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Kullervo Hynynen - One of the best experts on this subject based on the ideXlab platform.
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high intensity focused ultrasound sonothrombolysis the use of perfluorocarbon droplets to achieve clot lysis at reduced acoustic power
Ultrasound in Medicine and Biology, 2014Co-Authors: Kullervo Hynynen, Daniel Pajek, Alison Burgess, Yuexi HuangAbstract:Abstract The purpose of this study was to evaluate use of intravascular perfluorocarbon droplets to reduce the Sonication power required to achieve clot lysis with high-intensity focused ultrasound. High-intensity focused ultrasound with droplets was initially applied to blood clots in an in vitro flow apparatus, and inertial cavitation thresholds were determined. An embolic model for ischemic stroke was used to illustrate the feasibility of this technique in vivo . Recanalization with intravascular droplets was achieved in vivo at 24 ± 5% of the Sonication power without droplets. Recanalization occurred in 71% of rabbits that received 1-ms pulsed Sonications during continuous intravascular droplet infusion ( p = 0.041 vs controls). Preliminary experiments indicated that damage was confined to the ultrasonic focus, suggesting that tolerable treatments would be possible with a more tightly focused hemispheric array that allows the whole focus to be placed inside of the main arteries in the human brain.
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targeted disruption of the blood brain barrier with focused ultrasound association with cavitation activity
Physics in Medicine and Biology, 2006Co-Authors: Nathan Mcdannold, Natalia Vykhodtseva, Kullervo HynynenAbstract:Acoustic emission was monitored during focused ultrasound exposures in conjunction with an ultrasound contrast agent (Optison®) in order to determine if cavitation activity is associated with the induction of blood–brain barrier disruption (BBBD). Thirty-four locations were sonicated (frequency: 260 kHz) at targets 10 mm deep in rabbit brain (N = 9). The Sonications were applied at peak pressure amplitudes ranging from 0.11 to 0.57 MPa (burst length: 10 ms; repetition frequency of 1 Hz; duration: 20 s). Acoustic emission was recorded with a focused passive cavitation detector. This emission was recorded at each location during Sonications with and without Optison®. Detectable wideband acoustic emission was observed only at 0.40 and 0.57 MPa. BBBD was observed in contrast MRI after Sonication at 0.29–0.57 MPa. The appearance of small regions of extravasated erythrocytes appeared to be associated with this wideband emission signal. The results thus suggest that BBBD resulting from focused ultrasound pulses in the presence of Optison® can occur without indicators for inertial cavitation in vivo, wideband emission and extravasation. If inertial cavitation is not responsible for the BBBD, other ultrasound/microbubble interactions are likely the source. A significant increase in the emission signal due to Optison® at the second and third harmonics of the ultrasound driving frequency was found to correlate with BBBD and might be useful as an online method to indicate when the disruption occurs.
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local and reversible blood brain barrier disruption by noninvasive focused ultrasound at frequencies suitable for trans skull Sonications
NeuroImage, 2005Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Ferenc A Jolesz, Nickolai Sheikov, Natalia VykhodtsevaAbstract:The purpose of this study was to test the hypothesis that burst ultrasound in the presence of an ultrasound contrast agent can disrupt the blood-brain barrier (BBB) with acoustic parameters suitable for completely noninvasive exposure through the skull. The 10-ms exposures were targeted in the brains of 22 rabbits with a frequency of 690 kHz, a repetition frequency of 1 Hz, and peak rarefactional pressure amplitudes up to 3.1 MPa. The total exposure (Sonication) time was 20 s. Prior to each Sonication, a bolus of ultrasound contrast agent was injected intravenously. Contrast-enhanced MR images were obtained after the Sonications to detect localized BBB disruption via local enhancement in the brain. Brain sections were stained with HE at 0.8 MPa, 90%; and at 1.4 MPa, 100% of the sonicated locations showed enhancement. The histology findings following 4 h survival indicated that brain tissue necrosis was induced in approximately 70-80% of the sonicated locations at a pressure amplitude level of 2.3 MPa or higher. At lower pressure amplitudes, however, small areas of erythrocyte extravasation were seen. The electron microscopy findings demonstrated HRP passage through vessel walls via both transendothelial and paraendothelial routes. These results demonstrate that completely noninvasive focal disruption of the BBB is possible.
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noninvasive mr imaging guided focal opening of the blood brain barrier in rabbits
Radiology, 2001Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Natalia Vykhodtseva, Ferenc A JoleszAbstract:PURPOSE: To determine if focused ultrasound beams can be used to locally open the blood-brain barrier without damage to surrounding brain tissue and if magnetic resonance (MR) imaging can be used to monitor this procedure. MATERIALS AND METHODS: The brains of 18 rabbits were sonicated (pulsed Sonication) in four to six locations, with temporal peak acoustic power ranging from 0.2 to 11.5 W. Prior to each Sonication, a bolus of ultrasonographic (US) contrast agent was injected into the ear vein of the rabbit. A series of fast or spoiled gradient-echo MR images were obtained during the Sonications to monitor the temperature elevation and potential tissue changes. Contrast material-enhanced MR images obtained minutes after Sonications and repeated 1-48 hours later were used to depict blood-brain barrier opening. Whole brain histologic evaluation was performed. RESULTS: Opening of the blood-brain barrier was confirmed with detection of MR imaging contrast agent at the targeted locations. The lowest power levels used produced blood-brain barrier opening without damage to the surrounding neurons. Contrast enhancement correlated with the focal signal intensity changes in the magnitude fast spoiled gradient-echo MR images. CONCLUSION: The blood-brain barrier can be consistently opened with focused ultrasound exposures in the presence of a US contrast agent. MR imaging signal intensity changes may be useful in the detection of blood-brain barrier opening during Sonication.
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mr imaging guided focused ultrasound surgery of fibroadenomas in the breast a feasibility study
Radiology, 2001Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Oliver Pomeroy, Darrell N Smith, Peter E Huber, J Kettenbach, Janet K Baum, Samuel Singer, Ferenc A JoleszAbstract:PURPOSE: To test the feasibility of noninvasive magnetic resonance (MR) imaging–guided focused ultrasound surgery (FUS) of benign fibroadenomas in the breast. MATERIALS AND METHODS: Eleven fibroadenomas in nine patients under local anesthesia were treated with MR imaging-guided FUS. Based on a T2-weighted definition of target volumes, sequential Sonications were delivered to treat the entire target. Temperature-sensitive phase-difference–based MR imaging was performed during each Sonication to monitor focus localization and tissue temperature changes. After the procedure, T2-weighted and contrast material–enhanced T1-weighted MR imaging were performed to evaluate immediate and long-term effects. RESULTS: Thermal imaging sequences were improved over the treatment period, with 82% (279 of 342) of the hot spots visible in the last seven treatments. The MR imager was used to measure temperature elevation (12.8°–49.9°C) from these treatments. Eight of the 11 lesions treated demonstrated complete or partial lac...
Nathan Mcdannold - One of the best experts on this subject based on the ideXlab platform.
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controlled ultrasound induced blood brain barrier disruption using passive acoustic emissions monitoring
PLOS ONE, 2012Co-Authors: Costas D Arvanitis, Natalia Vykhodtseva, Margaret S Livingstone, Nathan McdannoldAbstract:The ability of ultrasonically-induced oscillations of circulating microbubbles to permeabilize vascular barriers such as the blood-brain barrier (BBB) holds great promise for noninvasive targeted drug delivery. A major issue has been a lack of control over the procedure to ensure both safe and effective treatment. Here, we evaluated the use of passively-recorded acoustic emissions as a means to achieve this control. An acoustic emissions monitoring system was constructed and integrated into a clinical transcranial MRI-guided focused ultrasound system. Recordings were analyzed using a spectroscopic method that isolates the acoustic emissions caused by the microbubbles during Sonication. This analysis characterized and quantified harmonic oscillations that occur when the BBB is disrupted, and broadband emissions that occur when tissue damage occurs. After validating the system's performance in pilot studies that explored a wide range of exposure levels, the measurements were used to control the ultrasound exposure level during transcranial Sonications at 104 volumes over 22 weekly sessions in four macaques. We found that increasing the exposure level until a large harmonic emissions signal was observed was an effective means to ensure BBB disruption without broadband emissions. We had a success rate of 96% in inducing BBB disruption as measured by in contrast-enhanced MRI, and we detected broadband emissions in less than 0.2% of the applied bursts. The magnitude of the harmonic emissions signals was significantly (P<0.001) larger for Sonications where BBB disruption was detected, and it correlated with BBB permeabilization as indicated by the magnitude of the MRI signal enhancement after MRI contrast administration (R2 = 0.78). Overall, the results indicate that harmonic emissions can be a used to control focused ultrasound-induced BBB disruption. These results are promising for clinical translation of this technology.
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targeted disruption of the blood brain barrier with focused ultrasound association with cavitation activity
Physics in Medicine and Biology, 2006Co-Authors: Nathan Mcdannold, Natalia Vykhodtseva, Kullervo HynynenAbstract:Acoustic emission was monitored during focused ultrasound exposures in conjunction with an ultrasound contrast agent (Optison®) in order to determine if cavitation activity is associated with the induction of blood–brain barrier disruption (BBBD). Thirty-four locations were sonicated (frequency: 260 kHz) at targets 10 mm deep in rabbit brain (N = 9). The Sonications were applied at peak pressure amplitudes ranging from 0.11 to 0.57 MPa (burst length: 10 ms; repetition frequency of 1 Hz; duration: 20 s). Acoustic emission was recorded with a focused passive cavitation detector. This emission was recorded at each location during Sonications with and without Optison®. Detectable wideband acoustic emission was observed only at 0.40 and 0.57 MPa. BBBD was observed in contrast MRI after Sonication at 0.29–0.57 MPa. The appearance of small regions of extravasated erythrocytes appeared to be associated with this wideband emission signal. The results thus suggest that BBBD resulting from focused ultrasound pulses in the presence of Optison® can occur without indicators for inertial cavitation in vivo, wideband emission and extravasation. If inertial cavitation is not responsible for the BBBD, other ultrasound/microbubble interactions are likely the source. A significant increase in the emission signal due to Optison® at the second and third harmonics of the ultrasound driving frequency was found to correlate with BBBD and might be useful as an online method to indicate when the disruption occurs.
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local and reversible blood brain barrier disruption by noninvasive focused ultrasound at frequencies suitable for trans skull Sonications
NeuroImage, 2005Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Ferenc A Jolesz, Nickolai Sheikov, Natalia VykhodtsevaAbstract:The purpose of this study was to test the hypothesis that burst ultrasound in the presence of an ultrasound contrast agent can disrupt the blood-brain barrier (BBB) with acoustic parameters suitable for completely noninvasive exposure through the skull. The 10-ms exposures were targeted in the brains of 22 rabbits with a frequency of 690 kHz, a repetition frequency of 1 Hz, and peak rarefactional pressure amplitudes up to 3.1 MPa. The total exposure (Sonication) time was 20 s. Prior to each Sonication, a bolus of ultrasound contrast agent was injected intravenously. Contrast-enhanced MR images were obtained after the Sonications to detect localized BBB disruption via local enhancement in the brain. Brain sections were stained with HE at 0.8 MPa, 90%; and at 1.4 MPa, 100% of the sonicated locations showed enhancement. The histology findings following 4 h survival indicated that brain tissue necrosis was induced in approximately 70-80% of the sonicated locations at a pressure amplitude level of 2.3 MPa or higher. At lower pressure amplitudes, however, small areas of erythrocyte extravasation were seen. The electron microscopy findings demonstrated HRP passage through vessel walls via both transendothelial and paraendothelial routes. These results demonstrate that completely noninvasive focal disruption of the BBB is possible.
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noninvasive mr imaging guided focal opening of the blood brain barrier in rabbits
Radiology, 2001Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Natalia Vykhodtseva, Ferenc A JoleszAbstract:PURPOSE: To determine if focused ultrasound beams can be used to locally open the blood-brain barrier without damage to surrounding brain tissue and if magnetic resonance (MR) imaging can be used to monitor this procedure. MATERIALS AND METHODS: The brains of 18 rabbits were sonicated (pulsed Sonication) in four to six locations, with temporal peak acoustic power ranging from 0.2 to 11.5 W. Prior to each Sonication, a bolus of ultrasonographic (US) contrast agent was injected into the ear vein of the rabbit. A series of fast or spoiled gradient-echo MR images were obtained during the Sonications to monitor the temperature elevation and potential tissue changes. Contrast material-enhanced MR images obtained minutes after Sonications and repeated 1-48 hours later were used to depict blood-brain barrier opening. Whole brain histologic evaluation was performed. RESULTS: Opening of the blood-brain barrier was confirmed with detection of MR imaging contrast agent at the targeted locations. The lowest power levels used produced blood-brain barrier opening without damage to the surrounding neurons. Contrast enhancement correlated with the focal signal intensity changes in the magnitude fast spoiled gradient-echo MR images. CONCLUSION: The blood-brain barrier can be consistently opened with focused ultrasound exposures in the presence of a US contrast agent. MR imaging signal intensity changes may be useful in the detection of blood-brain barrier opening during Sonication.
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mr imaging guided focused ultrasound surgery of fibroadenomas in the breast a feasibility study
Radiology, 2001Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Oliver Pomeroy, Darrell N Smith, Peter E Huber, J Kettenbach, Janet K Baum, Samuel Singer, Ferenc A JoleszAbstract:PURPOSE: To test the feasibility of noninvasive magnetic resonance (MR) imaging–guided focused ultrasound surgery (FUS) of benign fibroadenomas in the breast. MATERIALS AND METHODS: Eleven fibroadenomas in nine patients under local anesthesia were treated with MR imaging-guided FUS. Based on a T2-weighted definition of target volumes, sequential Sonications were delivered to treat the entire target. Temperature-sensitive phase-difference–based MR imaging was performed during each Sonication to monitor focus localization and tissue temperature changes. After the procedure, T2-weighted and contrast material–enhanced T1-weighted MR imaging were performed to evaluate immediate and long-term effects. RESULTS: Thermal imaging sequences were improved over the treatment period, with 82% (279 of 342) of the hot spots visible in the last seven treatments. The MR imager was used to measure temperature elevation (12.8°–49.9°C) from these treatments. Eight of the 11 lesions treated demonstrated complete or partial lac...
Natalia Vykhodtseva - One of the best experts on this subject based on the ideXlab platform.
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controlled ultrasound induced blood brain barrier disruption using passive acoustic emissions monitoring
PLOS ONE, 2012Co-Authors: Costas D Arvanitis, Natalia Vykhodtseva, Margaret S Livingstone, Nathan McdannoldAbstract:The ability of ultrasonically-induced oscillations of circulating microbubbles to permeabilize vascular barriers such as the blood-brain barrier (BBB) holds great promise for noninvasive targeted drug delivery. A major issue has been a lack of control over the procedure to ensure both safe and effective treatment. Here, we evaluated the use of passively-recorded acoustic emissions as a means to achieve this control. An acoustic emissions monitoring system was constructed and integrated into a clinical transcranial MRI-guided focused ultrasound system. Recordings were analyzed using a spectroscopic method that isolates the acoustic emissions caused by the microbubbles during Sonication. This analysis characterized and quantified harmonic oscillations that occur when the BBB is disrupted, and broadband emissions that occur when tissue damage occurs. After validating the system's performance in pilot studies that explored a wide range of exposure levels, the measurements were used to control the ultrasound exposure level during transcranial Sonications at 104 volumes over 22 weekly sessions in four macaques. We found that increasing the exposure level until a large harmonic emissions signal was observed was an effective means to ensure BBB disruption without broadband emissions. We had a success rate of 96% in inducing BBB disruption as measured by in contrast-enhanced MRI, and we detected broadband emissions in less than 0.2% of the applied bursts. The magnitude of the harmonic emissions signals was significantly (P<0.001) larger for Sonications where BBB disruption was detected, and it correlated with BBB permeabilization as indicated by the magnitude of the MRI signal enhancement after MRI contrast administration (R2 = 0.78). Overall, the results indicate that harmonic emissions can be a used to control focused ultrasound-induced BBB disruption. These results are promising for clinical translation of this technology.
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targeted disruption of the blood brain barrier with focused ultrasound association with cavitation activity
Physics in Medicine and Biology, 2006Co-Authors: Nathan Mcdannold, Natalia Vykhodtseva, Kullervo HynynenAbstract:Acoustic emission was monitored during focused ultrasound exposures in conjunction with an ultrasound contrast agent (Optison®) in order to determine if cavitation activity is associated with the induction of blood–brain barrier disruption (BBBD). Thirty-four locations were sonicated (frequency: 260 kHz) at targets 10 mm deep in rabbit brain (N = 9). The Sonications were applied at peak pressure amplitudes ranging from 0.11 to 0.57 MPa (burst length: 10 ms; repetition frequency of 1 Hz; duration: 20 s). Acoustic emission was recorded with a focused passive cavitation detector. This emission was recorded at each location during Sonications with and without Optison®. Detectable wideband acoustic emission was observed only at 0.40 and 0.57 MPa. BBBD was observed in contrast MRI after Sonication at 0.29–0.57 MPa. The appearance of small regions of extravasated erythrocytes appeared to be associated with this wideband emission signal. The results thus suggest that BBBD resulting from focused ultrasound pulses in the presence of Optison® can occur without indicators for inertial cavitation in vivo, wideband emission and extravasation. If inertial cavitation is not responsible for the BBBD, other ultrasound/microbubble interactions are likely the source. A significant increase in the emission signal due to Optison® at the second and third harmonics of the ultrasound driving frequency was found to correlate with BBBD and might be useful as an online method to indicate when the disruption occurs.
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local and reversible blood brain barrier disruption by noninvasive focused ultrasound at frequencies suitable for trans skull Sonications
NeuroImage, 2005Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Ferenc A Jolesz, Nickolai Sheikov, Natalia VykhodtsevaAbstract:The purpose of this study was to test the hypothesis that burst ultrasound in the presence of an ultrasound contrast agent can disrupt the blood-brain barrier (BBB) with acoustic parameters suitable for completely noninvasive exposure through the skull. The 10-ms exposures were targeted in the brains of 22 rabbits with a frequency of 690 kHz, a repetition frequency of 1 Hz, and peak rarefactional pressure amplitudes up to 3.1 MPa. The total exposure (Sonication) time was 20 s. Prior to each Sonication, a bolus of ultrasound contrast agent was injected intravenously. Contrast-enhanced MR images were obtained after the Sonications to detect localized BBB disruption via local enhancement in the brain. Brain sections were stained with HE at 0.8 MPa, 90%; and at 1.4 MPa, 100% of the sonicated locations showed enhancement. The histology findings following 4 h survival indicated that brain tissue necrosis was induced in approximately 70-80% of the sonicated locations at a pressure amplitude level of 2.3 MPa or higher. At lower pressure amplitudes, however, small areas of erythrocyte extravasation were seen. The electron microscopy findings demonstrated HRP passage through vessel walls via both transendothelial and paraendothelial routes. These results demonstrate that completely noninvasive focal disruption of the BBB is possible.
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noninvasive mr imaging guided focal opening of the blood brain barrier in rabbits
Radiology, 2001Co-Authors: Kullervo Hynynen, Nathan Mcdannold, Natalia Vykhodtseva, Ferenc A JoleszAbstract:PURPOSE: To determine if focused ultrasound beams can be used to locally open the blood-brain barrier without damage to surrounding brain tissue and if magnetic resonance (MR) imaging can be used to monitor this procedure. MATERIALS AND METHODS: The brains of 18 rabbits were sonicated (pulsed Sonication) in four to six locations, with temporal peak acoustic power ranging from 0.2 to 11.5 W. Prior to each Sonication, a bolus of ultrasonographic (US) contrast agent was injected into the ear vein of the rabbit. A series of fast or spoiled gradient-echo MR images were obtained during the Sonications to monitor the temperature elevation and potential tissue changes. Contrast material-enhanced MR images obtained minutes after Sonications and repeated 1-48 hours later were used to depict blood-brain barrier opening. Whole brain histologic evaluation was performed. RESULTS: Opening of the blood-brain barrier was confirmed with detection of MR imaging contrast agent at the targeted locations. The lowest power levels used produced blood-brain barrier opening without damage to the surrounding neurons. Contrast enhancement correlated with the focal signal intensity changes in the magnitude fast spoiled gradient-echo MR images. CONCLUSION: The blood-brain barrier can be consistently opened with focused ultrasound exposures in the presence of a US contrast agent. MR imaging signal intensity changes may be useful in the detection of blood-brain barrier opening during Sonication.
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histologic effects of high intensity pulsed ultrasound exposure with subharmonic emission in rabbit brain in vivo
Ultrasound in Medicine and Biology, 1995Co-Authors: Natalia Vykhodtseva, Kullervo Hynynen, Christakis DamianouAbstract:In this study, the threshold for subharmonic emission during in vivo Sonication of rabbit brain was investigated. In addition, the histologic effects of pulsed Sonication above this threshold were studied. Two spherically curved focused ultrasound transducers with a diameter of 80 mm and a radius of curvature of 70 mm were used in the Sonications. The operating frequencies of the transducers were 0.936 and 1.72 MHz. The Sonication duration was varied between 0.001 and 1 s and the repetition frequency between 0.1 and 5 Hz. The threshold for subharmonic emission at the frequency of 0.936 MHz was found to be approximately 2000 W cm−2 and 3600 W cm−2 for pulse durations of 1 s and 0.001 s, respectively. The threshold was approximately 1.5-fold as high at a frequency of 1.72 MHz. However, there was considerable variation from experiment to experiment. The multiple pulse experiments at a frequency of 1.72 MHz and an intensity of 7000 W cm−2 showed that the histologic effects ranged from no observable damage of the tissue, to blood-brain barrier breakage, to local haemorrhagia, to local destruction of the tissue, to gross hemorrhage resulting in the death of the animal. The severity of the tissue damage increased as the pulse duration, number of pulses and their repetition frequency increased. The results indicate that the end point of the tissue damage may be controlled by selecting the Sonication parameters. Such control over tissue effects can have several different applications when brain disorders are treated.
Albert Alier - One of the best experts on this subject based on the ideXlab platform.
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Sonication in shoulder surgery: is it necessary?
International Orthopaedics, 2020Co-Authors: Carlos Torrens, Lluis Puig, Anna Fraile, Fernando Santana, Albert AlierAbstract:Purpose The objective of the present study was to determine whether Sonication yields greater sensitivity when compared with the traditional tissue culture in detecting peri-implant infections in shoulder surgery. Methods It is a retrospective study that includes 99 shoulder surgeries with implants explanted. The inclusion criteria required at least four tissue cultures, Sonication of the material explanted, and a minimum follow-up of two years. Patients were classified according to the definition of periprosthetic shoulder infection of the 2018 International Consensus Meeting on Orthopedic Infections. The classifications are definitive infection, probable infection, possible infection, and unlikely infection. Results Among the 99 surgical procedures, 31 were considered definitive infections, 11 possible/probable infections, and 57 unlikely infections. Considering the cases with a definitive infection, the sensitivity of the tissue culture was 87.09% and the sensitivity of Sonication stood at 80.64% ( p = 0.406). Analyzing the cases with a definitive infection and those having a possible/probable infection together and comparing them with those with unlikely infection, the sensitivity of Sonication was 80.4% and the sensitivity of the tissue culture came to 91.4%. The specificity of the Sonication was 98.1% and the specificity of the tissue culture was 99.6%. Conclusion The sensitivity of Sonication in shoulder surgery (80.64%) is not superior to the sensitivity of the tissue culture (87.09%). Specificity remains high with both methods, being 98.1% in the Sonication group and 99.6% in the tissue culture. Sonication brings no benefit to the detection of shoulder per-implant infections.
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improved diagnosis of orthopedic implant associated infection by inoculation of Sonication fluid into blood culture bottles
Journal of Clinical Microbiology, 2015Co-Authors: Maria Eugenia Portillo, Margarita Salvado, Ana Siverio, Albert Alier, Lluisa Sorli, Santos Martinez, Daniel Perezprieto, Andrej Trampuz, Juan Pablo Horcajada, Lluis PuigverdieAbstract:ABSTRACT Sonication improved the diagnosis of orthopedic implant-associated infections (OIAI). We investigated the diagnostic performance of Sonication fluid inoculated into blood culture bottles in comparison with that of intraoperative tissue and Sonication fluid cultures. Consecutive patients with removed orthopedic hardware were prospectively included and classified as having OIAI or aseptic failure (AF) according to standardized criteria. The diagnostic procedure included the collection of five intraoperative tissue cultures and Sonication of the removed device, followed by conventional culture of the Sonication fluid. Cultures were incubated for 7 days (aerobic) or 14 days (anaerobic). In addition, 10 ml of Sonication fluid was inoculated into each aerobic and anaerobic BacT/Alert FAN blood culture bottle and incubated in the automated blood culture system for 5 days. Of 75 included patients, 39 had OIAI and 36 AF. The sensitivity of Sonication fluid inoculated into blood culture bottles (100%) was higher than that of conventional Sonication fluid (87%; P = 0.05) or intraoperative tissue cultures (59%; P
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advantages of Sonication fluid culture for the diagnosis of prosthetic joint infection
Journal of Infection, 2014Co-Authors: Maria Eugenia Portillo, Margarita Salvado, Albert Alier, Lluisa Sorli, Santos Martinez, Juan Pablo Horcajada, Lluis PuigAbstract:Summary Objectives The sensitivity of periprosthetic tissue culture is inadequate for the diagnosis of prosthetic joint infection (PJI). We investigated and compared the values of Sonication fluid culture and periprosthetic tissue culture for diagnosing PJI. Methods Included were patients whose joint prosthesis had been removed for any reason. The resulting Sonication fluid and periprosthetic tissues were cultured for 14 days. Results Of 231 explanted prostheses, aseptic failure was diagnosed in 162 cases (70%) and PJI in 69 (30%). In PJI cases, Sonication fluid culture detected 62 microorganisms and periprosthetic tissue culture detected 45. Tissue and Sonication fluid cultures showed sensitivities of 61% and 81%, respectively ( p p = 0.013) of PJI cases respectively, and on day 2, in 26% and 48% ( p = 0.002) of cases. Four anaerobes grew in Sonication fluid culture after 7–13 days incubation, whereas tissue culture missed 3 of these. Prolonged incubation of Sonication fluid did not detect any organisms in the cases of aseptic failure. Conclusions Sonication fluid culture provides a more rapid diagnosis and detects about 30% more pathogens, although anaerobic organisms require up to 2 weeks of incubation.
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multiplex pcr of Sonication fluid accurately differentiates between prosthetic joint infection and aseptic failure
Journal of Infection, 2012Co-Authors: Maria Eugenia Portillo, Margarita Salvado, Albert Alier, Lluisa Sorli, Santos Martinez, Andrej Trampuz, Lluis Puig, Julia Gomez, Juan Pablo HorcajadaAbstract:Summary Objective Cultures have limited sensitivity in the diagnosis of prosthetic joint infection (PJI), especially in low-grade infections. We assessed the value of multiplex PCR in differentiating PJI from aseptic failure (AF). Methods Included were patients in whom the joint prosthesis was removed and submitted for Sonication. The resulting Sonication fluid was cultured and investigated by multiplex PCR, and compared with periprosthetic tissue culture. Results Among 86 explanted prostheses (56 knee, 25 hip, 3 elbow and 2 shoulder prostheses), AF was diagnosed in 62 cases (72%) and PJI in 24 cases (28%). PJI was more common detected by multiplex PCR ( n =23, 96%) than by periprosthetic tissue ( n =17, 71%, p =0.031) or Sonication fluid culture ( n =16, 67%, p =0.016). Among 12 patients with PJI who previously received antibiotics, periprosthetic tissue cultures were positive in 8 cases (67%), Sonication fluid cultures in 6 cases (50%) and multiplex PCR in 11 cases (92%). In AF cases, periprosthetic tissue grew organisms in 11% and Sonication fluid in 10%, whereas multiplex PCR detected no organisms. Conclusions Multiplex PCR of Sonication fluid demonstrated high sensitivity (96%) and specificity (100%) for diagnosing PJI, providing good discriminative power towards AF, especially in patients previously receiving antibiotics.
Hyungmin Kim - One of the best experts on this subject based on the ideXlab platform.
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focused ultrasound mediated non invasive brain stimulation examination of Sonication parameters
Brain Stimulation, 2014Co-Authors: Krisztina Fischer, Hyungmin Kim, Alan Chiu, Stephanie D Lee, Seungschik YooAbstract:Abstract Background Transcranial focused ultrasound (FUS) has emerged as a new brain stimulation modality. The range of Sonication parameters for successful brain stimulation warrants further investigation. Objective The objective of this study was to examine the range of FUS Sonication parameters that minimize the acoustic intensity/energy deposition while successfully stimulating the motor brain area in Sprague–Dawley rats. Methods We transcranially administered FUS to the somatomotor area of the rat brain and measured the acoustic intensity that caused excitatory effects with respect to different pulsing parameters (tone-burst duration, pulse-repetition frequency, duty cycle, and Sonication duration) at 350 and 650 kHz of fundamental frequency. Results We observed that motor responses were elicited at minimum threshold acoustic intensities (4.9–5.6 W/cm 2 in spatial-peak pulse-average intensity; 2.5–2.8 W/cm 2 in spatial-peak temporal-average intensity) in a limited range of Sonication parameters, i.e. 1–5 ms of tone-burst duration, 50% of duty cycle, and 300 ms of Sonication duration, at 350 kHz fundamental frequency. We also found that the pulsed Sonication elicited motor responses at lower acoustic intensities than its equivalent continuous Sonication. Conclusion Our results suggest that the pulsed application of FUS selectively stimulates specific brain areas-of-interest at an acoustic intensity that is compatible with regulatory safety limits on biological tissue, thus allowing for potential applications in neurotherapeutics.