and RI values at rest and after apnoea were significantly increased in the total and MTX-treated RA populations vs control subjects. MCA CRC was also impaired, and basilar artery PI was higher in RA. More patients with RA had carotid plaques and increased cIMT. Linear regression analysis revealed that left PI(r) and RI(r) correlated with disease duration and that left PI(r), RI(r), PI(a), PI(h) and basilar PI correlated with disease activity. Right CRC inversely correlated with 28-joint Disease Activity Score. Disease activity was an independent determinant of left PI(a) and right CRC. Compared with long-term MTX treatment alone, the use of biologics in combination with MTX was associated with less impaired cerebral circulation. Impaired cerebral circulation was also associated with measures of carotid atherosclerosis. To our knowledge, this is the first study to show increased distal MCA and basilar artery occlusion in RA as determined by TCD. Patients with RA also had CRC defects. We also confirmed increased carotid plaque formation and increased cIMT. Biologics may beneficially influence some parameters in the intracranial vessels.

Additional prognostic value of physical examination, exercise testing, and arterial ultrasonography for coronary risk assessment in primary prevention.

Science.gov (United States)

Cournot, Maxime; Taraszkiewicz, Dorota; Cambou, Jean-Pierre; Galinier, Michel; Boccalon, Henri; Hanaire-Broutin, Hélène; Chamontin, Bernard; Carrié, Didier; Ferrières, Jean

2009-11-01

The choice of noninvasive tests used in primary prevention of cardiovascular diseases must be based on medical evidence. The aim of this study was to assess the additional prognostic value, over conventional risk factors, of physical examination, exercise testing, and arterial ultrasonography, in predicting a first coronary event. A prospective cohort study was conducted between 1996 and 2004 (n = 2,709), with follow-up in 2006 (response rate 96.6%). Participants had no history or symptoms of cardiovascular disease and had a standardized physical examination, a cardiac exercise testing, and carotid and femoral ultrasonography at baseline. Incident cases of definite coronary events were recorded during follow-up. Over the Framingham risk score, femoral bruit, positive exercise test, intima-media thickness >0.63 mm, and a femoral plaque provided significant additional information to the prediction model. The addition of the exercise test to the traditional risk factors, then the intima-media thickness and lastly the presence of femoral plaques, produces incremental increases in the area under the receiver operating characteristic curve (0.73-0.78, P = .02) and about a 50% increase in the positive predictive value (15.8%-31.4%), with no effect on the negative predictive value (96.4%-96.9%). Physical examination, exercise testing, and arterial ultrasonography provide incremental information on the risk of coronary event in asymptomatic adults. Exercise testing and femoral ultrasonography also improve the accuracy of the risk stratification.

Buffer management in wireless full-duplex systems

KAUST Repository

Bouacida, Nader

2015-10-19

Wireless full-duplex radios can simultaneously transmit and receive using the same frequency. In theory, this can double the throughput. In fact, there is only little work addressing aspects other than throughput gains in full-duplex systems. Over-buffering in today\\'s networks or the so-called “bufferbloat” phenomenon creates excessive end-to-end delays resulting in network performance degradation. Our analysis shows that full-duplex systems may suffer from high latency caused by bloated buffers. In this paper, we address the problem of buffer management in full-duplex networks by using Wireless Queue Management (WQM), which is an active queue management technique for wireless networks. Our solution is based on Relay Full-Duplex MAC (RFD-MAC), an asynchronous media access control protocol designed for relay full-duplexing. We compare the performance of WQM in full-duplex environment to Drop Tail mechanism over various scenarios. Our solution reduces the end-to-end delay by two orders of magnitude while achieving similar throughput in most of the cases.

Practical, real-time, full duplex wireless

KAUST Repository

Jain, Mayank; Choi, Jung Il; Kim, Taemin; Bharadia, Dinesh; Seth, Siddharth; Srinivasan, Kannan; Levis, Philip; Katti, Sachin; Sinha, Prasun

2011-01-01

This paper presents a full duplex radio design using signal inversion and adaptive cancellation. Signal inversion uses a simple design based on a balanced/unbalanced (Balun) transformer. This new design, unlike prior work, supports wideband and high power systems. In theory, this new design has no limitation on bandwidth or power. In practice, we find that the signal inversion technique alone can cancel at least 45dB across a 40MHz bandwidth. Further, combining signal inversion cancellation with cancellation in the digital domain can reduce self-interference by up to 73dB for a 10MHz OFDM signal. This paper also presents a full duplex medium access control (MAC) design and evaluates it using a testbed of 5 prototype full duplex nodes. Full duplex reduces packet losses due to hidden terminals by up to 88%. Full duplex also mitigates unfair channel allocation in AP-based networks, increasing fairness from 0.85 to 0.98 while improving downlink throughput by 110% and uplink throughput by 15%. These experimental results show that a re- design of the wireless network stack to exploit full duplex capability can result in significant improvements in network performance. © 2011 ACM.

Serum carotenoids reduce progression of early atherosclerosis in the carotid artery wall among Eastern Finnish men.

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Jouni Karppi

Full Text Available BACKGROUND: Several previous epidemiologic studies have shown that high blood levels of carotenoids may be protective against early atherosclerosis, but results have been inconsistent. We assessed the association between atherosclerotic progression, measured by intima-media thickness of the common carotid artery wall, and serum levels of carotenoids. METHODS: We studied the effect of carotenoids on progression of early atherosclerosis in a population-based study. The association between concentrations of serum carotenoids, and intima-media thickness of the common carotid artery wall was explored in 840 middle-aged men (aged 46-65 years from Eastern Finland. Ultrasonography of the common carotid arteries were performed at baseline and 7-year follow-up. Serum levels of carotenoids were analyzed at baseline. Changes in mean and maximum intima media thickness of carotid artery wall were related to baseline serum carotenoid levels in covariance analyses adjusted for covariates. RESULTS: In a covariance analysis with adjustment for age, ultrasound sonographer, maximum intima media thickness, examination year, body mass index, systolic blood pressure, smoking, physical activity, serum LDL cholesterol, family history of coronary heart disease, antihypertensive medication and serum high sensitivity C-reactive protein, 7-year change in maximum intima media thickness was inversely associated with lycopene (p = 0.005, α-carotene (p = 0.002 and β-carotene (p = 0.019, respectively. CONCLUSIONS: The present study shows that high serum concentrations of carotenoids may be protective against early atherosclerosis.

Rietveld and impedance analysis of cold and hot rolled duplex and lean duplex steels for application in paper and pulp industry

Energy Technology Data Exchange (ETDEWEB)

Esteves, Luiza; Lins, Vanessa de Freitas Cunha, E-mail: luizaeq@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Quimica; Paiva, Paulo Renato Perdigao [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET), Belo Horizonte, MG (Brazil); Viana, Adolfo Kalergis do Nascimento [APERAM South America, Timoteo, MG (Brazil)

2017-01-15

In this study, X-Ray Diffraction (XRD) and Rietveld Refinement were performed to identify and quantify the ferrite and austenite phase of cold and hot rolled duplex stainless steels (UNS S31803) and lean duplex stainless steels (UNS S32304). Electrochemical impedance spectroscopy (EIS) was applied to evaluate the chemical behavior of duplex and lean duplex stainless steels in white, green, and black liquors of paper and pulp industry. Rietveld analysis results showed a higher austenite content than the standard limit for duplex steels in the hot rolled condition. The hot rolling condition plays a major role in improving corrosion resistance in white liquor mainly for the lean duplex steel. (author)

Rietveld and impedance analysis of cold and hot rolled duplex and lean duplex steels for application in paper and pulp industry

International Nuclear Information System (INIS)

Esteves, Luiza; Lins, Vanessa de Freitas Cunha; Viana, Adolfo Kalergis do Nascimento

2017-01-01

In this study, X-Ray Diffraction (XRD) and Rietveld Refinement were performed to identify and quantify the ferrite and austenite phase of cold and hot rolled duplex stainless steels (UNS S31803) and lean duplex stainless steels (UNS S32304). Electrochemical impedance spectroscopy (EIS) was applied to evaluate the chemical behavior of duplex and lean duplex stainless steels in white, green, and black liquors of paper and pulp industry. Rietveld analysis results showed a higher austenite content than the standard limit for duplex steels in the hot rolled condition. The hot rolling condition plays a major role in improving corrosion resistance in white liquor mainly for the lean duplex steel. (author)

Prevalence of carotid artery calcifications detected on panoramic radiographs and confirmed by Doppler ultrasonography: Their relationship with systemic conditions

Directory of Open Access Journals (Sweden)

Thalita Queiroz Abreu

2015-01-01

Conclusions: CACs can be detected in PRJs, and are more frequent in common carotid arteries. No significant associations were detected between the presence of unilateral or bilateral CAC in PRJ and hypertension, diabetes, or obesity.

Thermal stability of DNA quadruplex-duplex hybrids.

Science.gov (United States)

Lim, Kah Wai; Khong, Zi Jian; Phan, Anh Tuân

2014-01-14

DNA has the capacity to adopt several distinct structural forms, such as duplex and quadruplex helices, which have been implicated in cellular processes and shown to exhibit important functional properties. Quadruplex-duplex hybrids, generated from the juxtaposition of these two structural elements, could find applications in therapeutics and nanotechnology. Here we used NMR and CD spectroscopy to investigate the thermal stability of two classes of quadruplex-duplex hybrids comprising fundamentally distinct modes of duplex and quadruplex connectivity: Construct I involves the coaxial orientation of the duplex and quadruplex helices with continual base stacking across the two components; Construct II involves the orthogonal orientation of the duplex and quadruplex helices with no base stacking between the two components. We have found that for both constructs, the stability of the quadruplex generally increases with the length of the stem-loop incorporated, with respect to quadruplexes comprising nonstructured loops of the same length, which showed a continuous drop in stability with increasing loop length. The stability of these complexes, particularly Construct I, can be substantially influenced by the base-pair steps proximal to the quadruplex-duplex junction. Bulges at the junction are largely detrimental to the adoption of the desired G-quadruplex topology for Construct I but not for Construct II. These findings should facilitate future design and prediction of quadruplex-duplex hybrids.

Prolonged CT urography in duplex kidney.

Science.gov (United States)

Gong, Honghan; Gao, Lei; Dai, Xi-Jian; Zhou, Fuqing; Zhang, Ning; Zeng, Xianjun; Jiang, Jian; He, Laichang

2016-05-13

Duplex kidney is a common anomaly that is frequently associated with multiple complications. Typical computed tomography urography (CTU) includes four phases (unenhanced, arterial, parenchymal and excretory) and has been suggested to considerably aid in the duplex kidney diagnosi. Unfortunately, regarding duplex kidney with prolonged dilatation, the affected parenchyma and tortuous ureters demonstrate a lack of or delayed excretory opacification. We used prolonged-delay CTU, which consists of another prolonged-delay phase (1- to 72-h delay; mean delay: 24 h) to opacify the duplicated ureters and affected parenchyma. Seventeen patients (9 males and 8 females; age range: 2.5-56 y; mean age: 40.4 y) with duplex kidney were included in this study. Unenhanced scans did not find typical characteristics of duplex kidney, except for irregular perirenal morphology. Duplex kidney could not be confirmed on typical four-phase CTU, whereas it could be easily diagnosed in axial and CT-3D reconstruction using prolonged CTU (prolonged-delay phase). Between January 2005 and October 2010, in this review board-approved study (with waived informed consent), 17 patients (9 males and 8 females; age range: 2.5 ~ 56 y; mean age: 40.4 y) with suspicious duplex kidney underwent prolonged CTU to opacify the duplicated ureters and confirm the diagnosis. Our results suggest the validity of prolonged CTU to aid in the evaluation of the function of the affected parenchyma and in the demonstration of urinary tract malformations.

Zoster duplex: a clinical report and etiologic analysis.

Science.gov (United States)

Zhang, Feng; Zhou, Jin

2015-01-01

Herpes zoster (HZ) duplex is a rare disease presentation. The mechanisms of varicella zoster virus (VZV) reactivation in multiple dermal regions are unknown. To present a HZ duplex case occurring in an immunocompetent woman and to analyze the possible underlying causes of HZ duplex. We present a HZ duplex case in an immunocompetent woman and analyzed the possible contributing factors in 36 HZ duplex cases. Continuously distributed variables were categorized by numbers and percentages. In our study, 24 cases (66.7%) were from Asia, 16 cases (44.4%) were in individuals ≥ 50 years of age, and 17 cases (47.2%) occurred in immunocompromised patients. Of the 36 cases, 23 involved women (63.9%) and 13 involved men. Eighteen patients suffering from HZ duplex, 13 of which were women (72.2%), did not suffer from any chronic systemic disease or have a long history of taking drugs. HZ duplex is a rare event that can occur in both immunocompetent and immunosuppressed individuals. HZ duplex might be associated with the Asia region, advanced age, immunosuppression, and being female.

Preoperative 3D FSE T1-Weighted MR Plaque Imaging for Severely Stenotic Cervical ICA: Accuracy of Predicting Emboli during Carotid Endarterectomy

Directory of Open Access Journals (Sweden)

Yasushi Ogasawara

2016-10-01

Full Text Available The aim of the present study was to determine whether preoperative three-dimensional (3D fast spin-echo (FSE T1-weighted magnetic resonance (MR plaque imaging for severely stenotic cervical carotid arteries could accurately predict the development of artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA. Seventy-five patients underwent preoperative MR plaque imaging and CEA under transcranial Doppler ultrasonography of the ipsilateral middle cerebral artery. On reformatted axial MR image slices showing the maximum plaque occupation rate (POR and maximum plaque intensity for each patient, the contrast ratio (CR was calculated by dividing the internal carotid artery plaque signal intensity by the sternocleidomastoid muscle signal intensity. For all patients, the area under the receiver operating characteristic curve (AUC—used to discriminate between the presence and absence of microembolic signals—was significantly greater for the CR on the axial image with maximum plaque intensity (CRmax intensity (0.941 than for that with the maximum POR (0.885 (p < 0.05. For 32 patients in whom both the maximum POR and the maximum plaque density were identified, the AUCs for the CR were 1.000. Preoperative 3D FSE T1-weighted MR plaque imaging accurately predicts the development of artery-to-artery emboli during exposure of the carotid arteries in CEA.

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study) : an interim analysis of a randomised controlled trial

NARCIS (Netherlands)

Ederle, Joerg; Dobson, Joanna; Featherstone, Roland L.; Bonati, Leo H.; van der Worp, H. Bart; de Borst, Gert J.; Lo, T. Hauw; Gaines, Peter; Dorman, Paul J.; Macdonald, Sumaira; Lyrer, Philippe A.; Hendriks, Johanna M.; McCollum, Charles; Nederkoorn, Paul J.; Brown, Martin M.; Algra, A.; Bamford, J.; Beard, J.; Bland, M.; Bradbury, A. W.; Brown, M. M.; Clifton, A.; Gaines, P.; Hacke, W.; Halliday, A.; Malik, I.; Mas, J. L.; McGuire, A. J.; Sidhu, P.; Venables, G.; Bradbury, A.; Brown, M. M.; Clifton, A.; Gaines, P.; Collins, R.; Molynewc, A.; Naylor, R.; Warlow, C.; Ferro, J. M.; Thomas, D.; Bonati, L. H.; Coward, L.; Dobson, J.; Ederle, J.; Featherstone, R. F.; Tindall, H.; McCabe, D. J. H.; Wallis, A.; Hendriks, J. M. H.; Hendriks, J. M.

2010-01-01

Background Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. Methods The International Carotid

Carotid angioplasty with stenting for chronic internal carotid artery occlusion: technical note

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Nozomu; Tanasawa, Toshihiko; Okada, Takeshi; Endo, Otone; Yamamoto, Naohito [Kainan Hospital Aichi Prefectural Welfare Federation of Agricultural Cooperatives, Department of Neurosurgery, Aichi (Japan); Miyachi, Shigeru; Hattori, Kenichi [Nagoya University Graduate School of Medicine, Department of Neurosurgery, Nagoya (Japan)

2006-11-15

Carotid angioplasty with stenting (CAS) is becoming accepted as an effective and reliable treatment option for severe carotid artery stenosis. However, it is rarely applied for carotid occlusion, especially in its chronic stage. We report our experience of CAS for chronic internal carotid artery occlusion representing compromised cerebral blood flow using various protection methods. A 77-year-old woman, who was already diagnosed with severe left internal carotid artery stenosis, suddenly had right hemiparesis and aphasia. At that time, she was treated conservatively because her neurological status was quite good, in spite of left carotid artery occlusion. Her symptoms improved in the short term, except slight aphasia, but deteriorated again 18 days from the onset, and magnetic resonance imaging (MRI) showed new ischemic lesions. CAS was then performed for the occluded carotid artery on the 23rd day from the first onset. Using the proximal protection technique, the occluded lesion was crossed carefully with a microguidewire. Stents were also placed successfully with the distal protection technique. The occluded carotid artery was completely recanalized without any unfavorable events or neurological deterioration. In this patient, CAS was successfully to treat chronic carotid artery occlusion. These procedures and techniques are reviewed and discussed. (orig.)

Carotid angioplasty with stenting for chronic internal carotid artery occlusion: technical note

International Nuclear Information System (INIS)

Kobayashi, Nozomu; Tanasawa, Toshihiko; Okada, Takeshi; Endo, Otone; Yamamoto, Naohito; Miyachi, Shigeru; Hattori, Kenichi

2006-01-01

Carotid angioplasty with stenting (CAS) is becoming accepted as an effective and reliable treatment option for severe carotid artery stenosis. However, it is rarely applied for carotid occlusion, especially in its chronic stage. We report our experience of CAS for chronic internal carotid artery occlusion representing compromised cerebral blood flow using various protection methods. A 77-year-old woman, who was already diagnosed with severe left internal carotid artery stenosis, suddenly had right hemiparesis and aphasia. At that time, she was treated conservatively because her neurological status was quite good, in spite of left carotid artery occlusion. Her symptoms improved in the short term, except slight aphasia, but deteriorated again 18 days from the onset, and magnetic resonance imaging (MRI) showed new ischemic lesions. CAS was then performed for the occluded carotid artery on the 23rd day from the first onset. Using the proximal protection technique, the occluded lesion was crossed carefully with a microguidewire. Stents were also placed successfully with the distal protection technique. The occluded carotid artery was completely recanalized without any unfavorable events or neurological deterioration. In this patient, CAS was successfully to treat chronic carotid artery occlusion. These procedures and techniques are reviewed and discussed. (orig.)

New assessment for the risk of ischemic stroke or carotid artery stenosis. Prognostic factor analysis in hypercholesterolemia patients

International Nuclear Information System (INIS)

Uematsu, Daisuke

2008-01-01

Concise and non-invasive methods to detect the risk of cerebrovascular disease in high risk patients are considered useful. The purpose of this pilot study was to evaluate the contribution to ischemic cerebrovascular risk of the Revised Atherosclerotic Index (RAI) which is calculated from the Atherogenic Index (AI), patient's age and number of risk factors of atherosclerotic disease. I studied retrospectively the serum lipid levels, carotid stenosis measured by ultrasonography and cerebral infarction diagnosed from the symptoms and CT in 56 hypercholesterolemic outpatients. I assessed the relation between the RAI and carotid stenoic findings, history of cerebral infarction, and type of cerebral infarction. I also assessed the relation between the RAI and changes in LDL-cholesterol level before and after atorvastatin administration. The RAI was significantly increased in patients with carotid lesions and cerebral infarction, but the AI was not. While the odds ratio of the AI for carotid lesions was high but not significantly so, that of the RAI increased with statistical significance. The odds ratio for cerebral infarction was high for the RAI but not for the AI. Furthermore, the RAI was significantly high in patients with aortic thrombotic cerebral infarction as compared to that in patients without any infarction. The serum lipids were well controlled under administration of atorvastatin and the mean RAI was also significantly decreased; however, more comprehensive control of risk factors might be necessary. The AI adjusted for patient's age and number of risk factors might be useful for assessing the risk of carotid lesion atherosclerosis and aortic thrombotic cerebral infarction. (author)

New assessment for the risk of ischemic stroke or carotid artery stenosis. Prognostic factor analysis in hypercholesterolemia patients

Energy Technology Data Exchange (ETDEWEB)

Uematsu, Daisuke [Uematsu Neurological Clinic, Saitama, Saitama (Japan)

2008-07-15

Concise and non-invasive methods to detect the risk of cerebrovascular disease in high risk patients are considered useful. The purpose of this pilot study was to evaluate the contribution to ischemic cerebrovascular risk of the Revised Atherosclerotic Index (RAI) which is calculated from the Atherogenic Index (AI), patient's age and number of risk factors of atherosclerotic disease. I studied retrospectively the serum lipid levels, carotid stenosis measured by ultrasonography and cerebral infarction diagnosed from the symptoms and CT in 56 hypercholesterolemic outpatients. I assessed the relation between the RAI and carotid stenoic findings, history of cerebral infarction, and type of cerebral infarction. I also assessed the relation between the RAI and changes in LDL-cholesterol level before and after atorvastatin administration. The RAI was significantly increased in patients with carotid lesions and cerebral infarction, but the AI was not. While the odds ratio of the AI for carotid lesions was high but not significantly so, that of the RAI increased with statistical significance. The odds ratio for cerebral infarction was high for the RAI but not for the AI. Furthermore, the RAI was significantly high in patients with aortic thrombotic cerebral infarction as compared to that in patients without any infarction. The serum lipids were well controlled under administration of atorvastatin and the mean RAI was also significantly decreased; however, more comprehensive control of risk factors might be necessary. The AI adjusted for patient's age and number of risk factors might be useful for assessing the risk of carotid lesion atherosclerosis and aortic thrombotic cerebral infarction. (author)

Maximizing synchronizability of duplex networks

Science.gov (United States)

Wei, Xiang; Emenheiser, Jeffrey; Wu, Xiaoqun; Lu, Jun-an; D'Souza, Raissa M.

2018-01-01

We study the synchronizability of duplex networks formed by two randomly generated network layers with different patterns of interlayer node connections. According to the master stability function, we use the smallest nonzero eigenvalue and the eigenratio between the largest and the second smallest eigenvalues of supra-Laplacian matrices to characterize synchronizability on various duplexes. We find that the interlayer linking weight and linking fraction have a profound impact on synchronizability of duplex networks. The increasingly large inter-layer coupling weight is found to cause either decreasing or constant synchronizability for different classes of network dynamics. In addition, negative node degree correlation across interlayer links outperforms positive degree correlation when most interlayer links are present. The reverse is true when a few interlayer links are present. The numerical results and understanding based on these representative duplex networks are illustrative and instructive for building insights into maximizing synchronizability of more realistic multiplex networks.

PNPLA3 GG genotype and carotid atherosclerosis in patients with non-alcoholic fatty liver disease.

Directory of Open Access Journals (Sweden)

Salvatore Petta

Full Text Available BACKGROUND AND AIM: To evaluate if the presence of carotid atherosclerosis in patients with NAFLD, could be related to gene variants influencing hepatic fat accumulation and the severity of liver damage. METHODS: We recorded anthropometric, metabolic and histological data(Kleiner score of 162 consecutive, biopsy-proven Sicilian NAFLD patients. Intima-media thickness(IMT, IMT thickening(IMT≥1 mm and carotid plaques(focal thickening of >1.3 mm at the level of common carotid artery were evaluated using ultrasonography. IL28B rs12979860 C>T, PNPLA3 rs738409 C>G, GCKR rs780094 C>T, LYPLAL1 rs12137855 C>T, and NCAN rs2228603 C>T single nucleotide polymorphisms were also assessed. The results were validated in a cohort of 267 subjects with clinical or histological diagnosis of NAFLD from Northern Italy, 63 of whom had follow-up examinations. RESULTS: Carotid plaques, IMT thickening and mean maximum IMT were similar in the two cohorts, whereas the prevalence of diabetes, obesity, NASH, and PNPLA3 GG polymorphism(21%vs.13%, p = 0.02 were significantly higher in the Sicilian cohort. In this cohort, the prevalence of carotid plaques and IMT thickening was higher in PNPLA3 GG compared to CC/CG genotype(53%vs.32%, p = 0.02; 62%vs.28%, p<0.001, respectively. These associations were confirmed at multivariate analyses (OR2.94;95%C.I. 1.12-7.71, p = 0.02, and OR4.11;95%C.I. 1.69-9.96, p = 0.002, respectively, although have been observed only in patients <50years. Also in the validation cohort, PNPLA3 GG genotype was independently associated with IMT thickening in younger patients only (OR: 6.00,95%C.I. 1.36-29, p = 0.01, and to IMT progression (p = 0.05 in patients with follow-up examinations. CONCLUSION: PNPLA3 GG genotype is associated with higher severity of carotid atherosclerosis in younger patients with NAFLD. Mechanisms underlying this association, and its clinical relevance need further investigations.

On the Secrecy Degrees of Freedom with Full-Duplex Communication

DEFF Research Database (Denmark)

Mahmood, Nurul Huda; Mogensen, Preben Elgaard

2017-01-01

of such an application. The potential of full duplex nodes in improving the physical layer security of a communication link is investigated in this contribution. We specifically derive the information theoretic secrecy degrees of freedom measure for a pair of nodes communicating in full duplex mode. Moreover, closed...... and the delay reduction of full duplex communication are somewhat limited in realistic network settings, leading researchers to study other possible applications of full duplex communication which can provide significantly higher gains over half duplex communication. Physical layer security is an example...... form expressions for the instantaneous and ergodic throughput gain of full duplex communication over conventional half duplex is derived. The secrecy degrees of freedom with full duplex is shown to be two as opposed to that of zero in half duplex mode....

Carotid artery disease progression and related neurologic events after carotid endarterectomy.

Science.gov (United States)

Avgerinos, Efthymios D; Go, Catherine; Ling, Jennifer; Naddaf, Abdallah; Steinmetz, Amy; Abou Ali, Adham N; Makaroun, Michel S; Chaer, Rabih A

2016-08-01

During the last decade, there has been a dramatic improvement in best medical treatment for patients with vascular disease. Yet, there is a paucity of contemporary long-term data for restenosis and contralateral internal carotid artery (ICA) progression. This study assessed ipsilateral and contralateral disease progression and cerebrovascular events after carotid endarterectomy (CEA). A consecutive cohort of CEAs between January 1, 2000, and December 31, 2010, was retrospectively analyzed. End points were restenosis ≥50% and ≥70%, contralateral carotid disease progression (50%-69%, 70%-99%, or occlusion) and stroke. Survival analysis and Cox regression models were used to assess the effect of baseline predictors. During the 11-year study period, 1639 patients underwent 1782 CEAs (50.0% patch closure, 23.9% primary closure, 26.1% eversion, and 2.5% combined with coronary artery bypass grafting). The combined stroke/death rate was 2.6% overall and 1.8% in the asymptomatic cohort. The rate of restenosis ≥50% at 2, 5, and 10 years was 8.5%, 15.6%, 27.2%, and the rate for restenosis ≥70% was 3.4%, 6.5%, 10.2%, respectively. Restenosis ≥50% was predicted by hypertension (hazard ratio [HR], 2.09; P = .027), female gender (HR, 1.43; P = .042), and younger age (≤65 years; HR, 1.56; P = .016), but not by statins, surgical technique, symptoms, or other baseline risk factors. Restenoses remained asymptomatic in 125 of 148 (84.5%). Progression of contralateral ICA disease at 2, 5, and 10 years was estimated at 5.4%, 15.5%, and 46.8%, respectively. Contralateral progression was only predicted by smoking (HR, 1.74; P = .008). The stroke rate in patients with disease progression of the contralateral ICA was not different compared with those without progression (7.0% vs 3.3%; P = .063). Any-stroke rates at 2, 5, and 10 years were 4.6%, 7.3%, and 15.7%, respectively. Predictors were symptomatic lesion (HR, 1.48; P = .039), renal insufficiency, defined as a

Full-Duplex Relay Selection in Cognitive Underlay Networks

KAUST Repository

Khafagy, Mohammad Galal; Alouini, Mohamed-Slim; Aissa, Sonia

2017-01-01

In this work, we analyze the performance of full-duplex relay selection (FDRS) in spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay(s), thereby

Intracranial carotid anastomosis and partial aplasia of an internal carotid artery

International Nuclear Information System (INIS)

Huber, G.

1980-01-01

A rare arterial anastomosis between the right and left interal carotid arteries at the base at the skull, with aplasia of the cervical part of the left internal carotid artery is reported. The case is unusual because, in addition to the vascular anomaly of the carotid artery, there is an aneurysm of the anterior communicating artery and bilateral renal cysts. The condition is a complex malformation syndrome caused by defective regression of the third branchial artery. Because of the characteristic angiographic aspects such a case should be called transverse carotid anastomosis. (orig.)

Intracranial carotid anastomosis and partial aplasia of an internal carotid artery

Energy Technology Data Exchange (ETDEWEB)

Huber, G.

1980-12-01

A rare arterial anastomosis between the right and left internal carotid arteries at the base at the skull, with aplasia of the cervical part of the left internal carotid artery is reported. The case is unusual because, in addition to the vascular anomaly of the carotid artery, there is an aneurysm of the anterior communicating artery and bilateral renal cysts. The condition is a complex malformation syndrome caused by defective regression of the third branchial artery. Because of the characteristic angiographic aspects such a case should be called transverse carotid anastomosis.

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial.

LENUS (Irish Health Repository)

Ederle, Jörg

2010-03-20

Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy.

Associations of Triiodothyronine Levels with Carotid Atherosclerosis and Arterial Stiffness in Hemodialysis Patients

Science.gov (United States)

Kircelli, Fatih; Asci, Gulay; Carrero, Juan Jesus; Gungor, Ozkan; Demirci, Meltem Sezis; Ozbek, Suha Sureyya; Ceylan, Naim; Ozkahya, Mehmet; Toz, Huseyin; Ok, Ercan

2011-01-01

Summary Background and objectives End-stage renal disease is linked to alterations in thyroid hormone levels and/or metabolism, resulting in a high prevalence of subclinical hypothyroidism and low triiodothyronine (T3) levels. These alterations are involved in endothelial damage, cardiac abnormalities, and inflammation, but the exact mechanisms are unclear. In this study, we investigated the relationship between serum free-T3 (fT3) and carotid artery atherosclerosis, arterial stiffness, and vascular calcification in prevalent patients on conventional hemodialysis. Design, setting, participants, & measurements 137 patients were included. Thyroid-hormone levels were determined by chemiluminescent immunoassay, carotid artery–intima media thickness (CA-IMT) by Doppler ultrasonography, carotid-femoral pulse wave velocity (c-f PWV), and augmentation index by Sphygmocor device, and coronary artery calcification (CAC) scores by multi-slice computerized tomography. Results Mean fT3 level was 3.70 ± 1.23 pmol/L. Across decreasing fT3 tertiles, c-f PWV and CA-IMT values were incrementally higher, whereas CACs were not different. In adjusted ordinal logistic regression analysis, fT3 level (odds ratio, 0.81; 95% confidence interval, 0.68 to 0.97), age, and interdialytic weight gain were significantly associated with CA-IMT. fT3 level was associated with c-f PWV in nondiabetics but not in diabetics. In nondiabetics (n = 113), c-f PWV was positively associated with age and systolic BP but negatively with fT3 levels (odds ratio = 0.57, 95% confidence interval 0.39 to 0.83). Conclusions fT3 levels are inversely associated with carotid atherosclerosis but not with CAC in hemodialysis patients. Also, fT3 levels are inversely associated with surrogates of arterial stiffness in nondiabetics. PMID:21836150

Harvesting full-duplex rate gains in cellular networks with half-duplex user terminals

KAUST Repository

AlAmmouri, Ahmad

2016-07-26

Full-Duplex (FD) transceivers may be expensive in terms of complexity, power consumption, and price to be implemented in all user terminals. Therefore, techniques to exploit in-band full-duplex communication with FD base stations (BSs) and half-duplex (HD) users\\' equipment (UEs) are required. In this context, 3-node topology (3NT) has been recently proposed for FD BSs to reuse the uplink (UL) and downlink (DL) channels with HD terminals within the same cell. In this paper, we present a tractable mathematical framework, based on stochastic geometry, for 3NT in cellular networks. To this end, we propose a design paradigm via pulse-shaping and partial overlap between UL and DL channels to maximize the harvested rate gains in 3NT. The results show that 3NT achieves a close performance to networks with FD BSs and FD UEs, denoted by 2-node topology (2NT) networks. A maximum of 5% rate loss is reported when 3NT is compared to 2NT with efficient self-interference cancellation (SIC). If the SIC in 2NT is not efficient, 3NT highly outperforms 2NT. Consequently, we conclude that, irrespective to the UE duplexing scheme, it is sufficient to have FD BSs to harvest FD rate gains.

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial.

NARCIS (Netherlands)

Ederle, J.; Dobson, J.; Featherstone, R.L.; Bonati, L.H.; Worp, H.B. van der; Borst, G.J. de; Lo, T.H.; Gaines, P.; Dorman, P.J.; Macdonald, S.; Lyrer, P.A.; Hendriks, J.M.; McCollum, C.; Nederkoorn, P.J.; Brown, M.M.; Blankensteijn, J.D.; Leeuw, F.E. de; Schultze Kool, L.J.; Vliet, J.A. van der; et al.,

2010-01-01

BACKGROUND: Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. METHODS: The International

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial

NARCIS (Netherlands)

Ederle, Jörg; Dobson, Joanna; Featherstone, Roland L.; Bonati, Leo H.; van der Worp, H. Bart; de Borst, Gert J.; Lo, T. Hauw; Gaines, Peter; Dorman, Paul J.; Macdonald, Sumaira; Lyrer, Philippe A.; Hendriks, Johanna M.; McCollum, Charles; Nederkoorn, Paul J.; Brown, Martin M.; Algra, A.; Bamford, J.; Beard, J.; Bland, M.; Bradbury, A. W.; Brown, M. M.; Clifton, A.; Gaines, P.; Collins, R.; Molyneux, A.; Naylor, R.; Warlow, C.; Ferro, J. M.; Thomas, D.; Bonati, L. H.; Coward, L.; Dobson, J.; Ederle, J.; Featherstone, R. F.; Tindall, H.; McCabe, D. J. H.; Wallis, A.; Brooks, M.; Chambers, B.; Chan, A.; Chu, P.; Clark, D.; Dewey, H.; Donnan, G.; Fell, G.; Hoare, M.; Molan, M.; Roberts, A.; Roberts, N.; Beiles, B.; Bladin, C.; Clifford, C.; Grigg, M.; New, G.; Bell, R.; Bower, S.; Chong, W.; Holt, M.; Saunder, A.; Than, P. G.; Gett, S.; Leggett, D.; McGahan, T.; Quinn, J.; Ray, M.; Wong, A.; Woodruff, P.; Foreman, R.; Schultz, D.; Scroop, R.; Stanley, B.; Allard, B.; Atkinson, N.; Cambell, W.; Davies, S.; Field, P.; Milne, P.; Mitchell, P.; Tress, B.; Yan, B.; Beasley, A.; Dunbabin, D.; Stary, D.; Walker, S.; Cras, P.; d'Archambeau, O.; Hendriks, J. M. H.; van Schil, P.; St Blasius, A. Z.; Bosiers, M.; Deloose, K.; van Buggenhout, E.; de Letter, J.; Devos, V.; Ghekiere, J.; Vanhooren, G.; Astarci, P.; Hammer, F.; Lacroix, V.; Peeters, A.; Verbist, J.; Blair, J.-F.; Caron, J. L.; Daneault, N.; Giroux, M.-F.; Guilbert, F.; Lanthier, S.; Lebrun, L.-H.; Oliva, V.; Raymond, J.; Roy, D.; Soulez, G.; Weill, A.; Hill, M.; Hu, W.; Hudion, M.; Morrish, W.; Sutherland, G.; Wong, J.; Albäck, A.; Harno, H.; Ijäs, P.; Kaste, M.; Lepäntalo, M.; Mustanoja, S.; Paananen, T.; Porras, M.; Putaala, J.; Railo, M.; Sairanen, T.; Soinne, L.; Vehmas, A.; Vikatmaa, P.; Goertler, M.; Halloul, Z.; Skalej, M.; Brennan, P.; Kelly, C.; Leahy, A.; Moroney, J.; Thornton, J.; Koelemay, M. J. W.; Reekers, J. A. A.; Roos, Y. B. W. E. M.; Hendriks, J. M.; Koudstaal, P. J.; Pattynama, P. M. T.; van der Lugt, A.; van Dijk, L. C.; van Sambeek, M. R. H. M.; van Urk, H.; Verhagen, H. J. M.; Bruijninckx, C. M. A.; de Bruijn, S. F.; Keunen, R.; Knippenberg, B.; Mosch, A.; Treurniet, F.; van Dijk, L.; van Overhagen, H.; Wever, J.; de Beer, F. C.; van den Berg, J. S. P.; van Hasselt, B. A. A. M.; Zeilstra, D. J.; Boiten, J.; van Otterloo, J. C. A. de Mol; de Vries, A. C.; Lycklama a Nijeholt, G. J.; van der Kallen, B. F. W.; Blankensteijn, J. D.; de Leeuw, F. E.; Kool, L. J. Schultze; van der Vliet, J. A.; de Borst, G. J.; de Kort, G. A. P.; Kapelle, L. J.; Lo, T. H.; Mali, W. P. Th M.; Moll, F.; van der Worp, H. B.; Verhagen, H.; Barber, P. A.; Bourchier, R.; Hill, A.; Holden, A.; Stewart, J.; Bakke, S. J.; Krohg-Sørensen, K.; Skjelland, M.; Tennøe, B.; Bialek, P.; Biejat, Z.; Czepiel, W.; Czlonkowska, A.; Dowzenko, A.; Jedrzejewska, J.; Kobayashi, A.; Lelek, M.; Polanski, J.; Kirbis, J.; Milosevic, Z.; Zvan, B.; Blasco, J.; Chamorro, A.; Macho, J.; Obach, V.; Riambau, V.; San Roman, L.; Branera, J.; Canovas, D.; Estela, Jordi; Gaibar, A. Gimenez; Perendreu, J.; Björses, K.; Gottsater, A.; Ivancev, K.; Maetzsch, T.; Sonesson, B.; Berg, B.; Delle, M.; Formgren, J.; Gillgren, P.; Kall, T.-B.; Konrad, P.; Nyman, N.; Takolander, R.; Andersson, T.; Malmstedt, J.; Soderman, M.; Wahlgren, C.; Wahlgren, N.; Binaghi, S.; Hirt, L.; Michel, P.; Ruchat, P.; Engelter, S. T.; Fluri, F.; Guerke, L.; Jacob, A. L.; Kirsch, E.; Lyrer, P. A.; Radue, E.-W.; Stierli, P.; Wasner, M.; Wetzel, S.; Bonvin, C.; Kalangos, A.; Lovblad, K.; Murith, M.; Ruefenacht, D.; Sztajzel, R.; Higgins, N.; Kirkpatrick, P. J.; Martin, P.; Varty, K.; Adam, D.; Bell, J.; Crowe, P.; Gannon, M.; Henderson, M. J.; Sandler, D.; Shinton, R. A.; Scriven, J. M.; Wilmink, T.; D'Souza, S.; Egun, A.; Guta, R.; Punekar, S.; Seriki, D. M.; Thomson, G.; Brennan, J. A.; Enevoldson, T. P.; Gilling-Smith, G.; Gould, D. A.; Harris, P. L.; McWilliams, R. G.; Nasser, H.-C.; White, R.; Prakash, K. G.; Serracino-Inglott, F.; Subramanian, G.; Symth, J. V.; Walker, M. G.; Clarke, M.; Davis, M.; Dixit, S. A.; Dorman, P.; Dyker, A.; Ford, G.; Golkar, A.; Jackson, R.; Jayakrishnan, V.; Lambert, D.; Lees, T.; Louw, S.; Macdonald, S.; Mendelow, A. D.; Rodgers, H.; Rose, J.; Stansby, G.; Wyatt, M.; Baker, T.; Baldwin, N.; Jones, L.; Mitchell, D.; Munro, E.; Thornton, M.; Baker, D.; Davis, N.; Hamilton, G.; McCabe, D.; Platts, A.; Tibballs, J.; Cleveland, T.; Dodd, D.; Lonsdale, R.; Nair, R.; Nassef, A.; Nawaz, S.; Venables, G.; Belli, A.; Cloud, G.; Halliday, A.; Markus, H.; McFarland, R.; Morgan, R.; Pereira, A.; Thompson, A.; Chataway, J.; Cheshire, N.; Gibbs, R.; Hammady, M.; Jenkins, M.; Malik, I.; Wolfe, J.; Adiseshiah, M.; Bishop, C.; Brew, S.; Brookes, J.; Jäger, R.; Kitchen, N.; Ashleigh, R.; Butterfield, S.; Gamble, G. E.; McCollum, C.; Nasim, A.; O'Neill, P.; Edwards, R. D.; Lees, K. R.; MacKay, A. J.; Moss, J.

2010-01-01

BACKGROUND: Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. METHODS: The International

Duplex kidney: not just a drooping lily.

Science.gov (United States)

Doery, Ashlea J; Ang, Eileen; Ditchfield, Michael R

2015-04-01

Duplex kidneys are common, mostly asymptomatic and of no clinical significance. However, they can be associated with significant pathology, often with long-term morbidity. There is minimal literature on the review of the duplex kidney, its associated anomalies and complications. The purpose of this paper is to review our experience of imaging the spectrum of abnormalities associated with duplex kidneys in the paediatric population and correlate this with contemporary literature. A retrospective review of the radiology database in a tertiary paediatric centre was performed. A word search of the Radiology Information System for 'duplex' of patients under the age of 16 was undertaken and limited to studies performed between 2006 and 2013. Two hundred seventy-four patients were identified (age range 0-16, median 3 years, gender 59.9% female) who had 836 studies: ultrasound 598/836 (71.6%), nuclear medicine 180/836 (21.5%), micturating cystourethrogram 52/836 (6.2%), MRI 5/836 (duplex and no complication (151/274 = 55.1%), upper moiety obstruction, lower moiety reflux/scarring, multicystic dysplastic kidney, abnormal ureteric insertion and other pathology. Duplex kidneys are common and often not clinically significant. However, this study demonstrates almost 50% of paediatric patients investigated for duplex kidneys had complications requiring treatment. The most common complications were upper moiety obstruction associated with a ureterocele and lower moiety vesicoureteric reflux. Ultrasound was the most common modality for early detection of these complications. © 2015 The Royal Australian and New Zealand College of Radiologists.

Current Approaches for Carotid Endarterectomy

Directory of Open Access Journals (Sweden)

Cengiz Köksal

2010-12-01

Full Text Available Permanent neurologic injuries and death following stroke, necessitates more vigorous treatment of carotid disease. Carotid stenting and carotid endarterectomy are treatment options in many centers besides medical treatment. Whether the patient is symptomatic or asymtomatic, indications and management strategies for treatment remain controversial. Despite the debate, carotid endarterectomy is still accepted to be the most efficientintervention to decrease risk of stroke due to carotid artery stenosis.

Full Duplex Communications in 5G Small Cells

DEFF Research Database (Denmark)

Mahmood, Nurul Huda; Gatnau, Marta; Berardinelli, Gilberto

2017-01-01

Full duplex communication promises system performance improvement over conventional half duplex communication by allowing simultaneous transmission and reception. However, such concurrent communication results in strong self interference and an increase in the overall network interference, and can...... only be exploited when traffic is available in both directions. The potential throughput gains of full duplex communication over conventional half duplex transmission in a small cell network with asymmetric traffic conditions is investigated in this contribution. The throughput performance gains...... are analysed using tools from stochastic geometry, and further confirmed through extensive system level simulations. Our findings explicitly quantify how the gains from full duplex communication depend on the traffic profile and the inter-cell interference coupling. The demonstrated throughput gains and delay...

Mesh-covered (Roadsaver stent as a new treatment modality for symptomatic or high-risk carotid stenosis

Directory of Open Access Journals (Sweden)

Roman Machnik

2017-05-01

Full Text Available Introduction : Prevention of periprocedural stroke has a crucial role in carotid artery stenting (CAS procedures. Aim : To assess retrospectively 30-day safety and effectiveness of 41 procedures of internal and common carotid artery stenting using the Roadsaver double nitinol layer micromesh stent in 40 non-consecutive patients with symptomatic or high-risk carotid artery stenosis. Material and methods : The patients were men (n = 31 and women (n = 9; mean age was 67.8 ±7.9 years. Femoral access was used in 39 cases, whereas radial access was used in 2. Proximal (n = 27 or distal (n = 14 embolic neuroprotection was used. Results : The Roadsaver stents (nominal diameter 7, 8 or 9 mm, length 25 or 30 mm were implanted successfully in all cases. One minor stroke occurred after common carotid artery intubation with a guiding catheter (before stent deployment and one transient postprocedural ischemic attack (TIA of the ipsilateral cerebral hemisphere was observed. Internal/common carotid artery stenosis severity was evaluated by duplex Doppler. Maximal peak systolic velocity (PSV before CAS was in the range: 2.0–7.0 m/s, mean: 3.9 ±1.0 m/s, at 24–48 h after stenting mean PSV was 1.1 ±0.4 m/s (p < 0.05, and at 30 days 1.1 ±0.3 m/s (p < 0.05. Maximal end-diastolic velocity (EDV was 0.85–3.5 m/s, mean 1.4 ±0.5 m/s, at 24–48 h after stenting mean EDV was 0.3 ±0.1 m/s (p < 0.05, and at 30 days 0.4 ±0.1 m/s (p < 0.05. No restenosis or thrombosis was observed. Angiographic stenosis decreased from 82.9 ±9.1% (range: 61–97% to 19.3 ±7.3% (range: 0–34% (p < 0.05. Conclusions : The CAS using the Roadsaver stent seems to be safe and effective. Further studies involving larger patient populations and longer follow-up are needed.

Establishing experimental model of human internal carotid artery siphon segment in canine common carotid artery

International Nuclear Information System (INIS)

Cui Xuee; Li Minghua; Wang Yongli; Cheng Yingsheng; Li Wenbin

2005-01-01

Objective: To study the feasibility of establishing experimental model of human internal carotid artery siphon segment in canine common carotid artery (CCA) by end-to-end anastomoses of one side common carotid artery segment with the other side common carotid artery. Methods: Surgical techniques were used to make siphon model in 8 canines. One side CCA was taken as the parent artery and anastomosing with the cut off contra-lateral CCA segment which has passed through within the S-shaped glass tube. Two weeks after the creation of models angiography showed the model siphons were patent. Results: Experimental models of human internal carotid artery siphon segment were successfully made in all 8 dogs. Conclusions: It is practically feasible to establish experimental canine common carotid artery models of siphon segment simulating human internal carotid artery. (authors)

Data on carotid intima-media thickness and lipoprotein subclasses in type 1 diabetes from the Diabetes Control and Complications Trial and the Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC

Directory of Open Access Journals (Sweden)

Arpita Basu

2016-03-01

Full Text Available Type 1 diabetes (T1DM is associated with increased risk of macrovascular complications. We examined longitudinal associations of serum conventional lipids and nuclear magnetic resonance (NMR-determined lipoprotein subclasses with carotid intima-media thickness (IMT in adults with T1DM (n=455 enrolled in the Diabetes Control and Complications Trial (DCCT. Data on serum lipids and lipoproteins were collected at DCCT baseline (1983–89 and were correlated with common and internal carotid IMT determined by ultrasonography during the observational follow-up of the DCCT, the Epidemiology of Diabetes Interventions and Complications (EDIC study, at EDIC ‘Year 1’ (199–1996 and EDIC ‘Year 6’ (1998–2000. This article contains data on the associations of DCCT baseline lipoprotein profiles (NMR-based VLDL & chylomicrons, IDL/LDL and HDL subclasses and ‘conventional’ total, LDL-, HDL-, non-HDL-cholesterol and triglycerides with carotid IMT at EDIC Years 1 and 6, stratified by gender. The data are supplemental to our original research article describing detailed associations of DCCT baseline lipids and lipoprotein profiles with EDIC Year 12 carotid IMT (Basu et al. in press [1]. Keywords: Lipids and lipoproteins, Carotid intima-media thickness, Type 1 diabetes

[EVALUATION OF ARTERIAL STIFFNESS AND POSSIBILITY TO PREDICT CAROTID ATHEROSCLEROSIS IN PATIENTS WITH ESSENTIAL HYPERTENSION BASED ON AN OUTPATIENT FACILITY].

Science.gov (United States)

Polipanov, A G; Mamasaidov, Zh A; Geleskhanova, Yu N; Cheskidova, N B; Romanova, T A; Dzhumagulova, A S

2016-01-01

To estimate the possibility of predicting the presence and severity of coronary atherosclerosis from arterial stiffness characteristics and augmentation index (AIx) in patients with essential hypertension (EH) obtained under outpatient conditions. The general clinical examination of 15 patients aged 30-70 yr with EH was supplemented by measuring blood glucose and creatinine levels, the lipid status (LWLP, HDLP, TG), duplex scanning of carotid arteries, and evaluation of arterial stiffness by pulsed wave contour analysis. AIx and age were independent risk factors of coronary atherosclerosis in patients with EH and severity of its manifestations. AIx values over 25% were with high specificity (over 85%) associated with atherosclerotic lesions.

Anomalous external carotid artery-internal carotid artery anastomosis in two patients with proximal internal carotid arterial remnants

Energy Technology Data Exchange (ETDEWEB)

Kim, Chang Hun [Dept. of Neurology, Stroke Center, Myongji Hospital, Goyang (Korea, Republic of); Cho, Young Dae; Kang, Hyun Seung; Kim, Jeong Eun; Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Seung Chai [Dept. of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Ahn, Jun Hyong [Dept. of Neurosurgery, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

2015-08-15

Two angiographic instances of anomalous external carotid artery (ECA) and internal carotid artery (ICA) anastomosis are described, each occurring at the C2-3 level and bearing remnants of proximal ICA. The ICA remnant of one patient (identifiable immediately upon bifurcation of the common carotid artery) was hypoplastic, and that of the other patient was an occluded arterial stump. These features are not typical of non-bifurcating ICA. The occipital artery originated from an anomalous connection in one instance and from the main trunk of the ECA (just past the ECA-ICA connection) in the other.

Buffer management in wireless full-duplex systems

KAUST Repository

Bouacida, Nader; Showail, Ahmad; Shihada, Basem

2015-01-01

, we address the problem of buffer management in full-duplex networks by using Wireless Queue Management (WQM), which is an active queue management technique for wireless networks. Our solution is based on Relay Full-Duplex MAC (RFD

Ultrasonography in trauma

DEFF Research Database (Denmark)

Weile, Jesper; Nielsen, Klaus; Primdahl, Stine C

2017-01-01

BACKGROUND: The Focused Assessment with Sonography in Trauma (FAST) protocol is considered beneficial in emergent evaluation of trauma patients with blunt or penetrating injury and has become integrated into the Advanced Trauma Life Support (ATLS) protocol. No guidelines exist as to the use...... of ultrasonography in trauma in Denmark. We aimed to determine the current use of ultrasonography for assessing trauma patients in Denmark. METHODS: We conducted a nation-wide cross-sectional investigation of ultrasonography usage in trauma care. The first phase consisted of an Internet-based investigation....... Twenty-one (95.5%) of the guidelines included and recommended FAST as part of trauma assessment. The recommended person to perform the examination was the radiologist in n = 11 (50.0%), the surgeon in n = 6 (27.3%), the anesthesiologist in n = 1 (4.5%), and unspecified in n = 3 (13.6%) facilities. FAST...

Energy balance and deformation mechanisms of duplexes

Science.gov (United States)

Mitra, Gautam; Boyer, Steven E.

A duplex consists of a series of imbricate faults that are asymptotic to a roof thrust and a floor thrust. Depending on the final orientations of the imbricate faults and the final position of the branch lines, a duplex may be hinterland-dipping, foreland-dipping, or an antiformal stack. The exact geometry depends on various factors such as the initial dimensions of the individual slices (horses), their lithology, the amount of displacement (normalized to size of horse) on each fault, and the mechanics of movement along each fault. The energy required in duplex formation can be determined by calculating the total work involved in emplacing each horse: this is given by where W t=W p+W b+W g+W iWp is the work involved in initiating and propagating a fracture. Wb is the work involved in basal sliding, which may be frictional or some form of ductile flow, Wg is the work done against gravity during the emplacement of the horse, and Wi is the work involved in the internal deformation of the horse. By calculating and comparing these work terms it is possible to predict the conditions under which the different types of duplexes will form. Normally, the development of a hinterland-dipping duplex is most likely. However, if deformation conditions are favorable, displacements on individual imbricate faults may be very large compared to the size of the horses, leading to the formation of either antiformal stacks or foreland-dipping duplexes.

Mixing in the human carotid artery during carotid drug infusion studied with PET

International Nuclear Information System (INIS)

Junck, L.; Koeppe, R.A.; Greenberg, H.S.

1989-01-01

The safety and efficacy of drug infusion into the carotid artery require adequate mixing of the infused solution with carotid blood. Using positron emission tomography (PET), we studied the mixing of solutions infused into the human carotid artery in seven patients by analyzing the distribution of [15O]H2O infused into the carotid artery and by vein. At four infusion rates ranging from 0.5 to 10 ml/min, the variability in distribution averaged 16.5-17.8% among the pixels in a large volume of interest, without dependence on the infusion rate. The overall correlation between [15O]H2O influx with arterial infusion and [15O]H2O influx with venous injection was 0.78-0.82 at the four infusion rates, with no trend toward higher correlations at the faster infusion rates. The distribution into the anterior, middle, and posterior cerebral artery territories differed from distribution throughout the entire carotid territory by an average of 6.2-9.6% at the four infusion rates, with no trend toward smaller differences at the faster infusion rates. Infusions performed into a vinyl tube simulating the carotid artery indicated that at 0.5 ml/min, the velocity of fluid exiting the catheter makes no apparent contribution to mixing. We conclude that with infusions at the carotid bifurcation, mixing in the human carotid artery is complete or nearly complete over a wide range of infusion rates. The mixing appears to result from the patterns of blood flow within the artery, and not from jet effects at the catheter tip

On the Performance of In-Band Full-Duplex Cooperative Communications

KAUST Repository

Khafagy, Mohammad Galal

2016-01-01

-duplex potentials. Full-duplex relaying (FDR), where intermediate nodes may now support source-destination communication via simultaneous listening/forwarding, represents one of two full-duplex settings currently recommended for deployment in future fifth

MR imaging of carotid webs

International Nuclear Information System (INIS)

Boesen, Mari E.; Eswaradass, Prasanna Venkatesan; Singh, Dilip; Mitha, Alim P.; Menon, Bijoy K.; Goyal, Mayank; Frayne, Richard

2017-01-01

We propose a magnetic resonance (MR) imaging protocol for the characterization of carotid web morphology, composition, and vessel wall dynamics. The purpose of this case series was to determine the feasibility of imaging carotid webs with MR imaging. Five patients diagnosed with carotid web on CT angiography were recruited to undergo a 30-min MR imaging session. MR angiography (MRA) images of the carotid artery bifurcation were acquired. Multi-contrast fast spin echo (FSE) images were acquired axially about the level of the carotid web. Two types of cardiac phase resolved sequences (cineFSE and cine phase contrast) were acquired to visualize the elasticity of the vessel wall affected by the web. Carotid webs were identified on MRA in 5/5 (100%) patients. Multi-contrast FSE revealed vessel wall thickening and cineFSE demonstrated regional changes in distensibility surrounding the webs in these patients. Our MR imaging protocol enables an in-depth evaluation of patients with carotid webs: morphology (by MRA), composition (by multi-contrast FSE), and wall dynamics (by cineFSE). (orig.)

MR imaging of carotid webs

Energy Technology Data Exchange (ETDEWEB)

Boesen, Mari E. [University of Calgary, Department of Biomedical Engineering, Calgary (Canada); Foothills Medical Centre, Seaman Family MR Research Centre, Calgary (Canada); Eswaradass, Prasanna Venkatesan; Singh, Dilip; Mitha, Alim P.; Menon, Bijoy K. [University of Calgary, Department of Clinical Neurosciences, Calgary (Canada); Foothills Medical Centre, Calgary Stroke Program, Calgary (Canada); Goyal, Mayank [Foothills Medical Centre, Calgary Stroke Program, Calgary (Canada); University of Calgary, Department of Radiology, Calgary (Canada); Frayne, Richard [Foothills Medical Centre, Seaman Family MR Research Centre, Calgary (Canada); University of Calgary, Hotchkiss Brain Institute, Calgary (Canada)

2017-04-15

We propose a magnetic resonance (MR) imaging protocol for the characterization of carotid web morphology, composition, and vessel wall dynamics. The purpose of this case series was to determine the feasibility of imaging carotid webs with MR imaging. Five patients diagnosed with carotid web on CT angiography were recruited to undergo a 30-min MR imaging session. MR angiography (MRA) images of the carotid artery bifurcation were acquired. Multi-contrast fast spin echo (FSE) images were acquired axially about the level of the carotid web. Two types of cardiac phase resolved sequences (cineFSE and cine phase contrast) were acquired to visualize the elasticity of the vessel wall affected by the web. Carotid webs were identified on MRA in 5/5 (100%) patients. Multi-contrast FSE revealed vessel wall thickening and cineFSE demonstrated regional changes in distensibility surrounding the webs in these patients. Our MR imaging protocol enables an in-depth evaluation of patients with carotid webs: morphology (by MRA), composition (by multi-contrast FSE), and wall dynamics (by cineFSE). (orig.)

Long-term results after carotid artery stenting. Restenosis after carotid artery stenting using self-expandable stent

International Nuclear Information System (INIS)

Matsumoto, Yasushi; Furui, Eisuke; Tsuboi, Ken; Takahashi, Akira; Ezura, Masayuki

2008-01-01

Carotid artery stenting has emerged as an acceptable treatment alternative in patients with carotid artery stenosis. Although early clinical results of carotid artery stenting have shown promise, long, term clinical results remain less certain. We report the frequency, management, and clinical results of in-stent restenosis after carotid artery stenting using a self-expandable stent. Between August 1998 and September 2004, 80 carotid artery stenting procedures in 78 patients were performed. We evaluated 76 of the 80 procedures in 75 of the 78 patients treated during this period who had a minimum 6-month clinical and imaging (ultrasound and/or magnetic resonance angiography) follow-up. Recurrent stenosis (≥50%) after carotid artery stenting occurred in 3 (3.9%) patients. The recurrent stenosis occurred within one year after the procedure in all cases. The low rate of in-stent restenosis using self-expandable stent suggested that carotid artery stenting may be an effective alternative treatment for carotid artery stenosis, but more data of long-term follow-up are required. (author)

Full-Duplex MIMO Small-Cell Networks: Performance Analysis

OpenAIRE

Atzeni, Italo; Kountouris, Marios

2015-01-01

Full-duplex small-cell relays with multiple antennas constitute a core element of the envisioned 5G network architecture. In this paper, we use stochastic geometry to analyze the performance of wireless networks with full-duplex multiple-antenna small cells, with particular emphasis on the probability of successful transmission. To achieve this goal, we additionally characterize the distribution of the self-interference power of the full-duplex nodes. The proposed framework reveals useful ins...

Identification of intraluminal thrombus by ultrasonography in emergency department patients with acute deep venous thrombosis.

Science.gov (United States)

Mehta, Ninfa; Schecter, Joshua; Stone, Michael

2012-05-01

Traditionally, the diagnosis of deep venous thrombosis (DVT) using duplex ultrasonography (DU) has relied on the absence of venous compressibility. Visualization of an intraluminal thrombus is considered an uncommon finding. The purpose of this study is to determine the frequency of intraluminal thrombus in emergency department (ED) patients diagnosed with acute DVT. Retrospective chart review of adult ED patients with DU examinations demonstrating acute DVT. Patients with chronic DVT or patients in whom DU did not demonstrate DVT were excluded from data analysis. Study reports and ultrasound images were reviewed and analyzed for the presence of intraluminal thrombus. There were 189 patients who met inclusion criteria, of which 160 (85%) were found to have intraluminal thrombus. Intraluminal thrombi are present in the majority of patients in our ED in whom acute DVT is identified by DU. Copyright © 2012 Elsevier Inc. All rights reserved.

Bilateral Internal Carotid Artery Occlusion, External Carotid Artery Stenosis, and Vertebral Artery Kinking: May It Be Asymptomatic?

Science.gov (United States)

Fatic, Nikola; Jaffer, Usman; Ivana, Saicic; Gordana, Globarevic-Vukcevic; Markovic, Dragan; Kostic, Dusan; Davidovic, Lazar

2017-10-01

The clinical spectrum of internal carotid artery occlusion ranges from being a completely asymptomatic occlusion to a devastating stroke or death. The prevalence of asymptomatic internal carotid artery occlusion is unknown, particularly for bilateral occlusion. The distal branches of the external carotid artery anastomose with distal branches of the internal carotid artery provide important sources of collateral circulation to the brain. Stenosis of the external carotid artery with ipsilateral/bilateral internal occlusion may result in ischemic sequelae. Coiling or kinking of the vertebral artery is a rare morphological entity that is infrequently reported because it remains asymptomatic and has no clinical relevance. Currently, there is little evidence to support management strategies for this disease entity and no official recommendations for asymptomatic bilateral carotid artery occlusion. We present a case of a 62-year-old female with asymptomatic bilateral internal carotid artery occlusion, bilateral external carotid artery stenoses, and bilateral kinking of the vertebral artery at the V2 segment, who has been successfully managed conservatively for over 5 years. An individualized approach to management of patients with bilateral internal carotid artery occlusion, especially in combination with external carotid artery stenosis and elongation malformations of the vertebral artery is key to a successful strategy. Copyright © 2017 Elsevier Inc. All rights reserved.

Silent ischemia after neuroprotected percutaneous carotid stenting: a diffusion-weighted MRI study.

Science.gov (United States)

Piñero, P; González, A; Mayol, A; Martínez, E; González-Marcos, J R; Boza, F; Cayuela, A; Gil-Peralta, A

2006-01-01

To assess by diffusion-weighted MR imaging (DWI) the efficacy of cerebral protection devices in avoiding embolization and new ischemic lesions in patients with severe internal carotid artery (ICA) stenosis undergoing carotid artery stent placement (CAS). One hundred sixty-two CASs in the extracranial ICA were performed with the use of distal filters. Mean age of the patients was 68.5 years (range, 33-86) and 122 patients (75.3%) were symptomatic. MR imaging was performed in all patients during the 3-day period before CAS, and DWI was obtained within 24 hours after the procedure. Ninety-five patients (58.6%) were monitored by transcranial Doppler ultrasonography for microemboli detection in the territory of the middle cerebral artery (MCA), ipsilateral to the vessel being treated. Twenty-eight patients (17.3%) showed 58 new ischemic foci in DWI, and 13 patients (46.4%) had multiple foci. Location of new lesions was mainly in the vascular territory supplied by the treated vessel (19 patients; 67.9%), but also in the contralateral MCA (1 patient; 3.6%), and the posterior fossa (4 patients; 14.3%). A significant relationship (P neuroprotected CAS. Appearance of new ischemic lesions were only significantly related to the occurrence of TIA but not to the number of MES registered or other variables. Despite the encouraging results, the incidence of new ischemic lesions should promote research for safer techniques and devices.

Relationship between Waist Circumference and Elevation of Carotid Intima-media Thickness in Newly-diagnosed Diabetic Patients

Institute of Scientific and Technical Information of China (English)

ZHANG Lei; JIA Wei Ping; SHEN Yun; ZHOU Jian; PAN Jie Min; YU Hao Yong; CHEN Hai Bing; LI Qing; LI Ming; BAO Yu Qian

2014-01-01

Objective Waist circumference, as a brief indicator of visceral obesity, is associated with multi-metabolic disorders and cardiovascular diseases. The present study was aimed to find out the relationship between waist circumference and carotid intima media thickness (C-IMT), as well as the best waist circumference cutoff for identifying C-IMT elevation in Chinese male patients with newly-diagnosed diabetes. Methods Five hundred and seventy-eight patients from Department of Endocrinology and Metabolism in Shanghai Sixth People’s Hospital affiliated to Shanghai Jiao Tong University were enrolled. Both physical examination (for measurement of waist circumference) and carotid ultrasonography (for measurement of C-IMT) were performed. Results After grouping according to the quartiles of C-IMT, the waist circumference increased across all its quartiles. The waist circumference in 3rd and 4th quartiles (90.7±9.8 cm and 90.8±9.6 cm) was significant higher than in 1st and 2nd quartiles (P Conclusion Among newly-diagnosed diabetic male patients, waist circumference over 90 cm not only reflects sub-clinical atherosclerosis in early stage, but also predicts the progression of atherosclerosis.

Surgical techniques and curative effect of carotid endarterectomy for carotid artery stenosis

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Min HAN

2014-02-01

Full Text Available Objective To investigate the surgical techniques of carotid endarterectomy (CEA for treating carotid artery stenosis, in order to improve the surgical efficacy and reduce intraoperative adverse events and complications after operation. Methods Retrospective analysis was carried out on surgical data of 53 cases who were performed CEA from October 2010 to October 2013 in Department of Neurosurgery in Tianjin Huanhu Hospital. There were 39 males and 14 females, aged from 40 to 78 years old and mean age (60.34 ± 8.92 years old; the course of disease was from 2 d to 4 years. Twenty-six cases were diagnosed as right carotid stenosis, 15 cases left carotid stenosis and 12 cases double-sided carotid stenosis. Among all of those cases, 35 cases were diagnosed as moderate stenosis (30%-69%, 16 cases severe stenosis (70%-99% , and 2 cases complete occlusion. Results Among 53 patients, 50 patients underwent CEA; 2 cases underwent CEA and aneurysm clipping; one case underwent stent removal surgery and CEA because restenosis was found after carotid artery stenting (CAS. Postoperative neck CTA and fMRI showed good morphology of carotid artery, fluent blood flow and improved cerebral perfusion after operation. All of those patients were followed up for 3 to 24 months. One case died of myocardial infarction; 2 cases appeared skin numbness on the operating side of the neck, and the symptom disappeared 3 months later; one case appeared hoarseness after operation; 3 cases experienced mild transient ischemic attack (TIA and the symptom disappeared 2 months later. No case of stroke was found. Conclusions CEA is a safe and effective surgical approach to treat carotid stenosis. Correct and reasonable choices of the surgical indications and skilled surgical technique are the key to ensure the success of operation and to improve efficacy of the therapy. doi：10.3969/j.issn.1672-6731.2014.02.006Video: http://www.cjcnn.org/index.php/cjcnn/pages/view/v14n2a6

Ultrasonography of polycystic kidney

International Nuclear Information System (INIS)

Oh, Seung Chul; Cho, Seung Gi; Lee, Kwan Seh; Kim, Kun Sang

1980-01-01

Polycystic disease is defined as a heritable disorder with diffuse involvement of both kidneys. The term 'Polycystic disease' comprises at least two separate, genetically different disease-one with an onset typically in childhood (infantile polycystic disease) and the other with an onset typically in adulthood (adult polycystic disease). Adult polycystic kidney disease is the most common form of cystic kidney disease in humans. Ultrasonography is a very useful noninvasive diagnostic modality in the patient with clinically suspected renal diseases as well as screening test. 14 cases of ultrasonography in patient with polycystic kidney were reviewed. All cases show unilateral or bilateral enlarged kidneys. 7 cases reveal kidneys and liver replaced by multiple cysts of varing size. Screening ultrasonography for a familial tree is reported

[Results of duplex scanning of brachiocephalic arteries and estimation of the lipid spectrum in coronary heart disease and arterial hypertension in indigenous and alien population of Yamalo-Nenetsky Autonomous District].

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Gapon, L I; Sereda, T V; Leont'eva, A V; Gul'tiaeva, E P

2013-01-01

The work aimed at studying atherosclerotic lesions in brachiocephalic arteries and lipid spectrum in coronary heart disease (CHD) and arterial hypertension (AH) in indigenous and alien population of Yamalo-Nenetsky Autonomous District. It included 200 patients with CHD and AH (men and women aged 21-55 years, mean 48.2 +/- 07 yr). They were allocated to indigenous and alien groups (100 persons each). The patients matched for age and sex were examined by duplex scanning based at an outpatient facility (Salekhard). The indigenous population showed more pronounced thickening of the intima-media complex (IMC) of the common carotid artery (p = 0.001) and more frequent lesions of the main head arteries with stenosis of different severity (especially in internal carotid arteries). Total cholesterol, LDLP and atherogenicity index were similar in both groups and higher than normal. Indigenous subjects had less atherogenic structure of the lipid spectrum due to lower TG and VLDLP but higher HDLP levels.

Joint duplex mode selection, channel allocation, and power control for full-duplex cognitive femtocell networks

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Mingjie Feng

2015-02-01

Full Text Available In this paper, we aim to maximize the sum rate of a full-duplex cognitive femtocell network (FDCFN as well as guaranteeing the quality of service (QoS of users in the form of a required signal to interference plus noise ratios (SINR. We first consider the case of a pair of channels, and develop optimum-achieving power control solutions. Then, for the case of multiple channels, we formulate joint duplex model selection, power control, and channel allocation as a mixed integer nonlinear problem (MINLP, and propose an iterative framework to solve it. The proposed iterative framework consists of a duplex mode selection scheme, a near-optimal distributed power control algorithm, and a greedy channel allocation algorithm. We prove the convergence of the proposed iterative framework as well as a lower bound for the greedy channel allocation algorithm. Numerical results show that the proposed schemes effectively improve the sum rate of FDCFNs.

A study of disrupted carotid plaque using high-resolution MRI

International Nuclear Information System (INIS)

Yu Wei; Zhang Zhaoqi; Underhill, H.; Hatsukami, T.S.; Chun, Y.

2008-01-01

Objective: To evaluate distribution features of disrupted carotid plaque. Methods: Forty-three subjects with duplex ultrasound evidence of 50% to 99% stenosis were retrospectively analyzed. Plaques were categorized as disrupted if there was MRI evidence of fibrous cap rupture. Quantity measured areas of the lumen (LA), wall (WA), and plaque components. The morphological parameters used were total vessel area, vessel burden index, eccentricity index. Mann-Whitney test and Chi-square test appropriate used SPSS (v. 12.0). Results: There were 17 disrupted and 26 undisrupted lesions identified for comparison. Disrupted plaques showed a predominance of longer longitudinal length of large lip nucleus along the vessel wall (6 mm vs. 0 mm, U=126, P 2 vs. 30.18 mm 2 U=138 P<0.05) and a longer segment of stenosis when compared with the intact plaques. Conclusions: Disrupted plaques have significantly different characteristics in terms of both axial and longitudinal distribution. A combination of multi-plane and multi-contrast high resolution MRI may provide valuable information about overall lesion morphology and its association to vulnerability. (authors)

Improper Signaling for Virtual Full-Duplex Relay Systems

KAUST Repository

Gaafar, Mohamed; Amin, Osama; Schaefer, Rafael F.; Alouini, Mohamed-Slim

2017-01-01

Virtual full-duplex (VFD) is a powerful solution to compensate the rate loss of half-duplex relaying without the need to full-duplex capable nodes. Inter-relay interference (IRI) challenges the operation of VFD relaying systems. Recently, improper signaling is employed at both relays of the VFD to mitigate the IRI by imposing the same signal characteristics for both relays. To further boost the achievable rate performance, asymmetric time sharing VFD relaying system is adopted with different improper signals at the half-duplex relays. The joint tuning of the three design parameters improves the achievable rate performance at different ranges of IRI and different relays locations. Extensive simulation results are presented and analyzed to show the achievable rate gain of the proposed system and understand the system behavior.

Improper Signaling for Virtual Full-Duplex Relay Systems

KAUST Repository

Gaafar, Mohamed

2017-02-14

Virtual full-duplex (VFD) is a powerful solution to compensate the rate loss of half-duplex relaying without the need to full-duplex capable nodes. Inter-relay interference (IRI) challenges the operation of VFD relaying systems. Recently, improper signaling is employed at both relays of the VFD to mitigate the IRI by imposing the same signal characteristics for both relays. To further boost the achievable rate performance, asymmetric time sharing VFD relaying system is adopted with different improper signals at the half-duplex relays. The joint tuning of the three design parameters improves the achievable rate performance at different ranges of IRI and different relays locations. Extensive simulation results are presented and analyzed to show the achievable rate gain of the proposed system and understand the system behavior.

Ultra-short silicon MMI duplexer

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Yi, Huaxiang; Huang, Yawen; Wang, Xingjun; Zhou, Zhiping

2012-11-01

The fiber-to-the-home (FTTH) systems are growing fast these days, where two different wavelengths are used for upstream and downstream traffic, typically 1310nm and 1490nm. The duplexers are the key elements to separate these wavelengths into different path in central offices (CO) and optical network unit (ONU) in passive optical network (PON). Multimode interference (MMI) has some benefits to be a duplexer including large fabrication tolerance, low-temperature dependence, and low-polarization dependence, but its size is too large to integrate in conventional case. Based on the silicon photonics platform, ultra-short silicon MMI duplexer was demonstrated to separate the 1310nm and 1490nm lights. By studying the theory of self-image phenomena in MMI, the first order images are adopted in order to keep the device short. A cascaded MMI structure was investigated to implement the wavelength splitting, where both the light of 1310nm and 1490nm was input from the same port, and the 1490nm light was coupling cross the first MMI and output at the cross-port in the device while the 1310nm light was coupling through the first and second MMI and output at the bar-port in the device. The experiment was carried on with the SOI wafer of 340nm top silicon. The cascaded MMI was investigated to fold the length of the duplexer as short as 117μm with the extinct ratio over 10dB.

Ultrasonography of jaundice

International Nuclear Information System (INIS)

Cho, Byung Jae; Bae, Sang Hoon; Lee, Seung Ro; Kim, Chu Wan

1980-01-01

The importance of ultrasonography in the evaluation of jaundice is stressed with an analysis of 47 cases of jaundice. 31 cases proved to be obstructive and 16 non-obstructive jaundice. Obstructive jaundice could be differentiated from non-obstructive jaundice in all but 2 cases, (96%). The site of obstruction in 31 cases of obstructive jaundice could be predicted correctly in 23 cases of 31, (90%), and cause of obstruction with an accuracy of 35% as well. One can certainly recommend ultrasonography as an initial procedure of choice in jaundice patients

Full-duplex optical communication system

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Shay, Thomas M. (Inventor); Hazzard, David A. (Inventor); Horan, Stephen (Inventor); Payne, Jason A. (Inventor)

2004-01-01

A method of full-duplex electromagnetic communication wherein a pair of data modulation formats are selected for the forward and return data links respectively such that the forward data electro-magnetic beam serves as a carrier for the return data. A method of encoding optical information is used wherein right-hand and left-hand circular polarizations are assigned to optical information to represent binary states. An application for an earth to low earth orbit optical communications system is presented which implements the full-duplex communication and circular polarization keying modulation format.

Feasibility of Using Intravascular Ultrasonography for Assessment of Giant Cavernous Aneurysm after Endovascular Treatment: A Technical Report

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Majidi, Shahram; Grigoryan, Mikayel; Tekle, Wondwossen G; Watanabe, Masaki; Qureshi, Adnan I

2012-01-01

Introduction Intravascular ultrasonography (IVUS) has been shown as a valuable adjunct imaging tool during endovascular procedures but its value in detection of any recurrence during follow up after endovascular coil embolization of large and giant intracranial aneurysms is not reported. Methods A 41 years old man who had been treated using stent assisted coil embolization for cavernous segment aneurysm of the left internal carotid artery underwent 60 month angiographic follow up. Concurrently, IVUS catheter was advanced under fluoroscopic guidance inside the cavernous portion of the left internal carotid artery. Then IVUS images were used to visualize the stent, coil loops, and aneurysm neck. Results The angiographic images were limited because of superimposition of the aneurysm on the parent vessel in all projections. IVUS images demonstrated that the stent was patent along its whole length and there was no sign of stent deformity or in-stent thrombosis. Loops of the coil were visualized as hyperechoic signals inside the aneurysm and there was no sign of herniated loops of coil inside the stent. Conclusion In this case report, we observed that adjunct use of IVUS can provide valuable information not ascertained by angiography during follow up assessment of coil embolized aneurysm. PMID:22737259

l-Proline and RNA Duplex m-Value Temperature Dependence.

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Schwinefus, Jeffrey J; Baka, Nadia L; Modi, Kalpit; Billmeyer, Kaylyn N; Lu, Shutian; Haase, Lucas R; Menssen, Ryan J

2017-08-03

The temperature dependence of l-proline interactions with the RNA dodecamer duplex surface exposed after unfolding was quantified using thermal and isothermal titration denaturation monitored by uv-absorbance. The m-value quantifying proline interactions with the RNA duplex surface area exposed after unfolding was measured using RNA duplexes with GC content ranging between 17 and 83%. The m-values from thermal denaturation decreased with increasing GC content signifying increasingly favorable proline interactions with the exposed RNA surface area. However, m-values from isothermal titration denaturation at 25.0 °C were independent of GC content and less negative than those from thermal denaturation. The m-value from isothermal titration denaturation for a 50% GC RNA duplex decreased (became more negative) as the temperature increased and was in nearly exact agreement with the m-value from thermal denaturation. Since RNA duplex transition temperatures increased with GC content, the more favorable proline interactions with the high GC content duplex surface area observed from thermal denaturation resulted from the temperature dependence of proline interactions rather than the RNA surface chemical composition. The enthalpy contribution to the m-value was positive and small (indicating a slight increase in duplex unfolding enthalpy with proline) while the entropic contribution to the m-value was positive and increased with temperature. Our results will facilitate proline's use as a probe of solvent accessible surface area changes during biochemical reactions at different reaction temperatures.

Presentation of a glomus carotid tumor as carotid sinus syndrome with syncopal episodes

International Nuclear Information System (INIS)

Dickschas, A.; Harmann, B.; Herzog, T.; Marienhagen, J.

1987-01-01

An 80 year old patient was referred to neurology for clarification of her episodes of syncope. A set of radiological examinations indicated a diagnosis of paraganglion of the left carotid bifurcation. Using this case, an attempt is made to provide recommendations concerning the order of step-wise visualization techniques of clarifying glomus carotid tumors. This unusual case also provides an impetus for considering the physiology and pathogenesis of different forms of carotid sinus syndrome. (orig.) [de

Early control of distal internal carotid artery during carotid endarterectomy: does it reduce cerebral microemboli?

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Mommertz, G; Das, M; Langer, S; Koeppel, T A; Krings, T; Mess, W H; Schiefer, J; Jacobs, M J

2010-06-01

According to the results of the large trials on carotid endarterectomy (CEA), this type of surgery is only warranted if perioperative mortality and morbidity are kept considerably low. Less attention has been paid to methods of cerebral protection during CEA, although intraoperative transcranial Doppler (TCD) can visualise intracerebral microemboli (MES) during routine carotid dissection, although MES occur throughout the CEA, only those during dissection are related to neurological outcome. Prevention of MES by means of early control of the distal internal carotid artery dislodging from the carotid artery plaque during dissection is very likely the mechanism behind an eventual benefit from this approach. Hence, the amount of MES might serve as a surrogate parameter for the risk of periprocedural neurological events. So, the aim of the present study was to evaluate whether early control of the distal carotid artery during CEA is capable of reducing the number of MES by means of a prospective randomised trial. Twenty-eight patients (29 procedures) could be prospectively included in our study. Before surgery we randomly assigned the patients to two groups: group A (N.=12): CEA by means of early control of the distal internal carotid artery; group B (N.=17): CEA with dissection of the total carotid bifurcation before clamping the arteries. Periprocedurally, we continuously monitored the cerebral blood flow in the ipsilateral middle cerebral artery by means of TCD. Pre- and postoperative morbidity were independently verified by a neurologist control of the distal internal carotid artery did not reduce the occurrence of MES during dissection of the carotid bifurcation. Also, the total number of MES throughout the procedure and postoperatively was comparable between both groups. The procedure related times as well as the clinical outcome did not differ significantly. Thus, early control of the distal internal carotid artery has got no advantage but also no disadvantage

Carotid Angioplasty and Stenting

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Carotid angioplasty and stenting Overview Carotid angioplasty (kuh-ROT-id AN-jee-o-plas-tee) and stenting ... to better see and examine the blood vessels. Food and medications You'll receive instructions on what ...

The role of duplex stainless steels for downhole tubulars

International Nuclear Information System (INIS)

Francis, R.

1993-01-01

In sour conditions there is an increasing trend to turn to corrosion resistant alloys for downhole tubulars. The most commonly used CRA tubular is 13Cr, and there are thousands of feet in service. However, there are limits to the use of 13Cr, ie., the risk of sulphide stress corrosion cracking at high H 2 S levels, and the possibility of pitting or high corrosion rates in waters with high chloride contents. Where the service conditions are felt to be too severe for 13Cr alloys it has been traditional to switch to nickel base alloys such as alloys 825 and C-276 (UNS N08825 and N10276). The alloys are much more expensive than 13Cr, and in recent years the duplex stainless steels have been selected as alloys with superior corrosion and SSCC resistance compared with 13Cr, and having lower cost than nickel alloys. Originally the 22Cr duplex alloy (UNS 31803) was used, but more recently the 25Cr super duplex alloys (UNS S32760 and S32750) have become more available. The present paper reviews the data available for 13Cr and the limits of applicability. Data is also presented for laboratory tests for both the 22Cr and 25Cr super duplex alloys. There is extensive service experience with both 22Cr and 25Cr super duplex in the North Sea, covering both downhole tubulars, manifold and post wellhead equipment. Data is presented showing some of the sour condition being experienced in the North Sea by super duplex alloys. These results show that there is a substantial gap between the limits of use for 13Cr and the 25Cr super duplex stainless steel alloys. This means that in many sour environments super duplex stainless steel provides a cost effective alternative to nickel-base alloys

Transcranial Duplex Sonography Predicts Outcome following an Intracerebral Hemorrhage.

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Camps-Renom, P; Méndez, J; Granell, E; Casoni, F; Prats-Sánchez, L; Martínez-Domeño, A; Guisado-Alonso, D; Martí-Fàbregas, J; Delgado-Mederos, R

2017-08-01

Several radiologic features such as hematoma volume are related to poor outcome following an intracerebral hemorrhage and can be measured with transcranial duplex sonography. We sought to determine the prognostic value of transcranial duplex sonography in patients with intracerebral hemorrhage. We conducted a prospective study of patients diagnosed with spontaneous intracerebral hemorrhage. Transcranial duplex sonography examinations were performed within 2 hours of baseline CT, and we recorded the following variables: hematoma volume, midline shift, third ventricle and lateral ventricle diameters, and the pulsatility index in both MCAs. We correlated these data with the CT scans and assessed the prognostic value of the transcranial duplex sonography measurements. We assessed early neurologic deterioration during hospitalization and mortality at 1-month follow-up. We included 35 patients with a mean age of 72.2 ± 12.8 years. Median baseline hematoma volume was 9.85 mL (interquartile range, 2.74-68.29 mL). We found good agreement and excellent correlation between transcranial duplex sonography and CT when measuring hematoma volume ( r = 0.791; P duplex sonography measurements showed that hematoma volume was an independent predictor of early neurologic deterioration (OR, 1.078; 95% CI, 1.023-1.135) and mortality (OR, 1.089; 95% CI, 1.020-1.160). A second regression analysis with CT variables also demonstrated that hematoma volume was associated with early neurologic deterioration and mortality. When we compared the rating operation curves of both models, their predictive power was similar. Transcranial duplex sonography showed an excellent correlation with CT in assessing hematoma volume and midline shift in patients with intracerebral hemorrhage. Hematoma volume measured with transcranial duplex sonography was an independent predictor of poor outcome. © 2017 by American Journal of Neuroradiology.

Angioplasty and stent placement - carotid artery

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... medlineplus.gov/ency/article/002953.htm Angioplasty and stent placement - carotid artery To use the sharing features ... to remove plaque buildup ( endarterectomy ) Carotid angioplasty with stent placement Description Carotid angioplasty and stenting (CAS) is ...

A most spectrum-efficient duplexing system: CDD

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Lee, William C. Y.

2001-10-01

The game to play in wireless communications when it comes to increasing spectrum efficiency is to eliminate interference. Currently, all cellular systems use FDD (Frequency Division Duplexing) in an attempt to eliminate the interference from the adjacent cells. Through the use of many technologies only one type of interference remains and that is the adjacent base-tohome mobile interference. TDD (Time Division Duplexing) has not been used for mobile cellular systems, not only because of the adjacent base-to-home mobile interference, but also because of the additional adjacent base-to-home base interference, and adjacent mobile-to-home mobile interference. Therefore, TDD can only be used for small, confined area systems. CDD (Code Division Duplexing) can eliminate all three kinds of interference; the adjacent base-to-home mobile, the adjacent baseto-home base, and the adjacent mobile- to- home in cellular systems. Eliminating each of these interferences makes CDD the most spectrum efficient duplexing system. This talk will elaborate on a set of smart codes, which will make an efficient CDD system a reality.

[Risk factors of rupture of internal carotid artery during surgical resection of carotid body tumor].

Science.gov (United States)

Li, Y H; Wang, J S; Yao, C; Chang, G Q; Yin, H H; Li, S Q; Lü, W M; Hu, Z J; Wang, S M

2017-06-13

Objective: To investigate risk factors of rupture of internal carotid artery resection during carotid body tumor resection and to summarize our treatment experience. Methods: During the period from 1991 to 2016, rupture of internal carotid artery occurred in 27 patients (28 tumors) during surgical resection of carotid body tumor in the First Affiliated Hospital of Sun Yat-sen University. Their clinical and follow-up data were retrospectively collected and analyzed. For all patients underwent surgical resection during this period, Logistic regression analysis was used to investigate the risk factors of intraoperative rupture of internal carotid artery. Results: Of these 28 tumors, there were 15 (53.6%) tumors with diameter≥5 cm and 20 (71.4%) Shamblin Ⅲ tumors. Intraoperatively, shunt was applied for 8 (28.6%) cases. Thirteen (46.4%) patients underwent ligation of external carotid artery, while 2 (7.1%) patients accepted resection of cranial nerves. Direct closure/patchplasty, autologous vessels or graft reconstruction was used in 16, 10 and 2 cases, respectively. Postoperatively, stroke occurred in 4(14.3%) cases and cranial nerve deficit in 15 (53.6%) cases. During a median length of 36 (14-125) months, cranial nerve deficit persisted in 5 cases. Follow-up radiologic examination indicated 3 (10.7%) cases of targeted vessel occlusion. However, no new-onset stroke was identified. Among all patients underwent surgical resection of carotid body tumor, female ( OR =3.650, P =0.012), age≤25 years old ( OR =3.710, P =0.013) and Shamblin Ⅲ tumor ( OR =4.631, P =0.008) increase the risks of intraoperative carotid artery rupture. Conclusions: Shamblin Ⅲ tumor is the predictor of rupture of internal carotid artery. Intraoperative, properly increased blood pressure, intraoperative heparinization and use of shunt for those cases without well-compensated cranial collateral arteries are likely to decreasing the incidence of stroke.

Continuous Blood Glucose Monitoring May Detect Carotid Occlusion Intolerance during Carotid Artery Stenting.

Science.gov (United States)

Hiramatsu, Ryo; Furuse, Motomasa; Yagi, Ryokichi; Ohmura, Tomohisa; Ohnishi, Hiroyuki; Ikeda, Naokado; Nonoguchi, Naosuke; Kawabata, Shinji; Miyachi, Shigeru; Kuroiwa, Toshihiko

2018-02-05

The frequency of the occurrence of adverse events associated with carotid artery stenting (CAS) is usually low, but serious adverse events such as cerebral hyperperfusion syndrome (CHS) may occur. Real-time monitoring is ideal for the early detection of adverse events during the surgical procedure. This study aimed to evaluate continuous blood glucose (BG) monitoring for the detection of adverse events during CAS. Forty patients undergoing scheduled CAS were prospectively enrolled. An artificial pancreas was used for continuous BG monitoring (once per minute), using venous blood extracted at a rate of 2 mL/hr during CAS. The primary endpoint was a correlation between BG change and adverse events. CAS was discontinued in 1 patient, and BG was not measured in 5 patients (12.5%) because of the inability to extract blood. Among 34 evaluable patients, no patient developed CHS, but 3 patients (9%) experienced carotid occlusion intolerance. During CAS, BG was significantly higher in patients with carotid occlusion intolerance (median: 5 mg/dL) than in patients without carotid occlusion intolerance (median: 0 mg/dL) (P = 0.0221). A cutoff BG value ≥4 mg/dL during CAS showed 50% sensitivity and 100% specificity for the detection of carotid occlusion intolerance. There was no significant correlation between BG change and other adverse events. BG elevation may help detect carotid occlusion intolerance although it is still unknown whether BG monitoring can detect CHS. Further studies should validate that a cutoff BG elevation value of ≥4 mg/dL during CAS indicates carotid occlusion intolerance. Copyright © 2018 Elsevier Inc. All rights reserved.

p.Q192R SNP of PON1 seems not to be Associated with Carotid Atherosclerosis Risk Factors in an Asymptomatic and Normolipidemic Brazilian Population Sample

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Daniel Zanetti Scherrer

2015-07-01

Full Text Available Background:Evidences suggest that paraoxonase 1 (PON1 confers important antioxidant and anti-inflammatory properties when associated with high-density lipoprotein (HDL.Objective:To investigate the relationships between p.Q192R SNP of PON1, biochemical parameters and carotid atherosclerosis in an asymptomatic, normolipidemic Brazilian population sample.Methods:We studied 584 volunteers (females n = 326, males n = 258; 19-75 years of age. Total genomic DNA was extracted and SNP was detected in the TaqMan® SNP OpenArray® genotyping platform (Applied Biosystems, Foster City, CA. Plasma lipoproteins and apolipoproteins were determined and PON1 activity was measured using paraoxon as a substrate. High-resolution β-mode ultrasonography was used to measure cIMT and the presence of carotid atherosclerotic plaques in a subgroup of individuals (n = 317.Results:The presence of p.192Q was associated with a significant increase in PON1 activity (RR = 12.30 (11.38; RQ = 46.96 (22.35; QQ = 85.35 (24.83 μmol/min; p Conclusion:In low-risk individuals, the presence of the p.192Q variant of PON1 is associated with a beneficial plasma lipid profile but not with carotid atherosclerosis.

Carotid Velocities Determine Cerebral Blood Flow Deficits in Elderly Men with Carotid Stenosis <50%

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Arkadiusz Siennicki-Lantz

2012-01-01

Full Text Available To examine if mild carotid stenosis correlates with silent vascular brain changes, we studied a prospective population-based cohort “Men born in 1914.” Data from followups at ages 68 and 81, have been used. Carotid ultrasound was performed at age 81, and cerebral blood flow (CBF was measured with SPECT at age 82. Out of 123 stroke-free patients, carotid stenosis <50% was observed in 94% in the right and 89% in the left internal carotid arteries (ICAs. In these subjects, Peak Systolic Velocities in ICA correlated negatively with CBF in a majority of several brain areas, especially in mesial temporal area. Results were limited to normotensive until their seventies, who developed late-onset hypertension with a subsequent blood pressure, pulse pressure, and ankle-brachial index growth. Elderly with asymptomatic carotid stenosis <50% and peak systolic velocities in ICA 0.7–1.3 m/s, should be offered an intensified pharmacotherapy to prevent stroke or silent cerebrovascular events.

Transcranial Doppler ultrasonography predicts cardiovascular events after TIA

International Nuclear Information System (INIS)

Holzer, Katrin; Sadikovic, Suwad; Esposito, Lorena; Bockelbrink, Angelina; Sander, Dirk; Hemmer, Bernhard; Poppert, Holger

2009-01-01

Transient ischemic attack (TIA) patients are at high vascular risk. We assessed the value of extracranial (ECD) and transcranial (TCD) Doppler and duplex ultrasonography to predict clinical outcome after TIA. 176 consecutive TIA patients admitted to the Stroke Unit were recruited in the study. All patients received diffusion-weighted imaging, standardized ECD and TCD. At a median follow-up of 27 months, new vascular events were recorded. 22 (13.8%) patients experienced an ischemic stroke or TIA, 5 (3.1%) a myocardial infarction or acute coronary syndrome, and 5 (3.1%) underwent arterial revascularization. ECD revealed extracranial ≥ 50% stenosis or occlusions in 34 (19.3%) patients, TCD showed intracranial stenosis in 15 (9.2%) and collateral flow patterns due to extracranial stenosis in 5 (3.1%) cases. Multivariate analysis identified these abnormal ECD and TCD findings as predictors of new cerebral ischemic events (ECD: hazard ratio (HR) 4.30, 95% confidence interval (CI) 1.75 to 10.57, P = 0.01; TCD: HR 4.73, 95% CI 1.86 to 12.04, P = 0.01). Abnormal TCD findings were also predictive of cardiovascular ischemic events (HR 18.51, 95% CI 3.49 to 98.24, P = 0.001). TIA patients with abnormal TCD findings are at high risk to develop further cerebral and cardiovascular ischemic events

Reducing duplex examinations in patients with iatrogenic pseudoaneurysms.

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Stone, Patrick A; Aburahma, Ali F; Flaherty, Sarah K

2006-06-01

Ultrasound-guided thrombin injection has become the initial treatment of choice for femoral access-related pseudoaneurysms. Patients typically undergo serial duplex examinations to assess for spontaneous resolution of small iatrogenic pseudoaneurysms (IPSAs) (IPSAs (>2.5 cm). We evaluated the impact of a revised treatment algorithm that includes primary treatment of both small (2.5 cm), rather than observation of smaller ones, and attempts to establish a single duplex examination via a point-of-care treatment strategy. We reviewed 105 consecutive patients treated with ultrasound-guided thrombin injection from July 2001 through September 2004. Patient, IPSAs, characteristics, and treatment methods were examined. The number of duplex examinations per patient was evaluated over the treatment interval. Also, published cost data were used to compare primary treatment of small ISPAs vs observation with serial duplex examinations. Successful thrombosis occurred in 103 (98.1%) of 105 treated pseudoaneurysms. No minor or major complications occurred after thrombin injection in either small or large ISPAs, and both failures requiring operation were in the large aneurysm group. The recurrence rate for the series was 1.9% (2/105), and both recurrences were successfully treated with an additional thrombin injection. A single injection was successful in treating 43 (97.7%) of 44 small (IPSAs, and one required a second injection. Patients had an average of 3.3 duplex examinations in our first year of treatment experience, which declined to 1.5 by our third year with the institution of a point-of-care service model for all pseudoaneurysms. Based on this decreased use of duplex examination and an average treatment cohort of 35 IPSA patients per year our institution, we determined this results in a reduction of 35 hours of laboratory time and nearly 70 ultrasounds per year. Similarly for small pseudoaneurysms, a point-of-service primary treatment program rather than observation

Force-Induced Rupture of a DNA Duplex: From Fundamentals to Force Sensors.

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Mosayebi, Majid; Louis, Ard A; Doye, Jonathan P K; Ouldridge, Thomas E

2015-12-22

The rupture of double-stranded DNA under stress is a key process in biophysics and nanotechnology. In this article, we consider the shear-induced rupture of short DNA duplexes, a system that has been given new importance by recently designed force sensors and nanotechnological devices. We argue that rupture must be understood as an activated process, where the duplex state is metastable and the strands will separate in a finite time that depends on the duplex length and the force applied. Thus, the critical shearing force required to rupture a duplex depends strongly on the time scale of observation. We use simple models of DNA to show that this approach naturally captures the observed dependence of the force required to rupture a duplex within a given time on duplex length. In particular, this critical force is zero for the shortest duplexes, before rising sharply and then plateauing in the long length limit. The prevailing approach, based on identifying when the presence of each additional base pair within the duplex is thermodynamically unfavorable rather than allowing for metastability, does not predict a time-scale-dependent critical force and does not naturally incorporate a critical force of zero for the shortest duplexes. We demonstrate that our findings have important consequences for the behavior of a new force-sensing nanodevice, which operates in a mixed mode that interpolates between shearing and unzipping. At a fixed time scale and duplex length, the critical force exhibits a sigmoidal dependence on the fraction of the duplex that is subject to shearing.

Downlink Error Rates of Half-duplex Users in Full-duplex Networks over a Laplacian Inter-User Interference Limited and EGK fading

KAUST Repository

Soury, Hamza; Elsawy, Hesham; Alouini, Mohamed-Slim

2017-01-01

This paper develops a mathematical framework to study downlink error rates and throughput for half-duplex (HD) terminals served by a full-duplex (FD) base station (BS). The developed model is used to motivate long term pairing for users that have

Carotid Surgery in a District General Hospital

Science.gov (United States)

Fairgrieve, John

1981-01-01

The carotid surgical experience of Cheltenham General Hospital over a 13 year period (1968-81) is presented. This includes 42 operations for stenosis, and 12 further operations for carotid body tumour, carotid aneurysm, subclavian steal syndrome and trauma to the internal carotid artery. The operative techniques and complications are briefly discussed and reasons advanced for a more agressive approach to the problems of extra-cerebral carotid disease in this country. PMID:7185417

Cardiovascular magnetic resonance in carotid atherosclerotic disease

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Chen Huijun

2009-12-01

Full Text Available Abstract Atherosclerosis is a chronic, progressive, inflammatory disease affecting many vascular beds. Disease progression leads to acute cardiovascular events such as myocardial infarction, stroke and death. The diseased carotid alone is responsible for one third of the 700,000 new or recurrent strokes occurring yearly in the United States. Imaging plays an important role in the management of atherosclerosis, and cardiovascular magnetic resonance (CMR of the carotid vessel wall is one promising modality in the evaluation of patients with carotid atherosclerotic disease. Advances in carotid vessel wall CMR allow comprehensive assessment of morphology inside the wall, contributing substantial disease-specific information beyond luminal stenosis. Although carotid vessel wall CMR has not been widely used to screen for carotid atherosclerotic disease, many trials support its potential for this indication. This review summarizes the current state of knowledge regarding carotid vessel wall CMR and its potential clinical application for management of carotid atherosclerotic disease.

Carotid intima-media thickness in HIV patients treated with antiretroviral therapy

DEFF Research Database (Denmark)

Lebech, Anne-Mette; Wiinberg, Niels; Kristoffersen, Ulrik Sloth

2007-01-01

of carotid artery intima-media thickness (IMT) in non-smoking HIV patients with high or low serum cholesterol levels as well as in healthy volunteers. METHODS: HIV patients in ART with normal cholesterol (or=6 x 5 mmol l(-1); n=12) as well as healthy controls (n=14) were included. All were non-smokers...... and had never received medication for dyslipidaemia or hypertension. IMT was measured by ultrasonography. RESULTS: In HIV patients with normal cholesterol (or=6 x 5 mmol l(-1)) and in controls (5 x 1 +/- 0 x 9 mmol l(-1)) IMT were 683 +/- 119, 656 +/- 99 and 657 +/- 99 microm, respectively. Thus...... no correlation was found with total cholesterol or LDL cholesterol. CONCLUSIONS: In non-smoking HIV patients receiving ART no sign of accelerated atherosclerosis was found as assessed by IMT even not in hypercholesterolaemic HIV patients. IMT correlated with HDL cholesterol but not with LDL cholesterol. Based...

Capturing a DNA duplex under near-physiological conditions

Science.gov (United States)

Zhang, Huijuan; Xu, Wei; Liu, Xiaogang; Stellacci, Francesco; Thong, John T. L.

2010-10-01

We report in situ trapping of a thiolated DNA duplex with eight base pairs into a polymer-protected gold nanogap device under near-physiological conditions. The double-stranded DNA was captured by electrophoresis and covalently attached to the nanogap electrodes through sulfur-gold bonding interaction. The immobilization of the DNA duplex was confirmed by direct electrical measurements under near-physiological conditions. The conductance of the DNA duplex was estimated to be 0.09 μS. We also demonstrate the control of DNA dehybridization by heating the device to temperatures above the melting point of the DNA.

Ultrasound assessment of great saphenous vein insufficiency

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Chander RK

2015-06-01

Full Text Available Rajiv K Chander,1 Thomas S Monahan1,2 1Section of Vascular Surgery, Department of Surgery, University of Maryland School of Medicine, 2Department of Surgery, Baltimore Veterans Affairs Medical Center, Baltimore, MD, USA Abstract: Duplex ultrasonography is the ideal modality to assess great saphenous vein insufficiency. Duplex ultrasonography incorporates both gray scale images to delineate anatomy and color-Doppler imaging that visualizes the flow of blood in a structure. Assessment of great saphenous vein requires definition of the anatomy, augmentation of flow, evaluation for both superficial and deep vein thrombosis, and determining the presence of reflux. Currently, evolution in the treatment of reflux also relies on ultrasound for the treatment of the disease. Understanding the utilization of the ultrasound for the diagnosis and treatment of greater saphenous vein reflux is important for practitioners treating reflux disease. Keywords: duplex ultrasonography, small saphenous vein 

Exclusion of Atherosclerotic Plaque from the Circulation Using Stent-Grafts: Alternative to Carotid Stenting with a Protection Device?

International Nuclear Information System (INIS)

Peynircioglu, Bora; Geyik, Serdar; Yavuz, Kivilcim; Cil, Barbaros E.; Saatci, Isil; Cekirge, Saruhan

2007-01-01

Purpose. To retrospectively assess the feasibility, safety, and clinical mid-term outcome of patients undergoing carotid artery stenting with stent-grafts. Methods. Over a 4 year period stent-grafts were used in the endovascular treatment of symptomatic internal carotid artery stenosis in 12 patients (2 women, 10 men, aged 47-83 (mean 64) years). Protection devices were not used. Possible microembolic complications were evaluated by magnetic resonance imaging (MRI) examinations of the brain before and the day after the procedure in all patients. Mean follow-up was 22 months (range 1-42 months), by Doppler ultrasonography and conventional angiography as well as clinical examination .Results. The technical success rate was 100%. A total of 13 coronary stent-grafts were used. The mean stenosis rate (in terms of diameter) was 85% and the mean length of stent-grafts used was 20.9 mm. The mean diameter to which the stent-grafts were dilated was 4.66 mm. In-hospital complications occurred in 1 patient who suffered a minor femoral access hematoma that did not require transfusion or surgical decompression. Post-stenting diffusion-weighted MRI revealed several ipsilateral silent microemboli in only 1 case, which was completely asymptomatic. Two patients had a major stroke after 2 years of follow-up. Restenosis was found in 2 patients who underwent successful balloon dilatation followed by placement of a self-expandable bare stent within the stent-grafts. Conclusions. Stent-grafts may prevent microembolic complications during stenting of atherosclerotic carotid lesions in selected cases, offering immediate exclusion of the atherosclerotic lesion from the circulation by pressing the plaque against the vessel wall. Comparative, randomized studies in larger series of patients are needed with carotid-dedicated stent-graft designs

Comparison of the effects of surgical and natural menopause on carotid intima media thickness, osteoporosis, and homocysteine levels.

Science.gov (United States)

Özkaya, Enis; Cakir, Evrim; Okuyan, Erhan; Cakir, Caner; Ustün, Gülnihal; Küçüközkan, Tuncay

2011-01-01

Menopause is associated with increased cardiovascular risk factors. We designed this study to compare common carotid artery intima media thickness (IMT) and homocysteine level between women who had natural menopause and those who had surgical menopause and to correlate IMT, bone mineral density (BMD), and homocysteine level with time since menopause. Ninety healthy postmenopausal women aged 50 to 78 years who were not on hormone therapy (45 women who did not have a prior hysterectomy or oophorectomy and 45 women who had undergone hysterectomy with bilateral oophorectomy) were included in the study. B-mode ultrasonography of the carotid artery, BMD, and serum homocysteine level analysis were completed to evaluate the relationship between type of menopause, time since menopause, and subclinical atherosclerosis. Mean ± SD carotid artery IMT measurements were 0.72 ± 0.002 mm among women experiencing natural menopause and 0.88 ± 0.003 mm among women having bilateral oophorectomy (P = 0.002). After adjusting for time since menopause and age, the mean IMT also differed between the two groups: 0.76 ± 0.003 mm in the natural menopause group and 0.84 ± 0.003 mm in the bilateral oophorectomy group (P = 0.038). The age-adjusted carotid IMT was significantly positively associated with years since menopause (P = 0.001). Mean homocysteine measurements were 10.3 ± 5 μmol/L among women experiencing natural menopause and 9.1 ± 4 μmol/L among women who had bilateral oophorectomy (P = 0.216). Age-adjusted femur total, trochanter, and shaft BMDs were significantly lower in the surgical menopause group (P = 0.041, P = 0.034, and P = 0.046, respectively). Oophorectomy before natural menopause increases IMT but not homocysteine levels independent of age and time since menopause and is associated with lower BMD values after adjustment for age.

Validation of subclavian duplex velocity criteria to grade severity of subclavian artery stenosis.

Science.gov (United States)

Mousa, Albeir Y; Morkous, Ramez; Broce, Mike; Yacoub, Michael; Sticco, Andrew; Viradia, Ravi; Bates, Mark C; AbuRahma, Ali F

2017-06-01

Validation of subclavian duplex ultrasound velocity criteria (SDUS VC) to grade the severity of subclavian artery stenosis has not been established or systematically studied. Currently, there is a paucity of published literature and lack of practitioner consensus for how subclavian duplex velocity findings should be interpreted in patients with subclavian artery stenosis. The objective of the present study was to validate SDUS measurements using subclavian conventional or computed tomography angiogram (subclavian angiogram [SA])-derived measurements. Secondary objectives included measuring the correlation between SDUS peak systolic velocities and SA measurements, and to determine the optimal cutoff value for predicting significant stenosis (>70%). This is a retrospective review of all patients with suspected subclavian artery stenosis and a convenience sample of carotid artery patients who underwent SDUS and SA from May 1999 to July 2013. SA reference vessel and intralesion minimal lumen diameters were measured and compared with SDUS velocities obtained within 3 months of the imaging study. Percent stenosis was calculated using the North American Symptomatic Carotid Endarterectomy Trial method for detecting stenosis in a sufficiently large cohort. Receiver operating characteristic curves was generated for SDUS VC to predict >70% stenosis. Velocity cutoff points were determined with equal weighting of sensitivity and specificity. We examined 268 arteries for 177 patients. The majority of the arteries were for female patients (52.5%) with a mean age of 66.7 ± 11.1 years. Twenty-three arteries had retrograde vertebral artery flow and excluded from further analysis. For the remaining 245 arteries, the average peak systolic velocity was 212.6 ± 110.7 cm/s, with a range of 45-626 cm/s. Average stenosis was 25.8% ± 28.2%, with a range of 0% to 100%. Following receiver operating characteristic analysis, we found a cutoff value of >240 cm/s to be most predictive

Full-duplex wireless communications systems self-interference cancellation

CERN Document Server

Le-Ngoc, Tho

2017-01-01

This book introduces the development of self-interference (SI)-cancellation techniques for full-duplex wireless communication systems. The authors rely on estimation theory and signal processing to develop SI-cancellation algorithms by generating an estimate of the received SI and subtracting it from the received signal. The authors also cover two new SI-cancellation methods using the new concept of active signal injection (ASI) for full-duplex MIMO-OFDM systems. The ASI approach adds an appropriate cancelling signal to each transmitted signal such that the combined signals from transmit antennas attenuate the SI at the receive antennas. The authors illustrate that the SI-pre-cancelling signal does not affect the data-bearing signal. This book is for researchers and professionals working in wireless communications and engineers willing to understand the challenges of deploying full-duplex and practical solutions to implement a full-duplex system. Advanced-level students in electrical engineering and computer ...

Flow diversion in the treatment of carotid injury and carotid-cavernous fistula after transsphenoidal surgery

Science.gov (United States)

Lum, Cheemum; Ahmed, Muhammad E; Glikstein, Rafael; dos Santos, Marlise P; Lesiuk, Howard; Labib, Mohamed; Kassam, Amin B

2015-01-01

We describe a case of iatrogenic carotid injury with secondary carotid-cavernous fistula (CCF) treated with a silk flow diverter stent placed within the injured internal carotid artery and coils placed within the cavernous sinus. Flow diverters may offer a simple and potentially safe vessel-sparing option in this rare complication of transsphenoidal surgery. The management options are discussed and the relevant literature is reviewed. PMID:26015526

Tensile properties of duplex UNS S32205 and lean duplex UNS S32304 steels and the influence of short duration 475 ºC aging

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Sérgio Souto Maior Tavares

2012-12-01

Full Text Available Duplex stainless steels are high strength and corrosion resistant steels extensively used in the petrochemical and chemical industries. The aging at 475 ºC for long periods of time provokes embrittlement and deterioration of corrosion resistance. However, short duration aging at 475 ºC may be used as heat treatment to improve mechanical resistance with small decrease in the other properties. In this work the flow stress curves of lean duplex UNS S32304 and duplex UNS S32205 steels were modeled with Hollomon's equation and work hardening exponents (n were determined. The analyses were conducted in specimens annealed and heat treated at 475 ºC for short periods of time. The aging at 475 ºC for 4 hours, 8 hours and 12 hours promoted significant hardening with small decrease of ductility. The work hardening exponents of both steels were compared, being higher in the duplex steel than in the lean duplex grade.

Perancangan dan Implementasi Duplexer Mikrostrip untuk Frekuensi LTE pada band ke-7

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ENCENG SULAEMAN

2013-07-01

The necessary of mobile communication has increased in technology, now it released the new of technology is Long Term Evolution (LTE. Type of duplex is Frequency Division Duplex (FDD, designed a duplexer which it is capable for transmitting and receiving process at the same time with the different of frequency between uplink and downlink. Research of designed and implemented a duplexer using Hybrid Coupler and Bandstop filters based on Split Ring Resonators for the frequency band 7th on LTE technology at Base Transceiver Station (BTS. Duplexer is made by combining two coupler and two bandstop filter. The results of duplexer measurements, when Tx port transmit the signal to antenna port with attenuation at the downlink frequency center at 3.168 dB. Attenuation from antenna port to Rx port about 6 dB. Isolation between Tx port and Rx port about 15 dB. Keywords: Duplexer, Bandstop Filter, Split Ring Resonator, Hybrid Coupler, and Long Term Evolution.

Anterior Circulation Steal Syndrome

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Motahareh Afrakhteh

2017-02-01

Full Text Available Introduction: Arteriovenous fistula (AVF can be congenital or acquired. Congenital AVF are less common while acquired fistula are most frequently the result of penetrating trauma or iatrogenic action. Acquired common carotid jugular fistulas are uncommon in the head and neck region, accounting only 4 to 7% of all the traumatic AVFs encountered throughout the body that is not usually detected during the acute injury phase. Objective: For the first time in our center we diagnose and treat a carotid jugular vein fistula due to neck stab wound. Case Description: A 48 years old man with neck stab wound and strangulation was treated as an outpatient in a clinic with suturing the wound. he was stable and discharged without apparent neurologic deficit, after two days he was referred to our center due to left hemiparesis .in our assessment, Brain imaging showed right side hemodynamic infarct, in carotid duplex the flow was bidirectional and low RI, in angiography there was fistula from Right ICA to jugular vein, in left ICA angiography there was reversible flow from Right distal ICA to the fistula. After two times of brachychardia and asystolic cycle the patient was intubated and CPR was done. Cardiac arrest maybe because of cardiac problems dueto carotid jugular fistula. Approach: Due to carotid injury and high flow fistula, the Right ICA jugular fistula was obliterated by Balloon and ICA was also sacrificed. in left ICA Angiography the flow to Right ICA was stopped and MCA  and ACA got flow from left side .the patient was stable and after few days he could be extubated and he was discharged with stable condition. Discussion: Carotid jugular fistula is a rare complication of neck trauma, because its symptoms appear late, with neurologic deficit many times neurologist was suspect to dissection and maybe MRA and CTA report Carotid occlusion but Duplex is an efficient device to differentiated between these two disease. in dissection  there is prestenotic

Electron Beam Welding of Duplex Steels with using Heat Treatment

Science.gov (United States)

Schwarz, Ladislav; Vrtochová, Tatiana; Ulrich, Koloman

2010-01-01

This contribution presents characteristics, metallurgy and weldability of duplex steels with using concentrated energy source. The first part of the article describes metallurgy of duplex steels and the influence of nitrogen on their solidification. The second part focuses on weldability of duplex steels with using electron beam aimed on acceptable structure and corrosion resistance performed by multiple runs of defocused beam over the penetration weld.

Predictors of antegrade flow at internal carotid artery during carotid artery stenting with proximal protection.

Science.gov (United States)

Harada, Kei; Kakumoto, Kosuke; Oshikata, Shogo; Fukuyama, Kozo

2018-06-01

Carotid artery stenting (CAS) with proximal occlusion effectively prevent distal cerebral embolism by flow arrest at internal carotid artery (ICA); however, the method can expose antegrade flow at ICA due to incomplete flow arrest. The aim of this study was to identify predictors of antegrade flow during CAS with proximal protection. We retrospectively analyzed clinical and angiographic data among 143 lesions treated with CAS with proximal protection by occluding the common carotid artery (CCA) and external carotid artery (ECA). Flow arrest or antegrade flow at ICA was confirmed by contrast injection during proximal protection. Antegrade flow at ICA was observed in 12 lesions (8.4%). Compared with lesions in which flow arrest of ICA was achieved, the diameter of the superior thyroid artery (STA) was significantly larger (2.4 ± 0.34 vs. 1.4 ± 0.68 mm, p protection should be combined with proximal protection for the lesions with antegrade flow to prevent distal migration of the carotid debris.

Perancangan dan Implementasi Duplexer Mikrostrip untuk Frekuensi LTE pada band ke-7

Directory of Open Access Journals (Sweden)

ENCENG SULAEMAN

2017-06-01

Full Text Available ABSTRAK Kebutuhan akan komunikasi bergerak semakin mengalami peningkatan dalam dunia teknologi yang ada saat ini, maka hadirlah teknologi terbaru yaitu Long Term Evolution (LTE. Dengan teknik duplex jenis Frequency Division Duplex (FDD, dirancanglah duplexer yang mampu melakukan proses pengiriman dan penerimaan dalam satu waktu dengan frekuensi yang berbeda antara uplink dan downlink. Pada penelitian ini dirancang dan diimplementasikan sebuah duplekser dengan menggunakan metoda Hybrid Coupler dan Bandstop Filter berbasis Split Ring Resonator untuk band frekuensi ke-7 pada teknologi LTE di sisi Base Transceiver Station (BTS. Duplekser dibuat dengan menggabungkan dua buah hybrid Coupler dan dua buah Bandstop Filter. Hasil pengukuran duplexer saat port Tx mengirimkan sinyal ke antena dengan nilai redaman pada frekuensi tengah downlink sebesar 3.168 dB. Lalu pada saat antena menerima sinyal untuk diteruskan ke Rx terdapat redaman di frekuensi tengah uplink sebesar 6 dB. Sedangkan untuk isolasi dari port Tx-port Rx dihasilkan sebesar 15 dB. Kata kunci: Duplexer, Bandstop Filter, Split Ring Resonator, Hybrid Coupler, dan Long Term Evolution. ABSTRACT The necessary of mobile communication has increased in technology, now it released the new of technology is Long Term Evolution (LTE. Type of duplex is Frequency Division Duplex (FDD, designed a duplexer which it is capable for transmitting and receiving process at the same time with the different of frequency between uplink and downlink. Research of designed and implemented a duplexer using Hybrid Coupler and Bandstop filters based on Split Ring Resonators for the frequency band 7th on LTE technology at Base Transceiver Station (BTS. Duplexer is made by combining two coupler and two bandstop filter. The results of duplexer measurements, when Tx port transmit the signal to antenna port with attenuation at the downlink frequency center at 3.168 dB. Attenuation from antenna port to Rx port about 6 d

Renal damage in vesicoureteral reflux associated to duplex systems

International Nuclear Information System (INIS)

Orellana, P.; Velasquez, C.; Baquedano, P.

2002-01-01

Duplex system (DS) is a common occurrence and it can be associated to a range of ureteral and renal anomalies draining the two poles of the duplex kidneys, as vesicoureteral reflux (VUR) in the lower moiety and ureterocele in the upper moiety. The VUR in a duplex system can be primary or secondary (associated to an ureterocele). The assessment of parenchymal uptake and function of the whole and separate parts of the kidneys is important for therapeutical decisions. Objective: To determine the presence of renal damage, by dimercaptosuccinic acid (DMSA) scintigraphy in children with a refluxing DS and if there any difference between primary and secondary reflux. Patients and Methods: 36 children; 23 girls and 13 boys, with VUR into completely duplicated collecting systems was studied retrospectively (37 RU with DS, 35 unilateral and 1 bilateral), with a mean age of 2.43 y.o. (range: 1 month-11y.o.). All of the children underwent ultrasonography, voiding cystourethrogram and renal static scintigraphy. Among the 37 RU with VUR, 25 had primary VUR and 12 had VUR secondary to the presence of an ureterocele. Ten out of the 36 children (27.8%) were evaluated due to antenatal diagnosis and the remaining 26 (72.2%) after urinary tract infection (UTI). Results: Seventy percent of the 37 RU with VUR into completely duplicated collecting systems had renal damage demonstrated by renal static scintigraphy. Among the 25 RU with primary VUR, 19 (76%) had renal damage, 6 with a complete absence of function in the lower moiety. In this group, 80% of children was studied due to an UTI at a mean age of 3.3 y.o. In the group of children with secondary VUR, we observed a lower moiety with renal damage in 6/12 (50%), in 4 of them associated with an abnormal upper moiety. 7 out of 12 children (58.3%) had an abnormal upper moiety, 4 of them with a damage in lower moiety too. One children presented with renal exclusion. Half of these children were studied due to UTI, at a mean age of 1 y

Combined Effect of Hyperhomocysteinemia and Hypertension on the Presence of Early Carotid Artery Atherosclerosis.

Science.gov (United States)

Zhang, Zhongying; Fang, Xianghua; Hua, Yang; Liu, Beibei; Ji, Xunming; Tang, Zhe; Wang, Chunxiu; Guan, Shaochen; Wu, Xiaoguang; Liu, Hongjun; Gu, Xiang

2016-05-01

To examine the individual effect of elevated homocysteine and its combined effect with hypertension on early carotid artery atherosclerosis (ECAS). We recruited 1257 subjects from a community-based population in Beijing, China, aged 55 years and older. The definition of hyperhomocysteinemia was referred to as the presence of homocysteine concentrations greater than 15 µmol/L. Carotid intima-media thickness (CIMT), plaque, the sum of plaque thickness (plaque score, PS), and plaque location in common carotid artery were established by ultrasonography. The presence of increased CIMT (≥1.0 mm) and plaque was defined as ECAS. Age, sex, smoking, alcohol drinking, physical activity, total cholesterol, glucose, estimated glomerular filtration rate, hypoglycemic therapy, and lipid-lowering therapy were adjusted by logistic regression analysis. After adjustments for all potential confounders, the risks of presence of plaque, bilateral plaque, and high PS were significantly higher in the group with hyperhomocysteinemia as compared with reference group (the normal homocysteine and normotensive). The odds ratios (ORs) were 1.56 for presence of plaque (95% CI 1.05-2.33), 1.80 for bilateral plaque (95% CI 1.08-2.99), and 1.90 for high PS (95% CI 1.09-3.30), respectively. The group with both hyperhomocysteinemia and hypertension manifested the highest ORs of ECAS. The fully adjusted ORs were 1.67 for increased CIMT (95% CI 1.15-2.42), 2.48 for bilateral plaques (95% CI 1.54-3.99), and 2.69 for high PS (95% CI 1.61-4.47), correspondingly. Elevated homocysteine had a mild-to-moderate independent effect on ECAS. Combined with hypertension, hyperhomocysteinemia might increase the strength of the above-mentioned effects. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Increased common carotid artery wall thickness is associated with rapid progression of asymptomatic carotid stenosis.

Science.gov (United States)

Diomedi, Marina; Scacciatelli, Daria; Misaggi, Giulia; Balestrini, Simona; Balucani, Clotilde; Sallustio, Fabrizio; Di Legge, Silvia; Stanzione, Paolo; Silvestrini, Mauro

2014-01-01

This study aimed to identify clinical and ultrasound imaging predictors of progression of carotid luminal narrowing in subjects with asymptomatic moderate internal carotid artery (ICA) stenosis. A total of 571 subjects with asymptomatic moderate (50-69%) ICA stenoses were enrolled. They underwent ultrasound examination at baseline and after 12 months. Demographics, vascular risk factors, medications, plaque characteristics (surface and echogenicity) and common carotid intima-media thickness (IMT) were collected. At the follow-up examination, any change of ICA stenosis was graded in three categories (i) ≥70% to near occlusion, (ii) near occlusion, and (iii) occlusion. Progression of stenosis was defined as an increase in the stenosis degree by at least one category from baseline to follow-up. At 12 months, progression occurred in 142 subjects (prevalence rate 25%). At the multivariable logistic model, pathological IMT values (considered as binary variable: normal: ≤1 mm vs. pathologic: >1 mm) significantly predicted the risk for plaque progression after adjusting the model for possible confounders (OR 2.28, 95% CI 1.18-4.43, P = .014, multivariable logistic model). Our results confirm the role of carotid wall thickening as a marker of atherosclerosis. Carotid IMT measurement should be considered to implement risk stratification in patients with asymptomatic carotid disease.

The Duplex Society.

Science.gov (United States)

Schorr, Alvin L.

1984-01-01

The duplex society, in which the poor live in close proximity to others but in a separate compartment, is already with us. Unless something deeply changes about family income, more than one-third of future generations will come to adulthood having spent a portion of their childhood in official poverty. (RM)

On the Performance of In-Band Full-Duplex Cooperative Communications

KAUST Repository

Khafagy, Mohammad Galal

2016-06-01

In-band full-duplex, by which radios may simultaneously transmit and receive over the same channel, has been always considered practically-unfeasible due to the prohibitively strong self-interference. Indeed, a freshly-generated transmit signal power is typically ten orders of magnitude higher than that of a naturally-attenuated received signal. While unable to manage such an overwhelming interference, wireless communications resorted to half-duplex operation, transmitting and receiving over orthogonal channel resources. Recent research has demonstrated the practical feasibility of full-duplexing via successive sophisticated stages of signal suppression/cancellation, bringing this long-held assumption down and reviving the promising full-duplex potentials. Full-duplex relaying (FDR), where intermediate nodes may now support source-destination communication via simultaneous listening/forwarding, represents one of two full-duplex settings currently recommended for deployment in future fifth-generation (5G) systems. Theoretically, it has been widely accepted that FDR potentially doubles the channel capacity when compared to its half-duplex counterpart. Although FDR doubles the multiplexing gain, the effective signal-to-noise ratio (SNR) can be significantly degraded due to the residual self-interference (RSI) if not properly handled. In this work, efficient protocols are devised for different FDR settings. Selective cooperation is proposed for the canonical three-terminal FDR channel with RSI, which exploits the cooperative diversity offered by the independently fading source/relay message replicas arriving at the destination. Closed-form expressions are derived for the end-to-end SNR cumulative distribution function (CDF) under Rayleigh and Nakagami-m fading. Further, the offered diversity gain is presented as a function of the RSI scaling trend with the relay power. We show that the existing diversity problem in simple FDR protocols can be considerably fixed via

On full duplex Gaussian relay channels with self-interference

KAUST Repository

Behboodi, Arash; Chaaban, Anas; Mathar, Rudolf; Alouini, Mohamed-Slim

2016-01-01

Self interference (SI) in full duplex (FD) systems is the interference caused by the transmission stream on the reception stream. Being one of the main restrictive factors for performance of practical full duplex systems, however, not too much

Distance-dependent duplex DNA destabilization proximal to G-quadruplex/i-motif sequences

Science.gov (United States)

König, Sebastian L. B.; Huppert, Julian L.; Sigel, Roland K. O.; Evans, Amanda C.

2013-01-01

G-quadruplexes and i-motifs are complementary examples of non-canonical nucleic acid substructure conformations. G-quadruplex thermodynamic stability has been extensively studied for a variety of base sequences, but the degree of duplex destabilization that adjacent quadruplex structure formation can cause has yet to be fully addressed. Stable in vivo formation of these alternative nucleic acid structures is likely to be highly dependent on whether sufficient spacing exists between neighbouring duplex- and quadruplex-/i-motif-forming regions to accommodate quadruplexes or i-motifs without disrupting duplex stability. Prediction of putative G-quadruplex-forming regions is likely to be assisted by further understanding of what distance (number of base pairs) is required for duplexes to remain stable as quadruplexes or i-motifs form. Using oligonucleotide constructs derived from precedented G-quadruplexes and i-motif-forming bcl-2 P1 promoter region, initial biophysical stability studies indicate that the formation of G-quadruplex and i-motif conformations do destabilize proximal duplex regions. The undermining effect that quadruplex formation can have on duplex stability is mitigated with increased distance from the duplex region: a spacing of five base pairs or more is sufficient to maintain duplex stability proximal to predicted quadruplex/i-motif-forming regions. PMID:23771141

Optimization of welding variables for duplex stainless steel by GTAW and SMAW

International Nuclear Information System (INIS)

Ajmal, M.; Anwar, M.Y.; Nawaz, A.

2006-01-01

The main problems faced during the welding of duplex stainless steels are cleanliness and slag inclusions. In the present work the methods to eliminate these problems were studied during the welding of duplex stainless steel by Gas Tungsten Arc Welding (GTAW) and Shielded Metal Arc Welding (SMAW). Since the duplex stainless steel is an expensive material, the initial experiments for optimization of welding variables were. carried out on low carbon steel (CS) plates with duplex consumables. Welding of butt groove joints on CS plates was carried with various sets of welding variables i.e. current, voltage and arc energy using duplex consumables. The. radiographic inspection, micro-structural observations and hardness testing of the welds suggested the welding variables that will produce a sound weld on CS plate. These optimized variables were then used for the welding of edge groove joint and T -joint on duplex stainless steel by GTAW and SMAW processes. The hardness and micro-structural study of the joints produced on duplex stainless steel by GTAW and SMAW with duplex consumables were also studied. No slag inclusions and porosity were observed in the microstructure of these weldments and their properties were found similar to the parent metal. (author)

Cerebral hyperperfusion syndrome after carotid angioplasty

International Nuclear Information System (INIS)

Milosevic, Z.; Surlan, M.; Zvan, B.; Zaletel, M.

2002-01-01

Background. Cerebral hyperperfusion syndrome after carotid endarterectomy is an uncommon but well-defined entity. There are only few reports of ''hyperperfusion injury'' following carotid angioplasty. Case report. We report an unstable arterial hypertension and high-grade carotid stenosis in a 58-year-old, right-handed woman. After a stroke in the territory of middle cerebral artery carotid angioplasty was performed in the patient. Among risk factors, the long lasting arterial hypertension was the most pronounced. Immediately after the procedure, the patient was stable without any additional neurologic deficit. The second day, the patient had an epileptic seizure and CT revealed a small haemorrhage in the left frontal lobe. Conclusions. The combination of a high-grade carotid stenosis and unstable arterial pressure is probably an important prognostic factor in the pathogenesis of hyperperfusion syndrome. (author)

Duplex/quadruplex oligonucleotides: Role of the duplex domain in the stabilization of a new generation of highly effective anti-thrombin aptamers.

Science.gov (United States)

Russo Krauss, Irene; Napolitano, Valeria; Petraccone, Luigi; Troisi, Romualdo; Spiridonova, Vera; Mattia, Carlo Andrea; Sica, Filomena

2018-02-01

Recently, mixed duplex/quadruplex oligonucleotides have attracted great interest for use as biomedical aptamers. In the case of anti-thrombin aptamers, the addition of duplex-forming sequences to a G-quadruplex module identical or very similar to the best-known G-quadruplex of the Thrombin Binding Aptamer (HD1) results in new or improved biological properties, such as higher activity or different recognition properties with respect to HD1. Remarkably, this bimodular fold was hypothesized, based on its sequence, for the only anti-thrombin aptamer in advanced clinical trial, NU172. Whereas cation modulation of G-quadruplex conformation and stability is well characterized, only few data from similar analysis on duplex/quadruplex oligonucleotides exist. Here we have performed a characterization of structure and stability of four different duplex/quadruplex anti-thrombin aptamers, including NU172, in the presence of different cations and in physiological-mimicking conditions in comparison to HD1, by means of spectroscopic techniques (UV and circular dichroism) and differential scanning calorimetry. Our data show a strong reciprocal influence of each domain on the stability of the other and in particular suggest a stabilizing effect of the duplex region in the presence of solutions mimicking the physiological conditions, strengthening the idea that bimodular aptamers present better therapeutic potentialities than those containing a single G-quadruplex domain. Copyright © 2017 Elsevier B.V. All rights reserved.

Role of Ultrasonography in Acute Abdomen

International Nuclear Information System (INIS)

An, Ji Hyun; Lee, Yeon Hee; Kim, Tae Hoon; Yu, Pil Mun; Choi, Young Hi; Kim, Sang Joon; Kim, Seung Cheul; Cho, Jeong Hee; Jung, Jae Un

1996-01-01

Authors analyzed the distribution of diseases and compared ultrasonographic conclusions with confirmed diagnoses of emergency abdominal ultrasonographies in acute abdominal conditions. We evaluated the role of emergency abdominal ultrasonography especially in the decision of emergency operation. In one hundred and forty five patients, emergent abdominal ultrasonography was performed within on admission. We compared the sonographic conclusion with postoperative pathology and analyzed the diagnoses of medically treated diseases. Twenty-eight patients under vent surgery and 117 patients were treated conservatively. Among the surgically treated patients, 19 patients (70.4%) were correctly diagnosed by preoperative ultrasonography.These included acute appendicitis (N = 8), acute cholecystitis (n = 7), ovarian cyst torsion (n = 2), and liver abscess (n = 1). Correct preoperative diagnosis was not made in 9 patients, including acute appendicitis (n = 4),peritonitis due to bowel perforation (n = 2), ectopic pregnancy (n = 1), colonic diverticulitis (n = 1 ) and pelvic inflammatory disease (n = 1 ). Clinical follow up was possible in 50 patients among the non-operative patient group, and the clinical diagnoses were chronic liver disease (n = 14), acute pyelonephritis (n = 10), and biliary stone (n = 10). Emergent ultrasonography plays an important role in acute abdominal conditions by supporting the differential diagnosis of medical and surgical disease

Role of Ultrasonography in Acute Abdomen

Energy Technology Data Exchange (ETDEWEB)

An, Ji Hyun; Lee, Yeon Hee; Kim, Tae Hoon; Yu, Pil Mun; Choi, Young Hi; Kim, Sang Joon; Kim, Seung Cheul; Cho, Jeong Hee [Dankook University College of Medicine, Cheonan (Korea, Republic of); Jung, Jae Un [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1996-12-15

Authors analyzed the distribution of diseases and compared ultrasonographic conclusions with confirmed diagnoses of emergency abdominal ultrasonographies in acute abdominal conditions. We evaluated the role of emergency abdominal ultrasonography especially in the decision of emergency operation. In one hundred and forty five patients, emergent abdominal ultrasonography was performed within on admission. We compared the sonographic conclusion with postoperative pathology and analyzed the diagnoses of medically treated diseases. Twenty-eight patients underwent surgery and 117 patients were treated conservatively. Among the surgically treated patients, 19 patients (70.4%) were correctly diagnosed by preoperative ultrasonography.These included acute appendicitis (N = 8), acute cholecystitis (n = 7), ovarian cyst torsion (n = 2), and liver abscess (n = 1). Correct preoperative diagnosis was not made in 9 patients, including acute appendicitis (n = 4), peritonitis due to bowel perforation (n = 2), ectopic pregnancy (n = 1), colonic diverticulitis (n = 1) and pelvic inflammatory disease (n = 1). Clinical follow up was possible in 50 patients among the non-operative patient group, and the clinical diagnoses were chronic liver disease (n = 14), acute pyelonephritis (n = 10), and biliary stone (n = 10). Emergent ultrasonography plays an important role in acute abdominal conditions by supporting the differential diagnosis of medical and surgical disease

EFFECT OF INTERMETALLIC PHASES ON CORROSION BEHAVIOR AND MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL AND SUPER-DUPLEX STAINLESS STEEL

OpenAIRE

Prabhu Paulraj; Rajnish Garg

2015-01-01

Duplex Stainless Steels (DSS) and Super Duplex Stainless Steel (SDSS) have excellent integration of mechanical and corrosion properties. However, the formation of intermetallic phases is a major problem in their usage. The mechanical and corrosion properties are deteriorated due to the presence of intermetallic phases. These phases are induced during welding, prolonged exposure to high temperatures, and improper heat treatments. The main emphasis of this review article is on intermetallic pha...

International guidelines for contrast-enhanced ultrasonography

DEFF Research Database (Denmark)

Nolsøe, Christian Pállson; Lorentzen, Torben

2016-01-01

The intent of this review is to discuss and comment on common clinical scenarios in which contrast-enhanced ultrasonography (CEUS) may play a decisive role and to illustrate important points with typical cases. With the advent of CEUS, the scope of indications for ultrasonography has been dramati...

Stenosis of calcified carotid artery detected on Panoramic Radiography

Energy Technology Data Exchange (ETDEWEB)

Cho, So Yang; Oh, Won Mann; Yoon, Suk Ja; Yoon, Woong; Lee, Jae Seo; Kang, Byung Cheol [School of Dentistry, Chonnam National University, Seoul (Korea, Republic of); Palomo, Juan M. [Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland (United States)

2009-09-15

This study aimed to investigate the luminal stenosis of the internal carotid artery with calcification detected on panoramic radiographs. This study used fifty carotid arteries of 36 dental patients whose panoramic radiograph and computed tomography angiography (CTA) revealed the presence of carotid artery calcification. A neuroradiologist interpreted CTA to determine the degree of stenosis of the internal carotid arteries. The degree of stenosis was stratified in four stages; normal (no stenosis), mild stenosis (1-49%), moderate stenosis (50-69%) and severe stenosis (70-99%). Among the fifty carotid arteries with calcification detected on both panoramic radiography and CTA, 20 carotid arteries (40%) were normal, 29 carotid arteries (18%) had mild stenosis, 1 carotid artery (2%) had moderate stenosis, and there was none with severe stenosis. Sixty percent of the carotid arteries with calcification detected on both panoramic radiography and CTA had internal luminal stenosis, and two percent had moderate stenosis. When carotid atheroma is detected on panoramic radiograph, it is possible that the dental patient has luminal stenosis of the internal carotid artery.

An unfavorable dietary pattern is associated with symptomatic ischemic stroke and carotid atherosclerosis.

Science.gov (United States)

Mahe, Guillaume; Ronziere, Thomas; Laviolle, Bruno; Golfier, Véronique; Cochery, Thomas; De Bray, Jean-Michel; Paillard, François

2010-07-01

Ischemic strokes represent more than 80% of total strokes in Western countries. The influence of dietary factors on ischemic stroke risk is debated mainly because available data are limited. Our objective was to compare the dietary pattern of symptomatic ischemic stroke patients under 65 years old with control subjects using a validated 14-item food frequency questionnaire (FFQ). We also compared symptomatic ischemic stroke patients with carotid atherosclerosis with those without according to the presence or the absence of carotid plaque defined by duplex scanning. This was a case-control multi-center study that took place in one University hospital and two general hospitals in France. One hundred twenty-four symptomatic ischemic stroke patients (confirmation by a neurologist and imaging; 66% smokers) and 50 controls (34% smokers) without any known cardiovascular disease or previous nutritional advice were included. The main outcome measure(s) were intake scores for saturated (SFA), monounsaturated (MUFA), Omega-3 polyunsaturated (Omega-3 PUFA), and Omega-6 polyunsaturated fatty acids (Omega-6PUFA). Fruit and vegetables and an overall cardiovascular dietary score were evaluated with the FFQ. The overall cardiovascular score is calculated as (MUFA + Omega-3 PUFA + fruits and vegetables) - (SFA) scores. Compared with controls, ischemic stroke patients had a higher SFA score (6.6 +/- 3.0 vs 4.9 +/- 2.7; P vs 1.5 +/- 1.2; P vs 2.2 +/- 1.5; P = .013), Omega-6PUFA (2.6 +/- 2.5 vs 3.9 +/- 2.7; P = .002), fruit and vegetables (2.9 +/- 1.7 vs 3.8 +/- 1.6; P = .005), and a lower overall dietary score (-1.2 +/- 5.0 vs 2.5 +/- 4.4; P stroke patients with carotid atherosclerosis (n = 54) had a worse overall cardiovascular dietary score than those without (n = 68): -2.2 +/- 4.4 vs -0.2 +/- 5.2; P = .024. Compared with controls, ischemic stroke patients, especially those with carotid atherosclerosis, have an unfavorable dietary pattern (high SFA, low fruit and vegetables, and

Clinical Significance of the Champagne Bottle Neck Sign in the Extracranial Carotid Arteries of Patients with Moyamoya Disease.

Science.gov (United States)

Yasuda, C; Arakawa, S; Shimogawa, T; Kanazawa, Y; Sayama, T; Haga, S; Morioka, T

2016-05-26

The champagne bottle neck sign represents a rapid reduction in the extracranial ICA diameters and is a characteristic feature of Moyamoya disease. However, the clinical significance of the champagne bottle neck sign is unclear. We investigated the relationship between the champagne bottle neck sign and the clinical and hemodynamic stages of Moyamoya disease. We analyzed 14 patients with Moyamoya disease before revascularization (5 men, 9 women; age, 43.2 ± 19.3 years). The ratio of the extracranial ICA and common carotid artery diameters was determined using carotid ultrasonography or cerebral angiography; a ratio of champagne bottle neck sign-positive. The clinical disease stage was determined using the Suzuki angiographic grading system. CBF and cerebral vasoreactivity also were measured. The ICA/common carotid artery ratio (expressed as median [interquartile range]) decreased as the clinical stage advanced (stages I-II, 0.71 [0.60-0.77]; stages III-IV, 0.49 [0.45-0.57]; stages V-VI, 0.38 [0.34-0.47]; P champagne bottle neck sign-positive arteries were classified as Suzuki stage ≥III, 73% were symptomatic, and 89% exhibited reduced cerebral vasoreactivity. In contrast, all champagne bottle neck sign-negative arteries were Suzuki stage ≤III, 67% were asymptomatic, and all showed preserved cerebral vasoreactivity. The champagne bottle neck sign was related to advanced clinical stage, clinical symptoms, and impaired cerebral vasoreactivity. Thus, detection of the champagne bottle neck sign might be useful in determining the clinical and hemodynamic stages of Moyamoya disease. © 2016 American Society of Neuroradiology.

Transvaginal ultrasonography of rectal endometriosis

DEFF Research Database (Denmark)

Egekvist, Anne Gisselmann; Seyer-Hansen, Mikkel; Forman, Axel

Objectives: The aim of this present study was to evaluate the interobserver variation of transvaginal ultrasonographic measurements of endometriosis infiltrating the rectosigmoid wall. Methods: Transvaginal ultrasonography was performed independently by two observers. Observer 1 had several years...... of experience in ultrasonography while observer 2 was a medical student with no prior experience in ultrasonography or endometriosis. In 24 patient length, width and depth of endometriosis infiltrating the rectosigmoid bowel was measured. The differences between the observers were analysed by Bland and Altman...... for a relatively short period gives comparable scanning results between the two observers. It seems that transvaginal ultrasound could be used as a diagnostic tool for rectal endometriosis in most departments. However, the irregular morphology of the lesions makes the measurements very complex, and a strict...

Water-evaporation reduction by duplex films: application to the human tear film.

Science.gov (United States)

Cerretani, Colin F; Ho, Nghia H; Radke, C J

2013-09-01

Water-evaporation reduction by duplex-oil films is especially important to understand the physiology of the human tear film. Secreted lipids, called meibum, form a duplex film that coats the aqueous tear film and purportedly reduces tear evaporation. Lipid-layer deficiency is correlated with the occurrence of dry-eye disease; however, in-vitro experiments fail to show water-evaporation reduction by tear-lipid duplex films. We review the available literature on water-evaporation reduction by duplex-oil films and outline the theoretical underpinnings of spreading and evaporation kinetics that govern behavior of these systems. A dissolution-diffusion model unifies the data reported in the literature and identifies dewetting of duplex films into lenses as a key challenge to obtaining significant evaporation reduction. We develop an improved apparatus for measuring evaporation reduction by duplex-oil films including simultaneous assessment of film coverage, stability, and temperature, all under controlled external mass transfer. New data reported in this study fit into the larger body of work conducted on water-evaporation reduction by duplex-oil films. Duplex-oil films of oxidized mineral oil/mucin (MOx/BSM), human meibum (HM), and bovine meibum (BM) reduce water evaporation by a dissolution-diffusion mechanism, as confirmed by agreement between measurement and theory. The water permeability of oxidized-mineral-oil duplex films agrees with those reported in the literature, after correction for the presence of mucin. We find that duplex-oil films of bovine and human meibum at physiologic temperature reduce water evaporation only 6-8% for a 100-nm film thickness pertinent to the human tear film. Comparison to in-vivo human tear-evaporation measurements is inconclusive because evaporation from a clean-water surface is not measured and because the mass-transfer resistance is not characterized. Copyright © 2013 Elsevier B.V. All rights reserved.

Physical-Layer Security of a Buffer-Aided Full-Duplex Relaying System

KAUST Repository

El Shafie, Ahmed

2016-07-07

This letter proposes a novel hybrid half-/full-duplex relaying scheme to enhance the relay channel security. A source node (Alice) communicates with her destination node (Bob) in the presence of a buffer-aided full-duplex relay node (Rooney) and a potential eavesdropper (Eve). Rooney adopts two different relaying, namely randomize-and-forward and decode-andforward relaying strategies, to improve the security of the legitimate system. In the first relaying strategy, Rooney uses a codebook different from that used at Alice. In the second relaying strategy, Rooney and Alice use the same codebooks. In addition, Rooney switches between half-duplex and full-duplex modes to further enhance the security of the legitimate system. The numerical results demonstrate that our proposed scheme achieves a significant average secrecy end-to-end throughput improvement relative to the conventional bufferless full-duplex relaying scheme.

Physical-Layer Security of a Buffer-Aided Full-Duplex Relaying System

KAUST Repository

El Shafie, Ahmed; Salem, Ahmed Sultan; Al-Dhahir, Naofal

2016-01-01

This letter proposes a novel hybrid half-/full-duplex relaying scheme to enhance the relay channel security. A source node (Alice) communicates with her destination node (Bob) in the presence of a buffer-aided full-duplex relay node (Rooney) and a potential eavesdropper (Eve). Rooney adopts two different relaying, namely randomize-and-forward and decode-andforward relaying strategies, to improve the security of the legitimate system. In the first relaying strategy, Rooney uses a codebook different from that used at Alice. In the second relaying strategy, Rooney and Alice use the same codebooks. In addition, Rooney switches between half-duplex and full-duplex modes to further enhance the security of the legitimate system. The numerical results demonstrate that our proposed scheme achieves a significant average secrecy end-to-end throughput improvement relative to the conventional bufferless full-duplex relaying scheme.

Direct Doppler auscultation of the carotid arteries

International Nuclear Information System (INIS)

Nix, L.

1984-01-01

The results of the carotid Doppler examinations and contrast arteriograms are presented. The overall sensitivity of the carotid Doppler examinations in detecting severe stenosis or occlusion of the carotid artery was 92%. The Doppler studies correctly differentiated these two conditions in 84% of the diseased vessels. In carotid arteries with stenosis greater than or equal to 50%, the sensitivity of the Doppler examinations was 90%, and these studies suggested stenosis in all but two of the 36 abnormal examinations. In two patent carotids with greater than 90% stenosis, a signal could not be elicited, presumably because of the low blood flow through the severely stenotic segment

Ultrasonography and surgery of canine biliary diseases.

Science.gov (United States)

Vörös, K; Németh, T; Vrabély, T; Manczur, F; Tóth, J; Magdus, M; Perge, E

2001-01-01

Findings of hepatic and gallbladder ultrasonography were analyzed in 12 dogs with gallbladder and/or extrahepatic biliary tract obstruction and compared with the results of exploratory laparotomy. Hepatic ultrasonography demonstrated normal liver in 2 dogs and hepatic abnormalities in 10 animals. The following ultrasonographic diagnoses were established compared to surgical findings: gallbladder obstruction caused by bile sludge (correct/incorrect: 1/2, surgical diagnosis: choleliths in one case), gallbladder obstruction caused by neoplasm (0/1, surgical diagnosis: mucocele), gallbladder and extrahepatic biliary tract obstruction due to choleliths (3/3), extrahepatic biliary tract obstruction caused by pancreatic mass (1/1) and small intestinal volvulus (1/1). Bile peritonitis caused by gallbladder rupture (4/4) was correctly diagnosed by ultrasound, aided with ultrasonographically-guided abdominocentesis and peritoneal fluid analysis. Rupture of the gallbladder should be suspected in the presence of a small, echogenic gallbladder or in the absence of the organ together with free abdominal fluid during ultrasonography. Laparotomy was correctly indicated by ultrasonography in all cases. However, the direct cause of obstruction could not be determined in 2 of the 12 dogs by ultrasonography alone.

Characterization of thermal aging of duplex stainless steel by SQUID

International Nuclear Information System (INIS)

Isobe, Y.; Kamimura, A.; Aoki, K.; Nakayasu, F.

1995-01-01

Thermal aging is a growing concern for long-term-aged duplex stainless steel piping in nuclear power plants. Superconducting QUantum Interference Device (SQUID) was used for the detection of thermal aging of SUS329 rolled duplex stainless steel and SCS16 cast duplex stainless steel. It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to the changes in electromagnetic properties due to thermal aging

Acute internal carotid artery occlusion after carotid endarterectomy

Directory of Open Access Journals (Sweden)

Masatoshi Yunoki

2016-09-01

Full Text Available We report two cases of acute carotid artery (CA occlusion following carotid endarterectomy (CEA. Case 1: a 58-year-old man was admitted with transient right-sided hemiparesis. Magnetic resonance imaging (MRI and MR angiography (MRA revealed cerebral infarction in the left cerebral hemisphere and left CA stenosis. Ten days after admission, he underwent CEA. 24 h after surgery, he developed right hemiplegia. MRI and MRA demonstrated a slightly enlarged infarction and left internal carotid artery (ICA occlusion. Emergency reoperation was performed and complete recanalization achieved. The patient made a clinically significant recovery. Case 2: a 65 year-old man underwent a right-sided CEA for an asymptomatic 80% CA stenosis. 48 h after surgery, his family noticed he was slightly disorientated. MRI and MRA revealed multiple infarctions and right ICA occlusion. He was treated with antiplatelet therapy without reoperation because sufficient cross-flow from the left ICA through the anterior communicating artery was demonstrated by angiography, and his neurological symptoms were mild. His symptoms gradually alleviated and he was discharged 14 days after surgery. With ICA occlusion after CEA, immediate re-operation is mandatory with severe neurological symptoms, whereas individualized judgement is needed when the symptoms are mild.

Radiation-induced carotid artery atherosclerosis

International Nuclear Information System (INIS)

Gujral, Dorothy M.; Chahal, Navtej; Senior, Roxy; Harrington, Kevin J.; Nutting, Christopher M.

2014-01-01

Purpose: Carotid arteries frequently receive significant doses of radiation as collateral structures in the treatment of malignant diseases. Vascular injury following treatment may result in carotid artery stenosis (CAS) and increased risk of stroke and transient ischaemic attack (TIA). This systematic review examines the effect of radiotherapy (RT) on the carotid arteries, looking at the incidence of stroke in patients receiving neck radiotherapy. In addition, we consider possible surrogate endpoints such as CAS and carotid intima-medial thickness (CIMT) and summarise the evidence for radiation-induced carotid atherosclerosis. Materials and methods: From 853 references, 34 articles met the criteria for inclusion in this systematic review. These papers described 9 studies investigating the incidence of stroke/TIA in irradiated patients, 11 looking at CAS, and 14 examining CIMT. Results: The majority of studies utilised suboptimally-matched controls for each endpoint. The relative risk of stroke in irradiated patients ranged from 1.12 in patients with breast cancer to 5.6 in patients treated for head and neck cancer. The prevalence of CAS was increased by 16–55%, with the more modest increase seen in a study using matched controls. CIMT was increased in irradiated carotid arteries by 18–40%. Only two matched-control studies demonstrated a significant increase in CIMT of 36% and 22% (p = 0.003 and <0.001, respectively). Early prospective data demonstrated a significant increase in CIMT in irradiated arteries at 1 and 2 years after RT (p < 0.001 and <0.01, respectively). Conclusions: The incidence of stroke was significantly increased in patients receiving RT to the neck. There was a consistent difference in CAS and CIMT between irradiated and unirradiated carotid arteries. Future studies should optimise control groups

Ultrasonography in Obstertrics

International Nuclear Information System (INIS)

Lee, Hyon U.

1982-01-01

The usefulness of pulse-echo ultrasonography of the practices of obstetrics has been great. It is more reliable than many biochemical and biophysical technics that have been developed in recent years to try to improve pregnancy outcome. When carefully performed and accurately interpreted, it can supply most vital information about the status of the fetus without any known risks to both mother and the fetus itself. The main obstertricalindications of ultrasonography coule be summarized as follows. 1. Diagnosis of early pregnancy. 2. Fetal growth and its maturity. 3. Complications of pregnancy and abnormal pregnancy. a) Vaginal bleeding in early intrauterinepregnancy. b) Multiple pregnancy. c) Ectopic pregnancy d) Hydatidiform mole e) Pelvic mass complicated with pregnancy f) Fetal anomaly 4. Fetal presenation and attitude 5. Placentography

Optically neuronavigated ultrasonography in an intraoperative magnetic resonance imaging environment.

Science.gov (United States)

Katisko, Jani P A; Koivukangas, John P

2007-04-01

To develop a clinically useful method that shows the corresponding planes of intraoperative two-dimensional ultrasonography and intraoperative magnetic resonance imaging (MRI) scans determined with an optical neuronavigator from an intraoperative three-dimensional MRI scan data set, and to determine the qualitative and the quantitative spatial correspondence between the ultrasonography and MRI scans. An ultrasound probe was interlinked with an ergonomic and MRI scan-compatible ultrasonography probe tracker to the optical neuronavigator used in a low-field intraoperative MRI scan environment for brain surgery. Spatial correspondence measurements were performed using a custom-made ultrasonography/MRI scan phantom. In this work, instruments to combine intraoperatively collected ultrasonography and MRI scan data with an optical localization method in a magnetic environment were developed. The ultrasonography transducer tracker played an important role. Furthermore, a phantom for ultrasonography and MRI scanning was produced. This is the first report, to our knowledge, regarding the possibility of combining the two most important intraoperative imaging modalities used in neurosurgery, ultrasonography and MRI scanning, to guide brain tumor surgery. The method was feasible and, as shown in an illustrative surgical case, has direct clinical impact on image-guided brain surgery. The spatial deviation between the ultrasonography and the MRI scans was, on average, 1.90 +/- 1.30 mm at depths of 0 to 120 mm from the ultrasonography probe. The overall result of this work is a unique method to guide the neurosurgical operation with neuronavigated ultrasonography imaging in an intraoperative MRI scanning environment. The relevance of the method is emphasized in minimally invasive neurosurgery.

Duplex ultrasound: Indications and findings in a newly created ...

African Journals Online (AJOL)

Duplex ultrasound: Indications and findings in a newly created facility at the University of Calabar Teaching Hospital, Calabar. ... It is recommended that timely referrals be made, and mobile Doppler units be acquired to save more lives and limbs in the developing world. Keywords: Calabar, deep venous thrombosis, duplex ...

Ultrasonography in abdominal emergencies

International Nuclear Information System (INIS)

Risi, D.; Alessi, G.; Meli, C.; Marzano, M.; Fiori, E.; Caterino, S.

1989-01-01

From February 1986 to March 1988 113 abdominal US exams were performed in emergency situation to evaluate the accuracy of this methodology: 13 were blunt traumas, 18 post-operative complications. A real-time scanner with a linear probe of 5 MHz was employed. The results were confirmed by surgical and/or clinical and instrumental evaluation. In 81% of the examinations, ultrasonography allowed a diagnosis to be made. Gallbladder and biliary pathologies were the most common findings. The results (sensibility 96%, specificity 88%, accuracy 95%) confirm the affidability of ultrasonography in abdominal emergencies, as shown in literature

An unusual mode of DNA duplex association: Watson-Crick interaction of all-purine deoxyribonucleic acids.

Science.gov (United States)

Battersby, Thomas R; Albalos, Maria; Friesenhahn, Michel J

2007-05-01

Nucleic acid duplexes associating through purine-purine base pairing have been constructed and characterized in a remarkable demonstration of nucleic acids with mixed sequence and a natural backbone in an alternative duplex structure. The antiparallel deoxyribose all-purine duplexes associate specifically through Watson-Crick pairing, violating the nucleobase size-complementarity pairing convention found in Nature. Sequence-specific recognition displayed by these structures makes the duplexes suitable, in principle, for information storage and replication fundamental to molecular evolution in all living organisms. All-purine duplexes can be formed through association of purines found in natural ribonucleosides. Key to the formation of these duplexes is the N(3)-H tautomer of isoguanine, preferred in the duplex, but not in aqueous solution. The duplexes have relevance to evolution of the modern genetic code and can be used for molecular recognition of natural nucleic acids.

Two-dimensional 1H and 31P NMR spectra of a decamer oligodeoxyribonucleotide duplex and a quinoxaline ([MeCys3, MeCys7]TANDEM) drug duplex complex

International Nuclear Information System (INIS)

Powers, R.; Olsen, R.K.; Gorenstein, D.G.

1989-01-01

Assignment of the 1H and 31P NMR spectra of a decamer oligodeoxyribonucleotide duplex, d(CCCGATCGGG), and its quinoxaline ([MeCys3, MeCys7]TANDEM) drug duplex complex has been made by two-dimensional 1H-1H and heteronuclear 31P-1H correlated spectroscopy. The 31P chemical shifts of this 10 base pair oligonucleotide follow the general observation that the more internal the phosphate is located within the oligonucleotide sequence, the more upfield the 31P resonance occurs. While the 31P chemical shifts show sequence-specific variations, they also do not generally follow the Calladine rules previously demonstrated. 31P NMR also provides a convenient monitor of the phosphate ester backbone conformational changes upon binding of the drug to the duplex. Although the quinoxaline drug, [MeCys3, MeCys7]TANDEM, is generally expected to bind to duplex DNA by bis-intercalation, only small 31P chemical shift changes are observed upon binding the drug to duplex d(CCCGATCGGG). Additionally, only small perturbations in the 1H NMR and UV spectra are observed upon binding the drug to the decamer, although association of the drug stabilizes the duplex form relative to the other states. These results are consistent with a non-intercalative mode of association of the drug. Modeling and molecular mechanics energy minimization demonstrate that a novel structure in which the two quinoxaline rings of the drug binds in the minor groove of the duplex is possible

Criteria for the Segmentation of Vowels on Duplex Oscillograms.

Science.gov (United States)

Naeser, Margaret A.

This paper develops criteria for the segmentation of vowels on duplex oscillograms. Previous vowel duration studies have primarily used sound spectrograms. The use of duplex oscillograms, rather than sound spectrograms, permits faster production (real time) at less expense (adding machine paper may be used). The speech signal can be more spread…

Diagnostic nerve ultrasonography; Diagnostische Nervensonographie

Energy Technology Data Exchange (ETDEWEB)

Baeumer, T. [Universitaet zu Luebeck CBBM, Haus 66, Institut fuer Neurogenetik, Luebeck (Germany); Grimm, A. [Universitaetsklinikum Tuebingen, Klinik und Poliklinik fuer Neurologie, Tuebingen (Germany); Schelle, T. [Staedtisches Klinikum Dessau, Neurologische Klinik, Dessau (Germany)

2017-03-15

For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. Using ultrasonography for peripheral nerve diagnostics. With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves. (orig.) [German] Fuer die Diagnostik von Nervenlaesionen ist ein bildgebendes Verfahren zur Darstellung des peripheren Nervs und seiner ihn umgebenden Strukturen fuer eine aetiologische Einordnung erforderlich. Mit der klinisch-neurologischen Untersuchung und Elektrophysiologie ist eine funktionelle Aussage ueber die Nervenlaesion moeglich. In der Standard-MRT-Untersuchung wird der periphere Nerv nur unzureichend gut dargestellt. Die MRT-Neurographie ist ein sehr gutes, aber auch zeit- und ressourcenintensives Verfahren. Nutzung des Ultraschalls fuer die

Kronisk tarmiskæmi hos en yngre patient

DEFF Research Database (Denmark)

Hansen, Lars Koch; Kammerlander, Heidi; Cecere, Stefano

2012-01-01

A 46 year-old woman presented with classic symptoms. Computed tomography-angiography and duplex ultrasonography showed stenosis of the aa. mesenteria superior et inferior. The patient was moved to a university hospital and a percutaneous transluminal angioplasty with insertion of stents was perfo......A 46 year-old woman presented with classic symptoms. Computed tomography-angiography and duplex ultrasonography showed stenosis of the aa. mesenteria superior et inferior. The patient was moved to a university hospital and a percutaneous transluminal angioplasty with insertion of stents...... was performed. She was discharged shortly after feeling well....

Duplex-guided percutaneous transluminal angioplasty in iliac arterial occlusive disease.

Science.gov (United States)

Krasznai, A G; Sigterman, T A; Welten, R J; Heijboer, R; Sikkink, C J J M; van de Akker, L H J M; Bouwman, L H

2013-11-01

Chronic renal insufficiency (CRI) is a growing global problem. PTA can be performed without nephrotoxic contrast, utilizing Doppler-ultrasound (Duplex) guidance. Duplex-guided infra-inguinal interventions and access-related interventions have been reported. Duplex-guided iliac interventions have not been performed to any extent because of the anatomic location. In our study we evaluated the safety and efficacy of Duplex-guided percutaneous transluminal angioplasty (DuPTA) in iliac arteries. From June 2012 until February 2013, 31 patients (35 iliac lesions), underwent DuPTA. Indications ranged from Rutherford 3 to 5. Preoperative evaluation included Ankle Brachial Index (ABI), Duplex and MRA. Procedural success was defined as crossing the lesion with a guidewire and dilating or stenting the lesion. Clinical success was defined as 50% reduction in peak systolic velocity (PSV) or clinical improvement. PSV was evaluated after PTA, then at 2 weeks. Clinical results were assessed 2 weeks after the procedure. Procedural success was achieved in 94% of patients (33/35), all of whom also had clinical success. Post-procedural PSV reduction showed an average improvement of 63% (431 cm/s to 153 cm/s). Mean preoperative ABI was 0.72 and improved to 0.88 postoperatively. PTA using Duplex-guidance in significant iliac stenosis is a safe method with major advantages in patients at high risk for developing contrast-induced nephropathy. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Carotid chemoreceptor development and neonatal apnea.

Science.gov (United States)

MacFarlane, Peter M; Ribeiro, Ana P; Martin, Richard J

2013-01-01

The premature transition from fetal to neonatal life is accompanied by an immature respiratory neural control system. Most preterm infants exhibit recurrent apnea, resulting in repetitive oscillations in O(2) saturation (intermittent hypoxia, IH). Numerous factors are likely to play a role in the etiology of apnea including inputs from the carotid chemoreceptors. Despite major advances in our understanding of carotid chemoreceptor function in the early neonatal period, however, their contribution to the initiation of an apneic event and its eventual termination are still largely speculative. Recent findings have provided a detailed account of the postnatal changes in the incidence of hypoxemic events associated with apnea, and there is anecdotal evidence for a positive correlation with carotid chemoreceptor maturation. Furthermore, studies on non-human animal models have shown that chronic IH sensitizes the carotid chemoreceptors, which has been proposed to perpetuate the occurrence of apnea. An alternative hypothesis is that sensitization of the carotid chemoreceptors could represent an important protective mechanism to defend against severe hypoxemia. The purpose of this review, therefore, is to discuss how the carotid chemoreceptors may contribute to the initiation and termination of an apneic event in the neonate and the use of xanthine therapy in the prevention of apnea. Published by Elsevier B.V.

A Full-Duplex MAC Tailored for 5G Wireless Networks

Directory of Open Access Journals (Sweden)

Lucas de Melo Guimarães

2018-01-01

Full Text Available The increasing demands for high-data rate traffic stimulated the development of the fifth-generation (5G mobile networks. The envisioned 5G network is expected to meet its challenge by devising means to further improve spectrum usage. Many alternatives to enhance spectrum usage are being researched, such as massive MIMO, operation in mmWave frequency, cognitive radio, and the employment of full-duplex antennas. Efficient utilization of the potential of any of these technologies faces a set of challenges related to medium access control (MAC schemes. This work focuses on MAC schemes tailored for full-duplex antennas, since they are expected to play a major role in the foreseeable 5G networks. In this context, this paper presents a MAC layer technique to improve total transmission time when full-duplex antennas are employed. Several evaluations in different scenarios are conducted to assess the proposed MAC scheme. Numerical results show that the proposed scheme provides gains up to 156% when compared to a state-of-the-art full-duplex antenna MAC protocol. Compared to traditional half-duplex antenna MAC protocols, the proposed scheme yields gain up to 412%.

Stroke prevention-surgical and interventional approaches to carotid stenosis

Directory of Open Access Journals (Sweden)

Kumar Rajamani

2013-01-01

Full Text Available Extra cranial carotid artery stenosis is an important cause of stroke, which often needs treatment with carotid revascularization. To prevent stroke recurrence, carotid endarterectomy (CEA has been well-established for several decades for symptomatic high and moderate grade stenosis. Carotid stenting is a less invasive alternative to CEA and several recent trials have compared the efficacy of the 2 procedures in patients with carotid stenosis. Carotid artery stenting has emerged as a potential mode of therapy for high surgical risk patients with symptomatic high-grade stenosis. This review focuses on the current data available that will enable the clinician to decide optimal treatment strategies for patients with carotid stenosis.

Analysing Self Interference Cancellation in Full Duplex Radios

DEFF Research Database (Denmark)

Mahmood, Nurul Huda; Shafique Ansari, Imran; Berardinelli, Gilberto

2016-01-01

Full duplex communication promises a theoretical $100\\%$ throughput gain by doubling the number of simultaneous transmissions. Such compelling gains are conditioned on perfect cancellation of the self interference power resulting from simultaneous transmission and reception. Generally, self...... interference power is modelled as a noise-like constant level interference floor. However, experimental validations have shown that the self interference power is in practice a random variable depending on a number of factors such as the surrounding wireless environment and the degree of interference...... cancellation. In this study, we derive an analytical model for the residual self interference power, and demonstrate various applications of the derived model in analysing the performance of a Full Duplex radio. In general, full duplex communication is found to provide only modest throughput gains over half...

Nanopore Analysis of the 5-Guanidinohydantoin to Iminoallantoin Isomerization in Duplex DNA.

Science.gov (United States)

Zeng, Tao; Fleming, Aaron M; Ding, Yun; Ren, Hang; White, Henry S; Burrows, Cynthia J

2018-04-06

In DNA, guanine oxidation yields diastereomers of 5-guanidinohydantoin (Gh) as one of the major products. In nucleosides and single-stranded DNA, Gh is in a pH-dependent equilibrium with its constitutional isomer iminoallantoin (Ia). Herein, the isomerization reaction between Gh and Ia was monitored in duplex DNA using a protein nanopore by measuring the ionic current when duplex DNA interacts with the pore under an electrophoretic force. Monitoring current levels in this single-molecule method proved to be superior for analysis of population distributions in an equilibrating mixture of four isomers in duplex DNA as a function of pH. The results identified Gh as a major isomer observed when base paired with A, C, or G at pH 6.4-8.4, and Ia was a minor isomer of the reaction mixture that was only observed when the pH was >7.4 in the duplex DNA context. The present results suggest that Gh will be the dominant isomer in duplex DNA under physiological conditions regardless of the base-pairing partner in the duplex.

Development of oxide dispersion strengthened 2205 duplex stainless steel composite

Directory of Open Access Journals (Sweden)

Oladayo OLANIRAN

2015-05-01

Full Text Available Composites of duplex stainless steel were produced by oxide dispersion strengthening with comparatively improved mechanical properties by hot press sintering of partially stabilized Zirconia (PSZ, 3% yttria, mole fraction dispersion in 2205 duplex stainless steels. Ceramic oxide was added as reinforcement, while chromium (Cr and Nickel (Ni were incorporated to maintain the austenitic/ferritic phase balance of the duplex stainless steel. The powders and sintered were characterized in detail using scanning electron microscopy (SEM and X-ray diffraction (XRD. The microstructural evolution and phase formation during oxide dispersion strengthening of duplex stainless steel composites were investigated. The influence of composition variation of the reinforcements on the microstructural and corrosion behaviour in simulated mine water of the composites were investigated. In this manuscript, it was established that composition has great influence on the structure/properties relationship of the composites developed.

Artificial Intelligence Estimation of Carotid-Femoral Pulse Wave Velocity using Carotid Waveform.

Science.gov (United States)

Tavallali, Peyman; Razavi, Marianne; Pahlevan, Niema M

2018-01-17

In this article, we offer an artificial intelligence method to estimate the carotid-femoral Pulse Wave Velocity (PWV) non-invasively from one uncalibrated carotid waveform measured by tonometry and few routine clinical variables. Since the signal processing inputs to this machine learning algorithm are sensor agnostic, the presented method can accompany any medical instrument that provides a calibrated or uncalibrated carotid pressure waveform. Our results show that, for an unseen hold back test set population in the age range of 20 to 69, our model can estimate PWV with a Root-Mean-Square Error (RMSE) of 1.12 m/sec compared to the reference method. The results convey the fact that this model is a reliable surrogate of PWV. Our study also showed that estimated PWV was significantly associated with an increased risk of CVDs.

Insulin sensitivity and carotid intima-media thickness

DEFF Research Database (Denmark)

Kozakova, Michaela; Natali, Andrea; Dekker, Jacqueline

2013-01-01

Despite a wealth of experimental data in animal models, the independent association of insulin resistance with early carotid atherosclerosis in man has not been demonstrated. APPROACH AND RESULTS: We studied a European cohort of 525 men and 655 women (mean age, 44±8 years) free of conditions known...... to affect carotid wall (diabetes mellitus, hypertension, and dyslipidemia). All subjects received an oral glucose tolerance test, a euglycemic hyperinsulinemic clamp (M/I as a measure of insulin sensitivity), and B-mode carotid ultrasound. In 833 participants (380 men), the carotid ultrasound was repeated...

Measuring secondary phases in duplex stainless steels

Science.gov (United States)

Calliari, I.; Brunelli, K.; Dabalà, M.; Ramous, E.

2009-01-01

The use of duplex stainless steels is limited by their susceptibility to the formation of dangerous intermetallic phases resulting in detrimental effects on impact toughness and corrosion resistance. This precipitation and the quantitative determinations of the phases have received considerable attention and different precipitation sequences (σ phase, χ phase, and carbides) have been suggested. This study investigates the phase transformation during continuous cooling and isothermal treatments in commercial duplex stainless steel grades and the effects on alloy properties, and compares the most common techniques of analysis.

Cerebral intolerance during flow arrested carotid angioplasty.

Science.gov (United States)

St Louis, Myron; Park, Brian D; Dahn, Michael; Bozeman, Patricia

2012-01-01

The use of flow arrest as a means of providing cerebral protection during carotid angioplasty offers the advantages of improved efficiency of debris removal and the ability to provide protection under unfavorable (tortuous) anatomic circumstances. However, in contrast to the filtration methods of cerebral protection, this modality requires complete interruption of antegrade carotid artery flow during balloon angioplasty and stent deployment. We report our experience with 9 patients undergoing carotid angioplasty with the Mo.Ma device, which utilizes common and external carotid artery balloon occlusion during the angioplasty procedure. We assessed the clinical outcomes and intraprocedural hemodynamic data. The average duration of carotid occlusion was 8.3 minutes. Of the 9 patients, 2 patients (22%) experienced cerebral intolerance. No stroke occurred in this patient cohort. There appeared to be a poor relationship between procedure intolerance and the presence of significant contralateral stenosis or low carotid back pressure. Furthermore, the incidence of postangioplasty hypotension was not clearly related to cerebral intolerance. Carotid angioplasty with stenting can be safely conducted with flow arrest as an alternative to filter-type cerebral protection devices. However, because cerebral intolerance is not an infrequent occurrence with this approach, clinicians must be cognizant of management strategies for transient cerebral intolerance.

Emergency surgeon-performed hepatobiliary ultrasonography.

LENUS (Irish Health Repository)

Kell, M R

2012-02-03

BACKGROUND: Acute hepatobiliary pathology is a common general surgical emergency referral. Diagnosis requires imaging of the biliary tree by ultrasonography. The accuracy and impact of surgeon-performed ultrasonography (SUS) on the diagnosis of emergent hepatobiliary pathology was examined. METHODS: A prospective study, over a 6-month period, enrolled all patients with symptoms or signs of acute hepatobiliary pathology. Patients provided informed consent and underwent both SUS and standard radiology-performed ultrasonography (RUS). SUS was performed using a 2-5-MHz broadband portable ultrasound probe by two surgeons trained in ultrasonography, and RUS using a 2-5-MHz fixed unit. SUS results were correlated with those of RUS and pathological diagnoses. RESULTS: Fifty-three consecutive patients underwent 106 ultrasonographic investigations. SUS agreed with RUS in 50 (94.3 per cent) of 53 patients. SUS accurately detected cholelithiasis in all but two cases and no patient was inaccurately diagnosed as having cholelithiasis at SUS (95.2 per cent sensitivity and 100 per cent specificity). As an overall complementary diagnostic tool SUS provided the correct diagnosis in 96.2 per cent of patients. Time to scan was significantly shorter following SUS (3.1 versus 12.0 h, P < 0.05). CONCLUSION: SUS provides a rapid and accurate diagnosis of emergency hepatobiliary pathology and may contribute to the emergency management of hepatobiliary disease.

Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares.

Science.gov (United States)

Östling, Gerd; Persson, Margaretha; Hedblad, Bo; Gonçalves, Isabel

2013-11-01

Grey scale median (GSM) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut-off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with Adobe Photoshop(®) and with Artery Measurement System (AMS) on duplex ultrasound images of 100 consecutive medium- to large-sized carotid plaques of the Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for Adobe Photoshop(®) and AMS, respectively. Mean difference was 20·45 (95% CI: 19·17-21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi-square test revealed a kappa value of 0·68 when studying quartiles of GSM. The intra-observer variability was 1·9% for AMS and 2·5% for Adobe Photoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Diagnosis and management of carotid stenosis: a review.

Science.gov (United States)

Nussbaum, E S

2000-01-01

Since its introduction in the 1950s, carotid endarterectomy has become one of the most frequently performed operations in the United States. The tremendous appeal of a procedure that decreases the risk of stroke, coupled with the large number of individuals in the general population with carotid stenosis, has contributed to its popularity. To provide optimal patient care, the practicing physician must have a firm understanding of the proper evaluation and management of carotid stenosis. Nevertheless, because of the large number of clinical trials performed over the last decade addressing the treatment of stroke and carotid endarterectomy, the care of patients with carotid stenosis remains a frequently misunderstood topic. This review summarizes the current evaluation and treatment options for carotid stenosis and provides a rational management algorithm for this prevalent disease process.

Analysis of Structural Flexibility of Damaged DNA Using Thiol-Tethered Oligonucleotide Duplexes.

Directory of Open Access Journals (Sweden)

Masashi Fujita

Full Text Available Bent structures are formed in DNA by the binding of small molecules or proteins. We developed a chemical method to detect bent DNA structures. Oligonucleotide duplexes in which two mercaptoalkyl groups were attached to the positions facing each other across the major groove were prepared. When the duplex contained the cisplatin adduct, which was proved to induce static helix bending, interstrand disulfide bond formation under an oxygen atmosphere was detected by HPLC analyses, but not in the non-adducted duplex, when the two thiol-tethered nucleosides were separated by six base pairs. When the insert was five and seven base pairs, the disulfide bond was formed and was not formed, respectively, regardless of the cisplatin adduct formation. The same reaction was observed in the duplexes containing an abasic site analog and the (6–4 photoproduct. Compared with the cisplatin case, the disulfide bond formation was slower in these duplexes, but the reaction rate was nearly independent of the linker length. These results indicate that dynamic structural changes of the abasic site- and (6–4 photoproduct-containing duplexes could be detected by our method. It is strongly suggested that the UV-damaged DNA-binding protein, which specifically binds these duplexes and functions at the first step of global-genome nucleotide excision repair, recognizes the easily bendable nature of damaged DNA.

Duplex tab exhaust nozzle

Science.gov (United States)

Gutmark, Ephraim Jeff (Inventor); Martens, Steven (nmn) (Inventor)

2012-01-01

An exhaust nozzle includes a conical duct terminating in an annular outlet. A row of vortex generating duplex tabs are mounted in the outlet. The tabs have compound radial and circumferential aft inclination inside the outlet for generating streamwise vortices for attenuating exhaust noise while reducing performance loss.

Qualitative comparison of duplex Stirling and absorption refrigerators in domestic applications

Energy Technology Data Exchange (ETDEWEB)

Shao, H. [Global Cooling BV, Zutphen (Netherlands)

2000-07-01

A qualitative comparison has been carried out between the duplex Stirling and the absorption refrigerator for domestic applications. The duplex Stirling has many advantages over the absorption refrigerator on efficiency, modulation, suitability, operating costs, pollution reduction. Based on the state of the art of free-piston gas-bearing and linear-motor Stirling engines and coolers, it appears technically and economically feasible to develop the duplex Stirling to compete with the absorption refrigerator for heat-driven domestic refrigeration. (orig.)

Association of Microalbuminuria and Estimated Glomerular Filtration Rate With Carotid Intima-Media Thickness in Patients With Type 2 Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Dehdashti Shahrokh

2015-04-01

Full Text Available Background Atherosclerosis is the main cause of cardiovascular diseases, and its risk enhances in type 2 diabetes mellitus. Objectives This study aimed to evaluate Carotid Intima-Media Thickness (CIMT by carotid artery ultrasonography and assess its correlation with microalbuminuria and estimated Glomerular Filtration Rate (eGFR in the patients with type 2 diabetes mellitus. Patients and Methods This cross-sectional study was included 205 patients with Type 2 Diabetes Mellitus (T2DM. We recorded clinical and biochemical data such as FBS, lipid profile, and urinary albumin. Intima-media thickness of carotid arteries was measured in all patients by high frequency ultrasound. Results In simple correlation coefficients analysis, CIMT was significantly associated with total cholesterol (r = 0.197, P = 0.008, serum creatinine (r = 0.240, P = 0.001, and urinary albumin (r = 0.420, P = 0.000. Also, CIMT elevated significantly with the stage progression of chronic kidney disease (0.67 ± 0.15 mm in stage 1, 0.73 ± 0.22 mm in stage 2, and 0.82 ± 0.21 mm in stage 3 (P value = 0.024. In multivariate linear regression analysis, the duration of diabetes, weight, HDL, serum creatinine, urinary albumin, and estimated Glomerular Filtration Rate (eGFR were independently associated with CIMT (P value < 0.05 for all. Conclusions Our study shows a relationship between CIMT and renal parameters, including eGFR and albuminuria. This study confirms the importance of intensive examinations for early detection of atherosclerosis and treatment of risk factors.

Angiographic patterns of carotid-cavernous fistulas

International Nuclear Information System (INIS)

Georgieva, G.; Jekova, M.; Genov, P.; Hadjidekov, V.

2006-01-01

Full text: The aim of the study is to present our experience in angiographic evaluation of carotid-cavernous fistulas. 8 patients with carotid-cavernous fistula (6 men and 2 women, range of age from 15 to 62) are included in the study out of all undergone cerebral angiography for a four year period (1996 - 2000). All patients underwent CT brain examination, two out of 8 - MRI. Visualization of ipsi- and contra lateral cavernous sinus and ophthalmic vein dilatation are assessed. In all cases the communication between the internal carotid artery and the cavernous sinus has been assessed as direct. Near simultaneous visualization of the home internal carotid artery, the dilated ipsilateral cavernous sinus and dilated superior ophthalmic vein is found in 2 patients, simultaneous visualization of both cavernous sinuses - in two. In 1 patient the early visualization of the cavernous sinus through the fistula enabled visualization of ipsilateral main internal carotid artery from the contra lateral circulation through the communicating arteries.In 1 excessive contralateral cavernous sinus and contralateral superior ophthalmic vein dilatation is detected. In other 1 excessive flow to dilated ipsilateral cavernous sinus lead insufficient circulation in distal vessels. Digital subtraction Angiography remains the most suitable imaging method in carotid-cavernous fistula assessment regarding type of communication and level of following vessels morphology changes

Transabdominal Ultrasonography of the Small Bowel

Directory of Open Access Journals (Sweden)

Rudolf Kralik

2013-01-01

Full Text Available In the era of double balloon enteroscopy, capsule endoscopy, CT, and MRI enterography is transabdominal ultrasonography (TUS underestimated method for evaluation of small bowel pathology. As often initial imagine method in abdominal complaints, nowadays has TUS much better diagnostic potential than two decades ago. High-resolution ultrasound probes with harmonic imaging significantly improve resolution of bowel wall in real time, with possibility to asses bowel peristalsis. Color flow doppler enables evaluation of intramural bowel vascularisation, pulse wave doppler helps to quantificate flow in coeliac and superior mesenteric arteries. Small intestine contrast ultrasonography with oral contrast fluid, as well as contrast enhanced ultrasonography with intravenous microbubble contrast also improves small bowel imaging. We present a review of small intestine pathology that should be detected during ultrasound examinations, discuss technical requirements, advantages and limitations of TUS, typical ultrasound signs of Crohn's disease, ileus, celiac disease, intussusception, infectious enteritis, tumours, ischemic and haemorrhagic conditions of small bowel. In the hands of experienced investigator, despite some significant limitations(obesity, meteorism, is transabdominal ultrasonography reliable, noninvasive and inexpensive alternative method to computerised tomography (CT and magnetic resonance imaging (MRI in small bowel examination.

Rosuvastatin-Induced Carotid Plaque Regression in Patients With Inflammatory Joint Diseases: The Rosuvastatin in Rheumatoid Arthritis, Ankylosing Spondylitis and Other Inflammatory Joint Diseases Study.

Science.gov (United States)

Rollefstad, S; Ikdahl, E; Hisdal, J; Olsen, I C; Holme, I; Hammer, H B; Smerud, K T; Kitas, G D; Pedersen, T R; Kvien, T K; Semb, A G

2015-07-01

Patients with rheumatoid arthritis (RA) and carotid artery plaques have an increased risk of acute coronary syndromes. Statin treatment with the goal of achieving a low-density lipoprotein (LDL) cholesterol level of ≤1.8 mmoles/liter (≤70 mg/dl) is recommended for individuals in the general population who have carotid plaques. The aim of the ROsuvastatin in Rheumatoid Arthritis, Ankylosing Spondylitis and other inflammatory joint diseases (RORA-AS) study was to evaluate the effect of 18 months of intensive lipid-lowering treatment with rosuvastatin with regard to change in carotid plaque height. Eighty-six patients (60.5% of whom were female) with carotid plaques and inflammatory joint disease (55 with RA, 21 with AS, and 10 with psoriatic arthritis) were treated with rosuvastatin to obtain the LDL cholesterol goal. Carotid plaque height was evaluated by B-mode ultrasonography. The mean ± SD age of the patients was 60.8 ± 8.5 years, and the median compliance with rosuvastatin treatment was 97.9% (interquartile range [IQR] 96.0-99.4). At baseline, the median number and height of the carotid plaques were 1.0 (range 1-8) and 1.80 mm (IQR 1.60-2.10), respectively. The mean ± SD change in carotid plaque height after 18 months of treatment with rosuvastatin was -0.19 ± 0.35 mm (P < 0.0001). The mean ± SD baseline LDL cholesterol level was 4.0 ± 0.9 mmoles/liter (154.7 ± 34.8 mg/dl), and the mean reduction in the LDL cholesterol level was -2.3 mmoles/liter (95% confidence interval [95% CI] -2.48, -2.15) (-88.9 mg/dl [95% CI -95.9, -83.1]). The mean ± SD LDL cholesterol level during the 18 months of rosuvastatin treatment was 1.7 ± 0.4 mmoles/liter (area under the curve). After adjustment for age/sex/blood pressure, no linear relationship between a reduction in carotid plaque height and the level of LDL cholesterol exposure during the study period was observed. Attainment of the LDL cholesterol goal of ≤1.8 mmoles/liter (≤70

Carotid endarterectomy in patients with occlusion of the contralateral carotid artery. Perioperative risk and late results

DEFF Research Database (Denmark)

Sillesen, H; Schroeder, T; Rasmussen, L

1987-01-01

severe strokes when compared to patients with only minor reduction in CPP. In addition, the internal carotid artery blood flow following endarterectomy was significantly higher in the low pressure group (P less than 0.02). No patients were lost during follow-up, for a mean of 34 months. The cumulative....... Compared with a complication rate of about 5% previously reported from this institution, this clearly indicates contralateral carotid occlusion as a major risk factor in carotid surgery. Though not statistically significant, patients with severely reduced cerebral perfusion pressure (CPP) had suffered more...

Effect of non-alcoholic fatty liver disease on carotid artery intima-media thickness as a risk factor for atherosclerosis

Science.gov (United States)

Nahandi, Maryam Zaare; Ramazanzadeh, Elham; Abbaszadeh, Leili; Javadrashid, Reza; Shirazi, Koorosh Masnadi; Gholami, Nasrin

2014-01-01

Aim This study aimed to evaluate the effect of NAFLD on CIMT as a risk factor for atherosclerosis. Background The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide due to rise of obesity and diabetes mellitus (DM) prevalence. Non-invasive assessment of carotid intima-media thickness (CIMT) by high-resolution carotid B-mode ultrasonography is widely used for determining the atherosclerosis. Patients and methods In this case-control setting, 151 subjects were categorized in three groups: group I including 49 patients with NAFLD and DM; group II including 50 non-diabetic NAFLD patients; and the control including 52 normal subjects as group III. The right and left CIMTs and its maximum reading (CIMTmax) were measured by a skilled sonographist blind to the groups. The sonographic grading of the NAFLD was determined in group I and II. Results Median CIMTmax was significantly higher in group I comparing with group II and control group (pliver enzymes (in both groups, 0.6 mm, p= 0.402). Conclusion Based on our findings, there is a significant association between the presence of NAFLD and atherosclerosis. This association was independent to the DM presence. The grade of NAFLD and elevated liver function tests had no effect on severity of atherosclerosis. PMID:25436098

A Dual-Specific Targeting Approach Based on the Simultaneous Recognition of Duplex and Quadruplex Motifs.

Science.gov (United States)

Nguyen, Thi Quynh Ngoc; Lim, Kah Wai; Phan, Anh Tuân

2017-09-20

Small-molecule ligands targeting nucleic acids have been explored as potential therapeutic agents. Duplex groove-binding ligands have been shown to recognize DNA in a sequence-specific manner. On the other hand, quadruplex-binding ligands exhibit high selectivity between quadruplex and duplex, but show limited discrimination between different quadruplex structures. Here we propose a dual-specific approach through the simultaneous application of duplex- and quadruplex-binders. We demonstrated that a quadruplex-specific ligand and a duplex-specific ligand can simultaneously interact at two separate binding sites of a quadruplex-duplex hybrid harbouring both quadruplex and duplex structural elements. Such a dual-specific targeting strategy would combine the sequence specificity of duplex-binders and the strong binding affinity of quadruplex-binders, potentially allowing the specific targeting of unique quadruplex structures. Future research can be directed towards the development of conjugated compounds targeting specific genomic quadruplex-duplex sites, for which the linker would be highly context-dependent in terms of length and flexibility, as well as the attachment points onto both ligands.

Full-Duplex opportunistic relay selection in future spectrum-sharing networks

KAUST Repository

Khafagy, Mohammad Galal; Alouini, Mohamed-Slim; Aï ssa, Sonia

2015-01-01

We propose and analyze the performance of full-duplex relay selection in primary/secondary spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay, thereby allowing for a higher spectral efficiency. However, since the source and relay simultaneously transmit in FDR, their superimposed signal at the primary receiver should now satisfy the existing interference constraint which can considerably limit the secondary network throughput. In this regard, relay selection can offer an adequate solution to boost the secondary throughput while satisfying the imposed interference limit. We first analyze the performance of opportunistic relay selection among a cluster of full-duplex decode-and-forward relays with self-interference by deriving the exact cumulative distribution function of its end-to-end signal-to-noise ratio. Second, we evaluate the end-to-end performance of relay selection with interference constraints due to the presence of a primary receiver. Finally, the presented exact theoretical findings are verified by numerical simulations.

Full-Duplex opportunistic relay selection in future spectrum-sharing networks

KAUST Repository

Khafagy, Mohammad Galal

2015-06-01

We propose and analyze the performance of full-duplex relay selection in primary/secondary spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay, thereby allowing for a higher spectral efficiency. However, since the source and relay simultaneously transmit in FDR, their superimposed signal at the primary receiver should now satisfy the existing interference constraint which can considerably limit the secondary network throughput. In this regard, relay selection can offer an adequate solution to boost the secondary throughput while satisfying the imposed interference limit. We first analyze the performance of opportunistic relay selection among a cluster of full-duplex decode-and-forward relays with self-interference by deriving the exact cumulative distribution function of its end-to-end signal-to-noise ratio. Second, we evaluate the end-to-end performance of relay selection with interference constraints due to the presence of a primary receiver. Finally, the presented exact theoretical findings are verified by numerical simulations.

[A Duplex PCR Method for Detection of Babesia caballi and Theileria equi].

Science.gov (United States)

Zhang, Yang; Zhang, Yu-ting; Wang, Zhen-bao; Bolati; Li, Hai; Bayinchahan

2015-04-01

To develop a duplex PCR assay for detection of Babesia caballi and Theileria equi. Two pairs of primers were designed according to the BC48 gene of B. caballi and 18 s rRNA gene of T. equi, and a duplex PCR assay was developed by the optimization of reaction conditions. The specificity, sensitivity and reliability of the method were tested. The horse blood samples of suspected cases were collected from Yili region, and detected by the duplex PCR, microspopy, conventional PCR, and fluorescence quantitative PCR, and the results were compared. Using the duplex PCR assay, the specific fragments of 155 bp and 280 bp were amplified from DNA samples of B. caballi and T. equi, respectively. No specific fragment was amplified from DNA samples of B. bigemina, Theilerdia annulata, Theilerdia sergenti, Toxoplasma gondii, Neospora caninum, and Trypanosoma evansi. The limit of detection was 4.85 x 10(5) copies/L for B. caballi DNA and 4.85 x 10(4) copies/µl for T. equi DNA, respectively. Among the 24 blood samples, 11 were found B. caballi-positive by the duplex PCR assay, and 18 were T. equi-positive. The coincidence rate of microscopy, conventional PCR, and fluorescence quantitative PCR with duplex PCR was 91.7% (22/24), 95.8% (23/24), and 95.8% (23/24), respectively. A duplex PCR assay for simultaneous detection of B. caballi and T. equi is established.

Long-term outcomes after stenting versus endarterectomy for treatment of symptomatic carotid stenosis: the International Carotid Stenting Study (ICSS) randomised trial

NARCIS (Netherlands)

Bonati, Leo H.; Dobson, Joanna; Featherstone, Roland L.; Ederle, Jörg; van der Worp, H. Bart; de Borst, Gert J.; Mali, Willem P. Th M.; Beard, Jonathan D.; Cleveland, Trevor; Engelter, Stefan T.; Lyrer, Philippe A.; Ford, Gary A.; Dorman, Paul J.; Brown, Martin M.; Bamford, J.; Beard, J.; Bland, M.; Bradbury, A. W.; Brown, M. M.; Hacke, W.; Halliday, A.; Malik, I.; Mas, J. L.; McGuire, A. J.; Sidhu, P.; Venables, G.; Clifton, A.; Gaines, P.; Collins, R.; Molyneux, A.; Naylor, R.; Warlow, C.; Ferro, J. M.; Thomas, D.; Coward, L.; Dobson, J.; Doig, D.; Ederle, J.; Featherstone, R. F.; Kennedy, F.; Tindall, H.; Turner, E.; McCabe, D. J. H.; Wallis, A.; Brooks, M.; Chambers, B.; Koelemay, M. J. W.; Nederkoorn, P. J.; Reekers, J. A. A.; Roos, Y. B. W. E. M.

2015-01-01

Background Stenting is an alternative to endarterectomy for treatment of carotid artery stenosis, but long-term efficacy is uncertain. We report long-term data from the randomised International Carotid Stenting Study comparison of these treatments. Methods Patients with symptomatic carotid stenosis

Long-term outcomes after stenting versus endarterectomy for treatment of symptomatic carotid stenosis: the International Carotid Stenting Study (ICSS) randomised trial

NARCIS (Netherlands)

Bonati, L.H.; Dobson, J.; Featherstone, R.L.; Ederle, J.; Worp, H.B. van der; Borst, G.J. de; Mali, W.P.; Beard, J.D.; Cleveland, T.; Engelter, S.T.; Lyrer, P.A.; Ford, G.A.; Dorman, P.J.; Brown, M.M.; Leeuw, F.E. de; et al.,

2015-01-01

BACKGROUND: Stenting is an alternative to endarterectomy for treatment of carotid artery stenosis, but long-term efficacy is uncertain. We report long-term data from the randomised International Carotid Stenting Study comparison of these treatments. METHODS: Patients with symptomatic carotid

Development of a lean duplex stainless steel

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Liljas, M.; Johansson, P.; Liu Hui-Ping; Olsson, C.O.A. [Avesta Research Centre, Avesta (Sweden). Outokumpu Stainless

2008-06-15

The classic series of duplex stainless steels shows very high corrosion resistance and can be used for very demanding applications. A new lean duplex steel, LDX 2101 {sup registered} (EN 1.4162, UNS S32101), has been developed with corrosion resistance on a par with standard austenitic grades. Application areas include: structural components, chemical industry, tanks and containers. The steel was designed to have equal amounts of ferrite and austenite in annealed condition and with an austenite that is stable against strain-induced martensite. Thanks to its high nitrogen content, the steel has a fast austenite reformation when subjected to thermal cycling, e.g. welding. Unlike conventional duplex grades, the formation of intermetallic phase is very sluggish, although precipitation of nitrides and carbides has a certain impact on material properties after exposure in the temperature range 600 to 800 C. The precipitation behaviour after different isothermal treatments is described and its influence on different product properties is shown. A good agreement was found between impact toughness and corrosion resistance for a wide range of thermal treatments. (orig.)

Hybrid treatment of tandem, common carotid/innominate artery and ipsilateral carotid bifurcation stenoses by simultaneous, retrograde proximal stenting and eversion carotid endarterectomy: Preliminary results of a case series.

Science.gov (United States)

Illuminati, Giulio; Pizzardi, Giulia; Pasqua, Rocco; Frezzotti, Francesca; Palumbo, Piergaspare; Macrina, Francesco; Calio', Francesco

2018-04-01

Tandem stenoses of the internal carotid artery (ICA) and proximal, ipsilateral common carotid artery (CCA) or innominate artery can be treated with a hybrid approach, combining conventional carotid endarterectomy (CEA) and retrograde stenting of the proximal stenosis, through surgical exposure of the carotid bifurcation. The purpose of this study was to evaluate the results of combining eversion CEA with retrograde CCA/innominate artery stenting. From January 2015 to July 2017, 7 patients, 6 men of a mean age of 72 years (range 59-83 years) underwent simultaneous, retrograde stenting of the proximal CCA/innominate artery and an eversion CEA of the ipsilateral ICA, through surgical exposure of the carotid bifurcation, for severe tandem stenoses. The proximal stenosis involved the left proximal CCA in 4 patients, the proximal innominate artery in 2 patients and the right CCA in one patient. The procedure was performed under general anesthesia in a conventional operating room equipped with a mobile C-arm. A covered, balloon expandable stent was deployed over the proximal stenosis via a 6-F sheath directly introduced into the proximal CCA through the obliquely transected carotid bulb. After removing the sheath, debris were flushed through the carotid bulb and eversion CEA completed the procedure. Study endpoints were: postoperative stroke/mortality rate, cardiac mortality and morbidity, peripheral nerve injury, cervical hematoma, overall late survival, freedom from ipsilateral stroke and patency of arterial reconstruction. No postoperative mortality or neurologic morbidity was observed in any patient. Cervical hematomas and peripheral nerve injuries were likewise absent. At a mean follow-up of 18 months, all the patients were alive, free from neurologic events of new onset and free from restenosis. Combined proximal stenting and eversion CEA for tandem lesions seems a valid treatment, with the advantages of eversion CEA over other techniques of carotid bifurcation

Full-Duplex Communications in Large-Scale Cellular Networks

KAUST Repository

AlAmmouri, Ahmad

2016-04-01

In-band full-duplex (FD) communications have been optimistically promoted to improve the spectrum utilization and efficiency. However, the penetration of FD communications to the cellular networks domain is challenging due to the imposed uplink/downlink interference. This thesis presents a tractable framework, based on stochastic geometry, to study FD communications in multi-tier cellular networks. Particularly, we assess the FD communications effect on the network performance and quantify the associated gains. The study proves the vulnerability of the uplink to the downlink interference and shows that the improved FD rate gains harvested in the downlink (up to 97%) comes at the expense of a significant degradation in the uplink rate (up to 94%). Therefore, we propose a novel fine-grained duplexing scheme, denoted as α-duplex scheme, which allows a partial overlap between the uplink and the downlink frequency bands. We derive the required conditions to harvest rate gains from the α-duplex scheme and show its superiority to both the FD and half-duplex (HD) schemes. In particular, we show that the α-duplex scheme provides a simultaneous improvement of 28% for the downlink rate and 56% for the uplink rate. We also show that the amount of the overlap can be optimized based on the network design objective. Moreover, backward compatibility is an essential ingredient for the success of new technologies. In the context of in-band FD communication, FD base stations (BSs) should support HD users\\' equipment (UEs) without sacrificing the foreseen FD gains. The results show that FD-UEs are not necessarily required to harvest rate gains from FD-BSs. In particular, the results show that adding FD-UEs to FD-BSs offers a maximum of 5% rate gain over FD-BSs and HD-UEs case, which is a marginal gain compared to the burden required to implement FD transceivers at the UEs\\' side. To this end, we shed light on practical scenarios where HD-UEs operation with FD-BSs outperforms the

Safety of Carotid Artery Stenting in Elderly Patients with Severe Carotid Artery Stenosis

International Nuclear Information System (INIS)

Choi, Seul Kee; Kim, Seul Kee; Jeong, Min Young; Yoon, Woong

2012-01-01

To determine the safety of carotid artery stenting (CAS) using an emboli-protection device in elderly patients with severe carotid artery stenosis. Ninety consecutive patients who were at high risk for carotid endarterectomy underwent protected CAS using an emboli-protection device. Patients were divided into two groups by age: < 70 and ≥ 70. The primary outcome measure was the combined incidence of stroke, myocardial infarction (MI), and death within 30 days of CAS. The secondary outcome measures were technical success and hyperperfusion syndrome. Associations between age and the clinical outcomes were investigated. Overall, 30-day stroke, MI, and death rates were 6.7%. There was no significant difference in the primary outcome between the older age group (n = 56) and younger age group (n = 34) (8.9% and 2.9%, respectively; HR for age ≥ 70, 1.141; 95% CI, 0.875 to 1.488, p = 0.331). A logistic regression showed there was no independent variable associated with primary outcome. Technical success was achieved in all patients and there was no significant difference in the incidence of hyperperfusion syndrome between the two age groups. The results of this study suggest that protected CAS seems to be safe in elderly patients with severe carotid artery stenosis.

Angiographic diagnosis of the carotid artery pseudoaneurysm

International Nuclear Information System (INIS)

Qi Yueyong; Zou Liguang; Dai Shuhua; Tan Yinghui; Li Zhongyu; Zhou Zheng

2004-01-01

Objective: To create a further understanding of the angiographic features of the carotid artery pseudoaneurysm (CAPA) and to explore the clinical diagnostic value of angiography. Methods: Sixteen cases of CAPA with clinical and angiographic data were analyzed retrospectively. The angiographic appearances in all of the patients were observed dynamically and precisely with a double blind method by two experienced radiologists together and formed a consensus interpretation. Results: Angiography provided a definite diagnosis for all cases. The parent arteries included the common carotid artery (1 case), common carotid artery bifurcation (9 cases), internal carotid artery (5 cases) and external carotid artery (1 case). The angiographic features of the CAPA were: All cases showed the contrast media retension in the aneurysms; turbulent flow within aneurysm in 9 cases; the 'jetting sign' at the leak of the parent artery in 7 cases; increase angulation of the bifurcation of internal and external carotid arteries in 12 cases. Conclusions: Angiography is the most valuable examination method in diagnosis of CAPA, and it can not only provide definite diagnosis, but also play an important role in selection of therapeutic plan. (authors)

Ultrasensitive Detection of RNA and DNA Viruses Simultaneously Using Duplex UNDP-PCR Assay.

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Yong Huang

Full Text Available Mixed infection of multiple viruses is common in modern intensive pig rearing. However, there are no methods available to detect DNA and RNA viruses in the same reaction system in preclinical level. In this study, we aimed to develop a duplex ultrasensitive nanoparticle DNA probe-based PCR assay (duplex UNDP-PCR that was able to simultaneously detect DNA and RNA viruses in the same reaction system. PCV2 and TGEV are selected as representatives of the two different types of viruses. PCV2 DNA and TGEV RNA were simultaneously released from the serum sample by boiling with lysis buffer, then magnetic beads and gold nanoparticles coated with single and/or duplex specific probes for TGEV and PCV2 were added to form a sandwich-like complex with nucleic acids released from viruses. After magnetic separation, DNA barcodes specific for PCV2 and TGEV were eluted using DTT and characterized by specific PCR assay for specific DNA barcodes subsequently. The duplex UNDP-PCR showed similar sensitivity as that of single UNDP-PCR and was able to detect 20 copies each of PCV2 and TGEV in the serum, showing approximately 250-fold more sensitivity than conventional duplex PCR/RT-PCR assays. No cross-reaction was observed with other viruses. The positive detection rate of single MMPs- and duplex MMPs-based duplex UNDP-PCR was identical, with 29.6% for PCV2, 9.3% for TGEV and 3.7% for PCV2 and TGEV mixed infection. This duplex UNDP-PCR assay could detect TGEV (RNA virus and PCV2 (DNA virus from large-scale serum samples simultaneously without the need for DNA/RNA extraction, purification and reverse transcription of RNA, and showed a significantly increased positive detection rate for PCV2 (29% and TGEV (11.7% preclinical infection than conventional duplex PCR/RT-PCR. Therefore, the established duplex UNDP-PCR is a rapid and economical detection method, exhibiting high sensitivity, specificity and reproducibility.

Ultrasensitive Detection of RNA and DNA Viruses Simultaneously Using Duplex UNDP-PCR Assay

Science.gov (United States)

Wang, Zengguo; Zhang, Xiujuan; Zhao, Xiaomin; Du, Qian; Chang, Lingling; Tong, Dewen

2015-01-01

Mixed infection of multiple viruses is common in modern intensive pig rearing. However, there are no methods available to detect DNA and RNA viruses in the same reaction system in preclinical level. In this study, we aimed to develop a duplex ultrasensitive nanoparticle DNA probe-based PCR assay (duplex UNDP-PCR) that was able to simultaneously detect DNA and RNA viruses in the same reaction system. PCV2 and TGEV are selected as representatives of the two different types of viruses. PCV2 DNA and TGEV RNA were simultaneously released from the serum sample by boiling with lysis buffer, then magnetic beads and gold nanoparticles coated with single and/or duplex specific probes for TGEV and PCV2 were added to form a sandwich-like complex with nucleic acids released from viruses. After magnetic separation, DNA barcodes specific for PCV2 and TGEV were eluted using DTT and characterized by specific PCR assay for specific DNA barcodes subsequently. The duplex UNDP-PCR showed similar sensitivity as that of single UNDP-PCR and was able to detect 20 copies each of PCV2 and TGEV in the serum, showing approximately 250-fold more sensitivity than conventional duplex PCR/RT-PCR assays. No cross-reaction was observed with other viruses. The positive detection rate of single MMPs- and duplex MMPs-based duplex UNDP-PCR was identical, with 29.6% for PCV2, 9.3% for TGEV and 3.7% for PCV2 and TGEV mixed infection. This duplex UNDP-PCR assay could detect TGEV (RNA virus) and PCV2 (DNA virus) from large-scale serum samples simultaneously without the need for DNA/RNA extraction, purification and reverse transcription of RNA, and showed a significantly increased positive detection rate for PCV2 (29%) and TGEV (11.7%) preclinical infection than conventional duplex PCR/RT-PCR. Therefore, the established duplex UNDP-PCR is a rapid and economical detection method, exhibiting high sensitivity, specificity and reproducibility. PMID:26544710

Ultrasensitive Detection of RNA and DNA Viruses Simultaneously Using Duplex UNDP-PCR Assay.

Science.gov (United States)

Huang, Yong; Xing, Na; Wang, Zengguo; Zhang, Xiujuan; Zhao, Xiaomin; Du, Qian; Chang, Lingling; Tong, Dewen

2015-01-01

Mixed infection of multiple viruses is common in modern intensive pig rearing. However, there are no methods available to detect DNA and RNA viruses in the same reaction system in preclinical level. In this study, we aimed to develop a duplex ultrasensitive nanoparticle DNA probe-based PCR assay (duplex UNDP-PCR) that was able to simultaneously detect DNA and RNA viruses in the same reaction system. PCV2 and TGEV are selected as representatives of the two different types of viruses. PCV2 DNA and TGEV RNA were simultaneously released from the serum sample by boiling with lysis buffer, then magnetic beads and gold nanoparticles coated with single and/or duplex specific probes for TGEV and PCV2 were added to form a sandwich-like complex with nucleic acids released from viruses. After magnetic separation, DNA barcodes specific for PCV2 and TGEV were eluted using DTT and characterized by specific PCR assay for specific DNA barcodes subsequently. The duplex UNDP-PCR showed similar sensitivity as that of single UNDP-PCR and was able to detect 20 copies each of PCV2 and TGEV in the serum, showing approximately 250-fold more sensitivity than conventional duplex PCR/RT-PCR assays. No cross-reaction was observed with other viruses. The positive detection rate of single MMPs- and duplex MMPs-based duplex UNDP-PCR was identical, with 29.6% for PCV2, 9.3% for TGEV and 3.7% for PCV2 and TGEV mixed infection. This duplex UNDP-PCR assay could detect TGEV (RNA virus) and PCV2 (DNA virus) from large-scale serum samples simultaneously without the need for DNA/RNA extraction, purification and reverse transcription of RNA, and showed a significantly increased positive detection rate for PCV2 (29%) and TGEV (11.7%) preclinical infection than conventional duplex PCR/RT-PCR. Therefore, the established duplex UNDP-PCR is a rapid and economical detection method, exhibiting high sensitivity, specificity and reproducibility.

Considerations in Duplex Investment.

Science.gov (United States)

Wright, Arthur; Goen, Tom

Problems of duplex investment are noted in the introduction to this booklet designed to provide a technique by which the investment decision can be approached, develop estimates of typical costs and returns under differing conditions, and encourage investors to analyze objectives and conditions before the decision to buy or build is made. A…

Characteristics of Carotid Artery Structure and Mechanical Function and Their Relationships with Aortopathy in Patients with Bicuspid Aortic Valves

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Mihyun Kim

2017-08-01

Full Text Available Patients with a bicuspid aortic valve (BAV often have proximal aortic dilatation and systemic vascular dysfunction. We hypothesized that BAV patients would have different carotid artery structural and functional characteristics compared to tricuspid aortic valve (TAV patients. In 28 patients with surgically confirmed BAV and 27 patients with TAV, intima media thickness (IMT, number of plaques, fractional area change (FAC, global circumferential strain (GCS, and standard deviation of CS (SD-CS in both common carotid arteries were assessed using duplex ultrasound and velocity vector imaging (VVI. Patients with BAV were younger and had less co-morbidity, but showed a significantly larger ascending aorta (43.3 ± 7.5 vs. 37.0 ± 6.2 mm, p < 0.001 and a higher prevalence of aortopathy (61 vs. 30%, p = 0.021 than those with TAV. BAV patients showed a significantly lower IMT and fewer plaques. Although FAC and GCS were not significantly different between the two groups, they tended to be lower in the BAV group when each group was divided into three subgroups according to age. There was a significant age-dependent increase in IMT and decreases in FAC and GCS in the TAV group (p = 0.005, p = 0.001, p = 0.002, respectively, but this phenomenon was not evident in the BAV group (p = 0.074, p = 0.248, p = 0.394, respectively. BAV patients with aortopathy showed a higher SD-CS than those without aortopathy (p = 0.040, reflecting disordered mechanical function. In conclusion, BAV patients have different carotid artery structure and function compared with TAV patients, suggesting intrinsic vascular abnormalities that are less affected by established cardiovascular risk factors and more strongly related to the presence of aortopathy.

Management of radiation-induced accelerated carotid atherosclerosis

International Nuclear Information System (INIS)

Loftus, C.M.; Biller, J.; Hart, M.N.; Cornell, S.H.; Hiratzka, L.F.

1987-01-01

Patients with long survival following cervical irradiation are at risk for accelerated carotid atherosclerosis. The neurologic presentation in these patients mimics naturally occurring atheromatous disease, but patients often present at younger ages and with less concurrent coronary or systemic vascular disease. Hypercholesterolemia also contributes to this accelerated arteriosclerosis. Angiographic findings in this disorder include disproportionate involvement of the distal common carotid artery and unusually long carotid lesions. Pathologic findings include destruction of the internal elastic lamina and replacement of the normal intima and media with fibrous tissue. This article describes two surgical patients with radiation-induced accelerated carotid atherosclerosis who typify the presentation and characteristics of this disease

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

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Mehmet Akif Topçuoğlu

2015-08-01

Full Text Available Transcranial Doppler ultrasonography (TCD is a valuable tool for demonstrating cerebral circulatory arrest (CCA in the setting of brain death. Complete reversal of diastolic flow (to-and-fro flow and systolic spikes in bilateral terminal internal carotid arteries and vertebrobasilar circulation are considered as specific sonogram configurations supporting the diagnosis of CCA. Because of the possibility of sonic bone window impermeability, absence of any waveform in TCD is not confirmatory for CCA unless there is documentation of disappearance of a previously well detected signal by the same recording settings. Transcranial color-coded sonography (TCCS with B-mode imaging can reliably detect adequacy of bone windows with clarity contralateral skull and ipsilateral planum temporale visualization. Therefore, absence of detectable intracranial Doppler signal along with available ultrasound window in TCCS can confirm clinical diagnosis of brain death. We herein discuss this entity from the frame of a representative case.

Effect of Cavity Size of Mesoporous Silica on Short DNA Duplex Stability.

Science.gov (United States)

Masuda, Tsubasa; Shibuya, Yuuta; Arai, Shota; Kobayashi, Sayaka; Suzuki, Sotaro; Kijima, Jun; Itoh, Tetsuji; Sato, Yusuke; Nishizawa, Seiichi; Yamaguchi, Akira

2018-05-15

We studied the stabilities of short (4- and 3-bp) DNA duplexes within silica mesopores modified with a positively charged trimethyl aminopropyl (TMAP) monolayer (BJH pore diameter 1.6-7.4 nm). The DNA fragments with fluorescent dye were introduced into the pores, and their fluorescence resonance energy transfer (FRET) response was measured to estimate the structuring energies of the short DNA duplexes under cryogenic conditions (temperature 233-323 K). The results confirmed the enthalpic stability gain of the duplex within size-matched pores (1.6 and 2.3 nm). The hybridization equilibrium constants found for the size-matched pores were 2 orders of magnitude larger than those for large pores (≥3.5 nm), and this size-matching effect for the enhanced duplex stability was explained by a tight electrostatic interaction between the duplex and the surface TMAP groups. These results indicate the requirement of the precise regulation of mesopore size to ensure the stabilization of hydrogen-bonded supramolecular assemblies.

Renal pelvis urothelial carcinoma of the upper moiety in complete right renal duplex: a case report.

Science.gov (United States)

Zhang, Yiran; Yu, Quanfeng; Zhang, Zhihong; Liu, Ranlu; Xu, Yong

2015-01-01

Urothelial carcinoma (UC) originated from renal pelvis is the common tumor of the urinary system, however, neoplasia of the renal pelvis in duplex kidneys is extremely rare, especially in the complete renal and ureteral duplex cases. We present the first case of renal pelvis UC of the upper moiety in a complete right renal duplex. This male patient has bilateral complete renal and ureteral duplex. To the best of our knowledge, this is the first reported case of renal pelvis UC in a complete renal duplex system. After this experience we feel that the diagnosis of renal pelvis UC in duplex kidneys is not so easy, and once the diagnosis is determined, the whole renal duplex units and bladder cuff or ectopic orifice should be excised radically.

A Rare Diabetic Autonomic Neuropathy: Carotid Sinus Hypersensitivity

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Ahmet Kaya

2016-03-01

Full Text Available Carotid sinus hypersensitivity is a common cause of fainting and falls in the elderly, and can be diagnosed by carotid sinus massage. We present a 67-year-old diabetic man who was admitted with hyperglycemia. During thyroid examination, clouding of consciousness occurred with unilateral palpation. Asystole was documented for 4.8 seconds and suspected for 7 seconds upon carotid sinus massage. A cardioverter defibrillator was implanted. Carotid sinus hypersensitivity should be kept in mind when examining diabetic patients.

Serial 2-point ultrasonography plus D-Dimer vs whole-leg color-coded doppler ultrasonography for diagnosing suspected symptomatic deep vein thrombosis - A randomized controlled trial

NARCIS (Netherlands)

Bernardi, Enrico; Camporese, Giuseppe; Buller, Harry R.; Siragusa, Sergio; Imberti, Davide; Berchio, Arrigo; Ghirarduzzi, Angelo; Verlato, Fabio; Anastasio, Raffaela; Prati, Carolina; Piccioli, Andrea; Pesavento, Raffaele; Bova, Carlo; Maltempi, Patrizia; Zanatta, Nello; Cogo, Alberto; Cappelli, Roberto; Bucherini, Eugenio; Cuppini, Stefano; Noventa, Franco; Prandoni, Paolo

2008-01-01

Context Patients with suspected deep vein thrombosis ( DVT) of the lower extremities are usually investigated with ultrasonography either by the proximal veins ( 2-point ultrasonography) or the entire deep vein system ( whole- leg ultrasonography). The latter approach is thought to be better based

Bilateral carotid body tumor resection in a female patient

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Alfred Burgess

Full Text Available Introduction: Carotid body tumors also called carotid paragangliomas are rare neuroendocrine neoplasms derived from neural crest cells, approximately 3% of all paragangliomas occur in the head and neck area (Xiao and She, 2015; although they represent 65% of the head and neck paragangliomas (Georgiadis et al., 2008. Presentation of case: We present the therapeutic management of a 65-year-old woman with bilateral carotid body tumors. The patient presented to medical clinic for unrelated signs and symptoms of weight loss, dyspepsia, and epigastric pain. Physical examination showed bilateral non-tender neck masses for which imaging studies were ordered resulting in the diagnosis of bilateral carotid tumor. Surgical resection was staged with one week of distance between each tumor resection. Discussion: Carotid Body Tumors can arise from the paraganglia located within the adventitia of the medial aspect of the carotid bifurcation.Resection is the only curative treatment. Carotid body tumors resection represents a special challenge due to potential neurovascular complications. Conclusions: Surgical resection of carotid body tumors represents a special challenge to the surgeon because of the complex anatomical location of the tumor, including close relationship with the cranial nerves, involvement of the carotid vessels and large vascularization of the tumor. With the advance of diagnosis and improvement in surgical techniques as well as the understanding of biological behavior of tumors, surgical treatment has become a safer alternative for treating these tumors. Keywords: Carotid body tumor, Bilateral, Paraganglioma, Resection

An ultrasound-based comparative study on carotid plaques in HIV-positive patients vs. atherosclerotic and arteritis patients: atherosclerotic or inflammatory lesions?

Science.gov (United States)

Maggi, Paolo; Perilli, Francesco; Lillo, Antonio; Carito, Valentina; Epifani, Giuseppe; Bellacosa, Chiara; Pastore, Giuseppe; Regina, Guido

2007-02-01

We have previously described two cases of HIV-1-positive patients undergoing surgery for stenosis of the internal carotid arteries. Histology revealed an extensive inflammatory infiltration of the vascular wall and no evidence of atheromasic plaque. This unexpected pattern of carotid damage prompted us to perform a more accurate investigation of the characteristics of carotid plaques in a group of HIV-positive patients. The results were compared with those obtained from young patients affected by atherosclerosis of the epi-aortic vessels and patients with arteritis. The patients underwent ultrasonography of the epi-aortic vessels using one of the latest generation power color-Doppler with 7.5 MHz probes. The study population included 61 HIV-positive patients and 47 HIV-negative patients (37 atherosclerotic and 10 with arteritis). Compared with HIV-negative atherosclerotic patients, there were significantly higher proportions of HIV-positive patients with iso-hypoechogenic lesions (81.8 vs. 29%) that were homogeneous both in their parietal and endoluminal portions (96.7 vs. 21.6% and 88.5 vs. 54.0%, respectively), with a smooth or slightly irregular surface (99.0 vs. 56.7%) (P=0.001 for all differences). No statistically significant differences were seen between HIV-positive and arteritis patients. Our study evidenced that the ultrasonographic structure of the epi-aortic lesions in HIV-positive patients substantially differ from those of the plaques in atherosclerotic patients, although they share similar characteristics with patients affected by arteritis. Further investigations are warranted to better define the structure and the mechanism of onset of these lesions.

Hemodynamic study on flow patterns in the carotid bifurcation before and after carotid endarterectomy using cine magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Yamane, Kanji; Shima, Takeshi; Okada, Yoshikazu; Nishida, Masahiro; Okita, Shinji; Hanaguri, Katsuro [Chugoku Rousai Hospital, Kure, Hiroshima (Japan)

1993-11-01

Blood flow in the cervical carotid bifurcation was investigated by cine magnetic resonance imaging. In patients with stenosis, a low-intensity stream was demonstrated from the beginning of the carotid bulb, which was more distinct in the systolic phase. In patients with stenotic carotid bifurcations,the low-intensity flow was also present but was more prominent than in the non-stenotic bifurcation. This low-intensity stream may be due to the change from steady to turbulent flow due to the geometric characteristics of the carotid bifurcation or atheromatous plaque, similar to the flow separation phenomenon in fluid dynamics because of the coincidence of location and flow pattern. After carotid endarterectomy, turbulent flow was seen at the proximal and distal ends of the endarterectomy. Close follow-up and administration of antiplatelet agents are necessary to prevent restenosis due to mural thrombosis induced by such turbulent flow. (author).

Recommendations for Management of Patients with Carotid Stenosis

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Arijana Lovrencic-Huzjan

2012-01-01

Full Text Available Stroke is a one of the leading causes of morbidity and mortality in the world. Carotid atherosclerosis is recognized as an important factor in stroke pathophysiology and represents a key target in stroke prevention; multiple treatment modalities have been developed to battle this disease. Multiple randomized trials have shown the efficacy of carotid endarterectomy in secondary stroke prevention. Carotid stenting, a newer treatment option, presents a less invasive alternative to the surgical intervention on carotid arteries. Advances in medical therapy have also enabled further risk reduction in the overall incidence of stroke. Despite numerous trials and decades of clinical research, the optimal management of symptomatic and asymptomatic carotid disease remains controversial. We will attempt to highlight some of the pivotal trials already completed, discuss the current controversies and complexities in the treatment decision-making, and postulate on what likely lies ahead. This paper will highlight the complexities of decision-making optimal treatment recommendations for patients with symptomatic and asymptomatic carotid stenosis.

Efficacy of Surgical Therapy for Carotid Body Tumors

Institute of Scientific and Technical Information of China (English)

Li-shan Lian; Chang-wei Liu; Heng Guan; Yue-hong Zheng; Xing-ming Chen; Yong-jun Li

2011-01-01

Objective To evaluate the efficacy of surgical therapy for carotid body tumors.Methods A retrospective analysis was conducted,covering the diagnosis,surgical procedure,post-operative complications,and prognosis of 120 cases of carotid body tumors in Peking Union Medical College Hospital from 1949 to May,2011.Results Surgical excision was successfully performed in 111 cases with 117 tumors.In all those cases,50 underwent simple tumor resection,42 underwent resection of tumors and ligation of the external carotid arteries,7 underwent co-resection of tumors and common carotid arteries,internal carotid arteries,as well as external arteries without vascular reconstruction,and the other 12 cases experienced tumor resection and vascular reconstruction as internal carotid arteries were involved.After operation,3 cases developed cerebral infarction,30 cases showed cranial nerve palsy,including 15 cases of hypoglossal nerve damage,10 cases of vagus paralysis,and 5 cases of Horner's syndrome.Conclusion It is essential to make a proper surgical strategy,which can reduce postoperative complications.

Quantitative evaluation of high intensity signal on MIP images of carotid atherosclerotic plaques from routine TOF-MRA reveals elevated volumes of intraplaque hemorrhage and lipid rich necrotic core.

Science.gov (United States)

Yamada, Kiyofumi; Song, Yan; Hippe, Daniel S; Sun, Jie; Dong, Li; Xu, Dongxiang; Ferguson, Marina S; Chu, Baocheng; Hatsukami, Thomas S; Chen, Min; Zhou, Cheng; Yuan, Chun

2012-11-29

Carotid intraplaque hemorrhage (IPH) and lipid rich necrotic core (LRNC) have been associated with accelerated plaque growth, luminal narrowing, future surface disruption and development of symptomatic events. The aim of this study was to evaluate the quantitative relationships between high intensity signals (HIS) in the plaque on TOF-MRA and IPH or LRNC volumes as measured by multicontrast weighted CMR. Seventy six patients with a suspected carotid artery stenosis or carotid plaque by ultrasonography underwent multicontrast carotid CMR. HIS presence and volume were measured from TOF-MRA MIP images while IPH and LRNC volumes were separately measured from multicontrast CMR. For detecting IPH, HIS on MIP images overall had high specificity (100.0%, 95% CI: 93.0 - 100.0%) but relatively low sensitivity (32%, 95% CI: 20.8 - 47.9%). However, the sensitivity had a significant increasing relationship with underlying IPH volume (p = 0.033) and degree of stenosis (p = 0.022). Mean IPH volume was 2.7 times larger in those with presence of HIS than in those without (142.8 ± 97.7 mm(3) vs. 53.4 ± 56.3 mm(3), p = 0.014). Similarly, mean LRNC volume was 3.4 times larger in those with HIS present (379.8 ± 203.4 mm(3) vs. 111.3 ± 122.7 mm(3), p = 0.001). There was a strong correlation between the volume of the HIS region and the IPH volume measured from multicontrast CMR (r = 0.96, p routine, clinical TOF sequences. High intensity signals in carotid plaque on TOF-MRA MIP images are associated with increased intraplaque hemorrhage and lipid-rich necrotic core volumes. The technique is most sensitive in patients with moderate to severe stenosis.

Full-Duplex Relay Selection in Cognitive Underlay Networks

KAUST Repository

Khafagy, Mohammad Galal

2017-09-30

In this work, we analyze the performance of full-duplex relay selection (FDRS) in spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay(s), thereby allowing for a higher spectral efficiency. However, since the source and relay simultaneously transmit in FDR, their superimposed signal at the primary receiver should now satisfy the existing interference constraint, which can considerably limit the secondary network throughput. In this regard, relay selection can offer an adequate solution to boost the secondary throughput while satisfying the imposed interference limit. We first analyze the performance of opportunistic FDRS with residual self-interference (RSI) by deriving the exact cumulative distribution function of its end-to-end signal-to-interference-plus-noise ratio under Nakagami-m fading. We also evaluate the offered diversity gain of relay selection for different full-duplex cooperation schemes in the presence/absence of a direct source-destination link. When the adopted RSI link gain model is sublinear in the relay power, which agrees with recent research findings, we show that remarkable diversity gain can be recovered even in the presence of an interfering direct link. Second, we evaluate the end-to-end performance of FDRS with interference constraints due to the presence of a primary receiver. Finally, the presented exact theoretical findings are verified by numerical simulations.

THE INFLUENCE OF POSTHEAT TREATMENT ON FERRITE REDISTRIBUTION IN DUPLEX STEELS ELECTRON BEAM WELDS

OpenAIRE

Zita Iždinská; František Kolenič

2009-01-01

The duplex stainless steel is two-phase steel with the structure composed of austenite and ferrite with optimum austenite/ferrite proportion 50%. At present, classical arc processes for welding duplex steels are generally regarded as acceptable. On the other hand electron and laser beam welding is up to now considered less suitable for welding duplex steels. The submitted work presents the results of testing various thermal conditions at welding duplex stainless steel with electron beam. It w...

Comparisons of carotid artery stenting and carotid endoarterectomy in terms of diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Mitsuoka, Hiroshi; Shintani, Tsunehiro; Masuda, Mikio; Higashi, Shigeki

2009-01-01

The objective of this study was to compare two methods of treatment for carotid arterial stenosis, carotid endarterectomy (CEA) and carotid artery stenting (CAS), by means of diffusion-weighted MR imaging (DWI). Nineteen treatments in 18 cases during the 2007 academic year were included in this study. CAS was performed for 9 cases with 10 lesions (10 procedures), while 9 cases with 9 lesions (9 procedures) were treated by CEA. Patients were examined by a neurologist before and after the procedure, and had pre- and post-procedural DWI. No strokes or transient ischemic attacks (TIAs) were observed in these cases. New DWI lesions were found in 7 out of the 10 procedures of CAS imaged 24 hours postprocedure, (average: 2.0 lesions). No new lesions were detected on DWI of CEA cases (χ 2 =8.33, p=0.0039). Certain high-risk subsets may respond well to CAS with a very low incidence of clinically-evident neurologic events, but with significantly higher incidence of periprocedural micro-brain embolism. Currently, CEA should be the first choice of treatment for atherosclerotic carotid artery stenosis. (author)

In-Band α-Duplex Scheme for Cellular Networks: A Stochastic Geometry Approach

KAUST Repository

Alammouri, Ahmad

2016-07-13

In-band full-duplex (FD) communications have been optimistically promoted to improve the spectrum utilization and efficiency. However, the penetration of FD communications to the cellular networks domain is challenging due to the imposed uplink/downlink interference. This paper presents a tractable framework, based on stochastic geometry, to study FD communications in cellular networks. Particularly, we assess the FD communications effect on the network performance and quantify the associated gains. The study proves the vulnerability of the uplink to the downlink interference and shows that FD rate gains harvested in the downlink (up to 97%) come at the expense of a significant degradation in the uplink rate (up to 94%). Therefore, we propose a novel fine-grained duplexing scheme, denoted as -duplex scheme, which allows a partial overlap between the uplink and the downlink frequency bands. We derive the required conditions to harvest rate gains from the -duplex scheme and show its superiority to both the FD and half-duplex (HD) schemes. In particular, we show that the -duplex scheme provides a simultaneous improvement of 28% for the downlink rate and 56% for the uplink rate. Finally, we show that the amount of the overlap can be optimized based on the network design objective.

Stent impact on the geometry of the carotid bifurcation and the course of the internal carotid artery

International Nuclear Information System (INIS)

Berkefeld, J.; Zanella, F.E.; Rosendahl, H.; Theron, J.G.; Guimaraens, L.; Treggiari-Venzi, M.M.

2002-01-01

A measurement system is proposed to evaluate reconstructive effects of carotid stents on the geometry of the carotid bifurcation and the course of the internal carotid artery. To describe deviations of the stenotic internal carotid artery (ICA) from the extended axis of the common carotid artery (CCA) the CCA-ICA angle is measured between the CCA midaxis and the midaxis of the stenotic ICA segment. Maximal extensions of ICA tortuosities perpendicular to the course of the CCA axis are defined as ICA offset. The measurements were applied to DSA images of 224 carotid stenoses to evaluate variation and correlation between the two parameters. Comparative pre- and post-stent evaluation was performed in two series of 55 and 31 carotid stenoses treated with Wallstents and in a historic control group of 35 stenoses treated with Strecker stents. Straight course of the ICA was associated with low angle and low offset values, whereas tortuous course of the ICA showed larger angle and offset. A moderate linear correlation between the two parameters was found. Corresponding to a straightening of the stented segment, Wallstents reduced mean angle and offset values significantly. In five cases of the second series of Wallstents, transferrals of curves above the distal stent end associated with kinks were observed, and offset remained constant or increased. Strecker stent implantation caused no significant changes of bifurcational geometry. The proposed parameters corresponded to visual aspects of ICA tortuosity and detected reconstructive effects of self-expanding Wallstents on the ICA course. The measurement system may provide a basis for geometric evaluation of different stent types or implantation concepts with the aim: to optimize anatomic recanalization results in tortuous high angle-high offset bifurcations. (orig.)

Constructing canine carotid artery stenosis model by endovascular technique

International Nuclear Information System (INIS)

Cheng Guangsen; Liu Yizhi

2005-01-01

Objective: To establish a carotid artery stenosis model by endovascular technique suitable for neuro-interventional therapy. Methods: Twelve dogs were anesthetized, the unilateral segments of the carotid arteries' tunica media and intima were damaged by a corneous guiding wire of home made. Twenty-four carotid artery stenosis models were thus created. DSA examination was performed on postprocedural weeks 2, 4, 8, 10 to estimate the changes of those stenotic carotid arteries. Results: Twenty-four carotid artery stenosis models were successfully created in twelve dogs. Conclusions: Canine carotid artery stenosis models can be created with the endovascular method having variation of pathologic characters and hemodynamic changes similar to human being. It is useful for further research involving the new technique and new material for interventional treatment. (authors)

An evaluation of nuclear design characteristics of duplex burnable poison rods for extended cycle core

International Nuclear Information System (INIS)

Lee, D. J.; Kim, M. H.; Song, K. W.

2003-01-01

Nuclear design characteristics of duplex burnable poison rod were evaluated for three integral type burnable absorbers; Gadolinia, Erbia and IFBA. Inter-comparison was done for both 12 and 24 month cycle for Korean Standard Nuclear Plant. Fuel assemblies with duplex BP was designed to the equivalent assembly with 8 and 16 gadolinia BP 2 . Duplex BP is composed of inner region of natural U-Gd 2 O 3 , and outer shell of, UO 2 -Er2O 3 . In order to evaluate the duplex BP, assemblies with erbia and IFBA were compared with alternative options. A sensitivity studies were performed to the size of region, compositions and location of duplex BPs. It was shown that duplex BP gave favorable k-infinite curve to burnup, but IFBA provided the least residual reactivity penalty as EOC. Erbia was good for more negative MTCs. IFBA and erbia had better neutronic performance than gadolinia od duplex BP in the aspect of pin power peaking

Ultrasonography of the scrotum in adults

Energy Technology Data Exchange (ETDEWEB)

Kuhn, Anna L.; Scotegagna, Eduardo; Nowitaki, Kristina M.; Kim, Young M. [Dept. of UMass Memorial Medical Center, University of Massachusetts Medical Center, Worcester (United States)

2016-07-15

Ultrasonography is the ideal noninvasive imaging modality for evaluation of scrotal abnormalities. It is capable of differentiating the most important etiologies of acute scrotal pain and swelling, including epididymitis and testicular torsion, and is the imaging modality of choice in acute scrotal trauma. In patients presenting with palpable abnormality or scrotal swelling, ultrasonography can detect, locate, and characterize both intratesticular and extratesticular masses and other abnormalities. A 12-17 MHz high frequency linear array transducer provides excellent anatomic detail of the testicles and surrounding structures. In addition, vascular perfusion can be easily assessed using color and spectral Doppler analysis. In most cases of scrotal disease, the combination of clinical history, physical examination, and information obtained with ultrasonography is sufficient for diagnostic decision-making. This review covers the normal scrotal anatomy as well as various testicular and scrotal lesions.

Diabetic Nephropathy : Evaluation with Doppler Ultrasonography

International Nuclear Information System (INIS)

Sim, Jung Suk; Kim, Seung Hyup; Kang, Heung Sik; Park, Jae Hyung; Han, Man Chung

1996-01-01

To compare Doppler ultrasonography with laboratory tests in evaluation of diabetic nephropathy. Fifty-five patients (mean age = 60, M : F = 26 : 29) with diabetes mellitus underwent renal Doppler ultrasonography. Resistive indices were compared with degree of proteinuria, serum creatinine level, and creatinine clearance rate. Eighteen patients who showed no proteinuria or microscopic proteinuria had a mean resistive index (RI) of 0.72 (SD, 0.05), 16 patients with macroscopic proteinuria without nephrotic syndrome had a mean RI of 0.82 (SD, 0.13), and 21 patients with nephrotic syndrome had a mean RI of 0.90 (SD, 0.12). Renal RI correlated highly with serum creatinine level (r = 0.62) and creatinine clearance rate (r = -0.43). Renal Doppler ultrasonography provides a useful indication of renal function in diabetic nephropathy but cannot offer an advantage over conventional laboratory test

Surgeon-performed ultrasonography

DEFF Research Database (Denmark)

Todsen, Tobias

2017-01-01

Surgeons are increasingly using ultrasonography (US) in their clinical management of patients. However, US is a very user-dependent imaging modality and proper skills of the US operator are needed to ensure quality in patient care. This thesis explores the validity evidence for assessment...

CMOS serial link for fully duplexed data communication

Science.gov (United States)

Lee, Kyeongho; Kim, Sungjoon; Ahn, Gijung; Jeong, Deog-Kyoon

1995-04-01

This paper describes a CMOS serial link allowing fully duplexed 500 Mbaud serial data communication. The CMOS serial link is a robust and low-cost solution to high data rate requirements. A central charge pump PLL for generating multiphase clocks for oversampling is shared by several serial link channels. Fully duplexed serial data communication is realized in the bidirectional bridge by separating incoming data from the mixed signal on the cable end. The digital PLL accomplishes process-independent data recovery by using a low-ratio oversampling, a majority voting, and a parallel data recovery scheme. Mostly, digital approach could extend its bandwidth further with scaled CMOS technology. A single channel serial link and a charge pump PLL are integrated in a test chip using 1.2 micron CMOS process technology. The test chip confirms upto 500 Mbaud unidirectional mode operation and 320 Mbaud fully duplexed mode operation with pseudo random data patterns.

Ophthalmic masquerades of the atherosclerotic carotids

Directory of Open Access Journals (Sweden)

Anupriya Arthur

2014-01-01

Full Text Available Patients with carotid atherosclerosis can present with ophthalmic symptoms. These symptoms and signs can be due to retinal emboli, hypoperfusion of the retina and choroid, opening up of collateral channels, or chronic hypoperfusion of the globe (ocular ischemic syndrome. These pathological mechanisms can produce many interesting signs and a careful history can bring out important past symptoms pointing toward the carotid as the source of the patient′s presenting symptom. Such patients are at high risk for an ischemic stroke, especially in the subsequent few days following their first acute symptom. It is important for clinicians to be familiar with these ophthalmic symptoms and signs caused by carotid atherosclerosis for making an early diagnosis and to take appropriate measures to prevent a stroke. This review elaborates the clinical features, importance, and implications of various ophthalmic symptoms and signs resulting from atherosclerotic carotid artery disease.

Costs of secondary prevention of stroke by carotid endarterectomy

DEFF Research Database (Denmark)

Hædersdal, Carsten; Sørensen, Mette; Olsen, Tom Skyhøj

2012-01-01

We estimated the costs to the Danish National Health Service of preventing stroke due to carotid artery stenosis by carotid endarterectomy (CEA), including costs of identifying patients, Doppler ultrasound (DUS) examination and CEA.......We estimated the costs to the Danish National Health Service of preventing stroke due to carotid artery stenosis by carotid endarterectomy (CEA), including costs of identifying patients, Doppler ultrasound (DUS) examination and CEA....

Preoperative ultrasonographic findings of internal jugular veins and carotid arteries in kidney transplant recipients.

Science.gov (United States)

Choi, Ji Won; Kim, Gaab Soo; Lee, Seung Won; Park, Jeong Bo; Lee, Jeong Jin; Ko, Justin Sangwook

2016-08-01

Hemodialysis via the internal jugular vein (IJV) has been widely used for patients with end stage renal disease (ESRD) patients, as they have a higher risk of arterial diseases. We investigated the ultrasonographic findings of the IJV and carotid artery (CA) in recipients of kidney transplantation (KT) and identified factors influencing IJV/CA abnormalities. We enrolled 120 adult KT recipients. Patients in group A (n = 57) had a history of IJV hemodialysis, while those in group B (n = 63) were not yet on dialysis or undergoing dialysis methods not involving the IJV. The day before surgery, we evaluated the state of the IJV and CA using ultrasonography. We followed patients with IJV stenosis for six months after KT. Ultrasonography revealed that four patients (7%) in group A had IJV abnormalities, while no patients in group B had abnormalities (P = 0.118). Of the four patients with abnormalities, one with 57.4% stenosis normalized during follow- up. However, another patient with 90.1% stenosis progressed to occlusion, while the two patients with total occlusion remained the same. Twenty patients in group A (n = 11) and B (n = 9) had several CA abnormalities (P = 0.462). Upon multivariate analysis with stepwise selection, height and age were significantly correlated with IJV stenosis (P = 0.043, odds ratio = 0.9) and CA abnormality (P = 0.012, odds ratio = 1.1), respectively. IJV abnormalities (especially with a history of IJV hemodialysis) and CA abnormalities may be present in ESRD patients. Therefore, we recommend ultrasonographic evaluation before catheterization.

Diagnostic workup in carotid stenosis - a neurologist's perspective

International Nuclear Information System (INIS)

Rosenkranz, Michael; Gerloff, Christian

2010-01-01

Carotid artery stenosis is associated with the risk of stroke, myocardial infarction, and vascular death. In selected patients, revascularization of carotid narrowing by endarterectomy may reduce the risk of stroke distal to the stenosis. Carotid artery stenting has evolved as a potential alternative to endarterectomy. Four randomized clinical trials comparing safety and efficacy of endarterectomy versus stenting of symptomatic carotid stenosis have been published in recent years, but there remains some uncertainty about the implications of these trials for clinical routine. Both carotid stenting and endarterectomy are based on different treatment strategies which may result in different specific risk factors associated with each procedure. Hence, the procedural risk of either modality varies not only with the skills of the surgeon or the interventionalist but may depend on patient characteristics. It appears that the most important question is not whether one revascularization modality is superior but for which patient one modality is better than the other. A comprehensive diagnostic workup of patients with carotid stenosis based on a broad panel of covariates that affect the risk of vascular events may improve selection of patients for carotid revascularization and may help to decide for whom one revascularization modality is likely to be better than the other. (orig.)

The association of carotid cavernous fistula with Graves′ ophthalmopathy

Directory of Open Access Journals (Sweden)

Ozlem Celik

2013-01-01

Full Text Available Graves′ ophthalmopathy (GO is one of the frequent manifestations of the disorder which is an inflammatory process due to fibroblast infiltration, fibroblast proliferation and accumulation of glycosaminoglycans. Eye irritation, dryness, excessive tearing, visual blurring, diplopia, pain, visual loss, retroorbital discomfort are the symptoms and they can mimic carotid cavernous fistulas. Carotid cavernous fistulas are abnormal communications between the carotid arterial system and the cavernous sinus. The clinical manifestations of GO can mimic the signs of carotid cavernous fistulas. Carotid cavernous fistulas should be considered in the differential diagnosis of the GO patients especially who are not responding to the standard treatment and when there is a unilateral or asymmetric eye involvement. Here we report the second case report with concurrent occurrence of GO and carotid cavernous fistula in the literature.

The association of carotid cavernous fistula with Graves’ ophthalmopathy

Science.gov (United States)

Celik, Ozlem; Buyuktas, Deram; Islak, Civan; Sarici, A Murat; Gundogdu, A Sadi

2013-01-01

Graves’ ophthalmopathy (GO) is one of the frequent manifestations of the disorder which is an inflammatory process due to fibroblast infiltration, fibroblast proliferation and accumulation of glycosaminoglycans. Eye irritation, dryness, excessive tearing, visual blurring, diplopia, pain, visual loss, retroorbital discomfort are the symptoms and they can mimic carotid cavernous fistulas. Carotid cavernous fistulas are abnormal communications between the carotid arterial system and the cavernous sinus. The clinical manifestations of GO can mimic the signs of carotid cavernous fistulas. Carotid cavernous fistulas should be considered in the differential diagnosis of the GO patients especially who are not responding to the standard treatment and when there is a unilateral or asymmetric eye involvement. Here we report the second case report with concurrent occurrence of GO and carotid cavernous fistula in the literature. PMID:23571267

Optimisation of welding procedures for duplex and superduplex stainless steels

International Nuclear Information System (INIS)

Westin, Elin M.

2014-01-01

Austenitic stainless steels are increasingly being replaced by duplex grades that can offer similar corrosion resistance with far higher strength. This increased strength makes it possible to reduce material consumption whilst also decreasing transport and construction costs. Although established welding methods used for austenitic steels can be used for duplex steels, modification of the procedures can lead to improved results. This paper reviews the welding of duplex stainless steel and examines precautions that may be required. The advantages and disadvantages of different welding methods are highlighted and some high productivity solutions are presented. The application of a more efficient process with a high deposition rate (e.g. flux- cored arc welding) can decrease labour costs. Further close control of heat input and interpass temperature can result in more favourable microstructures and final properties. Although welding adversely affects the corrosion resistance of austenitic and duplex stainless steels, particularly the pitting resistance, relative to the parent material, this problem can be minimised by proper backing gas protection and subsequent pickling.

Features of residual stresses in duplex stainless steel butt welds

Science.gov (United States)

Um, Tae-Hwan; Lee, Chin-Hyung; Chang, Kyong-Ho; Nguyen Van Do, Vuong

2018-04-01

Duplex stainless steel finds increasing use as an alternative to austenitic stainless steel, particularly where chloride or sulphide stress corrosion cracking is of primary concern, due to the excellent combination of strength and corrosion resistance. During welding, duplex stainless steel does not create the same magnitude or distribution of weld-induced residual stresses as those in welded austenitic stainless steel due to the different physical and mechanical properties between them. In this work, an experimental study on the residual stresses in butt-welded duplex stainless steel is performed utilizing the layering technique to investigate the characteristics of residual stresses in the weldment. Three-dimensional thermos-mechanical-metallurgical finite element analysis is also performed to confirm the residual stress measurements.

Stent-induced flow disturbances in the ipsilateral external carotid artery following internal carotid artery stenting: a temporary cause of jaw claudication.

Science.gov (United States)

Giurgea, Georgiana-Aura; Haumer, Markus; Mlekusch, Irene; Sabeti-Sandor, Schila; Dick, Petra; Schillinger, Martin; Minar, Erich; Mlekusch, Wolfgang

2017-07-01

We hypothesize that stenting of the internal carotid artery can immediately impede blood flow to the external carotid artery by either plaque shift or stent coverage of the ostium, and thereby cause ischemic symptoms like ipsilateral jaw claudication. Thirty-three patients with high-grade asymptomatic stenosis of the internal carotid artery who underwent endovascular treatment were examined by ultrasound of the external carotid artery and performed an exercise test by chewing chewing gum synchronously to an electronic metronome for 3 min. Tests were performed before, the day after, and 1 week after the stenting procedure. Claudication time was defined as the timespan until occurrence of pain of the masseter muscle and/or chewing dyssynchrony to the metronome for more than 15 s. Ten patients with an isolated, atherosclerotic stenosis of the external carotid artery served as controls. A significantly reduced claudication time (in seconds) was recorded in patients who underwent carotid artery stenting compared to baseline values; median 89 (interquartile range, IQR, 57 to 124) vs. median 180 (IQR 153 to 180; p external carotid artery into faster or slower as 200 cm/sec, the effect was even accentuated. Stenting values showed improvement 1 week after but did not return to baseline levels. No respective changes were found in controls. Stenting of the internal carotid artery lead to ipsilateral flow deterioration at the external carotid artery resulting in temporary jaw claudication. This impairment attenuated over the time and was significantly reduced after 1 week.

Percutaneous transluminal angioplasty of the carotid artery

International Nuclear Information System (INIS)

Numaguchi, Y.; Tulane Univ., New Orleans, LA; Puyau, F.A.; Provenza, L.J.; Richardson, D.E.

1984-01-01

The successful dilatation of postsurgical concentric stenosis of an internal carotid artery using percutaneous transluminal angioplasty (PTA) is reported here. Only one such case has been previously documented. Review of the literature disclosed 16 patients who received transluminal angioplasty for stenosis of carotid arteries by percutaneous or open arteriotomy techniques. The authors feel that PTA may be the treatment of choice for postoperative concentric stenosis of a short segment of the carotid artery as opposed to surgical repair. (orig.)

Micromechanics of base pair unzipping in the DNA duplex

International Nuclear Information System (INIS)

Volkov, Sergey N; Paramonova, Ekaterina V; Yakubovich, Alexander V; Solov’yov, Andrey V

2012-01-01

All-atom molecular dynamics (MD) simulations of DNA duplex unzipping in a water environment were performed. The investigated DNA double helix consists of a Drew-Dickerson dodecamer sequence and a hairpin (AAG) attached to the end of the double-helix chain. The considered system is used to examine the process of DNA strand separation under the action of an external force. This process occurs in vivo and now is being intensively investigated in experiments with single molecules. The DNA dodecamer duplex is consequently unzipped pair by pair by means of the steered MD. The unzipping trajectories turn out to be similar for the duplex parts with G⋅C content and rather distinct for the parts with A⋅T content. It is shown that during the unzipping each pair experiences two types of motion: relatively quick rotation together with all the duplex and slower motion in the frame of the unzipping fork. In the course of opening, the complementary pair passes through several distinct states: (i) the closed state in the double helix, (ii) the metastable preopened state in the unzipping fork and (iii) the unbound state. The performed simulations show that water molecules participate in the stabilization of the metastable states of the preopened base pairs in the DNA unzipping fork. (paper)

Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by super duplex filler metal

Energy Technology Data Exchange (ETDEWEB)

Eghlimi, Abbas, E-mail: a.eghlimi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shamanian, Morteza [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Eskandarian, Masoomeh [Department of Materials Engineering, Shiraz University, Shiraz 71348-51154 (Iran, Islamic Republic of); Zabolian, Azam [Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Szpunar, Jerzy A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon SK S7N 5A9 (Canada)

2015-08-15

In the present paper, microstructural changes across an as-welded dissimilar austenitic/duplex stainless steel couple welded by a super duplex stainless steel filler metal using gas tungsten arc welding process is characterized with optical microscopy and electron back-scattered diffraction techniques. Accordingly, variations of microstructure, texture, and grain boundary character distribution of base metals, heat affected zones, and weld metal were investigated. The results showed that the weld metal, which was composed of Widmanstätten austenite side-plates and allotriomorphic grain boundary austenite morphologies, had the weakest texture and was dominated by low angle boundaries. The welding process increased the ferrite content but decreased the texture intensity at the heat affected zone of the super duplex stainless steel base metal. In addition, through partial ferritization, it changed the morphology of elongated grains of the rolled microstructure to twinned partially transformed austenite plateaus scattered between ferrite textured colonies. However, the texture of the austenitic stainless steel heat affected zone was strengthened via encouraging recrystallization and formation of annealing twins. At both interfaces, an increase in the special character coincident site lattice boundaries of the primary phase as well as a strong texture with <100> orientation, mainly of Goss component, was observed. - Graphical abstract: Display Omitted - Highlights: • Weld metal showed local orientation at microscale but random texture at macroscale. • Intensification of <100> orientated grains was observed adjacent to the fusion lines. • The austenite texture was weaker than that of the ferrite in all duplex regions. • Welding caused twinned partially transformed austenites to form at SDSS HAZ. • At both interfaces, the ratio of special CSL boundaries of the primary phase increased.

Retinal artery occlusion during carotid artery stenting with distal embolic protection device.

Science.gov (United States)

Kohara, Kotaro; Ishikawa, Tatsuya; Kobayashi, Tomonori; Kawamata, Takakazu

2018-01-01

Retinal artery occlusion associated with carotid artery stenosis is well known. Although it can also occur at the time of carotid artery stenting, retinal artery occlusion via the collateral circulation of the external carotid artery is rare. We encountered two cases of retinal artery occlusion that were thought to be caused by an embolus from the external carotid artery during carotid artery stenting with a distal embolic protection device for the internal carotid artery. A 71-year-old man presented with central retinal artery occlusion after carotid artery stenting using the Carotid Guardwire PS and a 77-year-old man presented with branch retinal artery occlusion after carotid artery stenting using the FilterWire EZ. Because additional new cerebral ischaemic lesions were not detected in either case by postoperative diffusion-weighted magnetic resonance imaging, it was highly likely that the debris that caused retinal artery occlusion passed through not the internal carotid artery but collaterals to retinal arteries from the external carotid artery, which was not protected by a distal embolic protection device. It is suggested that a distal protection device for the internal carotid artery alone cannot prevent retinal artery embolisation during carotid artery stenting and protection of the external carotid artery is important to avoid retinal artery occlusion.

Ultrasonography of Skin Changes in Legs with Chronic Venous Disease.

Science.gov (United States)

Caggiati, A

2016-10-01

In daily practice, ultrasonography (US) is used only to designate the location and pattern of venous lesions. Skin US is not performed between routine venous investigations. Skin morphology is evaluated by the same probes used for routine Duplex evaluation of superficial veins. US findings from evident skin lesions are comparatively evaluated with those from the surrounding apparently normal skin and from the contralateral leg. Inflammation and dermal edema can be found in the apparently normal skin of C2 legs. Swollen legs show thickening of the subcutaneous layer as a result of diffuse soaking or anechoic cavities, with or without dermal edema. Chronic hypodermitis is characterized by inflammatory edema in initial phases, and by liposclerosis in advanced cases. Recrudescence of inflammation provokes focal rarefactions of the subcutaneous layer, possibly related to ulcer opening. In legs with venous disorders, sonography refines clinical evaluation of the skin and may reveal changes not highlighted by inspection. Some of these changes could require further investigation because they have not yet been explained or described. Skin sonography should improve knowledge of the natural history of skin changes, as well as contribute to a better grading of venous diseases severity In particular, US evidence of cutaneous and subcutaneous changes in C2 legs should be considered to stratify the treatment in C2 legs, by identifying those in which varicose veins are not simply a cosmetic problem. Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Supraorbital cutaneous blood flow rate during carotid endarterectomy

DEFF Research Database (Denmark)

Hove, Jens D; Rosenberg, Iben; Sejrsen, Per

2006-01-01

: The supraorbital cutaneous blood flow rate was measured by the application of heat to the skin and following the subsequent dissipation of the heat in seven patients undergoing carotid endarterectomy. At the same time, the oxygenation in the right and left frontal region was monitored by near-infrared spectroscopy......BACKGROUND: The supraorbital skin region is supplied by the supraorbital artery, which is a branch of the internal carotid artery. The supraorbital cutaneous blood flow rate may therefore be influenced by changes in the internal carotid artery flow during carotid endarterectomy. METHODS...... (NIRS). RESULTS: During cross-clamping of the carotid artery, the ipsilateral NIRS-determined frontal oxygenation tended to decrease [67 +/- 13% to 61 +/- 11% (P = 0.06); contralateral 68 +/- 11% to 66 +/- 8%] as did the supraorbital cutaneous blood flow rate from 56 +/- 23 to 44 +/- 7 ml 100 g(-1) min...

Efficacy of different types of self-expandable stents in carotid artery stenting for carotid bifurcation stenosis.

Science.gov (United States)

Liu, Ya-min; Qin, Hao; Zhang, Bo; Wang, Yu-jing; Feng, Jun; Wu, Xiang

2016-02-01

Both open and closed loop self-expandable stents were used in carotid artery stenting (CAS) for carotid bifurcation stenosis. We sought to compare the efficacy of two types of stents in CAS. The data of 212 patients treated with CAS (42 and 170 cases implanted with closed and open loop stents, respectively) for carotid bifurcation stenosis and distal filtration protection devices were retrospectively analyzed. Between closed and open loop stents, there were no significant differences in hospitalization duration, NIHSS score before and after the treatment, stenosis at 12th month, and cumulative incidence of primary endpoint events within 30 days or from the 31st day to the 12th month; while there were significant differences in hemodynamic changes and rate of difficulty in recycling distal filtration protection devices. Use of open vs. closed loop stents for carotid bifurcation stenosis seems to be associated with similar incidence of complications, except for greater rate of hemodynamic changes and lower rate of difficulty in recycling the distal filtration protection devices.

Computed tomography of hepatocellular carcinoma. Comparison with scintigraphy and ultrasonography

Energy Technology Data Exchange (ETDEWEB)

Kaneko, Kuniyuki; Nakata, Hajime; Honda, Hiroshi [University of Occupational and Environmental Health, Kitakyushu, Fukuoka (Japan)

1983-09-01

The detectability of hepatocellular carcinoma by computed tomography (CT) was evaluated on 76 cases. The detectability by plain CT was 93% with only slight improvement following a drip infusion of contrast medium. A comparison of scintigraphy, ultrasonography, and CT was also done on 63 cases. From the standpoint of the overall detectability of the tumor, CT was as good as ultrasonography or scintigraphy. Several cases were positive only on either CT or ultrasonography but no case was positive on scintigraphy alone. We believe that the combination of CT and ultrasonography is the most reliable as the screening method.

Analyzing the Potential of Full Duplex in 5G Ultra-Dense Small Cell Networks

DEFF Research Database (Denmark)

Gatnau, Marta; Berardinelli, Gilberto; Mahmood, Nurul Huda

2016-01-01

Full duplex technology has become an attractive solution for future 5th Generation (5G) systems for accommodating the exponentially growing mobile traffic demand. Full duplex allows a node to transmit and receive simultaneously in the same frequency band, thus, theoretically, doubling the system...... throughput over conventional half duplex systems. A key limitation in building a feasible full duplex node is the self-interference, i.e., the interference generated by the transmitted signal to the desired signal received on the same node. This constraint has been overcome given the recent advances...... in the self-interference cancellation technology. However, there are other limitations in achieving the theoretical full duplex gain: residual self-interference, traffic constraints and inter-cell and intra-cell interference. The contribution of this article is twofold. Firstly, achievable levels of self...

Current global status of carotid artery stent placement.

Science.gov (United States)

Wholey, M H; Wholey, M; Bergeron, P; Diethrich, E B; Henry, M; Laborde, J C; Mathias, K; Myla, S; Roubin, G S; Shawl, F; Theron, J G; Yadav, J S; Dorros, G; Guimaraens, J; Higashida, R; Kumar, V; Leon, M; Lim, M; Londero, H; Mesa, J; Ramee, S; Rodriguez, A; Rosenfield, K; Teitelbaum, G; Vozzi, C

1998-05-01

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

Carotid body size on CTA: Correlation with comorbidities

International Nuclear Information System (INIS)

Cramer, J.A.; Wiggins, R.H.; Fudim, M.; Engelman, Z.J.; Sobotka, P.A.; Shah, L.M.

2014-01-01

Aim: To test the hypothesis that computed tomographic angiography (CTA) can identify carotid body enlargement in patients with sympathetically mediated diseases. Materials and methods: A retrospective chart review of all patients obtaining CTAs of the cervical vasculature at University of Utah Health Sciences Center over a 6-month period was performed. Widest axial measurements of both carotid bodies were performed on a picture archiving and communication system (PACS). Statistical analysis was then performed to compare the mean carotid body size between control patients and patients with diabetes mellitus, hypertension, and congestive heart failure. Results: Measurements were performed on 288 patients, with 134 controls. Of the remaining 154, 72 patients had diabetes mellitus, 46 had congestive heart failure, and 130 had hypertension. The control patients had a mean carotid body diameter of 2.3 mm. There was a statistically significant (p < 0.01) 20–25% increase in mean diameter with diabetes mellitus (2.8 mm), hypertension (2.7 mm), and congestive heart failure (2.7 mm; p < 0.01). Conclusions: This study found a 20–25% larger mean carotid body size in patients with diabetes mellitus, hypertension, and congestive heart failure relative to controls. However, this small enlargement should not mimic other carotid body diseases, such as a paraganglionoma. Moreover, these findings further support the proposed functional relationship between the carotid body and sympathetically mediated disease states

Duplex-tube sodium-indication steam generator

International Nuclear Information System (INIS)

Matal, O.; Martoch, J.

1984-01-01

The steam generator with duplex tubes and sodium indication is connected to the main sodium input and output via the inlet and outlet chambers and has indication spaces connected to the interspaces of the duplex tubes. The first indication space is linked with the auxiliary inlet pipe to the inlet chamber and the second indication space is connected with the auxiliary pipe to the outlet chamber. Mounted to the auxiliary inlet pipe is at least one closure, i.e., a valve or electromagnetic stop. Mounted on the auxiliary outlet pipe is an indication sensor, e.g., a sodium flow sensor. At least one indication space is provided with an alarm sensor, e.g., a thermocouple, a pressure gauge and one sensor to monitor the hydrogen content of sodium. (J.P.)

Probing of miniPEGγ-PNA-DNA Hybrid Duplex Stability with AFM Force Spectroscopy.

Science.gov (United States)

Dutta, Samrat; Armitage, Bruce A; Lyubchenko, Yuri L

2016-03-15

Peptide nucleic acids (PNA) are synthetic polymers, the neutral peptide backbone of which provides elevated stability to PNA-PNA and PNA-DNA hybrid duplexes. It was demonstrated that incorporation of diethylene glycol (miniPEG) at the γ position of the peptide backbone increased the thermal stability of the hybrid duplexes (Sahu, B. et al. J. Org. Chem. 2011, 76, 5614-5627). Here, we applied atomic force microscopy (AFM) based single molecule force spectroscopy and dynamic force spectroscopy (DFS) to test the strength and stability of the hybrid 10 bp duplex. This hybrid duplex consisted of miniPEGγ-PNA and DNA of the same length (γ(MP)PNA-DNA), which we compared to a DNA duplex with a homologous sequence. AFM force spectroscopy data obtained at the same conditions showed that the γ(MP)PNA-DNA hybrid is more stable than the DNA counterpart, 65 ± 15 pN vs 47 ± 15 pN, respectively. The DFS measurements performed in a range of pulling speeds analyzed in the framework of the Bell-Evans approach yielded a dissociation constant, koff ≈ 0.030 ± 0.01 s⁻¹ for γ(MP)PNA-DNA hybrid duplex vs 0.375 ± 0.18 s⁻¹ for the DNA-DNA duplex suggesting that the hybrid duplex is much more stable. Correlating the high affinity of γ(MP)PNA-DNA to slow dissociation kinetics is consistent with prior bulk characterization by surface plasmon resonance. Given the growing interest in γ(MP)PNA as well as other synthetic DNA analogues, the use of single molecule experiments along with computational analysis of force spectroscopy data will provide direct characterization of various modifications as well as higher order structures such as triplexes and quadruplexes.

Three-dimensional carotid ultrasound plaque texture predicts vascular events

DEFF Research Database (Denmark)

van Engelen, Arna; Wannarong, Thapat; Parraga, Grace

2014-01-01

BACKGROUND AND PURPOSE: Carotid ultrasound atherosclerosis measurements, including those of the arterial wall and plaque, provide a way to monitor patients at risk of vascular events. Our objective was to examine carotid ultrasound plaque texture measurements and the change in carotid plaque text...

Successful Endovascular Treatment of a Left Common Carotid Artery Aneurysm Following Failed Surgery of a Right Common Carotid Artery Aneurysm

International Nuclear Information System (INIS)

Cil, Barbaros E.; Ucar, Ibrahim; Ozsoy, Fatma; Arat, Anil; Yorgancioglu, Cem; Boeke, Erkmen

2005-01-01

Aneurysm of the common carotid artery is a rare and serious disease requiring prompt treatment in order to avoid neurologic complications. A 39-year-old man presented with voice impairment and a pulsatile mass at the right side of his neck and was found by color Doppler examination to have bilateral common carotid artery aneurysms of unknown origin. The right-sided large aneurysm was treated with placement of an 8 mm interposition Gore-Tex graft between the right common and internal carotid arteries. The surgical graft thrombosed 7 days after the surgery but the left-sided aneurysm was successfully treated by a Jostent peripheral stent-graft. Color Doppler examination showed a patent stent and no filling of the aneurysm on his first and sixth-month follow-up. Bilateral common carotid artery aneurysm is an exceptionally unusual condition and endovascular treatment of carotid artery aneurysms with covered stents may become an effective treatment alternative for these lesions

Ultrasonography of the equine shoulder

International Nuclear Information System (INIS)

Dik, K.J.

1996-01-01

Six horses with shoulder injuries were presented in this report with emphasis on the use of ultrasonography vs. radiography in diagnosis. The two imaging modalities represented valuable and complementary diagnostic procedures. Two horses had fracture fragments of the lateral humeral tuberosity, the accurate ultrasonographic findings encouraging clearer radiographic identification by oblique projections. In one horseultrasonography enabled more accurate localization of calcification within the supraspinatus muscle. In the remaining three cases ultrasonography visualized distension of the bicipital bursa due to aseptic bursitis, bursal hemorrhage, or associated with injury of the biceps brachii muscle and the underlying intermediate humeral tubercle, the bony involvement more clearly demonstrated radiographically

Impact of Duplex arterial mapping on decision making in non-acute ischemic limb patients.

Science.gov (United States)

Elbadawy, A; Aly, H; Ibrahim, M; Bakr, H

2015-12-01

The aim of this study was to demonstrate the impact of Duplex arterial mapping on decision making in non-acute ischemic limb patient group reporting pain onset between 15 days and 3 months. We prospectively evaluated patients presented with critical limb ischemia who reported pain onset of duration between 15 days and 3 months in one-year period. Our series included thirty cases (mean age=61.3 years old), as Duplex arterial mapping was the sole preoperative imaging tool performed in all of them. All patients, in whom duplex indicated thrombosis in long occluded segments, were candidates for fluoroscopically guided thrombectomy. When Duplex defined chronic arterial occlusions, patients underwent endovascular or bypass revascularisation procedures. Impact of Duplex wall interrogation on decision-making between the two groups (subacute and chronic) was measured. Duplex arterial mapping categorized correctly all 30 patients into either subacute ischemia with removable clot (N.=14) or chronic ischemia (N.=16). Fluoroscopic guided thrombectomy was performed in 14 cases when Duplex advised long occluded arterial segments as indicted by intact intima with echogenic thrombus inside. Bypass surgery was performed in 8 patients. Percutaneous transluminal angioplasty (PTA) was done in 7 cases and thrombendartrectomy of common femoral artery in a single case. One-year patency rate in our series was 86.6%. It was 71.4% in thrombosis group. Limb salvage rate was 93.3%. Duplex arterial mapping could be used to differentiate the subacute ischemia with removable thrombus and chronic arterial occlusions guiding for the best revascularization procedure accordingly.

On the Potential of Full Duplex Performance in 5G Ultra-Dense Small Cell Networks

DEFF Research Database (Denmark)

Gatnau, Marta; Fleischer, Marko; Berardinelli, Gilberto

2016-01-01

inter-cell interference and traffic constraints. In this paper, we first study the self-interference cancellation capabilities by using a real demonstrator. Results show that achieving ~110 dB of cancellation is already possible with the current available technology, thus providing the required level...... of isolation to build an operational full duplex node. Secondly, we investigate the inter-cell interference and traffic constraints impact on the full duplex performance in 5th generation systems. System level results show that both the traffic and the inter-cell interference can significantly reduce...... the potential gain of full duplex with respect to half duplex. However, for large traffic asymmetry, full duplex can boost the performance of the lightly loaded link....

Cardiac risk assessment before carotid endarterectomy

International Nuclear Information System (INIS)

Rabee, Hussein M.M.

2000-01-01

Preoperative cardiac assessment is an essential step to identify the patients at risk, optimize any dysfunction, anticipate perioperative and postoperative problems and plan special management. Carotid endarterectomy (CEA) has become one of the most commonly performed vascular procedures in Western countries. The awareness of the potential beneficial role and hazards of CEA is not proportionate to the magnitude of this problem in our countries, not only among patients, but also among the medical disciplines. This report is a retrospective analysis of the prevalence of coronary artery diseases among 442 patients who were referred to the Division of Vascular Surgery at the King Khalid University Hospital in Riyadh, Saudi Arabia with suspicion of carotid artery disease. Eighty-two patients proved to have significant carotid artery stenosis and had thorough preoperative cardiac assessment by senior cardiologist. All cases had clinical assessment and ECG, 66 cases had echocardiogram examination, 44 had Dipyridamole Thallium-scan and 12 had coronary angiogram. Sixty-eight patients underwent 76 carotid endarterectomy. Four of them had MI and only one case died during preoperative period. This study shows that cardiac screening studies have a potential role in the candidates for carotid surgery in influencing the decision to operate and intensify of perioperative monitoring and care. We believe that the teamwork should involve vascular surgeons, cardiologist and anesthetist to manage such critical patients properly. (author)

Diagnostic value of ultrasonography in evaluation and management ...

African Journals Online (AJOL)

Results: Common causes of acute abdominal emergencies in pediatric patients as noted on ultrasonography included nonspecifi c pain (28%), abdominal abscess (21%), acute appendicitis (7%) and intussusception (7%). Ultrasonography was diagnostic in 45.2% cases and supportive in 12.3% of the cases. As for as the fi ...

A study of radiation-induced cerebral vascular injury in nasopharyngeal carcinoma patients with radiation-induced temporal lobe necrosis.

Directory of Open Access Journals (Sweden)

Jianhong Ye

Full Text Available To investigate radiation-induced carotid and cerebral vascular injury and its relationship with radiation-induced temporal lobe necrosis in nasopharyngeal carcinoma (NPC patients.Fifty eight NPC patients with radiation-induced temporal lobe necrosis (TLN were recruited in the study. Duplex ultrasonography was used to scan bilateral carotid arterials to evaluate the intima-media thickness (IMT and occurrence of plaque formation. Flow velocities of bilateral middle cerebral arteries (MCAs, internal carotid arteries (ICAs and basal artery (BA were estimated through Transcranial Color Doppler (TCD. The results were compared with data from 33 patients who were free from radiation-induced temporal lobe necrosis after radiotherapy and 29 healthy individuals.Significant differences in IMT, occurrence of plaques of ICAs and flow velocities of both MCAs and ICAs were found between patients after radiotherapy and healthy individuals (p<0.05. IMT had positive correlation with post radiation interval (p = 0.049. Compared with results from patients without radiation-induced TLN, the mean IMT was significantly thicker in patients with TLN (p<0.001. Plaques were more common in patients with TLN than patients without TLN (p = 0.038. In addition, flow velocities of MCAs and ICAs in patients with TLN were much faster (p<0.001, p<0.001. Among patients with unilateral TLN, flow velocity of MCAs was significantly different between ipsilateral and contralateral sides to the lesion (p = 0.001.Thickening of IMT, occurrence of plaque formation and hemodynamic abnormality are more common in patients after radiotherapy, especially in those with TLN, compared with healthy individuals.

THE INFLUENCE OF POSTHEAT TREATMENT ON FERRITE REDISTRIBUTION IN DUPLEX STEELS ELECTRON BEAM WELDS

Directory of Open Access Journals (Sweden)

Zita Iždinská

2009-04-01

Full Text Available The duplex stainless steel is two-phase steel with the structure composed of austenite and ferrite with optimum austenite/ferrite proportion 50%. At present, classical arc processes for welding duplex steels are generally regarded as acceptable. On the other hand electron and laser beam welding is up to now considered less suitable for welding duplex steels. The submitted work presents the results of testing various thermal conditions at welding duplex stainless steel with electron beam. It was shown, that application of suitable postheat made possible to reduce the ferrite content in weld metal.

Quality assurance of lower limb venous duplex scans performed by vascular surgeons.

Science.gov (United States)

Kordowicz, A; Ferguson, G; Salaman, R; Onwudike, M

2015-02-01

Duplex scanning is the gold standard for investigating venous reflux; increasingly surgeons perform these scans themselves. There has been no data published analysing the accuracy of Duplex scans performed by vascular surgeons. We aimed to evaluate an objective method of comparing the results of lower limb Duplex scans performed by one consultant vascular surgeon with those performed by a vascular technologist. We assessed 100 legs with symptomatic varicose veins. Each patient underwent two lower limb venous Duplex scans; one performed by a consultant vascular surgeon and one by a vascular technologist. Scan results were randomised and sent to two consultant vascular surgeons blinded to the identity and experience of the sonographer. They were asked to recommend treatment. A k score was calculated in each case to assess the level of agreement between the scans performed by the consultant and the technologist. Eighty-one patients were studied (53 females). The kappa score for assessor 1 was 0.60 (95%CI:0.44-0.75) and for assessor 2 was 0.62 (95%CI:0.48-0.75). k scores >0.60 represent a substantial strength of agreement. Duplex scans performed by this surgeon were comparable to those performed by a vascular technologist. It is possible to quality-assure duplex performed by vascular surgeons without directly observing the scanning process or reviewing digitally recorded images. We propose standardisation of training, assessment and quality assurance for vascular surgeons wishing to perform ultrasound scans.

Multi-slice spiral CT diagnosis of carotid body tumor

International Nuclear Information System (INIS)

Li Peiling; Leng Renli; Li Shu; Xie Xiuli; Xu Ke

2006-01-01

Objective: to explore the Multi-slice spiral CT (MSCT) findings of carotid body tumor (CBT). Methods: Twelve cases of CBT proved by surgery were collected in this study and all patients accepted contrast-enhanced MSCT examination. Two-dimensional and three-dimensional post-processing were performed at diagnostic workstation using Aquilion 1.42. The CT features of CBT were analyzed. Results Each of 12 patients had one lesion. All lesions demonstrated well-marginated masses of homogeneous soft- tissue density with CT value within 29-48 HU on pre-enhanced images. All lesions were markedly enhanced with CT value over 200 HU on arterial-phase images, and the density of lesions decreased rapidly on delay- phase images. Twelve lesions were all located at the level of carotid artery bifurcation, 3 of them enveloping common carotid artery and internal/external carotid artery, and other 9 of them riding right on the carotid bifurcation. Internal carotid artery usually were shifted toward posterior-lateral, and external carotid artery toward anterior or anterior-medial. Conclusion: Contrast-enhanced MSCT examination not only can make a qualitative diagnosis of CBT, but determine its accurate location. It plays an importantly instructional role in clinical diagnosis and treatment. (authors)

Magnetic resonance angiography of the extracranial carotid and vertebral arteries

International Nuclear Information System (INIS)

Akimura, Tatsuo; Saito, Kenichi; Nakayama, Hisato; Kashiwagi, Shiro; Kato, Shoichi; Ito, Haruhide.

1994-01-01

To evaluate the contribution of magnetic resonance angiography (MRA) in the screening study of the extracranial carotid and vertebral arteries using the conventional head and neck coils, 500 consecutive MRAs of the cervical vessels were performed using 1.5 tesla magnetic resonance unit with circularly polarized head coil. The 5 cm-thick imaging plane was placed in coronal fashion including both carotid and vertebral arteries. The imaging sequence was three-dimensional (3D) fast imaging with steady precession (FISP). In 10 patients with failed head coil examination, 10 patients with possible carotid and vertebral diseases and 10 volunteers, the extracranial carotid and vertebral arteries were examined with the Helmholtz neck coil. Both 3D- and 2D-FISP were performed in each case. The imaging plane was placed in oblique sagittal fashion. In 458 out of 500 cases (91.6%), the extracranial carotid and vertebral arteries were successfully depicted using head coil. In 20 patients with high shoulders, the carotid bifurcations were out of range of the head coil. In these cases, carotid bifurcations and the origins of the carotid and vertebral arteries were successfully revealed using a neck coil. To evaluate the stenotic lesions and tortuous vessels, 2D-FISP sequence seemed to be more suitable than 3D-FISP. Compared with conventional angiography, MRA caused overestimation of the degree of stenotic lesions. For screening examination of the extracranial carotid and vertebral arteries, most cases can be evaluated only with the conventional head coil. If depiction of the carotid bifurcation fails and the examination of carotids or vertebrals down to the aortic arch is needed, neck coil examination is required. (author)

Selection of patients with infrainguinal arterial occlusive disease for percutaneous transluminal angioplasty with duplex scanning

International Nuclear Information System (INIS)

Bostroem Ardin, A.; Hellberg, A.; Ljungman, C.; Logason, K.; Karacagil, S.; Loefberg, A.M.; Andren, B.

2002-01-01

Aim: To evaluate the role of duplex scanning in the selection of patients with infrainguinal arterial occlusive disease for percutaneous transluminal angioplasty (PTA). Material and Methods: From January 1995 through May 2000, 702 patients (952 limbs), with chronic lower extremity ischemia due to infrainguinal atherosclerotic disease diagnosed by duplex scanning, were retrospectively studied. Diagnostic angiography (130 limbs) or infrainguinal PTA (108 limbs) was performed in 238 limbs. Two investigators retrospectively analyzed the duplex examinations and angiographies in a blinded manner and used similar criteria for the interpretation of lesions suitable or not suitable for PTA. Results: The superficial femoral, popliteal and crural artery lesions were correctly selected for PTA in 85%, 66% and 32%, respectively. The accuracy, sensitivity, specificity, negative predictive value and positive predictive value of duplex scanning to appropriately categorize femoropopliteal lesions as suitable or unsuitable for PTA were 89%, 83%, 92%, 94% and 78%, respectively. The accuracy of duplex scanning for predicting the performance of infrainguinal PTA was 83%. Conclusion: Duplex scanning has an important impact on the selection of treatment modalities in limbs with infrainguinal arterial occlusive disease. Femoropopliteal lesions can be reliably selected to PTA according to duplex scan findings

Templated Chemistry for Sequence-Specific Fluorogenic Detection of Duplex DNA

Science.gov (United States)

Li, Hao; Franzini, Raphael M.; Bruner, Christopher; Kool, Eric T.

2015-01-01

We describe the development of templated fluorogenic chemistry for detection of specific sequences of duplex DNA in solution. In this approach, two modified homopyrimidine oligodeoxynucleotide probes are designed to bind by triple helix formation at adjacent positions on a specific purine-rich target sequence of duplex DNA. One fluorescein-labeled probe contains an α-azidoether linker to a fluorescence quencher; the second (trigger) probe carries a triarylphosphine, designed to reduce the azide and cleave the linker. The data showed that at pH 5.6 these probes yielded a strong fluorescence signal within minutes on addition to a complementary homopurine duplex DNA target. The signal increased by a factor of ca. 60, and was completely dependent on the presence of the target DNA. Replacement of cytosine in the probes with pseudoisocytosine allowed the templated chemistry to proceed readily at pH 7. Single nucleotide mismatches in the target oligonucleotide slowed the templated reaction considerably, demonstrating high sequence selectivity. The use of templated fluorogenic chemistry for detection of duplex DNAs has not been previously reported and may allow detection of double stranded DNA, at least for homopurine-homopyrimidine target sites, under native, non-disturbing conditions. PMID:20859985

Podiatry Ankle Duplex Scan: Readily Learned and Accurate in Diabetes.

Science.gov (United States)

Normahani, Pasha; Powezka, Katarzyna; Aslam, Mohammed; Standfield, Nigel J; Jaffer, Usman

2018-03-01

We aimed to train podiatrists to perform a focused duplex ultrasound scan (DUS) of the tibial vessels at the ankle in diabetic patients; podiatry ankle (PodAnk) duplex scan. Thirteen podiatrists underwent an intensive 3-hour long simulation training session. Participants were then assessed performing bilateral PodAnk duplex scans of 3 diabetic patients with peripheral arterial disease. Participants were assessed using the duplex ultrasound objective structured assessment of technical skills (DUOSATS) tool and an "Imaging Score". A total of 156 vessel assessments were performed. All patients had abnormal waveforms with a loss of triphasic flow. Loss of triphasic flow was accurately detected in 145 (92.9%) vessels; the correct waveform was identified in 139 (89.1%) cases. Participants achieved excellent DUOSATS scores (median 24 [interquartile range: 23-25], max attainable score of 26) as well as "Imaging Scores" (8 [8-8], max attainable score of 8) indicating proficiency in technical skills. The mean time taken for each bilateral ankle assessment was 20.4 minutes (standard deviation ±6.7). We have demonstrated that a focused DUS for the purpose of vascular assessment of the diabetic foot is readily learned using intensive simulation training.

Apolipoprotein E and carotid artery atherosclerosis - The Rotterdam study

NARCIS (Netherlands)

Slooter, AJC; Bots, ML; Havekes, LM; del Sol, AI; Cruts, M; Grobbee, DE; Hofman, A; Van Broeckhoven, C; Witteman, JCM; van Duijn, CM

Background and Purpose-Carotid artery atherosclerosis is a strong predictor for future stroke. It is yet unclear whether the apolipoprotein E polymorphism (APOE) is related to atherosclerosis in the carotid arteries. The aim of the present study was to investigate the role of APOE in carotid artery

Toughness and other mechanical properties of the duplex stainless steel 2205

International Nuclear Information System (INIS)

Sieurin, H.; Sandstroem, R.

2003-01-01

The use and range of potential applications of duplex stainless steel continuously increase. An overview of the mechanical properties of duplex stainless steel 2205 is presented with focus on toughness properties. Impact and fracture toughness as well as strength results from the European research project, EcoPress, are presented. (orig.)

Data on genetic associations of carotid atherosclerosis markers in Mexican American and European American rheumatoid arthritis subjects

Directory of Open Access Journals (Sweden)

Rector Arya

2018-04-01

Full Text Available Carotid Intima-media thickness (CIMT and plaque are well established markers of subclinical atherosclerosis and are widely used for identifying subclinical atherosclerotic disease. We performed association analyses using Metabochip array to identify genetic variants that influence variation in CIMT and plaque, measured using B-mode ultrasonography, in rheumatoid arthritis (RA patients. Data on genetic associations of common variants associated with both CIMT and plaque in RA subjects involving Mexican Americans (MA and European Americans (EA populations are presented in this article. Strong associations were observed after adjusting for covariate effects including baseline clinical characteristics and statin use. Susceptibility loci and genes and/or nearest genes associated with CIMT in MAs and EAs with RA are presented. In addition, common susceptibility loci influencing CIMT and plaque in both MAs and EAs have been presented. Polygenic Risk Score (PRS plots showing complementary evidence for the observed CIMT and plaque association signals are also shown in this article. For further interpretation and details, please see the research article titled “A Genetic Association Study of Carotid Intima-Media Thickness (CIMT and Plaque in Mexican Americans and European Americans with Rheumatoid Arthritis” which is being published in Atherosclerosis (Arya et al., 2018 [1].(Arya et al., in press Thus, common variants in several genes exhibited significant associations with CIMT and plaque in both MAs and EAs as presented in this article. These findings may help understand the genetic architecture of subclinical atherosclerosis in RA populations.

Carotid artery stenting: Rationale, technique, and current concepts

International Nuclear Information System (INIS)

Yilmaz, Hasan; Pereira, Vitor Mendes; Narata, Ana-Paula; Sztajzel, Roman; Lovblad, Karl-Olof

2010-01-01

Carotid stenosis is a major risk factor for stroke. With the aging of the general population and the availability of non-invasive vascular imaging studies, the diagnosis of a carotid plaque is commonly made in medical practice. Asymptomatic and symptomatic carotid stenoses need to be considered separately because their natural history is different. Two large randomized controlled trials (RCTs) showed the effectiveness of carotid endarterectomy (CEA) in preventing ipsilateral ischemic events in patients with symptomatic severe stenosis. The benefit of surgery is much less for moderate stenosis and harmful in patients with stenosis less than 50%. Surgery has a marginal benefit in patients with asymptomatic stenosis. Improvements in medical treatment must be taken into consideration when interpreting the results of these previous trials which compared surgery against medical treatment available at the time the trials were conducted. Carotid artery stenting (CAS) might avoid the risks associated with surgery, including cranial nerve palsy, myocardial infarction, or pulmonary embolism. Therefore and additionally to well-established indications of CAS, this endovascular approach might be a valid alternative particularly in patients at high surgical risk. However, trials of endovascular treatment of carotid stenosis have failed to provide enough evidence to justify routine CAS as an alternative to CEA in patients suitable for surgery. More data from ongoing randomized trials of CEA versus CAS will be soon available. These results will help determining the role of CAS in the management of patients with carotid artery stenosis.

Doppler-ultrasonographic finding of air in the portal vein: a case report

Energy Technology Data Exchange (ETDEWEB)

Park, Ki Soon; Lee, Kwan Sup; Lee, Yul; Chung, Soo Young; Bae, Sang Hoon [College of Medicine, Hallym University, Seoul (Korea, Republic of)

1994-03-15

Classically air in the portal vein has been detected on plain radiography, but computed tomography and ultrasonography have been shown to be more sensitive. We report a case of air in the PV in a 10-day-old infant with pneumatosis intestinalis with its ultrasonographic and Doppler findings. The patient was a 10-day-old infant born by cesarean section at 41 weeks. Simple abdomen film revealed branching pattern of radiolucent air shadows within in contour of liver, gas distention of bowel loops and thickenod bowel walls with lincar intraluminal air shadows in abdomen, suggesting necrotizing enterocolitis. So we performed Doppler ultrasonography. Ultrasonography showed branching pattern of hyperechogenic dots and along the lumen of left portal vein. The color Doppler study revealed an aliasing duo to increased velocity and whirling pattern of blood flow, and the Duplex Doppler spectral display showed sharp, vertical bidirectional spikes by air in portal vein. Air in the portal vein can be easily diagnosed by the following signs: hyperechogenic dots in the portal vein on ultrasonography and vertical, sharp bidirectional spikes superimposed on the usual Doppler tracing of the portal vein on Duplex ultrasonography.

Doppler-ultrasonographic finding of air in the portal vein: a case report

International Nuclear Information System (INIS)

Park, Ki Soon; Lee, Kwan Sup; Lee, Yul; Chung, Soo Young; Bae, Sang Hoon

1994-01-01

Classically air in the portal vein has been detected on plain radiography, but computed tomography and ultrasonography have been shown to be more sensitive. We report a case of air in the PV in a 10-day-old infant with pneumatosis intestinalis with its ultrasonographic and Doppler findings. The patient was a 10-day-old infant born by cesarean section at 41 weeks. Simple abdomen film revealed branching pattern of radiolucent air shadows within in contour of liver, gas distention of bowel loops and thickenod bowel walls with lincar intraluminal air shadows in abdomen, suggesting necrotizing enterocolitis. So we performed Doppler ultrasonography. Ultrasonography showed branching pattern of hyperechogenic dots and along the lumen of left portal vein. The color Doppler study revealed an aliasing duo to increased velocity and whirling pattern of blood flow, and the Duplex Doppler spectral display showed sharp, vertical bidirectional spikes by air in portal vein. Air in the portal vein can be easily diagnosed by the following signs: hyperechogenic dots in the portal vein on ultrasonography and vertical, sharp bidirectional spikes superimposed on the usual Doppler tracing of the portal vein on Duplex ultrasonography

Hyperfusion syndrome after carotid endarterectomy

International Nuclear Information System (INIS)

Harrison, P.B.; Wong, M.J.; Belzberg, A.; Holden, J.

1991-01-01

This article describes the CT scans of two patients who, following carotid endarterectomy, developed headache and seizures suggestive of hyperperfusion syndrome. Their CT scans demonstrated ipsilateral mass effect and white matter hypodensity. One patient progressed to hemorrhage and died. Although infarction is described as the commonest neurologic event to occur after carotid endarterectomy, autopsy or cerebral blood flow studies in these patients suggests that the changes were due to hyperperfusion rather that infarction. (orig.)

Percutaneous angioplasty of carotid artery stenoses

Energy Technology Data Exchange (ETDEWEB)

Freitag, G.; Freitag, J.; Koch, R.D.; Wagemann, W.

1986-03-01

Percutaneous transluminal angioplasty (PTA) is a well-established method to remedy stenoses and short occlusions in the femoro-popliteal region and has also proved worthwhile in dilating stenoses of pelvic, renal and coronary arteries. Following successful experiments in animals, Mathias et al. employed angioplasty to treat carotid artery stenoses in the same way. To date, successful treatment of carotid artery stenoses has been described only in isolated recent reports. For fear of embolism, angioplasty has not yet become standard practice in this region. Because of the limited number of carotid artery stenoses treated so far, the risk involved cannot be reliably assessed. It is remarkable that no embolism has been reported for the greater number of dilated stenoses of the subclavian artery. Moreover, the report by Mathias et al. indicated that for 350 angioplasties of pelvifemoral arteries 1.1% embolisms occured after artery occlusions only, while no embolism was observed after stenoses. Having gained experience of applying PTA to the treatment of vascular obstructions of extremities, we have adopted this technique in the carotid area as well.

Base Pair Opening in a Deoxynucleotide Duplex Containing a cis-syn Thymine Cyclobutane Dimer Lesion

Science.gov (United States)

Wenke, Belinda B.; Huiting, Leah N.; Frankel, Elisa B.; Lane, Benjamin F.; Núñez, Megan E.

2014-01-01

The cis-syn thymine cyclobutane dimer is a DNA photoproduct implicated in skin cancer. We compared the stability of individual base pairs in thymine dimer-containing duplexes to undamaged parent 10-mer duplexes. UV melting thermodynamic measurements, CD spectroscopy, and 2D NOESY NMR spectroscopy confirm that the thymine dimer lesion is locally and moderately destabilizing within an overall B-form duplex conformation. We measured the rates of exchange of individual imino protons by NMR using magnetization transfer from water and determined the equilibrium constant for the opening of each base pair Kop. In the normal duplex Kop decreases from the frayed ends of the duplex toward the center, such that the central TA pair is the most stable with a Kop of 8×10−7. In contrast, base pair opening at the 5’T of the thymine dimer is facile. The 5’T of the dimer has the largest equilibrium constant (Kop =3×10−4) in its duplex, considerably larger than even the frayed penultimate base pairs. Notably, base pairing by the 3’T of the dimer is much more stable than by the 5’T, indicating that the predominant opening mechanism for the thymine dimer lesion is not likely to be flipping out into solution as a single unit. The dimer asymmetrically affects the stability of the duplex in its vicinity, destabilizing base pairing on its 5’ side more than on the 3’ side. The striking differences in base pair opening between parent and dimer duplexes occur independently of the duplex-single strand melting transitions. PMID:24328089

Effects of trimethylamine N-oxide and urea on DNA duplex and G-quadruplex.

Science.gov (United States)

Ueda, Yu-Mi; Zouzumi, Yu-Ki; Maruyama, Atsushi; Nakano, Shu-Ichi; Sugimoto, Naoki; Miyoshi, Daisuke

2016-01-01

We systematically investigated effects of molecular crowding with trimethylamine N -oxide (TMAO) as a zwitterionic and protective osmolyte and urea as a nonionic denaturing osmolyte on conformation and thermodynamics of the canonical DNA duplex and the non-canonical DNA G-quadruplex. It was found that TMAO and urea stabilized and destabilized, respectively, the G-quadruplex. On the other hand, these osmolytes generally destabilize the duplex; however, it was observed that osmolytes having the trimethylamine group stabilized the duplex at the lower concentrations because of a direct binding to a groove of the duplex. These results are useful not only to predict DNA structures and their thermodynamics under physiological environments in living cells, but also design of polymers and materials to regulate structure and stability of DNA sequences.

Influence of the filler material on the pitting corrosion in welded duplex stainless

International Nuclear Information System (INIS)

Munez, C. J.; Utrilla, M. V.; Urena, A.; Otero, E.

2007-01-01

In this work, it has been studied the pitting corrosion resistance of welding duplex stainless steel 2205. Unions were made by GMAW process with different fillers: duplex ER 2209 and two austenitic (ER 316LSi and ER 308LSi). the microstructure obtained with the duplex ER 2209 filler is similar to the duplex 2205 base material, but the unions produced with the austenitic fillers cause a decrease of the phases relationα/γ. To evaluate the influence of the filler on the weld, the pitting corrosion resistance was determined by electrochemical critical pitting temperature test (TCP) and the mechanical properties by the hardness. The phases imbalance produced for the dissimilar fillers bring out a variation of the pitting corrosion resistance and the mechanical properties. (Author)

Duplex sonography of the near-surface leg veins

International Nuclear Information System (INIS)

Mendoza, E.

2007-01-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins

Results of subclavian to carotid artery bypass for occlusive disease of the common carotid artery: A retrospective cohort study.

Science.gov (United States)

Illuminati, Giulio; Pizzardi, Giulia; Calio, Francesco G; Masci, Federica; Pasqua, Rocco; Frezzotti, Francesca; Peschillo, Simone

2018-05-01

Optimal treatment of significant atherosclerosis of the common carotid artery (CCA) is not well-defined. The purpose of this study was to evaluate the long-term results of prosthetic subclavian to carotid bypass for occlusive disease of the CCA. From January 1994 to December 2015, 45 patients, mean age 67 years, underwent an ipsilateral subclavian to carotid bypass for occlusive disease of the CCA. Thirty-eight patients (84%) presented with neurologic symptoms, including transitory ischemic attacks in 29 cases and minor strokes in 9 cases. The graft material consisted of a 7 mm polytetrafluoroethylene conduit, and the distal anastomosis was done on the carotid bulb in 21 patients, on the internal carotid artery in 19 cases, and on the distal CCA in 5 cases. Median length of follow-up was 58 months. Study endpoints were the combined postoperative stroke/mortality rate, graft infection, overall late survival, freedom from ipsilateral stroke, and graft patency. Postoperative stroke/mortality rate was 2%. No graft infection was observed throughout follow-up. At 60 months, overall survival, freedom from stroke, and graft patency were 71% (standard error [SE] = 0.07), 98% (SE = 0.02), and 95.5% (SE = 0.06), respectively. Subclavian to carotid bypass allows very good patency rates and excellent protection from postoperative and late stroke, remaining a benchmark for any other treatment method. Copyright © 2018. Published by Elsevier Ltd.

Dwell-Time Distribution, Long Pausing and Arrest of Single-Ribosome Translation through the mRNA Duplex.

Science.gov (United States)

Xie, Ping

2015-10-09

Proteins in the cell are synthesized by a ribosome translating the genetic information encoded on the single-stranded messenger RNA (mRNA). It has been shown that the ribosome can also translate through the duplex region of the mRNA by unwinding the duplex. Here, based on our proposed model of the ribosome translation through the mRNA duplex we study theoretically the distribution of dwell times of the ribosome translation through the mRNA duplex under the effect of a pulling force externally applied to the ends of the mRNA to unzip the duplex. We provide quantitative explanations of the available single molecule experimental data on the distribution of dwell times with both short and long durations, on rescuing of the long paused ribosomes by raising the pulling force to unzip the duplex, on translational arrests induced by the mRNA duplex and Shine-Dalgarno(SD)-like sequence in the mRNA. The functional consequences of the pauses or arrests caused by the mRNA duplex and the SD sequence are discussed and compared with those obtained from other types of pausing, such as those induced by "hungry" codons or interactions of specific sequences in the nascent chain with the ribosomal exit tunnel.

The Place of Ultrasonography in the Evaluation of Rib Fractures

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Fulya Bakılan

2015-12-01

Full Text Available Objective: The aim of this study was to investigate whether ultrasonography is superior to chest x-ray in detecting rib fractures in patients with minor blunt chest trauma and chest pain. Materials and Methods: Ultrasonography findings of 32 patients with minor blunt chest trauma showing no evidence of a rib fracture on anteroposterior chest x-rays, were documented. Presence of cortical discontinuities, acoustic shadows, reverberation artifacts, and hematoma by ultrasonography was proposed as the diagnostic criteria for detecting the rib fracture. Results: Rib fracture was detected in 20 patients (62.5% according to ultrasonography results. A mildly displaced fracture was detected in 7 patients (35%, hematoma was detected in 3 patients (15% and multiple fractures (in 5th, 6th, 7th, and 8th ribs were detected in 1 patient (5%. Conclusion: The results of our study showed that ultrasonography is superior to chest x-ray, in detecting rib fractures.

Staged bilateral carotid endarterectomy

DEFF Research Database (Denmark)

Schroeder, T; Sillesen, H; Engell, Hans Christian

1986-01-01

In a series of 56 staged bilateral carotid endarterectomies, new neurologic symptoms developed in 5% and 20% following the first and second procedure, respectively. All complications were transient or minor. The incidence of postendarterectomy hypertension was significantly higher following...... the second procedure, when operations were staged less than 3 weeks apart. A correlation between these hypertensive episodes and the occurrence of new neurologic symptoms could not be shown. However, as this correlation has been proved in several other reports, bilateral carotid endarterectomy is advised...... to be staged at least 3 weeks apart. In addition, a conservative attitude towards contralateral asymptomatic lesions is proposed....

The Place of Ultrasonography in the Evaluation of Rib Fractures

OpenAIRE

Fulya Bakılan; Gökhan Yüce; Ahmet Çağdaş Biçen; Tanju Keten

2015-01-01

Objective: The aim of this study was to investigate whether ultrasonography is superior to chest x-ray in detecting rib fractures in patients with minor blunt chest trauma and chest pain. Materials and Methods: Ultrasonography findings of 32 patients with minor blunt chest trauma showing no evidence of a rib fracture on anteroposterior chest x-rays, were documented. Presence of cortical discontinuities, acoustic shadows, reverberation artifacts, and hematoma by ultrasonography was...

Effect of Ultrasonography on Student Learning of Shoulder Anatomy and Landmarks.

Science.gov (United States)

de Vries, Kristen D; Brown, Rebecca; Mazzie, Joseph; Jung, Min-Kyung; Yao, Sheldon C; Terzella, Michael J

2018-01-01

Ultrasonography is becoming more common in clinical use, and it has been shown to have promising results when introduced into medical school curricula. To determine whether the use of ultrasonography as an educational supplement can improve osteopathic medical students' confidence and ability to locate 4 specific shoulder anatomical landmarks: the coracoid process, the transverse process of T1, the long head of the biceps within the bicipital groove, and the supraspinatus tendon. In this randomized controlled study, first-year osteopathic medical students aged 18 years or older were recruited and randomly assigned to a group with exposure (ultrasonography group) or without exposure (control group) to an ultrasonography machine. First, a survey was administered to measure students' baseline knowledge of shoulder anatomy, confidence in palpation skills, and opinion on anatomical landmark identification teaching methods. Next, students were shown presentations on shoulder anatomy and allowed to practice locating and palpating the specified landmarks. Students in the ultrasonography group were also given instruction on the use of ultrasonography. All students were asked to locate each of the 4 specified anatomical landmarks and then given a follow-up survey. A Mann Whitney U test was used to compare the confidence of the students before and after the intervention. A secondary analysis was performed to compare the degree of deviance from the correct position of the specified anatomical landmark between the ultrasonography and control groups. P values less than .05 were considered statistically significant. Sixty-four students participated. Compared with the control group, students in the ultrasonography group had a greater increase in confidence after the session in their ability to locate the coracoid process, bicipital tendon, and supraspinatus tendon (P=.022, P=.029, P=.44, respectively). Students in the ultrasonography group were also able to more accurately palpate

Duplex Healing of Selectively Thiolated Guanosine Mismatches through a Cd2+ Chemical Stimulus.

Science.gov (United States)

Lunn, Samantha M L; Hribesh, Samira; Whitfield, Colette J; Hall, Michael J; Houlton, Andrew; Bronowska, Agnieszka K; Tuite, Eimer M; Pike, Andrew R

2018-03-25

The on-column selective conversion of guanosine to thioguanosine (tG) yields modified oligomers that exhibit destabilisation over the fully complementary duplex. Restoration to a stabilised duplex is induced through thio-directed Cd 2+ coordination; a route for healing DNA damage. Short oligomers are G-specifically thiolated through a modified on-column protocol without the need for costly thioguanosine phosphoramidites. Addition of Cd 2+ ions to a duplex containing a highly disrupted tG central mismatch sequence, 3'-A 6 tG 4 T 6 -5', suggests a (tG) 8 Cd 2 central coordination regime, resulting in increased base stacking and duplex stability. Equilibrium molecular dynamic calculations support the hypothesis of metal-induced healing of the thiolated duplex. The 2 nm displacement of the central tG mismatched region is dramatically reduced after the addition of a chemical stimuli, Cd 2+ ions, returning to a minimized fluctuational state comparable to the unmodified fully complementary oligomer. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Doppler ultrasonography of the lower extremity arteries: anatomy and scanning guidelines

Energy Technology Data Exchange (ETDEWEB)

Hwang, Ji Young [Dept. of Radiology, Ewha Womans University School of Medicine, Seoul (Korea, Republic of)

2017-04-15

Doppler ultrasonography of the lower extremity arteries is a valuable technique, although it is less frequently indicated for peripheral arterial disease than for deep vein thrombosis or varicose veins. Ultrasonography can diagnose stenosis through the direct visualization of plaques and through the analysis of the Doppler waveforms in stenotic and poststenotic arteries. To perform Doppler ultrasonography of the lower extremity arteries, the operator should be familiar with the arterial anatomy of the lower extremities, basic scanning techniques, and the parameters used in color and pulsed-wave Doppler ultrasonography.

Doppler ultrasonography of the lower extremity arteries: anatomy and scanning guidelines

Directory of Open Access Journals (Sweden)

Ji Young Hwang

2017-04-01

Full Text Available Doppler ultrasonography of the lower extremity arteries is a valuable technique, although it is less frequently indicated for peripheral arterial disease than for deep vein thrombosis or varicose veins. Ultrasonography can diagnose stenosis through the direct visualization of plaques and through the analysis of the Doppler waveforms in stenotic and poststenotic arteries. To perform Doppler ultrasonography of the lower extremity arteries, the operator should be familiar with the arterial anatomy of the lower extremities, basic scanning techniques, and the parameters used in color and pulsed-wave Doppler ultrasonography.

Breaking the Transmitter-Receiver Isolation Barrier in Mobile Handsets with Spatial Duplexing

DEFF Research Database (Denmark)

Alrabadi, Osama; Tatomirescu, Alexandru; Knudsen, Mikael

2013-01-01

In full-duplex radio communication systems like eUTRAN, CDMA-2000, the radio transmitter (Tx) is active at the same time as the radio receiver (Rx). The Tx and the Rx will be using separate dedicated frequency bands and the Tx-Rx isolation is ensured by duplex filters. However, agile duplexers...... required for multiband operation are almost non-existent while dedicating a bank of narrowband filters is bulky and incurs considerable switching losses. In this article we propose an approach that dramatically reduces the complexity of the RF frontend, first by replacing the duplex filter with a spatial...... frequency bands as long as the antennas are made tunable. Moreover, the spatial filter may directly benefit from the balanced architecture of the power amplifiers (PAs) thus reducing the total system complexity and insertion loss. Finally, simulation and initial measurement results are provided...

Can Full Duplex reduce the discovery time in D2D Communication?

DEFF Research Database (Denmark)

Gatnau, Marta; Berardinelli, Gilberto; Mahmood, Nurul Huda

2016-01-01

Device-to-device (D2D) communication is considered as one of the key technologies to support new types of services, such as public safety and proximity-based applications. D2D communication requires a discovery phase, i.e., the node awareness procedure prior to the communication phase. Conventional...... half duplex transmission may not be sufficient to provide fast discovery and cope with the strict latency targets of future 5G services. On the other hand, in-band full duplex, by allowing simultaneous transmission and reception, may complete the discovery phase faster. In this paper, the potential...... of full duplex in providing fast discovery for the next 5th generation (5G) system supporting D2D communication is investigated. A design for such system is presented and evaluated via simulations, showing that full duplex can accelerate the discovery phase by supporting a higher transmission probability...

Urgent carotid stenting before cardiac surgery in a young male patient with acute ischemic stroke caused by aortic and carotid dissection

Directory of Open Access Journals (Sweden)

Popović Rade

2016-01-01

Full Text Available Introduction. Acute aortic dissection (AD is the most common life-threatening disorder affecting the aorta. Neurological symptoms are present in 17-40% of cases. The management of these patients is controversial. Case report. We presented a 37-year-old man admitted for complaining of left-sided weak-ness. Symptoms appeared two hours before admission. The patient had no headache, neither thoracic pain. Neurological examination showed mild confusion, left-sided hemiplegia, National Institutes of Health Stroke Scale (NIHSS score was 10. Ischemic stroke was suspected, brain multislice computed tomography (MSCT and angiography were performed and right intrapetrous internal carotid artery dissection noted. Subsequent color Doppler ultrasound of the carotid arteries showed dissection of the right common carotid artery (CCA. The patient underwent thoracic and abdominal MSCT aortography which showed ascending aortic dissection from the aortic root, propagating in the brachiocephalic artery and the right CCA. Digital subtraction angiography was performed subsequently and two stents were successfully implanted in the brachiocephalic artery and the right CCA prior to cardiac surgery, only 6 hours after admission. The ascending aorta was reconstructed with graft interposition and the aortic valve re-suspended. The patient was hemodynamically stable and with no neurologic deficit after surgery. Unfortinately, at the operative day 6, mediastinitis developed and after intensive treatment the patients died 35 days after admission. Conclusion. In young patients with suspected stroke and oscillatory neurological impairment urgent MSCT angiography of the brain and neck and/or Doppler sonography of the carotid and vertebral artery are mandatory to exclude carotid and aortic dissection. The prompt diagnosis permits urgent carotid stenting and cardiosurgery. To the best of our knowledge, this is the first published case of immediate carotid stenting in acute ischemic

On full duplex Gaussian relay channels with self-interference

KAUST Repository

Behboodi, Arash

2016-08-15

Self interference (SI) in full duplex (FD) systems is the interference caused by the transmission stream on the reception stream. Being one of the main restrictive factors for performance of practical full duplex systems, however, not too much is known about its effect on the fundamental limits of relaying systems. In this work, we consider the full duplex three-node relay channel with SI where SI is modeled as an additive Gaussian noise whose variance is dependent on instantaneous input power. The classical achievable rates and upper bounds for the single three-node relay channel no longer apply due to the structure of SI. Achievable rates for Decode-and-Forward (DF) and Compress-and-Forward (CF) and upper bounds on the capacity are derived assuming Gaussian inputs and SI. The deterministic model is also introduced and its capacity is characterized. The optimal joint source-relay distributions is discussed. Numerical results are provided comparing the achievable rates and upper bound. © 2016 IEEE.

Duplex recombinase polymerase amplification assays incorporating competitive internal controls for bacterial meningitis detection.

Science.gov (United States)

Higgins, Owen; Clancy, Eoin; Forrest, Matthew S; Piepenburg, Olaf; Cormican, Martin; Boo, Teck Wee; O'Sullivan, Nicola; McGuinness, Claire; Cafferty, Deirdre; Cunney, Robert; Smith, Terry J

2018-04-01

Recombinase polymerase amplification (RPA) is an isothermal nucleic acid amplification technology that provides rapid and robust infectious disease pathogen detection, ideal for point-of-care (POC) diagnostics in disease-prevalent low-resource countries. We have developed and evaluated three duplex RPA assays incorporating competitive internal controls for the detection of leading bacterial meningitis pathogens. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae singleplex RPA assays were initially developed and evaluated, demonstrating 100% specificity with limits of detection of 4.1, 8.5 and 3.9 genome copies per reaction, respectively. Each assay was further developed into internally controlled duplex RPA assays via the incorporation of internal amplification control templates. Clinical performance of each internally controlled duplex RPA assay was evaluated by testing 64 archived PCR-positive clinical samples. Compared to real-time PCR, all duplex RPA assays demonstrated 100% diagnostic specificity, with diagnostic sensitivities of 100%, 86.3% and 100% for the S. pneumoniae, N. meningitidis and H. influenzae assays, respectively. This study details the first report of internally controlled duplex RPA assays for the detection of bacterial meningitis pathogens: S. pneumoniae, N. meningitidis and H. influenzae. We have successfully demonstrated the clinical diagnostic utility of each duplex RPA assay, introducing effective diagnostic technology for POC bacterial meningitis identification in disease-prevalent developing countries. Copyright © 2018 Elsevier Inc. All rights reserved.

Sigma phase morphologies in cast and aged super duplex stainless steel

International Nuclear Information System (INIS)

Martins, Marcelo; Casteletti, Luiz Carlos

2009-01-01

Solution annealed and water quenched duplex and super duplex stainless steels are thermodynamically metastable systems at room temperature. These systems do not migrate spontaneously to a thermodynamically stable condition because an energy barrier separates the metastable and stable states. However, any heat input they receive, for example through isothermal treatment or through prolonged exposure to a voltaic arc in the welding process, cause them to reach a condition of stable equilibrium which, for super duplex stainless steels, means precipitation of intermetallic and carbide phases. These phases include the sigma phase, which is easily identified from its morphology, and its influence on the material's impact strength. The purpose of this work was to ascertain how 2-hour isothermal heat treatments at 920 deg. C and 980 deg. C affect the microstructure of ASTM A890/A890M GR 6A super duplex stainless steel. The sigma phase morphologies were found to be influenced by these two aging temperatures, with the material showing a predominantly lacy microstructure when heat treated at 920 deg. C and block-shaped when heat treated at 980 deg. C.

[Diagnostic utility of endoscopic ultrasonography elastography and contrast-enhanced harmonic endoscopic ultrasonography in a patient with type 2 autoimmune pancreatitis].

Science.gov (United States)

Yokode, Masataka; Shiomi, Hideyuki; Itai, Ryosuke; Mikami, Sakae; Yamashita, Yukimasa; Nakano, Ryota; Ezaki, Takeshi; Masuda, Atsuhiro; Zen, Yoh

2018-01-01

A referring hospital diagnosed a 57-year-old man with a pancreatic head mass. The initial endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) was inconclusive because of the small sample size. Endoscopic ultrasonography elastography (EUS-EG) and contrast-enhanced harmonic endoscopic ultrasonography (CE-EUS), conducted at our institute, raised the possibility of mass-forming pancreatitis or autoimmune pancreatitis (AIP). A repeat EUS-FNA revealed inflammatory changes, including a neutrophilic duct injury suggestive of type 2 AIP. The pancreatic lesion responded well to the steroid therapy. The present case suggests that EUS-EG and CE-EUS may be useful for diagnostic exclusion of pancreatic cancers, and the combined use of EUS-EG and CE-EUS, with EUS-FNA, may help characterize inflammatory pancreatic lesions.

Tricriticality in the q-neighbor Ising model on a partially duplex clique.

Science.gov (United States)

Chmiel, Anna; Sienkiewicz, Julian; Sznajd-Weron, Katarzyna

2017-12-01

We analyze a modified kinetic Ising model, a so-called q-neighbor Ising model, with Metropolis dynamics [Phys. Rev. E 92, 052105 (2015)PLEEE81539-375510.1103/PhysRevE.92.052105] on a duplex clique and a partially duplex clique. In the q-neighbor Ising model each spin interacts only with q spins randomly chosen from its whole neighborhood. In the case of a duplex clique the change of a spin is allowed only if both levels simultaneously induce this change. Due to the mean-field-like nature of the model we are able to derive the analytic form of transition probabilities and solve the corresponding master equation. The existence of the second level changes dramatically the character of the phase transition. In the case of the monoplex clique, the q-neighbor Ising model exhibits a continuous phase transition for q=3, discontinuous phase transition for q≥4, and for q=1 and q=2 the phase transition is not observed. On the other hand, in the case of the duplex clique continuous phase transitions are observed for all values of q, even for q=1 and q=2. Subsequently we introduce a partially duplex clique, parametrized by r∈[0,1], which allows us to tune the network from monoplex (r=0) to duplex (r=1). Such a generalized topology, in which a fraction r of all nodes appear on both levels, allows us to obtain the critical value of r=r^{*}(q) at which a tricriticality (switch from continuous to discontinuous phase transition) appears.

Magnetic resonance urography in duplex kidney with ectopic ureteral insertion

Directory of Open Access Journals (Sweden)

Conjeevaram Rajendrarao Thambidorai

2011-01-01

Full Text Available This is a report on the use of magnetic resonance urography (MRU in a 6-year-old girl who presented with urinary incontinence. She had a left duplex kidney with poorly functioning upper moiety and ectopic insertion of the dilated upper pole ureter. MRU has been shown to be superior to conventional imaging techniques in delineating poorly functioning moieties of duplex kidneys and ectopic ureters.

Granulomatous Prostatitis: Gray-scale Transrectal Ultrasonography and Color Doppler Ultrasonography Findings

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyoung Jung; Lim, Joo Won; Lee, Dong Ho; Ko, Young Tae; Kim, Eui Jong [Kyung Hee University Medical Center, Seoul (Korea, Republic of)

2007-12-15

We report here three cases of granulomatous prostatitis. All cases were confirmed by a transrectal ultrasonography (TRUS)-guided core biopsy of the prostate. Two cases received intravesical BCG therapy for a bladder tumor, and one case had no known predisposing condition. Gray-scale TRUS showed low echoic nodules in the outer gland in all cases. Color Doppler ultrasonography (CDUS) showed several dot-like blood flows within the low echoic nodules in two cases and several dot-like blood flows and short linear blood flows within the low echoic nodules in one case. Gray-scale TRUS findings of granulomatous prostatitis are similar to findings of prostate cancer. On CDUS, several dot-like blood flows or short linear blood flows were noted within the low echoic nodules in patients with granulomatous prostatitis. If low echoic nodules with dot-like or short linear blood flows are noted in patients with genitourinary tract tuberculosis or previous BCG therapy, granulomatous prostatitis should be included in the differential diagnosis. However, a prostatic biopsy is required for a final diagnosis

[A Multimedia Tutorial to Train Ultrasonography of the Thyroid for Medical Students].

Science.gov (United States)

Ritter, Julia; Wolfram, Maximilian; Schuler, Stefan; Guntinas-Lichius, Orlando

2017-11-01

Physicians in education often have poor experience in practice and assessment of ultrasonography on entering their profession, due to a deficiency of training offers during their study of medicine. Hence, a multimedia device for stepwise learning and training ultrasonography of the thyroid was developed. A software for a portable ultrasonography system was used to design a multimedia device for ultrasonography of the thyroid. It allows the user to illustrate texts and pictorial material simultaneously with ultrasound examination in order to compare own findings with examples from a database. The device was evaluated by 8 medical students and compared to a tutor-guided training. A structured, stepwise manual for ultrasonography of the thyroid with a large content of examples in different sectional images was designed for simultaneous reconstruction with the ultrasonography device. The informative content of the device and the replicability of the examination procedure were evaluated positively. Assessment respecting clarity, eligibility for users without experience and learning success was varying. The tutorial to learn and train ultrasonography of the thyroid is an instrument for self-learning and improving practical education in ultrasonography in medical education. In the next version, the manual for the examination will be structured in greater detail. © Georg Thieme Verlag KG Stuttgart · New York.

Carotid bifurcation calcium and correlation with percent stenosis of the internal carotid artery on CT angiography

International Nuclear Information System (INIS)

McKinney, Alexander M.; Casey, Sean O.; Teksam, Mehmet; Truwit, Charles L.; Kieffer, Stephen; Lucato, Leandro T.; Smith, Maurice

2005-01-01

The aim of this paper was to determine the correlation between calcium burden (expressed as a volume) and extent of stenosis of the origin of the internal carotid artery (ICA) by CT angiography (CTA). Previous studies have shown that calcification in the coronary arteries correlates with significant vessel stenosis, and severe calcification (measured by CT) in the carotid siphon correlates with significant (greater than 50% stenosis) as determined angiographically. Sixty-one patients (age range 50-85 years) underwent CT of the neck with intravenous administration of iodinated contrast for a variety of conditions. Images were obtained with a helical multidetector array CT scanner and reviewed on a three-dimensional workstation. A single observer manipulated window and level to segment calcified plaque from vascular enhancement in order to quantify vascular calcium volume (cc) in the region of the bifurcation of the common carotid artery/ICA origin, and to measure the extent of ICA stenosis near the origin. A total of 117 common carotid artery bifurcations were reviewed. A ''significant'' stenosis was defined arbitrarily as >40% (to detect lesions before they become hemodynamically significant) of luminal diameter on CTA using NASCET-like criteria. All ''significant'' stenoses (21 out of 117 carotid bifurcations) had measurable calcium. We found a relatively strong correlation between percent stenosis and the calcium volume (Pearson's r= 0.65, P<0.0001). We also found that there was an even stronger correlation between the square root of the calcium volume and the percent stenosis as measured by CTA (r= 0.77, P<0.0001). Calcium volumes of 0.01, 0.03, 0.06, 0.09 and 0.12 cc were used as thresholds to evaluate for a ''significant'' stenosis. A receiver operating characteristic (ROC) curve demonstrated that thresholds of 0.06 cc (sensitivity 88%, specificity 87%) and 0.03 cc (sensitivity 94%, specificity 76%) generated the best combinations of sensitivity and

Advanced Asymptomatic Carotid Disease and Cognitive Impairment: An Understated Link?

Directory of Open Access Journals (Sweden)

Irena Martinić-Popović

2012-01-01

Full Text Available Advanced carotid disease is known to be associated with symptomatic cerebrovascular diseases, such as stroke or transient ischemic attack (TIA, as well as with poststroke cognitive impairment. However, cognitive decline often occurs in patients with advanced carotid stenosis without clinically evident stroke or TIA, so it is also suspected to be an independent risk factor for dementia. Neurosonological methods enable simple and noninvasive assessment of carotid stenosis in patients at risk of advanced atherosclerosis. Cognitive status in patients diagnosed with advanced carotid stenosis is routinely not taken into consideration, although if cognitive impairment is present, such patients should probably be called symptomatic. In this paper, we discuss results of some most important studies that investigated cognitive status of patients with asymptomatic advanced carotid disease and possible mechanisms involved in the causal relationship between asymptomatic advanced carotid disease and cognitive decline.

Venous filling time using air-plethysmography correlates highly with great saphenous vein reflux time using duplex.

Science.gov (United States)

Lattimer, C R; Azzam, M; Kalodiki, E; Geroulakos, G

2014-03-01

Venous filling time (VFT90) is the time taken to reach 90% of the venous volume in the calf. It is recorded by air-plethysmography (APG(®)) and is assumed to measure global venous reflux duration. However, this has never been confirmed by duplex. The aim of the study was to compare VFT on APG to venous reflux time/duration (RT) measured simultaneously with duplex on the same patients. Twenty-six consecutive patients, M:F = 16:10, age (25-78), C1 = 1, C2 = 4, C3 = 8, C4a = 6, C4b = 4, C5 = 2, C6 = 1, underwent simultaneous APG with duplex. The venous filling index (VFI, mL/second), VFT90 (seconds), great saphenous vein (GSV) RT on duplex, averaged thigh GSV diameter and thigh length (length) between the APG sensor air-cuff and duplex transducer were recorded. The VFT100 was calculated by VFT90/0.9. The additional time taken to fill the thigh was achieved using the VFI, length and deep vein diameter (d), to determine the corrected reflux duration: CRD = VFT100 + (length × πd(2)/4 (1/VFI)). Twenty-five patients are presented. One patient with very mild reflux (VFT90 = 55.9 seconds) had an indeterminate endpoint on duplex and was excluded. The median (range) VFI and GSV diameter was 4.9(1.3-15.5) mL/second and 7(4-17) mm, respectively. The VFT90 and VFT100 both correlated with RT on duplex (Spearman, P duplex RT at 24 (16.9) versus 28 (20) seconds respectively, P duplex by performing simultaneous measurements. There was an excellent correlation between the VFT90 versus duplex RT, thereby comparing reverse flow in a single superficial vein against the legs overall venous haemodynamic status. These tests can both be used in the quantification of reflux.

Evaluation of Microstructure and Mechanical Properties in Dissimilar Austenitic/Super Duplex Stainless Steel Joint

Science.gov (United States)

Rahmani, Mehdi; Eghlimi, Abbas; Shamanian, Morteza

2014-10-01

To study the effect of chemical composition on microstructural features and mechanical properties of dissimilar joints between super duplex and austenitic stainless steels, welding was attempted by gas tungsten arc welding process with a super duplex (ER2594) and an austenitic (ER309LMo) stainless steel filler metal. While the austenitic weld metal had vermicular delta ferrite within austenitic matrix, super duplex stainless steel was mainly comprised of allotriomorphic grain boundary and Widmanstätten side plate austenite morphologies in the ferrite matrix. Also the heat-affected zone of austenitic base metal comprised of large austenite grains with little amounts of ferrite, whereas a coarse-grained ferritic region was observed in the heat-affected zone of super duplex base metal. Although both welded joints showed acceptable mechanical properties, the hardness and impact strength of the weld metal produced using super duplex filler metal were found to be better than that obtained by austenitic filler metal.

Ultrasonography of the Kidney

DEFF Research Database (Denmark)

Lindskov Hansen, Kristoffer; Nielsen, Michael Bachmann; Ewertsen, Caroline

2016-01-01

Ultrasonography of the kidneys is essential in the diagnosis and management of kidney-related diseases. The kidneys are easily examined, and most pathological changes in the kidneys are distinguishable with ultrasound. In this pictorial review, the most common findings in renal ultrasound...

Carotid artery bypass in acute postendarterectomy thrombosis.

Science.gov (United States)

Paty, P S; Darling, R C; Cordero, J A; Shah, D M; Chang, B B; Leather, R P

1996-08-01

Carotid endarterectomy has demonstrated excellent results over the past 2 decades with combined stroke mortality of improvement in symptoms in 79% (11 of 14) of the patients and complete resolution in 57% (8 of 14). In long-term follow up (1 to 41 months), there have been no occlusions and one restenosis requiring revision at 11 months. Carotid artery bypass can be performed safely with acceptable results. The use of autogenous venous conduits allows reconstruction with an endothelial lined conduit that may improve results in patients with acute postoperative neurologic deficit secondary to thrombosis of the endarterectomized carotid artery.

Endoscopic Ultrasonography in the Diagnosis of Gastric Subepithelial Lesions

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Eun Jeong Gong

2016-09-01

Full Text Available Subepithelial lesions occasionally found in the stomach of patients undergoing endoscopy may be either benign lesions or tumors with malignant potential. They may also appear due to extrinsic compression. Discrimination of gastric subepithelial lesions begins with meticulous endoscopic examination for size, shape, color, mobility, consistency, and appearance of the overlying mucosa. Accurate diagnosis can be achieved with endoscopic ultrasonography, which provides useful information on the exact size, layer-of-origin, and characteristic morphologic features to support a definitive diagnosis. Endoscopic ultrasonography also aids in the prediction of malignant potential, especially in gastrointestinal stromal tumors. Features of subepithelial lesions identified on endoscopic ultrasonography can be used to determine whether further diagnostic procedures such as endoscopic resection, fine needle aspiration, or core biopsy are required. Endoscopic ultrasonography is a valuable tool for diagnosis and clinical decision making during follow-up of gastric subepithelial lesions.

Evaluation of breast symptoms with mammography and ultrasonography

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Emine Devolli Disha

2011-12-01

Full Text Available Introduction: Aim of the study was to discern which are more frequent symptoms presented in malign and benign masses diagnosed by mammography and ultrasonography.Methods: Our study group consisted of 546 female patients, with breast symptoms such as palpable lumps (40.8%, pain in the breast (26%, localized lumpiness or nodularity (13.7%, nipple retraction (11.2%, nipplebloody discharge (5.1% and redness and swelling of the breast (3.1%. All 546 patients were examined by ultrasonography and mammography. Biopsy was performed according to the findings of mammography and ultrasonography.Results: In breast cancer detection ultrasonography showed an efficiency of 79.4% compared to 55.0% for mammography in detecting breast lump, in the case of nipple retraction mammography showed an efficiency of 89.1% compared to 80.4% for ultrasound, while the lowest efficiency for mammography was in the cases with localized lumpiness or nodularity 17.1% compared to 45.7% for ultrasound. In detecting fibrocystic changes where the most common symptoms was pain, ultrasonography showed an efficiency of 99.3 % compared to 84.2 % for mammography.Conclusions: Our study confirmed that breast lumps are detectable in the majority of patients with breast cancer. The most frequent symptoms in patient with benign lesions were pain or localized discomfort. The diagnostic accuracy for carcinomas of the breast and for benign lesions according to symptoms was higher for ultrasound than for mammography.

Color-coded duplex sonography in the study of thyroid pathologic conditions

International Nuclear Information System (INIS)

Anguissola, R.; Bozzini, A.; Campani, R.; Bottinelli, O.; Genovese, E.; Guglielmoni, B.; Fulle, I.; Bandi, G.

1991-01-01

The authors examined 110 patients with suspected pathologic conditions of the thyroid by means of color-coded duplex US. In addition to the information yielded by conventional US, this technique allows organ vascularization to be demonstrated. Five normal patients were considered as a control group: no tissue vascularization was demonstrated in these cases. In 8 patients presenting with carcinoma or recurrences, vascularization was markedly increased both peripheral and central to the nodule. A few doubts are still to be solved as to the diagnostic value of color-coded duplex US in the evaluation of non-carcinomas nodular pathologic conditions. As a matter of fact, non-functioning avascular adenomas can be demonstrated only in a very low percentage of cases (66%). Color-coded duplex US proved extremely sensitive and specific in depicting malignant neoplasms. Moreover, the use of fine.needle biopsy could be optimized and subsequently reduced. Color-coded duplex US proved to be markedly superior to othe rmethods and techniques in the study of thyroid diseases, especially thyroiditis and multiple pathologic conditions. The simultaneous presence of hypocapture at scintigraphy and peripheral and central vascularization in a single nodule or within multinodular struma at color-Doppler was highly suggestive of malignant thyroid neoplasm. Color-coded duplex US is a low-cost technique, which can be performed on an outpatient basis. Moreover, it is not invasive, nor does it damage the thyroid. That is why its use is almost mandatory in the study of pathologic conditions of the thyroid

Treatment of a symptomatic intrathoracic internal carotid artery

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Christopher R. Brown

2017-09-01

Full Text Available Intrathoracic common carotid artery bifurcations are an anatomic anomaly with such rarity that only six cases have been reported to date. The true incidence of and preferred treatment options for a diseased intrathoracic common carotid artery bifurcation or internal carotid artery (ICA have not been clearly described. This case report describes a 72-year-old man who experienced a postoperative right hemispheric stoke after an aortic valve replacement, radiofrequency maze procedure, and left atrial appendage clip. Postoperative cerebrovascular evaluation revealed a severely diseased intrathoracic ICA that was treated by ligation of the diseased proximal ICA and transposition of the distal ICA to the disease-free external carotid artery. The patient provided written consent to present the history, data, and images in this manuscript.

Development of a panel of seven duplex real-time PCR assays for detecting 13 streptococcal superantigens.

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Yang, Peng; Peng, Xiaomin; Cui, Shujuan; Shao, Junbin; Zhu, Xuping; Zhang, Daitao; Liang, Huijie; Wang, Quanyi

2013-07-30

Streptococcal superantigens (SAgs) are the major virulence factors of infection in humans for group A Streptococcus (GAS) bacteria. A panel consisting of seven duplex real-time PCR assays was developed to simultaneously detect 13 streptococcal SAgs and one internal control which may be important in the control of GAS-mediated diseases. Primer and probe sequences were selected based on the highly conserved region from an alignment of nucleotide sequences of the 13 streptococcal SAgs. The reaction conditions of the duplex real-time PCR were optimized and the specificity of the duplex assays was evaluated using SAg positive strains. The limit of detection of the duplex assays was determined by using 10-fold serial dilutions of the DNA of 13 streptococcal SAgs and compared to a conventional polymerase chain reaction (PCR) method for evaluating the duplex assays sensitivity. Using the duplex assays, we were able to differentiate between 13 SAgs from Streptococcus strains and other non-Streptococcus bacteria without cross-reaction. On the other hand, the limit of detection of the duplex assays was at least one or two log dilutions lower than that of the conventional PCR. The panel was highly specific (100%) and the limit of detection of these duplex groups was at least ten times lower than that obtained by using a conventional PCR method.

Inconsistent Correlation Between Carotid Artery Intima-Media Thickness and Peripheral Arterial Tonometry: Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

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Lemos, Sara P; Passos, Valéria Maria A; Brant, Luisa C C; Bensenor, Isabela J M; Ribeiro, Antônio Luiz P; Barreto, Sandhi Maria

2015-08-01

To estimate the association between 2 markers for atherosclerosis, measurements of carotid artery intima-media thickness (IMT) and of peripheral arterial tonometry (PAT), and to evaluate the role of traditional cardiovascular risk factors in this association.We applied the 2 diagnostic tests to 588 participants from the ELSA-Brazil longitudinal study cohort. The PAT measurements, obtained with the EndoPAT2000, were the reactive hyperemia index (RHI), the Framingham RHI (F-RHI), and the mean basal pulse amplitude (BPA). We used the mean of the mean scores of carotid IMT of the distal layers of the left and right common carotids obtained by ultrasonography after 3 cardiac cycles. We used linear regression and the Spearman correlation coefficient to test the relationship between the 2 markers, and multiple linear regressions to exam the relationship between the RHI/F-RHI scores and the mean BPA and IMT scores after adjusting for cardiovascular risk factors.In the multivariate analysis, RHI (but not F-RHI) was positively correlated with the mean of the means of the IMT values after adjusting for sex and risk factors connected with both measures (β = 0.05, P = 0.02). Mean BPA did not remain significantly associated with IMT after adjusting for common risk factors.We found that the higher the IMT (or the worse the IMT), the higher the RHI (or the better the endothelial function). F-RHI was not associated with IMT. These 2 results are against the direction that one would expect and may imply that digital endothelial function (RHI and F-RHI) and IMT correspond to distinct and independent stages of the complex atherosclerosis process and represent different pathways in the disease's progression. Therefore, IMT and PAT measures may be considered complementary and not interchangeable.

Carotid Artery Stenting in a Patient with Spontaneous Recanalization of a Proximal Internal Carotid Artery Occlusion: a Case Report

International Nuclear Information System (INIS)

Kim, Eui Jong; Koh, Jun Seok; Choi, Woo Suk

2006-01-01

We report here on a rare case of carotid artery angioplasty and stenting in a patient with spontaneous recanalization after complete occlusion of the proximal internal carotid artery (ICA). The patient initially showed severe stenosis at the left proximal ICA on MR angiography (MRA). Digital subtraction angiography (DSA) performed three days after MRA showed complete occlusion of the proximal ICA. The follow-up DSA after four weeks showed recanalization of the ICA, and then carotid artery stenting was successfully performed. There has been no neurologic complication during more than one year follow-up. cute internal carotid artery (ICA) occlusions may result in profound disability and death (1). An occluded ICA can spontaneously recanalize, but this doesn't happen frequently, and the natural course of a proximal ICA occlusion and its possibility of recanalization, including the exact time of recanalization after occlusion, are not well known (2, 3). A few studies have reported the incidence of spontaneous recanalization of the proximal internal carotid artery, which has mostly occurred in patients with ICA dissections (4 6). A few limited studies have reported a considerable incidence of spontaneous recanalization in patients with underlying atherosclerotic lesion or atherothombotic diseases (2). The possibility of repeated occlusion and repeated cerebral ischemic infarction may exist for the patients exhibiting spontaneous recanalization of the ICA and underlying atherosclerosis. We report here on a case of carotid artery stenting (CAS) in a patient who exhibited underlying atherosclerosis with spontaneous recanalization after complete occlusion of the proximal ICA

The changes of individual carotid artery wall layer by aging and carotid intima-media thickness value for high risk.

Science.gov (United States)

Bae, Jang-Ho; Kim, Wuon-Shik; Lee, Moo-Sik; Kim, Kee-Sik; Park, Jeong Bae; Youn, Ho-Joong; Park, Chang-Gyu; Hong, Kyung-Soon; Kim, Jang-Young; Jeong, Jin-Won; Park, Jong Chun; Lim, Do-Sun; Kim, Moo Hyun; Woo, Jeong Taek

2016-12-01

It is still unclear which layer (intima or media) is mainly involved in increased carotid intima-media thickness (CIMT) by aging and also unclear regarding CIMT value suggesting high cardiovascular risk, although 75th percentile value of CIMT is known as a high risk in asymptomatic adults. We sought to find the changes of carotid intima thickness (CIT) and carotid media thickness (CMT) by aging and the 75th percentile value of CIMT in asymptomatic Korean adults. This is an observational cohort study. Carotid ultrasound findings (n=2204 from 12 hospitals) were prospectively collected. The carotid images were sent to Korea Research Institute of Standards and Science for analysis using specialized software which can measure intima and media wall also. Mean age was 58.1±13.5 years old (52% of men). Pearson's correlation coefficient between age and right CIMT (r=.489, Pvalue was 0.778 and 0.771 mm, respectively. Mean right CIT was 0.311±0.069 and 0.303±0.064 mm (P=.009), and mean right CMT was 0.391±0.124 and 0.388±0.131 mm (P=.694) in male and female, respectively. Left carotid ultrasound findings showed similar to the right one. An increased CIMT by aging was mainly due to increased CMT rather than CIT in asymptomatic adults. The 75th percentile values of right CIMT were 0.778 and 0.771 mm in asymptomatic Korean male and female adults, respectively. © 2016 John Wiley & Sons Ltd.

Angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid artery

International Nuclear Information System (INIS)

Na, Dong Gyu; Han, Moon Hee; Chang, Kee Hyun; Han, Gi Seok; Yeon, Kung Mo

1995-01-01

The purpose of this study is to describe the angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid arteries and to evaluate the extent of angiographic assessment needed before embolization. We retrospectively reviewed 10 cervicofacial vascular lesions with previously ligated carotid artery, which were 6 cases of arteriovenous malformation, 2 cases of carotid cavernous fistula, 1 case of hemangioma and 1 case of arteriovenous malformation with carotid cavernous fistula. The previously ligated arteries are proximal external carotid artery (n = 5), branches of external carotid artery (n = 2) and common carotid artery (n = 3). Common carotid artery or internal carotid artery (n = 9), vertebral artery (n = 5), ipsilateral external carotid artery (n = 4), contralateral external carotid artery (n = 5), costocervical trunk (n = 2), thyrocervical trunk (n = 2) were assessed by conventional angiography. Angiography of both carotid and vertebral arteries was performed in 5 cases. The collateral vascular channels were inferolateral trunk of internal carotid artery (n = 8), vertebral artery (n = 5), contralateral external carotid artery (n = 5), ipsilateral external carotid artery (n = 4), deep cervical artery (n = 2) and ascending cervical artery (n = 1). Embolization were performed in 9 cases with operative cannulation (n = 4), embolization via collateral branches of ipsilateral external carotid artery (n = 1), embolization via collateral branches of contralateral external carotid artery (n = 3) and balloon occlusion via direct puncture (n = 1). The collateral channels in cervicofacial vascular lesions with previously ligated carotid artery were inferolateral trunk of internal carotid artery, contralateral or ipsilateral external carotid artery, vertebral artery, deep cervical artery and ascending cervical artery on angiography. Complete angiographic assessment of possible collateral channels is mandatory for the

Carotid cavernous fistula after elective carotid endarterectomy: Case report

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Andres Asser

2014-12-01

This is a case to illustrate a rare complication of carotid artery surgery. The patient had atherosclerotic vessel damage of ICA visible on earlier CT scans. This combined with abrupt increase of transmural pressure due to the revascularization procedure could possibly lead to arterial wall rupture and fistula formation.

Numerical simulation of hydrogen-assisted crack initiation in austenitic-ferritic duplex steels

International Nuclear Information System (INIS)

Mente, Tobias

2015-01-01

Duplex stainless steels have been used for a long time in the offshore industry, since they have higher strength than conventional austenitic stainless steels and they exhibit a better ductility as well as an improved corrosion resistance in harsh environments compared to ferritic stainless steels. However, despite these good properties the literature shows some failure cases of duplex stainless steels in which hydrogen plays a crucial role for the cause of the damage. Numerical simulations can give a significant contribution in clarifying the damage mechanisms. Because they help to interpret experimental results as well as help to transfer results from laboratory tests to component tests and vice versa. So far, most numerical simulations of hydrogen-assisted material damage in duplex stainless steels were performed at the macroscopic scale. However, duplex stainless steels consist of approximately equal portions of austenite and δ-ferrite. Both phases have different mechanical properties as well as hydrogen transport properties. Thus, the sensitivity for hydrogen-assisted damage is different in both phases, too. Therefore, the objective of this research was to develop a numerical model of a duplex stainless steel microstructure enabling simulation of hydrogen transport, mechanical stresses and strains as well as crack initiation and propagation in both phases. Additionally, modern X-ray diffraction experiments were used in order to evaluate the influence of hydrogen on the phase specific mechanical properties. For the numerical simulation of the hydrogen transport it was shown, that hydrogen diffusion strongly depends on the alignment of austenite and δ-ferrite in the duplex stainless steel microstructure. Also, it was proven that the hydrogen transport is mainly realized by the ferritic phase and hydrogen is trapped in the austenitic phase. The numerical analysis of phase specific mechanical stresses and strains revealed that if the duplex stainless steel is

Nuclear medicine and ultrasonography in the acute cholecystitis diagnosis

International Nuclear Information System (INIS)

Schmillevitch, J.; Serson, D.; Camera, A.J.; Oliveira Nunes, J.E. de; Bazzo, J.M.B.

1980-01-01

Newer modalities for the evaluation of gallbladder include cholescintigraphy and ultrasonography. The IDA-Tc 99m presents functional informations with regard to cystic duct patency. The ultrasonography demonstrates the topographic anatomy of gallbladder, and morfologic alterations. Both analysis are preconized in acute cholecystitis. (Author) [pt

Hemodynamic significance of internal carotid artery disease

DEFF Research Database (Denmark)

Schroeder, T

1988-01-01

Neurologic symptoms in the region of an internal carotid artery stenosis are considered to be embolic in most instances. Only in a subgroup has carotid occlusive disease with impairment of the collateral supply, caused a state of hemodynamic failure with marked reduction of perfusion pressure. Th...

EFFECT OF INTERMETALLIC PHASES ON CORROSION BEHAVIOR AND MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL AND SUPER-DUPLEX STAINLESS STEEL

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Prabhu Paulraj

2015-08-01

Full Text Available Duplex Stainless Steels (DSS and Super Duplex Stainless Steel (SDSS have excellent integration of mechanical and corrosion properties. However, the formation of intermetallic phases is a major problem in their usage. The mechanical and corrosion properties are deteriorated due to the presence of intermetallic phases. These phases are induced during welding, prolonged exposure to high temperatures, and improper heat treatments. The main emphasis of this review article is on intermetallic phases and their effects on corrosion and mechanical properties. First the effect of various alloying elements on DSS and SDSS has been discussed followed by formation of various intermetallic phases. The intermetallic phases affect impact toughness and corrosion resistance significantly. Their deleterious effect on weldments has also been reviewed.