Ultrasound in medicine & biology
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Ultrasound Med Biol · Nov 2014
Ultrasound visibility of spinal structures and local anesthetic spread in children undergoing caudal block.
This study assessed ultrasound visibility of spinal structures in children and observed the extent of local anesthetic spread within the epidural space during caudal block. Spinal structures were evaluated with ultrasound from the sacral area to the thoracic area in 80 children, and drug spread levels were observed after caudal injection of 0.5, 1.0, 1.25 and 1.5 mL/kg local anesthetic. ⋯ Drug spread was higher with increasing volume (p < 0.001) and in children ≤12 mo more than children >12 mo (p < 0.001); drug spread was significantly correlated with age (R(2) = 0.534). Spread levels assessed with ultrasound were roughly two to three segments lower than those in previous radiologic studies.
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Ultrasound Med Biol · Sep 2014
Automatic identification of needle insertion site in epidural anesthesia with a cascading classifier.
Ultrasound imaging was used to detect the anatomic structure of lumbar spine from the transverse view, to facilitate needle insertion in epidural anesthesia. The interspinous images that represent proper needle insertion sites were identified automatically with image processing and pattern recognition techniques. ⋯ To improve the accuracy of identification, we propose a cascading classifier that successfully located the proper needle insertion site on all of the 36 video streams collected from pregnant patients. The results indicate that the proposed image identification procedure is able to identify the ultrasound images of lumbar spine in an automatic manner, so as to facilitate the anesthetists' work to identify the needle insertion point precisely and effectively.
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Ultrasound Med Biol · Sep 2014
Comparative StudyTaller-than-wide sign for predicting thyroid microcarcinoma: comparison and combination of two ultrasonographic planes.
The aims of this study were to investigate the accuracy of using the taller-than-wide (TTW) sign in two ultrasonographic planes to predict thyroid microcarcinoma, and to confirm the hypothesis that the presence of a TTW sign in both the transverse and longitudinal ultrasonographic planes strongly suggests thyroid microcarcinoma. Nine hundred forty-two thyroid nodules ≤1 cm were submitted to surgical-histopathologic and ultrasonographic examination. TTW signs were divided into three types based on their detection only in the transverse plane (TTTW type, n = 100), only in the longitudinal plane (LTTW type, n = 61) or in both planes (BTTW type, n = 131). ⋯ However, there was no significant difference between the A(z) values for the TTTW and LTTW signs (p > 0.05). Therefore, both the LTTW and TTTW signs are reliable markers of thyroid microcarcinoma. The BTTW sign strongly suggests thyroid microcarcinoma.
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Ultrasound Med Biol · Aug 2014
Quantification of carotid plaque neovascularization using contrast-enhanced ultrasound with histopathologic validation.
We sought to evaluate contrast-enhanced ultrasound (CEUS) imaging for the quantification of carotid plaque neovascularization. Seventeen patients underwent carotid endarterectomy after standard ultrasound and CEUS. Semiquantitative and quantitative analyses of contrast enhancement within the plaque were performed using a visual interpretation scale and quantitative analysis software, respectively. ⋯ Semiquantitative and quantitative analyses were not correlated with macrophage infiltration at the plaque. Contrast enhancement in the carotid plaque was correlated with neovascularity at the histopathologic exam. Furthermore, semiquantitative and quantitative measurements were highly correlated with each other, suggesting that either can be used to detect intraplaque neovascularization.
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Ultrasound Med Biol · Jul 2014
Acoustically active injection catheter guided by ultrasound: navigation tests in acutely ischemic porcine hearts.
Catheters are increasingly used therapeutically and investigatively. With complex usage comes a need for more accurate intracardiac localization than traditional guidance can provide. An injection catheter navigated by ultrasound was designed and then tested in an open-chest model of acute ischemia in eight pigs. ⋯ Sonomicrometry was used to measure distances between the two crystals and then compared with measurements from 2-D echocardiographic images. Complete data were obtained from seven pigs, and the correlation between sonomicrometry and ultrasound measurements was excellent (p < 0.0001, ρ = 0.9820), as was the intraclass correlation coefficient (0.96) between two observers. These initial experimental results suggest high accuracy of ultrasound navigation of the acoustically active catheter prototype located inside the beating left ventricle.