The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
K Tsang - One of the best experts on this subject based on the ideXlab platform.
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Case report Ultrasound-guided lumbar plexus block through the Acoustic Window of the lumbar ultrasound trident
2015Co-Authors: Manoj K Karmakar, Wing H Kwok, K Tsang, W. Ngan D. KeeAbstract:Lumbar plexus block (LPB) is frequently used in combination with an ipsilateral sacral plexus or sciatic nerve block for lower limb surgery. This is traditionally performed using surface ana-tomical landmarks, and the site for local anaesthetic injection is confirmed by observing quadriceps muscle contraction to peripheral nerve stimulation. In this report, we describe a technique of ultrasound-guided LPB that was successfully used, in conjunction with a sciatic nerve block, for anaesthesia during emergency lower limb surgery. The anatomy, sonographic features, technique of identifying the lumbar plexus, and the potential benefits of using this approach are discussed
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ultrasound guided lumbar plexus block through the Acoustic Window of the lumbar ultrasound trident
BJA: British Journal of Anaesthesia, 2008Co-Authors: Manoj K Karmakar, A M H Ho, Wing H Kwok, Xiang Li, K TsangAbstract:Abstract Lumbar plexus block (LPB) is frequently used in combination with an ipsilateral sacral plexus or sciatic nerve block for lower limb surgery. This is traditionally performed using surface anatomical landmarks, and the site for local anaesthetic injection is confirmed by observing quadriceps muscle contraction to peripheral nerve stimulation. In this report, we describe a technique of ultrasound-guided LPB that was successfully used, in conjunction with a sciatic nerve block, for anaesthesia during emergency lower limb surgery. The anatomy, sonographic features, technique of identifying the lumbar plexus, and the potential benefits of using this approach are discussed.
J Lewko - One of the best experts on this subject based on the ideXlab platform.
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accuracy of transcranial color doppler ultrasonography in the diagnosis of middle cerebral artery spasm determined by receiver operating characteristic analysis
Journal of Neurosurgery, 2002Co-Authors: Zenon Mariak, Jaroslaw Krejza, Miroslaw Swiercz, Kazimierz Kordecki, J LewkoAbstract:Object. The value of transcranial Doppler ultrasonography for the detection of middle cerebral artery (MCA) spasm has been asserted. None of the published studies, however, has adequately scrutinized the overall diagnostic accuracy of this procedure. There are only sporadic reports concerning the utility of transcranial color Doppler (TCCD) ultrasonography, although this method has been proved to be more precise. In this study the authors attempted to estimate the performance of TCCD ultrasonography in detecting MCA narrowing by using receiver operating characteristic (ROC) curve analysis, based on TCCD studies obtained in a relatively large, randomly selected population of patients. Methods. Transcranial color Doppler ultrasonography studies were obtained in 100 consecutive patients (54 men and 46 women ages 18–74 years, median age 50 years) routinely referred by neurosurgeons for intraarterial angiography. The M1 segment of the MCA was insonated using a 2.5-MHz probe via a temporal Acoustic Window, and ...
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transcranial color doppler sonography of basal cerebral arteries in 182 healthy subjects age and sex variability and normal reference values for blood flow parameters
American Journal of Roentgenology, 1999Co-Authors: Jaroslaw Krejza, Zenon Mariak, J Lewko, Jerzy Walecki, P Szydlik, Andrzej UstymowiczAbstract:Only a limited number of transcranial color-coded Doppler studies have provided ranges for the normal reference values of cerebral hemodynamic parameters. These reports are not fully convergent in relation to the range of values or to the age and sex dependence of blood flow parameters. The aim of the present study was to provide data regarding normal reference ranges.We examined 182 healthy volunteers (79 men and 103 women; age range, 20-86 years old) with color-coded Doppler sonography via a temporal Acoustic Window with a 2.5-MHz transcranial probe. The subjects were divided into three age groups: 20-40 years old (group 1), 41-60 years old (group 2), and more than 60 years old (group 3). Angle-corrected peak systolic, end-diastolic, and mean velocities as well as impedance indexes were determined in anterior, middle, and posterior cerebral arteries.Mean velocity values for middle, anterior, and posterior cerebral arteries in age group 1 were 81+/-20, 56+/-14, and 52+/-12 cm/sec (mean +/- SD), respectiv...
Manoj K Karmakar - One of the best experts on this subject based on the ideXlab platform.
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Case report Ultrasound-guided lumbar plexus block through the Acoustic Window of the lumbar ultrasound trident
2015Co-Authors: Manoj K Karmakar, Wing H Kwok, K Tsang, W. Ngan D. KeeAbstract:Lumbar plexus block (LPB) is frequently used in combination with an ipsilateral sacral plexus or sciatic nerve block for lower limb surgery. This is traditionally performed using surface ana-tomical landmarks, and the site for local anaesthetic injection is confirmed by observing quadriceps muscle contraction to peripheral nerve stimulation. In this report, we describe a technique of ultrasound-guided LPB that was successfully used, in conjunction with a sciatic nerve block, for anaesthesia during emergency lower limb surgery. The anatomy, sonographic features, technique of identifying the lumbar plexus, and the potential benefits of using this approach are discussed
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ultrasound guided lumbar plexus block through the Acoustic Window of the lumbar ultrasound trident
BJA: British Journal of Anaesthesia, 2008Co-Authors: Manoj K Karmakar, A M H Ho, Wing H Kwok, Xiang Li, K TsangAbstract:Abstract Lumbar plexus block (LPB) is frequently used in combination with an ipsilateral sacral plexus or sciatic nerve block for lower limb surgery. This is traditionally performed using surface anatomical landmarks, and the site for local anaesthetic injection is confirmed by observing quadriceps muscle contraction to peripheral nerve stimulation. In this report, we describe a technique of ultrasound-guided LPB that was successfully used, in conjunction with a sciatic nerve block, for anaesthesia during emergency lower limb surgery. The anatomy, sonographic features, technique of identifying the lumbar plexus, and the potential benefits of using this approach are discussed.
Zenon Mariak - One of the best experts on this subject based on the ideXlab platform.
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accuracy of transcranial color doppler ultrasonography in the diagnosis of middle cerebral artery spasm determined by receiver operating characteristic analysis
Journal of Neurosurgery, 2002Co-Authors: Zenon Mariak, Jaroslaw Krejza, Miroslaw Swiercz, Kazimierz Kordecki, J LewkoAbstract:Object. The value of transcranial Doppler ultrasonography for the detection of middle cerebral artery (MCA) spasm has been asserted. None of the published studies, however, has adequately scrutinized the overall diagnostic accuracy of this procedure. There are only sporadic reports concerning the utility of transcranial color Doppler (TCCD) ultrasonography, although this method has been proved to be more precise. In this study the authors attempted to estimate the performance of TCCD ultrasonography in detecting MCA narrowing by using receiver operating characteristic (ROC) curve analysis, based on TCCD studies obtained in a relatively large, randomly selected population of patients. Methods. Transcranial color Doppler ultrasonography studies were obtained in 100 consecutive patients (54 men and 46 women ages 18–74 years, median age 50 years) routinely referred by neurosurgeons for intraarterial angiography. The M1 segment of the MCA was insonated using a 2.5-MHz probe via a temporal Acoustic Window, and ...
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transcranial color doppler sonography of basal cerebral arteries in 182 healthy subjects age and sex variability and normal reference values for blood flow parameters
American Journal of Roentgenology, 1999Co-Authors: Jaroslaw Krejza, Zenon Mariak, J Lewko, Jerzy Walecki, P Szydlik, Andrzej UstymowiczAbstract:Only a limited number of transcranial color-coded Doppler studies have provided ranges for the normal reference values of cerebral hemodynamic parameters. These reports are not fully convergent in relation to the range of values or to the age and sex dependence of blood flow parameters. The aim of the present study was to provide data regarding normal reference ranges.We examined 182 healthy volunteers (79 men and 103 women; age range, 20-86 years old) with color-coded Doppler sonography via a temporal Acoustic Window with a 2.5-MHz transcranial probe. The subjects were divided into three age groups: 20-40 years old (group 1), 41-60 years old (group 2), and more than 60 years old (group 3). Angle-corrected peak systolic, end-diastolic, and mean velocities as well as impedance indexes were determined in anterior, middle, and posterior cerebral arteries.Mean velocity values for middle, anterior, and posterior cerebral arteries in age group 1 were 81+/-20, 56+/-14, and 52+/-12 cm/sec (mean +/- SD), respectiv...
Jaroslaw Krejza - One of the best experts on this subject based on the ideXlab platform.
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suitability of temporal bone Acoustic Window conventional tcd versus transcranial color coded duplex sonography
Journal of Neuroimaging, 2007Co-Authors: Jaroslaw Krejza, Maciej Swiat, Mikolaj A Pawlak, Grzegorz Oszkinis, John B Weigele, Robert W Hurst, Scott E KasnerAbstract:ABSTRACT PURPOSE AND BACKGROUND To determine whether the proportion of patients with suitable temporal bone Acoustic Windows is different for conventional transcranial Doppler sonography (TCD) and transcranial color-coded duplex sonography (TCCS), based on a head-to-head comparison in the same population of patients. SUBJECTS AND METHODS Ninety patients, age 22–88 years (mean 57.1 ± 11.7 years), 46 women and 44 men, 66 Caucasian, 19 African-American, and five Hispanic, underwent routine conventional TCD and the TCCS examination close in time to each other. Suitability of temporal bone Acoustic Window was defined by ability to insonate the middle and posterior and/or anterior cerebral arteries, while partial suitability was defined by ability to detect the posterior cerebral artery but not the middle cerebral artery. To compare proportions of suitable temporal bone Windows for both sonographic methods, exact sign test by Liddell was used. RESULTS. Bilateral absence of temporal bone Acoustic Window was reported in six patients when studied with both conventional TCD and TCCS, whereas at least unilateral absence was reported in 10 patients. Partial, at least unilateral, suitability was reported in 11 patients with conventional TCD, and in 7 with TCCS. All differences in proportions were not significant (two-sided P>0.05). CONCLUSIONS: This study suggests that success rate of insonating the intracranial vessels through the temporal bone Acoustic Window is the same for conventional TCD and imaging TCCS.
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accuracy of transcranial color doppler ultrasonography in the diagnosis of middle cerebral artery spasm determined by receiver operating characteristic analysis
Journal of Neurosurgery, 2002Co-Authors: Zenon Mariak, Jaroslaw Krejza, Miroslaw Swiercz, Kazimierz Kordecki, J LewkoAbstract:Object. The value of transcranial Doppler ultrasonography for the detection of middle cerebral artery (MCA) spasm has been asserted. None of the published studies, however, has adequately scrutinized the overall diagnostic accuracy of this procedure. There are only sporadic reports concerning the utility of transcranial color Doppler (TCCD) ultrasonography, although this method has been proved to be more precise. In this study the authors attempted to estimate the performance of TCCD ultrasonography in detecting MCA narrowing by using receiver operating characteristic (ROC) curve analysis, based on TCCD studies obtained in a relatively large, randomly selected population of patients. Methods. Transcranial color Doppler ultrasonography studies were obtained in 100 consecutive patients (54 men and 46 women ages 18–74 years, median age 50 years) routinely referred by neurosurgeons for intraarterial angiography. The M1 segment of the MCA was insonated using a 2.5-MHz probe via a temporal Acoustic Window, and ...
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transcranial color doppler sonography of basal cerebral arteries in 182 healthy subjects age and sex variability and normal reference values for blood flow parameters
American Journal of Roentgenology, 1999Co-Authors: Jaroslaw Krejza, Zenon Mariak, J Lewko, Jerzy Walecki, P Szydlik, Andrzej UstymowiczAbstract:Only a limited number of transcranial color-coded Doppler studies have provided ranges for the normal reference values of cerebral hemodynamic parameters. These reports are not fully convergent in relation to the range of values or to the age and sex dependence of blood flow parameters. The aim of the present study was to provide data regarding normal reference ranges.We examined 182 healthy volunteers (79 men and 103 women; age range, 20-86 years old) with color-coded Doppler sonography via a temporal Acoustic Window with a 2.5-MHz transcranial probe. The subjects were divided into three age groups: 20-40 years old (group 1), 41-60 years old (group 2), and more than 60 years old (group 3). Angle-corrected peak systolic, end-diastolic, and mean velocities as well as impedance indexes were determined in anterior, middle, and posterior cerebral arteries.Mean velocity values for middle, anterior, and posterior cerebral arteries in age group 1 were 81+/-20, 56+/-14, and 52+/-12 cm/sec (mean +/- SD), respectiv...
