Ultrasound in medicine & biology
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Ultrasound Med Biol · Jul 2009
Ultrasonographic evaluation of hyoid-larynx approximation in dysphagic stroke patients.
Hyoid-larynx approximation is an essential part of the swallowing process, and is related to airway protection. We aimed to evaluate the reliability of ultrasonographic examination of hyoid-larynx approximation and measure the approximation in stroke patients with or without dysphagia. Fifteen normal subjects and 40 stroke patients with or without dysphagia admitted to the Department of Rehabilitation Medicine of a tertiary hospital between July 2006 and February 2007 participated in this study. ⋯ Among stroke patients, hyoid-larynx approximation was less in the dysphagia group than in the nondysphagia group. In conclusion, ultrasound can quantitatively measure hyoid-larynx approximation with good reliability. Hyoid-larynx approximation was significantly reduced in stroke patients with dysphagia.
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Ultrasound Med Biol · Jul 2009
Simulation of intracranial acoustic fields in clinical trials of sonothrombolysis.
Two clinical trials have used ultrasound to improve tPA thrombolysis in patients with acute ischemic stroke. The Combined Lysis of Thrombus in Brain Ischemia Using Transcranial Ultrasound and Systemic tPA (CLOTBUST) trial reported accelerated recanalisation of the middle cerebral artery (MCA) in patients with symptoms of MCA infarction, which were monitored with 2-MHz transcranial Doppler. In CLOTBUST, there was no increased bleeding as evidenced by cranial computed tomography. ⋯ This simulated pressure is below the threshold for both inertial and stable acoustic cavitation but likewise lower than any acoustic pressure that has been reported as sufficient for effective sonothrombolysis. Simulating the pressure field of ultrasound protocols for clinical trials of sonothrombolysis may help explain mechanisms of adverse effects. Such simulations could prove useful in the initial design and optimization of future protocols for this promising therapy of ischemic stroke.
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Ultrasound Med Biol · Jun 2009
Detection of residual disc hernia material and confirmation of nerve root decompression at lumbar disc herniation surgery by intraoperative ultrasound.
The aim of lumbar disc herniation surgery is the removal of herniated disc material (HDM) and complete decompression of the nerve root. As some patients present with residual HDM, we examined the ability of intraoperative ultrasound (IOUS) to detect this material. Between February 2006 and June 2007, we used IOUS in 30 patients undergoing surgery for lumbar disc herniation. ⋯ In two patients, IOUS detected residual disc material; the surgical procedure was resumed and sufficient removal was accomplished. IOUS monitoring is safe, convenient and inexpensive. It is also highly useful for the detection of residual HDM and the confirmation of adequate nerve root decompression.
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Ultrasound Med Biol · Apr 2009
ReviewLow-intensity pulsed ultrasound for the treatment of bone delayed union or nonunion: a review.
The goal of this review is to present the most updated knowledge derived from basic science, animal studies and clinical trials, concerning biophysical stimulation of bone repair through low-intensity pulsed ultrasound (LIPUS), with particular reference to the management of delayed unions and nonunions. Low-intensity pulsed ultrasound LIPUS has been proved to significantly stimulate and accelerate fresh fracture healing in animal studies and in randomized controlled clinical trials. ⋯ Outcomes depend on the site of nonunion, time elapsed from trauma, stability at the site of nonunion and host type. The detailed biophysical process by which low-intensity pulsed ultrasound LIPUS stimulates bone regeneration still remains unknown, even if various effects on bone cells in vitro and in vivo have been described.
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Ultrasound Med Biol · Apr 2009
The axial distribution of lesion-site atherosclerotic plaque components: an in vivo volumetric intravascular ultrasound radio-frequency analysis of lumen stenosis, necrotic core and vessel remodeling.
Radio-frequency intravascular ultrasound (IVUS) analysis characterizes atherosclerotic plaques into necrotic core (NC), dense calcium (DC), fibrofatty (FF) and fibrotic (FI) tissue. We studied axial plaque component distribution with respect to stenosis and remodeling. Preintervention virtual histology (VH) IVUS was performed in 81 pts (90 de novo lesions: 43 left anterior descending artery [LAD] and 47 right coronary artery [RCA]). ⋯ The remodeling index was larger at the MaxNC than MLA sites and correlated with the NC area both at the MLA (r(2) 0.068, p = 0.013) and at the MaxNC (r(2) 0.074, p = 0.009). In conclusion, grey-scale and VH-IVUS analysis showed that the MLA is rarely at the site of greatest instability (largest NC and remodeling) and necrotic core on VH is correlated with remodeling index. These in vivo findings are consistent with previously reported histopathologic data and have important implications for the detection and treatment of coronary artery disease.